Pin new dependency: github.com/google/cel-go v0.9.0

vendor/github.com/antlr/antlr4/runtime/Go/antlr/LICENSE

@@ -0,0 +1,26 @@
+Copyright 2021 The ANTLR Project
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+    3. Neither the name of the copyright holder nor the names of its
+    contributors may be used to endorse or promote products derived from this
+    software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn.go

@@ -0,0 +1,152 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+var ATNInvalidAltNumber int
+
+type ATN struct {
+	// DecisionToState is the decision points for all rules, subrules, optional
+	// blocks, ()+, ()*, etc. Used to build DFA predictors for them.
+	DecisionToState []DecisionState
+
+	// grammarType is the ATN type and is used for deserializing ATNs from strings.
+	grammarType int
+
+	// lexerActions is referenced by action transitions in the ATN for lexer ATNs.
+	lexerActions []LexerAction
+
+	// maxTokenType is the maximum value for any symbol recognized by a transition in the ATN.
+	maxTokenType int
+
+	modeNameToStartState map[string]*TokensStartState
+
+	modeToStartState []*TokensStartState
+
+	// ruleToStartState maps from rule index to starting state number.
+	ruleToStartState []*RuleStartState
+
+	// ruleToStopState maps from rule index to stop state number.
+	ruleToStopState []*RuleStopState
+
+	// ruleToTokenType maps the rule index to the resulting token type for lexer
+	// ATNs. For parser ATNs, it maps the rule index to the generated bypass token
+	// type if ATNDeserializationOptions.isGenerateRuleBypassTransitions was
+	// specified, and otherwise is nil.
+	ruleToTokenType []int
+
+	states []ATNState
+}
+
+func NewATN(grammarType int, maxTokenType int) *ATN {
+	return &ATN{
+		grammarType:          grammarType,
+		maxTokenType:         maxTokenType,
+		modeNameToStartState: make(map[string]*TokensStartState),
+	}
+}
+
+// NextTokensInContext computes the set of valid tokens that can occur starting
+// in state s. If ctx is nil, the set of tokens will not include what can follow
+// the rule surrounding s. In other words, the set will be restricted to tokens
+// reachable staying within the rule of s.
+func (a *ATN) NextTokensInContext(s ATNState, ctx RuleContext) *IntervalSet {
+	return NewLL1Analyzer(a).Look(s, nil, ctx)
+}
+
+// NextTokensNoContext computes the set of valid tokens that can occur starting
+// in s and staying in same rule. Token.EPSILON is in set if we reach end of
+// rule.
+func (a *ATN) NextTokensNoContext(s ATNState) *IntervalSet {
+	if s.GetNextTokenWithinRule() != nil {
+		return s.GetNextTokenWithinRule()
+	}
+
+	s.SetNextTokenWithinRule(a.NextTokensInContext(s, nil))
+	s.GetNextTokenWithinRule().readOnly = true
+
+	return s.GetNextTokenWithinRule()
+}
+
+func (a *ATN) NextTokens(s ATNState, ctx RuleContext) *IntervalSet {
+	if ctx == nil {
+		return a.NextTokensNoContext(s)
+	}
+
+	return a.NextTokensInContext(s, ctx)
+}
+
+func (a *ATN) addState(state ATNState) {
+	if state != nil {
+		state.SetATN(a)
+		state.SetStateNumber(len(a.states))
+	}
+
+	a.states = append(a.states, state)
+}
+
+func (a *ATN) removeState(state ATNState) {
+	a.states[state.GetStateNumber()] = nil // Just free the memory; don't shift states in the slice
+}
+
+func (a *ATN) defineDecisionState(s DecisionState) int {
+	a.DecisionToState = append(a.DecisionToState, s)
+	s.setDecision(len(a.DecisionToState) - 1)
+
+	return s.getDecision()
+}
+
+func (a *ATN) getDecisionState(decision int) DecisionState {
+	if len(a.DecisionToState) == 0 {
+		return nil
+	}
+
+	return a.DecisionToState[decision]
+}
+
+// getExpectedTokens computes the set of input symbols which could follow ATN
+// state number stateNumber in the specified full parse context ctx and returns
+// the set of potentially valid input symbols which could follow the specified
+// state in the specified context. This method considers the complete parser
+// context, but does not evaluate semantic predicates (i.e. all predicates
+// encountered during the calculation are assumed true). If a path in the ATN
+// exists from the starting state to the RuleStopState of the outermost context
+// without Matching any symbols, Token.EOF is added to the returned set.
+//
+// A nil ctx defaults to ParserRuleContext.EMPTY.
+//
+// It panics if the ATN does not contain state stateNumber.
+func (a *ATN) getExpectedTokens(stateNumber int, ctx RuleContext) *IntervalSet {
+	if stateNumber < 0 || stateNumber >= len(a.states) {
+		panic("Invalid state number.")
+	}
+
+	s := a.states[stateNumber]
+	following := a.NextTokens(s, nil)
+
+	if !following.contains(TokenEpsilon) {
+		return following
+	}
+
+	expected := NewIntervalSet()
+
+	expected.addSet(following)
+	expected.removeOne(TokenEpsilon)
+
+	for ctx != nil && ctx.GetInvokingState() >= 0 && following.contains(TokenEpsilon) {
+		invokingState := a.states[ctx.GetInvokingState()]
+		rt := invokingState.GetTransitions()[0]
+
+		following = a.NextTokens(rt.(*RuleTransition).followState, nil)
+		expected.addSet(following)
+		expected.removeOne(TokenEpsilon)
+		ctx = ctx.GetParent().(RuleContext)
+	}
+
+	if following.contains(TokenEpsilon) {
+		expected.addOne(TokenEOF)
+	}
+
+	return expected
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_config.go

@@ -0,0 +1,295 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+)
+
+type comparable interface {
+	equals(other interface{}) bool
+}
+
+// ATNConfig is a tuple: (ATN state, predicted alt, syntactic, semantic
+// context). The syntactic context is a graph-structured stack node whose
+// path(s) to the root is the rule invocation(s) chain used to arrive at the
+// state. The semantic context is the tree of semantic predicates encountered
+// before reaching an ATN state.
+type ATNConfig interface {
+	comparable
+
+	hash() int
+
+	GetState() ATNState
+	GetAlt() int
+	GetSemanticContext() SemanticContext
+
+	GetContext() PredictionContext
+	SetContext(PredictionContext)
+
+	GetReachesIntoOuterContext() int
+	SetReachesIntoOuterContext(int)
+
+	String() string
+
+	getPrecedenceFilterSuppressed() bool
+	setPrecedenceFilterSuppressed(bool)
+}
+
+type BaseATNConfig struct {
+	precedenceFilterSuppressed bool
+	state                      ATNState
+	alt                        int
+	context                    PredictionContext
+	semanticContext            SemanticContext
+	reachesIntoOuterContext    int
+}
+
+func NewBaseATNConfig7(old *BaseATNConfig) *BaseATNConfig { // TODO: Dup
+	return &BaseATNConfig{
+		state:                   old.state,
+		alt:                     old.alt,
+		context:                 old.context,
+		semanticContext:         old.semanticContext,
+		reachesIntoOuterContext: old.reachesIntoOuterContext,
+	}
+}
+
+func NewBaseATNConfig6(state ATNState, alt int, context PredictionContext) *BaseATNConfig {
+	return NewBaseATNConfig5(state, alt, context, SemanticContextNone)
+}
+
+func NewBaseATNConfig5(state ATNState, alt int, context PredictionContext, semanticContext SemanticContext) *BaseATNConfig {
+	if semanticContext == nil {
+		panic("semanticContext cannot be nil") // TODO: Necessary?
+	}
+
+	return &BaseATNConfig{state: state, alt: alt, context: context, semanticContext: semanticContext}
+}
+
+func NewBaseATNConfig4(c ATNConfig, state ATNState) *BaseATNConfig {
+	return NewBaseATNConfig(c, state, c.GetContext(), c.GetSemanticContext())
+}
+
+func NewBaseATNConfig3(c ATNConfig, state ATNState, semanticContext SemanticContext) *BaseATNConfig {
+	return NewBaseATNConfig(c, state, c.GetContext(), semanticContext)
+}
+
+func NewBaseATNConfig2(c ATNConfig, semanticContext SemanticContext) *BaseATNConfig {
+	return NewBaseATNConfig(c, c.GetState(), c.GetContext(), semanticContext)
+}
+
+func NewBaseATNConfig1(c ATNConfig, state ATNState, context PredictionContext) *BaseATNConfig {
+	return NewBaseATNConfig(c, state, context, c.GetSemanticContext())
+}
+
+func NewBaseATNConfig(c ATNConfig, state ATNState, context PredictionContext, semanticContext SemanticContext) *BaseATNConfig {
+	if semanticContext == nil {
+		panic("semanticContext cannot be nil")
+	}
+
+	return &BaseATNConfig{
+		state:                      state,
+		alt:                        c.GetAlt(),
+		context:                    context,
+		semanticContext:            semanticContext,
+		reachesIntoOuterContext:    c.GetReachesIntoOuterContext(),
+		precedenceFilterSuppressed: c.getPrecedenceFilterSuppressed(),
+	}
+}
+
+func (b *BaseATNConfig) getPrecedenceFilterSuppressed() bool {
+	return b.precedenceFilterSuppressed
+}
+
+func (b *BaseATNConfig) setPrecedenceFilterSuppressed(v bool) {
+	b.precedenceFilterSuppressed = v
+}
+
+func (b *BaseATNConfig) GetState() ATNState {
+	return b.state
+}
+
+func (b *BaseATNConfig) GetAlt() int {
+	return b.alt
+}
+
+func (b *BaseATNConfig) SetContext(v PredictionContext) {
+	b.context = v
+}
+func (b *BaseATNConfig) GetContext() PredictionContext {
+	return b.context
+}
+
+func (b *BaseATNConfig) GetSemanticContext() SemanticContext {
+	return b.semanticContext
+}
+
+func (b *BaseATNConfig) GetReachesIntoOuterContext() int {
+	return b.reachesIntoOuterContext
+}
+
+func (b *BaseATNConfig) SetReachesIntoOuterContext(v int) {
+	b.reachesIntoOuterContext = v
+}
+
+// An ATN configuration is equal to another if both have the same state, they
+// predict the same alternative, and syntactic/semantic contexts are the same.
+func (b *BaseATNConfig) equals(o interface{}) bool {
+	if b == o {
+		return true
+	}
+
+	var other, ok = o.(*BaseATNConfig)
+
+	if !ok {
+		return false
+	}
+
+	var equal bool
+
+	if b.context == nil {
+		equal = other.context == nil
+	} else {
+		equal = b.context.equals(other.context)
+	}
+
+	var (
+		nums = b.state.GetStateNumber() == other.state.GetStateNumber()
+		alts = b.alt == other.alt
+		cons = b.semanticContext.equals(other.semanticContext)
+		sups = b.precedenceFilterSuppressed == other.precedenceFilterSuppressed
+	)
+
+	return nums && alts && cons && sups && equal
+}
+
+func (b *BaseATNConfig) hash() int {
+	var c int
+	if b.context != nil {
+		c = b.context.hash()
+	}
+
+	h := murmurInit(7)
+	h = murmurUpdate(h, b.state.GetStateNumber())
+	h = murmurUpdate(h, b.alt)
+	h = murmurUpdate(h, c)
+	h = murmurUpdate(h, b.semanticContext.hash())
+	return murmurFinish(h, 4)
+}
+
+func (b *BaseATNConfig) String() string {
+	var s1, s2, s3 string
+
+	if b.context != nil {
+		s1 = ",[" + fmt.Sprint(b.context) + "]"
+	}
+
+	if b.semanticContext != SemanticContextNone {
+		s2 = "," + fmt.Sprint(b.semanticContext)
+	}
+
+	if b.reachesIntoOuterContext > 0 {
+		s3 = ",up=" + fmt.Sprint(b.reachesIntoOuterContext)
+	}
+
+	return fmt.Sprintf("(%v,%v%v%v%v)", b.state, b.alt, s1, s2, s3)
+}
+
+type LexerATNConfig struct {
+	*BaseATNConfig
+	lexerActionExecutor            *LexerActionExecutor
+	passedThroughNonGreedyDecision bool
+}
+
+func NewLexerATNConfig6(state ATNState, alt int, context PredictionContext) *LexerATNConfig {
+	return &LexerATNConfig{BaseATNConfig: NewBaseATNConfig5(state, alt, context, SemanticContextNone)}
+}
+
+func NewLexerATNConfig5(state ATNState, alt int, context PredictionContext, lexerActionExecutor *LexerActionExecutor) *LexerATNConfig {
+	return &LexerATNConfig{
+		BaseATNConfig:       NewBaseATNConfig5(state, alt, context, SemanticContextNone),
+		lexerActionExecutor: lexerActionExecutor,
+	}
+}
+
+func NewLexerATNConfig4(c *LexerATNConfig, state ATNState) *LexerATNConfig {
+	return &LexerATNConfig{
+		BaseATNConfig:                  NewBaseATNConfig(c, state, c.GetContext(), c.GetSemanticContext()),
+		lexerActionExecutor:            c.lexerActionExecutor,
+		passedThroughNonGreedyDecision: checkNonGreedyDecision(c, state),
+	}
+}
+
+func NewLexerATNConfig3(c *LexerATNConfig, state ATNState, lexerActionExecutor *LexerActionExecutor) *LexerATNConfig {
+	return &LexerATNConfig{
+		BaseATNConfig:                  NewBaseATNConfig(c, state, c.GetContext(), c.GetSemanticContext()),
+		lexerActionExecutor:            lexerActionExecutor,
+		passedThroughNonGreedyDecision: checkNonGreedyDecision(c, state),
+	}
+}
+
+func NewLexerATNConfig2(c *LexerATNConfig, state ATNState, context PredictionContext) *LexerATNConfig {
+	return &LexerATNConfig{
+		BaseATNConfig:                  NewBaseATNConfig(c, state, context, c.GetSemanticContext()),
+		lexerActionExecutor:            c.lexerActionExecutor,
+		passedThroughNonGreedyDecision: checkNonGreedyDecision(c, state),
+	}
+}
+
+func NewLexerATNConfig1(state ATNState, alt int, context PredictionContext) *LexerATNConfig {
+	return &LexerATNConfig{BaseATNConfig: NewBaseATNConfig5(state, alt, context, SemanticContextNone)}
+}
+
+func (l *LexerATNConfig) hash() int {
+	var f int
+	if l.passedThroughNonGreedyDecision {
+		f = 1
+	} else {
+		f = 0
+	}
+	h := murmurInit(7)
+	h = murmurUpdate(h, l.state.hash())
+	h = murmurUpdate(h, l.alt)
+	h = murmurUpdate(h, l.context.hash())
+	h = murmurUpdate(h, l.semanticContext.hash())
+	h = murmurUpdate(h, f)
+	h = murmurUpdate(h, l.lexerActionExecutor.hash())
+	h = murmurFinish(h, 6)
+	return h
+}
+
+func (l *LexerATNConfig) equals(other interface{}) bool {
+	var othert, ok = other.(*LexerATNConfig)
+
+	if l == other {
+		return true
+	} else if !ok {
+		return false
+	} else if l.passedThroughNonGreedyDecision != othert.passedThroughNonGreedyDecision {
+		return false
+	}
+
+	var b bool
+
+	if l.lexerActionExecutor != nil {
+		b = !l.lexerActionExecutor.equals(othert.lexerActionExecutor)
+	} else {
+		b = othert.lexerActionExecutor != nil
+	}
+
+	if b {
+		return false
+	}
+
+	return l.BaseATNConfig.equals(othert.BaseATNConfig)
+}
+
+
+func checkNonGreedyDecision(source *LexerATNConfig, target ATNState) bool {
+	var ds, ok = target.(DecisionState)
+
+	return source.passedThroughNonGreedyDecision || (ok && ds.getNonGreedy())
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_config_set.go

@@ -0,0 +1,387 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import "fmt"
+
+type ATNConfigSet interface {
+	hash() int
+	Add(ATNConfig, *DoubleDict) bool
+	AddAll([]ATNConfig) bool
+
+	GetStates() *Set
+	GetPredicates() []SemanticContext
+	GetItems() []ATNConfig
+
+	OptimizeConfigs(interpreter *BaseATNSimulator)
+
+	Equals(other interface{}) bool
+
+	Length() int
+	IsEmpty() bool
+	Contains(ATNConfig) bool
+	ContainsFast(ATNConfig) bool
+	Clear()
+	String() string
+
+	HasSemanticContext() bool
+	SetHasSemanticContext(v bool)
+
+	ReadOnly() bool
+	SetReadOnly(bool)
+
+	GetConflictingAlts() *BitSet
+	SetConflictingAlts(*BitSet)
+
+	FullContext() bool
+
+	GetUniqueAlt() int
+	SetUniqueAlt(int)
+
+	GetDipsIntoOuterContext() bool
+	SetDipsIntoOuterContext(bool)
+}
+
+// BaseATNConfigSet is a specialized set of ATNConfig that tracks information
+// about its elements and can combine similar configurations using a
+// graph-structured stack.
+type BaseATNConfigSet struct {
+	cachedHash int
+
+	// configLookup is used to determine whether two BaseATNConfigSets are equal. We
+	// need all configurations with the same (s, i, _, semctx) to be equal. A key
+	// effectively doubles the number of objects associated with ATNConfigs. All
+	// keys are hashed by (s, i, _, pi), not including the context. Wiped out when
+	// read-only because a set becomes a DFA state.
+	configLookup *Set
+
+	// configs is the added elements.
+	configs []ATNConfig
+
+	// TODO: These fields make me pretty uncomfortable, but it is nice to pack up
+	// info together because it saves recomputation. Can we track conflicts as they
+	// are added to save scanning configs later?
+	conflictingAlts *BitSet
+
+	// dipsIntoOuterContext is used by parsers and lexers. In a lexer, it indicates
+	// we hit a pred while computing a closure operation. Do not make a DFA state
+	// from the BaseATNConfigSet in this case. TODO: How is this used by parsers?
+	dipsIntoOuterContext bool
+
+	// fullCtx is whether it is part of a full context LL prediction. Used to
+	// determine how to merge $. It is a wildcard with SLL, but not for an LL
+	// context merge.
+	fullCtx bool
+
+	// Used in parser and lexer. In lexer, it indicates we hit a pred
+	// while computing a closure operation. Don't make a DFA state from a.
+	hasSemanticContext bool
+
+	// readOnly is whether it is read-only. Do not
+	// allow any code to manipulate the set if true because DFA states will point at
+	// sets and those must not change. It not protect other fields; conflictingAlts
+	// in particular, which is assigned after readOnly.
+	readOnly bool
+
+	// TODO: These fields make me pretty uncomfortable, but it is nice to pack up
+	// info together because it saves recomputation. Can we track conflicts as they
+	// are added to save scanning configs later?
+	uniqueAlt int
+}
+
+func NewBaseATNConfigSet(fullCtx bool) *BaseATNConfigSet {
+	return &BaseATNConfigSet{
+		cachedHash: -1,
+		configLookup:     NewSet(nil, equalATNConfigs),
+		fullCtx:          fullCtx,
+	}
+}
+
+// Add merges contexts with existing configs for (s, i, pi, _), where s is the
+// ATNConfig.state, i is the ATNConfig.alt, and pi is the
+// ATNConfig.semanticContext. We use (s,i,pi) as the key. Updates
+// dipsIntoOuterContext and hasSemanticContext when necessary.
+func (b *BaseATNConfigSet) Add(config ATNConfig, mergeCache *DoubleDict) bool {
+	if b.readOnly {
+		panic("set is read-only")
+	}
+
+	if config.GetSemanticContext() != SemanticContextNone {
+		b.hasSemanticContext = true
+	}
+
+	if config.GetReachesIntoOuterContext() > 0 {
+		b.dipsIntoOuterContext = true
+	}
+
+	existing := b.configLookup.add(config).(ATNConfig)
+
+	if existing == config {
+		b.cachedHash = -1
+		b.configs = append(b.configs, config) // Track order here
+
+		return true
+	}
+
+	// Merge a previous (s, i, pi, _) with it and save the result
+	rootIsWildcard := !b.fullCtx
+	merged := merge(existing.GetContext(), config.GetContext(), rootIsWildcard, mergeCache)
+
+	// No need to check for existing.context because config.context is in the cache,
+	// since the only way to create new graphs is the "call rule" and here. We cache
+	// at both places.
+	existing.SetReachesIntoOuterContext(intMax(existing.GetReachesIntoOuterContext(), config.GetReachesIntoOuterContext()))
+
+	// Preserve the precedence filter suppression during the merge
+	if config.getPrecedenceFilterSuppressed() {
+		existing.setPrecedenceFilterSuppressed(true)
+	}
+
+	// Replace the context because there is no need to do alt mapping
+	existing.SetContext(merged)
+
+	return true
+}
+
+func (b *BaseATNConfigSet) GetStates() *Set {
+	states := NewSet(nil, nil)
+
+	for i := 0; i < len(b.configs); i++ {
+		states.add(b.configs[i].GetState())
+	}
+
+	return states
+}
+
+func (b *BaseATNConfigSet) HasSemanticContext() bool {
+	return b.hasSemanticContext
+}
+
+func (b *BaseATNConfigSet) SetHasSemanticContext(v bool) {
+	b.hasSemanticContext = v
+}
+
+func (b *BaseATNConfigSet) GetPredicates() []SemanticContext {
+	preds := make([]SemanticContext, 0)
+
+	for i := 0; i < len(b.configs); i++ {
+		c := b.configs[i].GetSemanticContext()
+
+		if c != SemanticContextNone {
+			preds = append(preds, c)
+		}
+	}
+
+	return preds
+}
+
+func (b *BaseATNConfigSet) GetItems() []ATNConfig {
+	return b.configs
+}
+
+func (b *BaseATNConfigSet) OptimizeConfigs(interpreter *BaseATNSimulator) {
+	if b.readOnly {
+		panic("set is read-only")
+	}
+
+	if b.configLookup.length() == 0 {
+		return
+	}
+
+	for i := 0; i < len(b.configs); i++ {
+		config := b.configs[i]
+
+		config.SetContext(interpreter.getCachedContext(config.GetContext()))
+	}
+}
+
+func (b *BaseATNConfigSet) AddAll(coll []ATNConfig) bool {
+	for i := 0; i < len(coll); i++ {
+		b.Add(coll[i], nil)
+	}
+
+	return false
+}
+
+func (b *BaseATNConfigSet) Equals(other interface{}) bool {
+	if b == other {
+		return true
+	} else if _, ok := other.(*BaseATNConfigSet); !ok {
+		return false
+	}
+
+	other2 := other.(*BaseATNConfigSet)
+
+	return b.configs != nil &&
+		// TODO: b.configs.equals(other2.configs) && // TODO: Is b necessary?
+		b.fullCtx == other2.fullCtx &&
+		b.uniqueAlt == other2.uniqueAlt &&
+		b.conflictingAlts == other2.conflictingAlts &&
+		b.hasSemanticContext == other2.hasSemanticContext &&
+		b.dipsIntoOuterContext == other2.dipsIntoOuterContext
+}
+
+func (b *BaseATNConfigSet) hash() int {
+	if b.readOnly {
+		if b.cachedHash == -1 {
+			b.cachedHash = b.hashCodeConfigs()
+		}
+
+		return b.cachedHash
+	}
+
+	return b.hashCodeConfigs()
+}
+
+func (b *BaseATNConfigSet) hashCodeConfigs() int {
+	h := murmurInit(1)
+	for _, c := range b.configs {
+		if c != nil {
+			h = murmurUpdate(h, c.hash())
+		}
+	}
+	return murmurFinish(h, len(b.configs))
+}
+
+func (b *BaseATNConfigSet) Length() int {
+	return len(b.configs)
+}
+
+func (b *BaseATNConfigSet) IsEmpty() bool {
+	return len(b.configs) == 0
+}
+
+func (b *BaseATNConfigSet) Contains(item ATNConfig) bool {
+	if b.configLookup == nil {
+		panic("not implemented for read-only sets")
+	}
+
+	return b.configLookup.contains(item)
+}
+
+func (b *BaseATNConfigSet) ContainsFast(item ATNConfig) bool {
+	if b.configLookup == nil {
+		panic("not implemented for read-only sets")
+	}
+
+	return b.configLookup.contains(item) // TODO: containsFast is not implemented for Set
+}
+
+func (b *BaseATNConfigSet) Clear() {
+	if b.readOnly {
+		panic("set is read-only")
+	}
+
+	b.configs = make([]ATNConfig, 0)
+	b.cachedHash = -1
+	b.configLookup = NewSet(nil, equalATNConfigs)
+}
+
+func (b *BaseATNConfigSet) FullContext() bool {
+	return b.fullCtx
+}
+
+func (b *BaseATNConfigSet) GetDipsIntoOuterContext() bool {
+	return b.dipsIntoOuterContext
+}
+
+func (b *BaseATNConfigSet) SetDipsIntoOuterContext(v bool) {
+	b.dipsIntoOuterContext = v
+}
+
+func (b *BaseATNConfigSet) GetUniqueAlt() int {
+	return b.uniqueAlt
+}
+
+func (b *BaseATNConfigSet) SetUniqueAlt(v int) {
+	b.uniqueAlt = v
+}
+
+func (b *BaseATNConfigSet) GetConflictingAlts() *BitSet {
+	return b.conflictingAlts
+}
+
+func (b *BaseATNConfigSet) SetConflictingAlts(v *BitSet) {
+	b.conflictingAlts = v
+}
+
+func (b *BaseATNConfigSet) ReadOnly() bool {
+	return b.readOnly
+}
+
+func (b *BaseATNConfigSet) SetReadOnly(readOnly bool) {
+	b.readOnly = readOnly
+
+	if readOnly {
+		b.configLookup = nil // Read only, so no need for the lookup cache
+	}
+}
+
+func (b *BaseATNConfigSet) String() string {
+	s := "["
+
+	for i, c := range b.configs {
+		s += c.String()
+
+		if i != len(b.configs)-1 {
+			s += ", "
+		}
+	}
+
+	s += "]"
+
+	if b.hasSemanticContext {
+		s += ",hasSemanticContext=" + fmt.Sprint(b.hasSemanticContext)
+	}
+
+	if b.uniqueAlt != ATNInvalidAltNumber {
+		s += ",uniqueAlt=" + fmt.Sprint(b.uniqueAlt)
+	}
+
+	if b.conflictingAlts != nil {
+		s += ",conflictingAlts=" + b.conflictingAlts.String()
+	}
+
+	if b.dipsIntoOuterContext {
+		s += ",dipsIntoOuterContext"
+	}
+
+	return s
+}
+
+type OrderedATNConfigSet struct {
+	*BaseATNConfigSet
+}
+
+func NewOrderedATNConfigSet() *OrderedATNConfigSet {
+	b := NewBaseATNConfigSet(false)
+
+	b.configLookup = NewSet(nil, nil)
+
+	return &OrderedATNConfigSet{BaseATNConfigSet: b}
+}
+
+func equalATNConfigs(a, b interface{}) bool {
+	if a == nil || b == nil {
+		return false
+	}
+
+	if a == b {
+		return true
+	}
+
+	var ai, ok = a.(ATNConfig)
+	var bi, ok1 = b.(ATNConfig)
+
+	if !ok || !ok1 {
+		return false
+	}
+
+	nums := ai.GetState().GetStateNumber() == bi.GetState().GetStateNumber()
+	alts := ai.GetAlt() == bi.GetAlt()
+	cons := ai.GetSemanticContext().equals(bi.GetSemanticContext())
+
+	return nums && alts && cons
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_deserialization_options.go

@@ -0,0 +1,25 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+var ATNDeserializationOptionsdefaultOptions = &ATNDeserializationOptions{true, false, false}
+
+type ATNDeserializationOptions struct {
+	readOnly                      bool
+	verifyATN                     bool
+	generateRuleBypassTransitions bool
+}
+
+func NewATNDeserializationOptions(CopyFrom *ATNDeserializationOptions) *ATNDeserializationOptions {
+	o := new(ATNDeserializationOptions)
+
+	if CopyFrom != nil {
+		o.readOnly = CopyFrom.readOnly
+		o.verifyATN = CopyFrom.verifyATN
+		o.generateRuleBypassTransitions = CopyFrom.generateRuleBypassTransitions
+	}
+
+	return o
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_deserializer.go

@@ -0,0 +1,828 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"encoding/hex"
+	"fmt"
+	"strconv"
+	"strings"
+	"unicode/utf16"
+)
+
+// This is the earliest supported serialized UUID.
+// stick to serialized version for now, we don't need a UUID instance
+var BaseSerializedUUID = "AADB8D7E-AEEF-4415-AD2B-8204D6CF042E"
+var AddedUnicodeSMP = "59627784-3BE5-417A-B9EB-8131A7286089"
+
+// This list contains all of the currently supported UUIDs, ordered by when
+// the feature first appeared in this branch.
+var SupportedUUIDs = []string{BaseSerializedUUID, AddedUnicodeSMP}
+
+var SerializedVersion = 3
+
+// This is the current serialized UUID.
+var SerializedUUID = AddedUnicodeSMP
+
+type LoopEndStateIntPair struct {
+	item0 *LoopEndState
+	item1 int
+}
+
+type BlockStartStateIntPair struct {
+	item0 BlockStartState
+	item1 int
+}
+
+type ATNDeserializer struct {
+	deserializationOptions *ATNDeserializationOptions
+	data                   []rune
+	pos                    int
+	uuid                   string
+}
+
+func NewATNDeserializer(options *ATNDeserializationOptions) *ATNDeserializer {
+	if options == nil {
+		options = ATNDeserializationOptionsdefaultOptions
+	}
+
+	return &ATNDeserializer{deserializationOptions: options}
+}
+
+func stringInSlice(a string, list []string) int {
+	for i, b := range list {
+		if b == a {
+			return i
+		}
+	}
+
+	return -1
+}
+
+// isFeatureSupported determines if a particular serialized representation of an
+// ATN supports a particular feature, identified by the UUID used for
+// serializing the ATN at the time the feature was first introduced. Feature is
+// the UUID marking the first time the feature was supported in the serialized
+// ATN. ActualUuid is the UUID of the actual serialized ATN which is currently
+// being deserialized. It returns true if actualUuid represents a serialized ATN
+// at or after the feature identified by feature was introduced, and otherwise
+// false.
+func (a *ATNDeserializer) isFeatureSupported(feature, actualUUID string) bool {
+	idx1 := stringInSlice(feature, SupportedUUIDs)
+
+	if idx1 < 0 {
+		return false
+	}
+
+	idx2 := stringInSlice(actualUUID, SupportedUUIDs)
+
+	return idx2 >= idx1
+}
+
+func (a *ATNDeserializer) DeserializeFromUInt16(data []uint16) *ATN {
+	a.reset(utf16.Decode(data))
+	a.checkVersion()
+	a.checkUUID()
+
+	atn := a.readATN()
+
+	a.readStates(atn)
+	a.readRules(atn)
+	a.readModes(atn)
+
+	sets := make([]*IntervalSet, 0)
+
+	// First, deserialize sets with 16-bit arguments <= U+FFFF.
+	sets = a.readSets(atn, sets, a.readInt)
+	// Next, if the ATN was serialized with the Unicode SMP feature,
+	// deserialize sets with 32-bit arguments <= U+10FFFF.
+	if (a.isFeatureSupported(AddedUnicodeSMP, a.uuid)) {
+		sets = a.readSets(atn, sets, a.readInt32)
+	}
+
+	a.readEdges(atn, sets)
+	a.readDecisions(atn)
+	a.readLexerActions(atn)
+	a.markPrecedenceDecisions(atn)
+	a.verifyATN(atn)
+
+	if a.deserializationOptions.generateRuleBypassTransitions && atn.grammarType == ATNTypeParser {
+		a.generateRuleBypassTransitions(atn)
+		// Re-verify after modification
+		a.verifyATN(atn)
+	}
+
+	return atn
+
+}
+
+func (a *ATNDeserializer) reset(data []rune) {
+	temp := make([]rune, len(data))
+
+	for i, c := range data {
+		// Don't adjust the first value since that's the version number
+		if i == 0 {
+			temp[i] = c
+		} else if c > 1 {
+			temp[i] = c - 2
+		} else {
+		    temp[i] = c + 65533
+		}
+	}
+
+	a.data = temp
+	a.pos = 0
+}
+
+func (a *ATNDeserializer) checkVersion() {
+	version := a.readInt()
+
+	if version != SerializedVersion {
+		panic("Could not deserialize ATN with version " + strconv.Itoa(version) + " (expected " + strconv.Itoa(SerializedVersion) + ").")
+	}
+}
+
+func (a *ATNDeserializer) checkUUID() {
+	uuid := a.readUUID()
+
+	if stringInSlice(uuid, SupportedUUIDs) < 0 {
+		panic("Could not deserialize ATN with UUID: " + uuid + " (expected " + SerializedUUID + " or a legacy UUID).")
+	}
+
+	a.uuid = uuid
+}
+
+func (a *ATNDeserializer) readATN() *ATN {
+	grammarType := a.readInt()
+	maxTokenType := a.readInt()
+
+	return NewATN(grammarType, maxTokenType)
+}
+
+func (a *ATNDeserializer) readStates(atn *ATN) {
+	loopBackStateNumbers := make([]LoopEndStateIntPair, 0)
+	endStateNumbers := make([]BlockStartStateIntPair, 0)
+
+	nstates := a.readInt()
+
+	for i := 0; i < nstates; i++ {
+		stype := a.readInt()
+
+		// Ignore bad types of states
+		if stype == ATNStateInvalidType {
+			atn.addState(nil)
+
+			continue
+		}
+
+		ruleIndex := a.readInt()
+
+		if ruleIndex == 0xFFFF {
+			ruleIndex = -1
+		}
+
+		s := a.stateFactory(stype, ruleIndex)
+
+		if stype == ATNStateLoopEnd {
+			loopBackStateNumber := a.readInt()
+
+			loopBackStateNumbers = append(loopBackStateNumbers, LoopEndStateIntPair{s.(*LoopEndState), loopBackStateNumber})
+		} else if s2, ok := s.(BlockStartState); ok {
+			endStateNumber := a.readInt()
+
+			endStateNumbers = append(endStateNumbers, BlockStartStateIntPair{s2, endStateNumber})
+		}
+
+		atn.addState(s)
+	}
+
+	// Delay the assignment of loop back and end states until we know all the state
+	// instances have been initialized
+	for j := 0; j < len(loopBackStateNumbers); j++ {
+		pair := loopBackStateNumbers[j]
+
+		pair.item0.loopBackState = atn.states[pair.item1]
+	}
+
+	for j := 0; j < len(endStateNumbers); j++ {
+		pair := endStateNumbers[j]
+
+		pair.item0.setEndState(atn.states[pair.item1].(*BlockEndState))
+	}
+
+	numNonGreedyStates := a.readInt()
+
+	for j := 0; j < numNonGreedyStates; j++ {
+		stateNumber := a.readInt()
+
+		atn.states[stateNumber].(DecisionState).setNonGreedy(true)
+	}
+
+	numPrecedenceStates := a.readInt()
+
+	for j := 0; j < numPrecedenceStates; j++ {
+		stateNumber := a.readInt()
+
+		atn.states[stateNumber].(*RuleStartState).isPrecedenceRule = true
+	}
+}
+
+func (a *ATNDeserializer) readRules(atn *ATN) {
+	nrules := a.readInt()
+
+	if atn.grammarType == ATNTypeLexer {
+		atn.ruleToTokenType = make([]int, nrules) // TODO: initIntArray(nrules, 0)
+	}
+
+	atn.ruleToStartState = make([]*RuleStartState, nrules) // TODO: initIntArray(nrules, 0)
+
+	for i := 0; i < nrules; i++ {
+		s := a.readInt()
+		startState := atn.states[s].(*RuleStartState)
+
+		atn.ruleToStartState[i] = startState
+
+		if atn.grammarType == ATNTypeLexer {
+			tokenType := a.readInt()
+
+			if tokenType == 0xFFFF {
+				tokenType = TokenEOF
+			}
+
+			atn.ruleToTokenType[i] = tokenType
+		}
+	}
+
+	atn.ruleToStopState = make([]*RuleStopState, nrules) //initIntArray(nrules, 0)
+
+	for i := 0; i < len(atn.states); i++ {
+		state := atn.states[i]
+
+		if s2, ok := state.(*RuleStopState); ok {
+			atn.ruleToStopState[s2.ruleIndex] = s2
+			atn.ruleToStartState[s2.ruleIndex].stopState = s2
+		}
+	}
+}
+
+func (a *ATNDeserializer) readModes(atn *ATN) {
+	nmodes := a.readInt()
+
+	for i := 0; i < nmodes; i++ {
+		s := a.readInt()
+
+		atn.modeToStartState = append(atn.modeToStartState, atn.states[s].(*TokensStartState))
+	}
+}
+
+func (a *ATNDeserializer) readSets(atn *ATN, sets []*IntervalSet, readUnicode func() int) []*IntervalSet {
+	m := a.readInt()
+
+	for i := 0; i < m; i++ {
+		iset := NewIntervalSet()
+
+		sets = append(sets, iset)
+
+		n := a.readInt()
+		containsEOF := a.readInt()
+
+		if containsEOF != 0 {
+			iset.addOne(-1)
+		}
+
+		for j := 0; j < n; j++ {
+			i1 := readUnicode()
+			i2 := readUnicode()
+
+			iset.addRange(i1, i2)
+		}
+	}
+
+	return sets
+}
+
+func (a *ATNDeserializer) readEdges(atn *ATN, sets []*IntervalSet) {
+	nedges := a.readInt()
+
+	for i := 0; i < nedges; i++ {
+		var (
+			src      = a.readInt()
+			trg      = a.readInt()
+			ttype    = a.readInt()
+			arg1     = a.readInt()
+			arg2     = a.readInt()
+			arg3     = a.readInt()
+			trans    = a.edgeFactory(atn, ttype, src, trg, arg1, arg2, arg3, sets)
+			srcState = atn.states[src]
+		)
+
+		srcState.AddTransition(trans, -1)
+	}
+
+	// Edges for rule stop states can be derived, so they are not serialized
+	for i := 0; i < len(atn.states); i++ {
+		state := atn.states[i]
+
+		for j := 0; j < len(state.GetTransitions()); j++ {
+			var t, ok = state.GetTransitions()[j].(*RuleTransition)
+
+			if !ok {
+				continue
+			}
+
+			outermostPrecedenceReturn := -1
+
+			if atn.ruleToStartState[t.getTarget().GetRuleIndex()].isPrecedenceRule {
+				if t.precedence == 0 {
+					outermostPrecedenceReturn = t.getTarget().GetRuleIndex()
+				}
+			}
+
+			trans := NewEpsilonTransition(t.followState, outermostPrecedenceReturn)
+
+			atn.ruleToStopState[t.getTarget().GetRuleIndex()].AddTransition(trans, -1)
+		}
+	}
+
+	for i := 0; i < len(atn.states); i++ {
+		state := atn.states[i]
+
+		if s2, ok := state.(*BaseBlockStartState); ok {
+			// We need to know the end state to set its start state
+			if s2.endState == nil {
+				panic("IllegalState")
+			}
+
+			// Block end states can only be associated to a single block start state
+			if s2.endState.startState != nil {
+				panic("IllegalState")
+			}
+
+			s2.endState.startState = state
+		}
+
+		if s2, ok := state.(*PlusLoopbackState); ok {
+			for j := 0; j < len(s2.GetTransitions()); j++ {
+				target := s2.GetTransitions()[j].getTarget()
+
+				if t2, ok := target.(*PlusBlockStartState); ok {
+					t2.loopBackState = state
+				}
+			}
+		} else if s2, ok := state.(*StarLoopbackState); ok {
+			for j := 0; j < len(s2.GetTransitions()); j++ {
+				target := s2.GetTransitions()[j].getTarget()
+
+				if t2, ok := target.(*StarLoopEntryState); ok {
+					t2.loopBackState = state
+				}
+			}
+		}
+	}
+}
+
+func (a *ATNDeserializer) readDecisions(atn *ATN) {
+	ndecisions := a.readInt()
+
+	for i := 0; i < ndecisions; i++ {
+		s := a.readInt()
+		decState := atn.states[s].(DecisionState)
+
+		atn.DecisionToState = append(atn.DecisionToState, decState)
+		decState.setDecision(i)
+	}
+}
+
+func (a *ATNDeserializer) readLexerActions(atn *ATN) {
+	if atn.grammarType == ATNTypeLexer {
+		count := a.readInt()
+
+		atn.lexerActions = make([]LexerAction, count) // initIntArray(count, nil)
+
+		for i := 0; i < count; i++ {
+			actionType := a.readInt()
+			data1 := a.readInt()
+
+			if data1 == 0xFFFF {
+				data1 = -1
+			}
+
+			data2 := a.readInt()
+
+			if data2 == 0xFFFF {
+				data2 = -1
+			}
+
+			lexerAction := a.lexerActionFactory(actionType, data1, data2)
+
+			atn.lexerActions[i] = lexerAction
+		}
+	}
+}
+
+func (a *ATNDeserializer) generateRuleBypassTransitions(atn *ATN) {
+	count := len(atn.ruleToStartState)
+
+	for i := 0; i < count; i++ {
+		atn.ruleToTokenType[i] = atn.maxTokenType + i + 1
+	}
+
+	for i := 0; i < count; i++ {
+		a.generateRuleBypassTransition(atn, i)
+	}
+}
+
+func (a *ATNDeserializer) generateRuleBypassTransition(atn *ATN, idx int) {
+	bypassStart := NewBasicBlockStartState()
+
+	bypassStart.ruleIndex = idx
+	atn.addState(bypassStart)
+
+	bypassStop := NewBlockEndState()
+
+	bypassStop.ruleIndex = idx
+	atn.addState(bypassStop)
+
+	bypassStart.endState = bypassStop
+
+	atn.defineDecisionState(bypassStart.BaseDecisionState)
+
+	bypassStop.startState = bypassStart
+
+	var excludeTransition Transition
+	var endState ATNState
+
+	if atn.ruleToStartState[idx].isPrecedenceRule {
+		// Wrap from the beginning of the rule to the StarLoopEntryState
+		endState = nil
+
+		for i := 0; i < len(atn.states); i++ {
+			state := atn.states[i]
+
+			if a.stateIsEndStateFor(state, idx) != nil {
+				endState = state
+				excludeTransition = state.(*StarLoopEntryState).loopBackState.GetTransitions()[0]
+
+				break
+			}
+		}
+
+		if excludeTransition == nil {
+			panic("Couldn't identify final state of the precedence rule prefix section.")
+		}
+	} else {
+		endState = atn.ruleToStopState[idx]
+	}
+
+	// All non-excluded transitions that currently target end state need to target
+	// blockEnd instead
+	for i := 0; i < len(atn.states); i++ {
+		state := atn.states[i]
+
+		for j := 0; j < len(state.GetTransitions()); j++ {
+			transition := state.GetTransitions()[j]
+
+			if transition == excludeTransition {
+				continue
+			}
+
+			if transition.getTarget() == endState {
+				transition.setTarget(bypassStop)
+			}
+		}
+	}
+
+	// All transitions leaving the rule start state need to leave blockStart instead
+	ruleToStartState := atn.ruleToStartState[idx]
+	count := len(ruleToStartState.GetTransitions())
+
+	for count > 0 {
+		bypassStart.AddTransition(ruleToStartState.GetTransitions()[count-1], -1)
+		ruleToStartState.SetTransitions([]Transition{ruleToStartState.GetTransitions()[len(ruleToStartState.GetTransitions())-1]})
+	}
+
+	// Link the new states
+	atn.ruleToStartState[idx].AddTransition(NewEpsilonTransition(bypassStart, -1), -1)
+	bypassStop.AddTransition(NewEpsilonTransition(endState, -1), -1)
+
+	MatchState := NewBasicState()
+
+	atn.addState(MatchState)
+	MatchState.AddTransition(NewAtomTransition(bypassStop, atn.ruleToTokenType[idx]), -1)
+	bypassStart.AddTransition(NewEpsilonTransition(MatchState, -1), -1)
+}
+
+func (a *ATNDeserializer) stateIsEndStateFor(state ATNState, idx int) ATNState {
+	if state.GetRuleIndex() != idx {
+		return nil
+	}
+
+	if _, ok := state.(*StarLoopEntryState); !ok {
+		return nil
+	}
+
+	maybeLoopEndState := state.GetTransitions()[len(state.GetTransitions())-1].getTarget()
+
+	if _, ok := maybeLoopEndState.(*LoopEndState); !ok {
+		return nil
+	}
+
+	var _, ok = maybeLoopEndState.GetTransitions()[0].getTarget().(*RuleStopState)
+
+	if maybeLoopEndState.(*LoopEndState).epsilonOnlyTransitions && ok {
+		return state
+	}
+
+	return nil
+}
+
+// markPrecedenceDecisions analyzes the StarLoopEntryState states in the
+// specified ATN to set the StarLoopEntryState.precedenceRuleDecision field to
+// the correct value.
+func (a *ATNDeserializer) markPrecedenceDecisions(atn *ATN) {
+	for _, state := range atn.states {
+		if _, ok := state.(*StarLoopEntryState); !ok {
+			continue
+		}
+
+		// We analyze the ATN to determine if a ATN decision state is the
+		// decision for the closure block that determines whether a
+		// precedence rule should continue or complete.
+		if atn.ruleToStartState[state.GetRuleIndex()].isPrecedenceRule {
+			maybeLoopEndState := state.GetTransitions()[len(state.GetTransitions())-1].getTarget()
+
+			if s3, ok := maybeLoopEndState.(*LoopEndState); ok {
+				var _, ok2 = maybeLoopEndState.GetTransitions()[0].getTarget().(*RuleStopState)
+
+				if s3.epsilonOnlyTransitions && ok2 {
+					state.(*StarLoopEntryState).precedenceRuleDecision = true
+				}
+			}
+		}
+	}
+}
+
+func (a *ATNDeserializer) verifyATN(atn *ATN) {
+	if !a.deserializationOptions.verifyATN {
+		return
+	}
+
+	// Verify assumptions
+	for i := 0; i < len(atn.states); i++ {
+		state := atn.states[i]
+
+		if state == nil {
+			continue
+		}
+
+		a.checkCondition(state.GetEpsilonOnlyTransitions() || len(state.GetTransitions()) <= 1, "")
+
+		switch s2 := state.(type) {
+		case *PlusBlockStartState:
+			a.checkCondition(s2.loopBackState != nil, "")
+
+		case *StarLoopEntryState:
+			a.checkCondition(s2.loopBackState != nil, "")
+			a.checkCondition(len(s2.GetTransitions()) == 2, "")
+
+			switch s2 := state.(type) {
+			case *StarBlockStartState:
+				var _, ok2 = s2.GetTransitions()[1].getTarget().(*LoopEndState)
+
+				a.checkCondition(ok2, "")
+				a.checkCondition(!s2.nonGreedy, "")
+
+			case *LoopEndState:
+				var s3, ok2 = s2.GetTransitions()[1].getTarget().(*StarBlockStartState)
+
+				a.checkCondition(ok2, "")
+				a.checkCondition(s3.nonGreedy, "")
+
+			default:
+				panic("IllegalState")
+			}
+
+		case *StarLoopbackState:
+			a.checkCondition(len(state.GetTransitions()) == 1, "")
+
+			var _, ok2 = state.GetTransitions()[0].getTarget().(*StarLoopEntryState)
+
+			a.checkCondition(ok2, "")
+
+		case *LoopEndState:
+			a.checkCondition(s2.loopBackState != nil, "")
+
+		case *RuleStartState:
+			a.checkCondition(s2.stopState != nil, "")
+
+		case *BaseBlockStartState:
+			a.checkCondition(s2.endState != nil, "")
+
+		case *BlockEndState:
+			a.checkCondition(s2.startState != nil, "")
+
+		case DecisionState:
+			a.checkCondition(len(s2.GetTransitions()) <= 1 || s2.getDecision() >= 0, "")
+
+		default:
+			var _, ok = s2.(*RuleStopState)
+
+			a.checkCondition(len(s2.GetTransitions()) <= 1 || ok, "")
+		}
+	}
+}
+
+func (a *ATNDeserializer) checkCondition(condition bool, message string) {
+	if !condition {
+		if message == "" {
+			message = "IllegalState"
+		}
+
+		panic(message)
+	}
+}
+
+func (a *ATNDeserializer) readInt() int {
+	v := a.data[a.pos]
+
+	a.pos++
+
+	return int(v)
+}
+
+func (a *ATNDeserializer) readInt32() int {
+	var low = a.readInt()
+	var high = a.readInt()
+	return low | (high << 16)
+}
+
+//TODO
+//func (a *ATNDeserializer) readLong() int64 {
+//    panic("Not implemented")
+//    var low = a.readInt32()
+//    var high = a.readInt32()
+//    return (low & 0x00000000FFFFFFFF) | (high << int32)
+//}
+
+func createByteToHex() []string {
+	bth := make([]string, 256)
+
+	for i := 0; i < 256; i++ {
+		bth[i] = strings.ToUpper(hex.EncodeToString([]byte{byte(i)}))
+	}
+
+	return bth
+}
+
+var byteToHex = createByteToHex()
+
+func (a *ATNDeserializer) readUUID() string {
+	bb := make([]int, 16)
+
+	for i := 7; i >= 0; i-- {
+		integer := a.readInt()
+
+		bb[(2*i)+1] = integer & 0xFF
+		bb[2*i] = (integer >> 8) & 0xFF
+	}
+
+	return byteToHex[bb[0]] + byteToHex[bb[1]] +
+		byteToHex[bb[2]] + byteToHex[bb[3]] + "-" +
+		byteToHex[bb[4]] + byteToHex[bb[5]] + "-" +
+		byteToHex[bb[6]] + byteToHex[bb[7]] + "-" +
+		byteToHex[bb[8]] + byteToHex[bb[9]] + "-" +
+		byteToHex[bb[10]] + byteToHex[bb[11]] +
+		byteToHex[bb[12]] + byteToHex[bb[13]] +
+		byteToHex[bb[14]] + byteToHex[bb[15]]
+}
+
+func (a *ATNDeserializer) edgeFactory(atn *ATN, typeIndex, src, trg, arg1, arg2, arg3 int, sets []*IntervalSet) Transition {
+	target := atn.states[trg]
+
+	switch typeIndex {
+	case TransitionEPSILON:
+		return NewEpsilonTransition(target, -1)
+
+	case TransitionRANGE:
+		if arg3 != 0 {
+			return NewRangeTransition(target, TokenEOF, arg2)
+		}
+
+		return NewRangeTransition(target, arg1, arg2)
+
+	case TransitionRULE:
+		return NewRuleTransition(atn.states[arg1], arg2, arg3, target)
+
+	case TransitionPREDICATE:
+		return NewPredicateTransition(target, arg1, arg2, arg3 != 0)
+
+	case TransitionPRECEDENCE:
+		return NewPrecedencePredicateTransition(target, arg1)
+
+	case TransitionATOM:
+		if arg3 != 0 {
+			return NewAtomTransition(target, TokenEOF)
+		}
+
+		return NewAtomTransition(target, arg1)
+
+	case TransitionACTION:
+		return NewActionTransition(target, arg1, arg2, arg3 != 0)
+
+	case TransitionSET:
+		return NewSetTransition(target, sets[arg1])
+
+	case TransitionNOTSET:
+		return NewNotSetTransition(target, sets[arg1])
+
+	case TransitionWILDCARD:
+		return NewWildcardTransition(target)
+	}
+
+	panic("The specified transition type is not valid.")
+}
+
+func (a *ATNDeserializer) stateFactory(typeIndex, ruleIndex int) ATNState {
+	var s ATNState
+
+	switch typeIndex {
+	case ATNStateInvalidType:
+		return nil
+
+	case ATNStateBasic:
+		s = NewBasicState()
+
+	case ATNStateRuleStart:
+		s = NewRuleStartState()
+
+	case ATNStateBlockStart:
+		s = NewBasicBlockStartState()
+
+	case ATNStatePlusBlockStart:
+		s = NewPlusBlockStartState()
+
+	case ATNStateStarBlockStart:
+		s = NewStarBlockStartState()
+
+	case ATNStateTokenStart:
+		s = NewTokensStartState()
+
+	case ATNStateRuleStop:
+		s = NewRuleStopState()
+
+	case ATNStateBlockEnd:
+		s = NewBlockEndState()
+
+	case ATNStateStarLoopBack:
+		s = NewStarLoopbackState()
+
+	case ATNStateStarLoopEntry:
+		s = NewStarLoopEntryState()
+
+	case ATNStatePlusLoopBack:
+		s = NewPlusLoopbackState()
+
+	case ATNStateLoopEnd:
+		s = NewLoopEndState()
+
+	default:
+		panic(fmt.Sprintf("state type %d is invalid", typeIndex))
+	}
+
+	s.SetRuleIndex(ruleIndex)
+
+	return s
+}
+
+func (a *ATNDeserializer) lexerActionFactory(typeIndex, data1, data2 int) LexerAction {
+	switch typeIndex {
+	case LexerActionTypeChannel:
+		return NewLexerChannelAction(data1)
+
+	case LexerActionTypeCustom:
+		return NewLexerCustomAction(data1, data2)
+
+	case LexerActionTypeMode:
+		return NewLexerModeAction(data1)
+
+	case LexerActionTypeMore:
+		return LexerMoreActionINSTANCE
+
+	case LexerActionTypePopMode:
+		return LexerPopModeActionINSTANCE
+
+	case LexerActionTypePushMode:
+		return NewLexerPushModeAction(data1)
+
+	case LexerActionTypeSkip:
+		return LexerSkipActionINSTANCE
+
+	case LexerActionTypeType:
+		return NewLexerTypeAction(data1)
+
+	default:
+		panic(fmt.Sprintf("lexer action %d is invalid", typeIndex))
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_simulator.go

@@ -0,0 +1,50 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+var ATNSimulatorError = NewDFAState(0x7FFFFFFF, NewBaseATNConfigSet(false))
+
+type IATNSimulator interface {
+	SharedContextCache() *PredictionContextCache
+	ATN() *ATN
+	DecisionToDFA() []*DFA
+}
+
+type BaseATNSimulator struct {
+	atn                *ATN
+	sharedContextCache *PredictionContextCache
+	decisionToDFA      []*DFA
+}
+
+func NewBaseATNSimulator(atn *ATN, sharedContextCache *PredictionContextCache) *BaseATNSimulator {
+	b := new(BaseATNSimulator)
+
+	b.atn = atn
+	b.sharedContextCache = sharedContextCache
+
+	return b
+}
+
+func (b *BaseATNSimulator) getCachedContext(context PredictionContext) PredictionContext {
+	if b.sharedContextCache == nil {
+		return context
+	}
+
+	visited := make(map[PredictionContext]PredictionContext)
+
+	return getCachedBasePredictionContext(context, b.sharedContextCache, visited)
+}
+
+func (b *BaseATNSimulator) SharedContextCache() *PredictionContextCache {
+	return b.sharedContextCache
+}
+
+func (b *BaseATNSimulator) ATN() *ATN {
+	return b.atn
+}
+
+func (b *BaseATNSimulator) DecisionToDFA() []*DFA {
+	return b.decisionToDFA
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_state.go

@@ -0,0 +1,386 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import "strconv"
+
+// Constants for serialization.
+const (
+	ATNStateInvalidType    = 0
+	ATNStateBasic          = 1
+	ATNStateRuleStart      = 2
+	ATNStateBlockStart     = 3
+	ATNStatePlusBlockStart = 4
+	ATNStateStarBlockStart = 5
+	ATNStateTokenStart     = 6
+	ATNStateRuleStop       = 7
+	ATNStateBlockEnd       = 8
+	ATNStateStarLoopBack   = 9
+	ATNStateStarLoopEntry  = 10
+	ATNStatePlusLoopBack   = 11
+	ATNStateLoopEnd        = 12
+
+	ATNStateInvalidStateNumber = -1
+)
+
+var ATNStateInitialNumTransitions = 4
+
+type ATNState interface {
+	GetEpsilonOnlyTransitions() bool
+
+	GetRuleIndex() int
+	SetRuleIndex(int)
+
+	GetNextTokenWithinRule() *IntervalSet
+	SetNextTokenWithinRule(*IntervalSet)
+
+	GetATN() *ATN
+	SetATN(*ATN)
+
+	GetStateType() int
+
+	GetStateNumber() int
+	SetStateNumber(int)
+
+	GetTransitions() []Transition
+	SetTransitions([]Transition)
+	AddTransition(Transition, int)
+
+	String() string
+	hash() int
+}
+
+type BaseATNState struct {
+	// NextTokenWithinRule caches lookahead during parsing. Not used during construction.
+	NextTokenWithinRule *IntervalSet
+
+	// atn is the current ATN.
+	atn *ATN
+
+	epsilonOnlyTransitions bool
+
+	// ruleIndex tracks the Rule index because there are no Rule objects at runtime.
+	ruleIndex int
+
+	stateNumber int
+
+	stateType int
+
+	// Track the transitions emanating from this ATN state.
+	transitions []Transition
+}
+
+func NewBaseATNState() *BaseATNState {
+	return &BaseATNState{stateNumber: ATNStateInvalidStateNumber, stateType: ATNStateInvalidType}
+}
+
+func (as *BaseATNState) GetRuleIndex() int {
+	return as.ruleIndex
+}
+
+func (as *BaseATNState) SetRuleIndex(v int) {
+	as.ruleIndex = v
+}
+func (as *BaseATNState) GetEpsilonOnlyTransitions() bool {
+	return as.epsilonOnlyTransitions
+}
+
+func (as *BaseATNState) GetATN() *ATN {
+	return as.atn
+}
+
+func (as *BaseATNState) SetATN(atn *ATN) {
+	as.atn = atn
+}
+
+func (as *BaseATNState) GetTransitions() []Transition {
+	return as.transitions
+}
+
+func (as *BaseATNState) SetTransitions(t []Transition) {
+	as.transitions = t
+}
+
+func (as *BaseATNState) GetStateType() int {
+	return as.stateType
+}
+
+func (as *BaseATNState) GetStateNumber() int {
+	return as.stateNumber
+}
+
+func (as *BaseATNState) SetStateNumber(stateNumber int) {
+	as.stateNumber = stateNumber
+}
+
+func (as *BaseATNState) GetNextTokenWithinRule() *IntervalSet {
+	return as.NextTokenWithinRule
+}
+
+func (as *BaseATNState) SetNextTokenWithinRule(v *IntervalSet) {
+	as.NextTokenWithinRule = v
+}
+
+func (as *BaseATNState) hash() int {
+	return as.stateNumber
+}
+
+func (as *BaseATNState) String() string {
+	return strconv.Itoa(as.stateNumber)
+}
+
+func (as *BaseATNState) equals(other interface{}) bool {
+	if ot, ok := other.(ATNState); ok {
+		return as.stateNumber == ot.GetStateNumber()
+	}
+
+	return false
+}
+
+func (as *BaseATNState) isNonGreedyExitState() bool {
+	return false
+}
+
+func (as *BaseATNState) AddTransition(trans Transition, index int) {
+	if len(as.transitions) == 0 {
+		as.epsilonOnlyTransitions = trans.getIsEpsilon()
+	} else if as.epsilonOnlyTransitions != trans.getIsEpsilon() {
+		as.epsilonOnlyTransitions = false
+	}
+
+	if index == -1 {
+		as.transitions = append(as.transitions, trans)
+	} else {
+		as.transitions = append(as.transitions[:index], append([]Transition{trans}, as.transitions[index:]...)...)
+		// TODO: as.transitions.splice(index, 1, trans)
+	}
+}
+
+type BasicState struct {
+	*BaseATNState
+}
+
+func NewBasicState() *BasicState {
+	b := NewBaseATNState()
+
+	b.stateType = ATNStateBasic
+
+	return &BasicState{BaseATNState: b}
+}
+
+type DecisionState interface {
+	ATNState
+
+	getDecision() int
+	setDecision(int)
+
+	getNonGreedy() bool
+	setNonGreedy(bool)
+}
+
+type BaseDecisionState struct {
+	*BaseATNState
+	decision  int
+	nonGreedy bool
+}
+
+func NewBaseDecisionState() *BaseDecisionState {
+	return &BaseDecisionState{BaseATNState: NewBaseATNState(), decision: -1}
+}
+
+func (s *BaseDecisionState) getDecision() int {
+	return s.decision
+}
+
+func (s *BaseDecisionState) setDecision(b int) {
+	s.decision = b
+}
+
+func (s *BaseDecisionState) getNonGreedy() bool {
+	return s.nonGreedy
+}
+
+func (s *BaseDecisionState) setNonGreedy(b bool) {
+	s.nonGreedy = b
+}
+
+type BlockStartState interface {
+	DecisionState
+
+	getEndState() *BlockEndState
+	setEndState(*BlockEndState)
+}
+
+// BaseBlockStartState is the start of a regular (...) block.
+type BaseBlockStartState struct {
+	*BaseDecisionState
+	endState *BlockEndState
+}
+
+func NewBlockStartState() *BaseBlockStartState {
+	return &BaseBlockStartState{BaseDecisionState: NewBaseDecisionState()}
+}
+
+func (s *BaseBlockStartState) getEndState() *BlockEndState {
+	return s.endState
+}
+
+func (s *BaseBlockStartState) setEndState(b *BlockEndState) {
+	s.endState = b
+}
+
+type BasicBlockStartState struct {
+	*BaseBlockStartState
+}
+
+func NewBasicBlockStartState() *BasicBlockStartState {
+	b := NewBlockStartState()
+
+	b.stateType = ATNStateBlockStart
+
+	return &BasicBlockStartState{BaseBlockStartState: b}
+}
+
+// BlockEndState is a terminal node of a simple (a|b|c) block.
+type BlockEndState struct {
+	*BaseATNState
+	startState ATNState
+}
+
+func NewBlockEndState() *BlockEndState {
+	b := NewBaseATNState()
+
+	b.stateType = ATNStateBlockEnd
+
+	return &BlockEndState{BaseATNState: b}
+}
+
+// RuleStopState is the last node in the ATN for a rule, unless that rule is the
+// start symbol. In that case, there is one transition to EOF. Later, we might
+// encode references to all calls to this rule to compute FOLLOW sets for error
+// handling.
+type RuleStopState struct {
+	*BaseATNState
+}
+
+func NewRuleStopState() *RuleStopState {
+	b := NewBaseATNState()
+
+	b.stateType = ATNStateRuleStop
+
+	return &RuleStopState{BaseATNState: b}
+}
+
+type RuleStartState struct {
+	*BaseATNState
+	stopState        ATNState
+	isPrecedenceRule bool
+}
+
+func NewRuleStartState() *RuleStartState {
+	b := NewBaseATNState()
+
+	b.stateType = ATNStateRuleStart
+
+	return &RuleStartState{BaseATNState: b}
+}
+
+// PlusLoopbackState is a decision state for A+ and (A|B)+. It has two
+// transitions: one to the loop back to start of the block, and one to exit.
+type PlusLoopbackState struct {
+	*BaseDecisionState
+}
+
+func NewPlusLoopbackState() *PlusLoopbackState {
+	b := NewBaseDecisionState()
+
+	b.stateType = ATNStatePlusLoopBack
+
+	return &PlusLoopbackState{BaseDecisionState: b}
+}
+
+// PlusBlockStartState is the start of a (A|B|...)+ loop. Technically it is a
+// decision state; we don't use it for code generation. Somebody might need it,
+// it is included for completeness. In reality, PlusLoopbackState is the real
+// decision-making node for A+.
+type PlusBlockStartState struct {
+	*BaseBlockStartState
+	loopBackState ATNState
+}
+
+func NewPlusBlockStartState() *PlusBlockStartState {
+	b := NewBlockStartState()
+
+	b.stateType = ATNStatePlusBlockStart
+
+	return &PlusBlockStartState{BaseBlockStartState: b}
+}
+
+// StarBlockStartState is the block that begins a closure loop.
+type StarBlockStartState struct {
+	*BaseBlockStartState
+}
+
+func NewStarBlockStartState() *StarBlockStartState {
+	b := NewBlockStartState()
+
+	b.stateType = ATNStateStarBlockStart
+
+	return &StarBlockStartState{BaseBlockStartState: b}
+}
+
+type StarLoopbackState struct {
+	*BaseATNState
+}
+
+func NewStarLoopbackState() *StarLoopbackState {
+	b := NewBaseATNState()
+
+	b.stateType = ATNStateStarLoopBack
+
+	return &StarLoopbackState{BaseATNState: b}
+}
+
+type StarLoopEntryState struct {
+	*BaseDecisionState
+	loopBackState          ATNState
+	precedenceRuleDecision bool
+}
+
+func NewStarLoopEntryState() *StarLoopEntryState {
+	b := NewBaseDecisionState()
+
+	b.stateType = ATNStateStarLoopEntry
+
+	// False precedenceRuleDecision indicates whether s state can benefit from a precedence DFA during SLL decision making.
+	return &StarLoopEntryState{BaseDecisionState: b}
+}
+
+// LoopEndState marks the end of a * or + loop.
+type LoopEndState struct {
+	*BaseATNState
+	loopBackState ATNState
+}
+
+func NewLoopEndState() *LoopEndState {
+	b := NewBaseATNState()
+
+	b.stateType = ATNStateLoopEnd
+
+	return &LoopEndState{BaseATNState: b}
+}
+
+// TokensStartState is the Tokens rule start state linking to each lexer rule start state.
+type TokensStartState struct {
+	*BaseDecisionState
+}
+
+func NewTokensStartState() *TokensStartState {
+	b := NewBaseDecisionState()
+
+	b.stateType = ATNStateTokenStart
+
+	return &TokensStartState{BaseDecisionState: b}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/atn_type.go

@@ -0,0 +1,11 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// Represent the type of recognizer an ATN applies to.
+const (
+	ATNTypeLexer  = 0
+	ATNTypeParser = 1
+)

vendor/github.com/antlr/antlr4/runtime/Go/antlr/char_stream.go

@@ -0,0 +1,12 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+type CharStream interface {
+	IntStream
+	GetText(int, int) string
+	GetTextFromTokens(start, end Token) string
+	GetTextFromInterval(*Interval) string
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/common_token_factory.go

@@ -0,0 +1,56 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// TokenFactory creates CommonToken objects.
+type TokenFactory interface {
+	Create(source *TokenSourceCharStreamPair, ttype int, text string, channel, start, stop, line, column int) Token
+}
+
+// CommonTokenFactory is the default TokenFactory implementation.
+type CommonTokenFactory struct {
+	// copyText indicates whether CommonToken.setText should be called after
+	// constructing tokens to explicitly set the text. This is useful for cases
+	// where the input stream might not be able to provide arbitrary substrings of
+	// text from the input after the lexer creates a token (e.g. the
+	// implementation of CharStream.GetText in UnbufferedCharStream panics an
+	// UnsupportedOperationException). Explicitly setting the token text allows
+	// Token.GetText to be called at any time regardless of the input stream
+	// implementation.
+	//
+	// The default value is false to avoid the performance and memory overhead of
+	// copying text for every token unless explicitly requested.
+	copyText bool
+}
+
+func NewCommonTokenFactory(copyText bool) *CommonTokenFactory {
+	return &CommonTokenFactory{copyText: copyText}
+}
+
+// CommonTokenFactoryDEFAULT is the default CommonTokenFactory. It does not
+// explicitly copy token text when constructing tokens.
+var CommonTokenFactoryDEFAULT = NewCommonTokenFactory(false)
+
+func (c *CommonTokenFactory) Create(source *TokenSourceCharStreamPair, ttype int, text string, channel, start, stop, line, column int) Token {
+	t := NewCommonToken(source, ttype, channel, start, stop)
+
+	t.line = line
+	t.column = column
+
+	if text != "" {
+		t.SetText(text)
+	} else if c.copyText && source.charStream != nil {
+		t.SetText(source.charStream.GetTextFromInterval(NewInterval(start, stop)))
+	}
+
+	return t
+}
+
+func (c *CommonTokenFactory) createThin(ttype int, text string) Token {
+	t := NewCommonToken(nil, ttype, TokenDefaultChannel, -1, -1)
+	t.SetText(text)
+
+	return t
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/common_token_stream.go

@@ -0,0 +1,447 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"strconv"
+)
+
+// CommonTokenStream is an implementation of TokenStream that loads tokens from
+// a TokenSource on-demand and places the tokens in a buffer to provide access
+// to any previous token by index. This token stream ignores the value of
+// Token.getChannel. If your parser requires the token stream filter tokens to
+// only those on a particular channel, such as Token.DEFAULT_CHANNEL or
+// Token.HIDDEN_CHANNEL, use a filtering token stream such a CommonTokenStream.
+type CommonTokenStream struct {
+	channel int
+
+	// fetchedEOF indicates whether the Token.EOF token has been fetched from
+	// tokenSource and added to tokens. This field improves performance for the
+	// following cases:
+	//
+	// consume: The lookahead check in consume to preven consuming the EOF symbol is
+	// optimized by checking the values of fetchedEOF and p instead of calling LA.
+	//
+	// fetch: The check to prevent adding multiple EOF symbols into tokens is
+	// trivial with bt field.
+	fetchedEOF bool
+
+	// index indexs into tokens of the current token (next token to consume).
+	// tokens[p] should be LT(1). It is set to -1 when the stream is first
+	// constructed or when SetTokenSource is called, indicating that the first token
+	// has not yet been fetched from the token source. For additional information,
+	// see the documentation of IntStream for a description of initializing methods.
+	index int
+
+	// tokenSource is the TokenSource from which tokens for the bt stream are
+	// fetched.
+	tokenSource TokenSource
+
+	// tokens is all tokens fetched from the token source. The list is considered a
+	// complete view of the input once fetchedEOF is set to true.
+	tokens []Token
+}
+
+func NewCommonTokenStream(lexer Lexer, channel int) *CommonTokenStream {
+	return &CommonTokenStream{
+		channel:     channel,
+		index:       -1,
+		tokenSource: lexer,
+		tokens:      make([]Token, 0),
+	}
+}
+
+func (c *CommonTokenStream) GetAllTokens() []Token {
+	return c.tokens
+}
+
+func (c *CommonTokenStream) Mark() int {
+	return 0
+}
+
+func (c *CommonTokenStream) Release(marker int) {}
+
+func (c *CommonTokenStream) reset() {
+	c.Seek(0)
+}
+
+func (c *CommonTokenStream) Seek(index int) {
+	c.lazyInit()
+	c.index = c.adjustSeekIndex(index)
+}
+
+func (c *CommonTokenStream) Get(index int) Token {
+	c.lazyInit()
+
+	return c.tokens[index]
+}
+
+func (c *CommonTokenStream) Consume() {
+	SkipEOFCheck := false
+
+	if c.index >= 0 {
+		if c.fetchedEOF {
+			// The last token in tokens is EOF. Skip the check if p indexes any fetched.
+			// token except the last.
+			SkipEOFCheck = c.index < len(c.tokens)-1
+		} else {
+			// No EOF token in tokens. Skip the check if p indexes a fetched token.
+			SkipEOFCheck = c.index < len(c.tokens)
+		}
+	} else {
+		// Not yet initialized
+		SkipEOFCheck = false
+	}
+
+	if !SkipEOFCheck && c.LA(1) == TokenEOF {
+		panic("cannot consume EOF")
+	}
+
+	if c.Sync(c.index + 1) {
+		c.index = c.adjustSeekIndex(c.index + 1)
+	}
+}
+
+// Sync makes sure index i in tokens has a token and returns true if a token is
+// located at index i and otherwise false.
+func (c *CommonTokenStream) Sync(i int) bool {
+	n := i - len(c.tokens) + 1 // TODO: How many more elements do we need?
+
+	if n > 0 {
+		fetched := c.fetch(n)
+		return fetched >= n
+	}
+
+	return true
+}
+
+// fetch adds n elements to buffer and returns the actual number of elements
+// added to the buffer.
+func (c *CommonTokenStream) fetch(n int) int {
+	if c.fetchedEOF {
+		return 0
+	}
+
+	for i := 0; i < n; i++ {
+		t := c.tokenSource.NextToken()
+
+		t.SetTokenIndex(len(c.tokens))
+		c.tokens = append(c.tokens, t)
+
+		if t.GetTokenType() == TokenEOF {
+			c.fetchedEOF = true
+
+			return i + 1
+		}
+	}
+
+	return n
+}
+
+// GetTokens gets all tokens from start to stop inclusive.
+func (c *CommonTokenStream) GetTokens(start int, stop int, types *IntervalSet) []Token {
+	if start < 0 || stop < 0 {
+		return nil
+	}
+
+	c.lazyInit()
+
+	subset := make([]Token, 0)
+
+	if stop >= len(c.tokens) {
+		stop = len(c.tokens) - 1
+	}
+
+	for i := start; i < stop; i++ {
+		t := c.tokens[i]
+
+		if t.GetTokenType() == TokenEOF {
+			break
+		}
+
+		if types == nil || types.contains(t.GetTokenType()) {
+			subset = append(subset, t)
+		}
+	}
+
+	return subset
+}
+
+func (c *CommonTokenStream) LA(i int) int {
+	return c.LT(i).GetTokenType()
+}
+
+func (c *CommonTokenStream) lazyInit() {
+	if c.index == -1 {
+		c.setup()
+	}
+}
+
+func (c *CommonTokenStream) setup() {
+	c.Sync(0)
+	c.index = c.adjustSeekIndex(0)
+}
+
+func (c *CommonTokenStream) GetTokenSource() TokenSource {
+	return c.tokenSource
+}
+
+// SetTokenSource resets the c token stream by setting its token source.
+func (c *CommonTokenStream) SetTokenSource(tokenSource TokenSource) {
+	c.tokenSource = tokenSource
+	c.tokens = make([]Token, 0)
+	c.index = -1
+}
+
+// NextTokenOnChannel returns the index of the next token on channel given a
+// starting index. Returns i if tokens[i] is on channel. Returns -1 if there are
+// no tokens on channel between i and EOF.
+func (c *CommonTokenStream) NextTokenOnChannel(i, channel int) int {
+	c.Sync(i)
+
+	if i >= len(c.tokens) {
+		return -1
+	}
+
+	token := c.tokens[i]
+
+	for token.GetChannel() != c.channel {
+		if token.GetTokenType() == TokenEOF {
+			return -1
+		}
+
+		i++
+		c.Sync(i)
+		token = c.tokens[i]
+	}
+
+	return i
+}
+
+// previousTokenOnChannel returns the index of the previous token on channel
+// given a starting index. Returns i if tokens[i] is on channel. Returns -1 if
+// there are no tokens on channel between i and 0.
+func (c *CommonTokenStream) previousTokenOnChannel(i, channel int) int {
+	for i >= 0 && c.tokens[i].GetChannel() != channel {
+		i--
+	}
+
+	return i
+}
+
+// GetHiddenTokensToRight collects all tokens on a specified channel to the
+// right of the current token up until we see a token on DEFAULT_TOKEN_CHANNEL
+// or EOF. If channel is -1, it finds any non-default channel token.
+func (c *CommonTokenStream) GetHiddenTokensToRight(tokenIndex, channel int) []Token {
+	c.lazyInit()
+
+	if tokenIndex < 0 || tokenIndex >= len(c.tokens) {
+		panic(strconv.Itoa(tokenIndex) + " not in 0.." + strconv.Itoa(len(c.tokens)-1))
+	}
+
+	nextOnChannel := c.NextTokenOnChannel(tokenIndex+1, LexerDefaultTokenChannel)
+	from := tokenIndex + 1
+
+	// If no onchannel to the right, then nextOnChannel == -1, so set to to last token
+	var to int
+
+	if nextOnChannel == -1 {
+		to = len(c.tokens) - 1
+	} else {
+		to = nextOnChannel
+	}
+
+	return c.filterForChannel(from, to, channel)
+}
+
+// GetHiddenTokensToLeft collects all tokens on channel to the left of the
+// current token until we see a token on DEFAULT_TOKEN_CHANNEL. If channel is
+// -1, it finds any non default channel token.
+func (c *CommonTokenStream) GetHiddenTokensToLeft(tokenIndex, channel int) []Token {
+	c.lazyInit()
+
+	if tokenIndex < 0 || tokenIndex >= len(c.tokens) {
+		panic(strconv.Itoa(tokenIndex) + " not in 0.." + strconv.Itoa(len(c.tokens)-1))
+	}
+
+	prevOnChannel := c.previousTokenOnChannel(tokenIndex-1, LexerDefaultTokenChannel)
+
+	if prevOnChannel == tokenIndex-1 {
+		return nil
+	}
+
+	// If there are none on channel to the left and prevOnChannel == -1 then from = 0
+	from := prevOnChannel + 1
+	to := tokenIndex - 1
+
+	return c.filterForChannel(from, to, channel)
+}
+
+func (c *CommonTokenStream) filterForChannel(left, right, channel int) []Token {
+	hidden := make([]Token, 0)
+
+	for i := left; i < right+1; i++ {
+		t := c.tokens[i]
+
+		if channel == -1 {
+			if t.GetChannel() != LexerDefaultTokenChannel {
+				hidden = append(hidden, t)
+			}
+		} else if t.GetChannel() == channel {
+			hidden = append(hidden, t)
+		}
+	}
+
+	if len(hidden) == 0 {
+		return nil
+	}
+
+	return hidden
+}
+
+func (c *CommonTokenStream) GetSourceName() string {
+	return c.tokenSource.GetSourceName()
+}
+
+func (c *CommonTokenStream) Size() int {
+	return len(c.tokens)
+}
+
+func (c *CommonTokenStream) Index() int {
+	return c.index
+}
+
+func (c *CommonTokenStream) GetAllText() string {
+	return c.GetTextFromInterval(nil)
+}
+
+func (c *CommonTokenStream) GetTextFromTokens(start, end Token) string {
+	if start == nil || end == nil {
+		return ""
+	}
+
+	return c.GetTextFromInterval(NewInterval(start.GetTokenIndex(), end.GetTokenIndex()))
+}
+
+func (c *CommonTokenStream) GetTextFromRuleContext(interval RuleContext) string {
+	return c.GetTextFromInterval(interval.GetSourceInterval())
+}
+
+func (c *CommonTokenStream) GetTextFromInterval(interval *Interval) string {
+	c.lazyInit()
+	c.Fill()
+
+	if interval == nil {
+		interval = NewInterval(0, len(c.tokens)-1)
+	}
+
+	start := interval.Start
+	stop := interval.Stop
+
+	if start < 0 || stop < 0 {
+		return ""
+	}
+
+	if stop >= len(c.tokens) {
+		stop = len(c.tokens) - 1
+	}
+
+	s := ""
+
+	for i := start; i < stop+1; i++ {
+		t := c.tokens[i]
+
+		if t.GetTokenType() == TokenEOF {
+			break
+		}
+
+		s += t.GetText()
+	}
+
+	return s
+}
+
+// Fill gets all tokens from the lexer until EOF.
+func (c *CommonTokenStream) Fill() {
+	c.lazyInit()
+
+	for c.fetch(1000) == 1000 {
+		continue
+	}
+}
+
+func (c *CommonTokenStream) adjustSeekIndex(i int) int {
+	return c.NextTokenOnChannel(i, c.channel)
+}
+
+func (c *CommonTokenStream) LB(k int) Token {
+	if k == 0 || c.index-k < 0 {
+		return nil
+	}
+
+	i := c.index
+	n := 1
+
+	// Find k good tokens looking backward
+	for n <= k {
+		// Skip off-channel tokens
+		i = c.previousTokenOnChannel(i-1, c.channel)
+		n++
+	}
+
+	if i < 0 {
+		return nil
+	}
+
+	return c.tokens[i]
+}
+
+func (c *CommonTokenStream) LT(k int) Token {
+	c.lazyInit()
+
+	if k == 0 {
+		return nil
+	}
+
+	if k < 0 {
+		return c.LB(-k)
+	}
+
+	i := c.index
+	n := 1 // We know tokens[n] is valid
+
+	// Find k good tokens
+	for n < k {
+		// Skip off-channel tokens, but make sure to not look past EOF
+		if c.Sync(i + 1) {
+			i = c.NextTokenOnChannel(i+1, c.channel)
+		}
+
+		n++
+	}
+
+	return c.tokens[i]
+}
+
+// getNumberOfOnChannelTokens counts EOF once.
+func (c *CommonTokenStream) getNumberOfOnChannelTokens() int {
+	var n int
+
+	c.Fill()
+
+	for i := 0; i < len(c.tokens); i++ {
+		t := c.tokens[i]
+
+		if t.GetChannel() == c.channel {
+			n++
+		}
+
+		if t.GetTokenType() == TokenEOF {
+			break
+		}
+	}
+
+	return n
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/dfa.go

@@ -0,0 +1,183 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"sort"
+	"sync"
+)
+
+type DFA struct {
+	// atnStartState is the ATN state in which this was created
+	atnStartState DecisionState
+
+	decision int
+
+	// states is all the DFA states. Use Map to get the old state back; Set can only
+	// indicate whether it is there.
+	states map[int]*DFAState
+	statesMu sync.RWMutex
+
+	s0 *DFAState
+	s0Mu sync.RWMutex
+
+	// precedenceDfa is the backing field for isPrecedenceDfa and setPrecedenceDfa.
+	// True if the DFA is for a precedence decision and false otherwise.
+	precedenceDfa bool
+	precedenceDfaMu sync.RWMutex
+}
+
+func NewDFA(atnStartState DecisionState, decision int) *DFA {
+	return &DFA{
+		atnStartState: atnStartState,
+		decision:      decision,
+		states:        make(map[int]*DFAState),
+	}
+}
+
+// getPrecedenceStartState gets the start state for the current precedence and
+// returns the start state corresponding to the specified precedence if a start
+// state exists for the specified precedence and nil otherwise. d must be a
+// precedence DFA. See also isPrecedenceDfa.
+func (d *DFA) getPrecedenceStartState(precedence int) *DFAState {
+	if !d.getPrecedenceDfa() {
+		panic("only precedence DFAs may contain a precedence start state")
+	}
+
+	// s0.edges is never nil for a precedence DFA
+	if precedence < 0 || precedence >= len(d.getS0().getEdges()) {
+		return nil
+	}
+
+	return d.getS0().getIthEdge(precedence)
+}
+
+// setPrecedenceStartState sets the start state for the current precedence. d
+// must be a precedence DFA. See also isPrecedenceDfa.
+func (d *DFA) setPrecedenceStartState(precedence int, startState *DFAState) {
+	if !d.getPrecedenceDfa() {
+		panic("only precedence DFAs may contain a precedence start state")
+	}
+
+	if precedence < 0 {
+		return
+	}
+
+	// Synchronization on s0 here is ok. When the DFA is turned into a
+	// precedence DFA, s0 will be initialized once and not updated again. s0.edges
+	// is never nil for a precedence DFA.
+	s0 := d.getS0()
+	if precedence >= s0.numEdges() {
+		edges := append(s0.getEdges(), make([]*DFAState, precedence+1-s0.numEdges())...)
+		s0.setEdges(edges)
+		d.setS0(s0)
+	}
+
+	s0.setIthEdge(precedence, startState)
+}
+
+func (d *DFA) getPrecedenceDfa() bool {
+	d.precedenceDfaMu.RLock()
+	defer d.precedenceDfaMu.RUnlock()
+	return d.precedenceDfa
+}
+
+// setPrecedenceDfa sets whether d is a precedence DFA. If precedenceDfa differs
+// from the current DFA configuration, then d.states is cleared, the initial
+// state s0 is set to a new DFAState with an empty outgoing DFAState.edges to
+// store the start states for individual precedence values if precedenceDfa is
+// true or nil otherwise, and d.precedenceDfa is updated.
+func (d *DFA) setPrecedenceDfa(precedenceDfa bool) {
+	if d.getPrecedenceDfa() != precedenceDfa {
+		d.setStates(make(map[int]*DFAState))
+
+		if precedenceDfa {
+			precedenceState := NewDFAState(-1, NewBaseATNConfigSet(false))
+
+			precedenceState.setEdges(make([]*DFAState, 0))
+			precedenceState.isAcceptState = false
+			precedenceState.requiresFullContext = false
+			d.setS0(precedenceState)
+		} else {
+			d.setS0(nil)
+		}
+
+		d.precedenceDfaMu.Lock()
+		defer d.precedenceDfaMu.Unlock()
+		d.precedenceDfa = precedenceDfa
+	}
+}
+
+func (d *DFA) getS0() *DFAState {
+	d.s0Mu.RLock()
+	defer d.s0Mu.RUnlock()
+	return d.s0
+}
+
+func (d *DFA) setS0(s *DFAState) {
+	d.s0Mu.Lock()
+	defer d.s0Mu.Unlock()
+	d.s0 = s
+}
+
+func (d *DFA) getState(hash int) (*DFAState, bool) {
+	d.statesMu.RLock()
+	defer d.statesMu.RUnlock()
+	s, ok := d.states[hash]
+	return s, ok
+}
+
+func (d *DFA) setStates(states map[int]*DFAState) {
+	d.statesMu.Lock()
+	defer d.statesMu.Unlock()
+	d.states = states
+}
+
+func (d *DFA) setState(hash int, state *DFAState) {
+	d.statesMu.Lock()
+	defer d.statesMu.Unlock()
+	d.states[hash] = state
+}
+
+func (d *DFA) numStates() int {
+	d.statesMu.RLock()
+	defer d.statesMu.RUnlock()
+	return len(d.states)
+}
+
+type dfaStateList []*DFAState
+
+func (d dfaStateList) Len() int           { return len(d) }
+func (d dfaStateList) Less(i, j int) bool { return d[i].stateNumber < d[j].stateNumber }
+func (d dfaStateList) Swap(i, j int)      { d[i], d[j] = d[j], d[i] }
+
+// sortedStates returns the states in d sorted by their state number.
+func (d *DFA) sortedStates() []*DFAState {
+	vs := make([]*DFAState, 0, len(d.states))
+
+	for _, v := range d.states {
+		vs = append(vs, v)
+	}
+
+	sort.Sort(dfaStateList(vs))
+
+	return vs
+}
+
+func (d *DFA) String(literalNames []string, symbolicNames []string) string {
+	if d.getS0() == nil {
+		return ""
+	}
+
+	return NewDFASerializer(d, literalNames, symbolicNames).String()
+}
+
+func (d *DFA) ToLexerString() string {
+	if d.getS0() == nil {
+		return ""
+	}
+
+	return NewLexerDFASerializer(d).String()
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/dfa_serializer.go

@@ -0,0 +1,152 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// DFASerializer is a DFA walker that knows how to dump them to serialized
+// strings.
+type DFASerializer struct {
+	dfa           *DFA
+	literalNames  []string
+	symbolicNames []string
+}
+
+func NewDFASerializer(dfa *DFA, literalNames, symbolicNames []string) *DFASerializer {
+	if literalNames == nil {
+		literalNames = make([]string, 0)
+	}
+
+	if symbolicNames == nil {
+		symbolicNames = make([]string, 0)
+	}
+
+	return &DFASerializer{
+		dfa:           dfa,
+		literalNames:  literalNames,
+		symbolicNames: symbolicNames,
+	}
+}
+
+func (d *DFASerializer) String() string {
+	if d.dfa.getS0() == nil {
+		return ""
+	}
+
+	buf := ""
+	states := d.dfa.sortedStates()
+
+	for _, s := range states {
+		if s.edges != nil {
+			n := len(s.edges)
+
+			for j := 0; j < n; j++ {
+				t := s.edges[j]
+
+				if t != nil && t.stateNumber != 0x7FFFFFFF {
+					buf += d.GetStateString(s)
+					buf += "-"
+					buf += d.getEdgeLabel(j)
+					buf += "->"
+					buf += d.GetStateString(t)
+					buf += "\n"
+				}
+			}
+		}
+	}
+
+	if len(buf) == 0 {
+		return ""
+	}
+
+	return buf
+}
+
+func (d *DFASerializer) getEdgeLabel(i int) string {
+	if i == 0 {
+		return "EOF"
+	} else if d.literalNames != nil && i-1 < len(d.literalNames) {
+		return d.literalNames[i-1]
+	} else if d.symbolicNames != nil && i-1 < len(d.symbolicNames) {
+		return d.symbolicNames[i-1]
+	}
+
+	return strconv.Itoa(i - 1)
+}
+
+func (d *DFASerializer) GetStateString(s *DFAState) string {
+	var a, b string
+
+	if s.isAcceptState {
+		a = ":"
+	}
+
+	if s.requiresFullContext {
+		b = "^"
+	}
+
+	baseStateStr := a + "s" + strconv.Itoa(s.stateNumber) + b
+
+	if s.isAcceptState {
+		if s.predicates != nil {
+			return baseStateStr + "=>" + fmt.Sprint(s.predicates)
+		}
+
+		return baseStateStr + "=>" + fmt.Sprint(s.prediction)
+	}
+
+	return baseStateStr
+}
+
+type LexerDFASerializer struct {
+	*DFASerializer
+}
+
+func NewLexerDFASerializer(dfa *DFA) *LexerDFASerializer {
+	return &LexerDFASerializer{DFASerializer: NewDFASerializer(dfa, nil, nil)}
+}
+
+func (l *LexerDFASerializer) getEdgeLabel(i int) string {
+	return "'" + string(i) + "'"
+}
+
+func (l *LexerDFASerializer) String() string {
+	if l.dfa.getS0() == nil {
+		return ""
+	}
+
+	buf := ""
+	states := l.dfa.sortedStates()
+
+	for i := 0; i < len(states); i++ {
+		s := states[i]
+
+		if s.edges != nil {
+			n := len(s.edges)
+
+			for j := 0; j < n; j++ {
+				t := s.edges[j]
+
+				if t != nil && t.stateNumber != 0x7FFFFFFF {
+					buf += l.GetStateString(s)
+					buf += "-"
+					buf += l.getEdgeLabel(j)
+					buf += "->"
+					buf += l.GetStateString(t)
+					buf += "\n"
+				}
+			}
+		}
+	}
+
+	if len(buf) == 0 {
+		return ""
+	}
+
+	return buf
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/dfa_state.go

@@ -0,0 +1,198 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"sync"
+)
+
+// PredPrediction maps a predicate to a predicted alternative.
+type PredPrediction struct {
+	alt  int
+	pred SemanticContext
+}
+
+func NewPredPrediction(pred SemanticContext, alt int) *PredPrediction {
+	return &PredPrediction{alt: alt, pred: pred}
+}
+
+func (p *PredPrediction) String() string {
+	return "(" + fmt.Sprint(p.pred) + ", " + fmt.Sprint(p.alt) + ")"
+}
+
+// DFAState represents a set of possible ATN configurations. As Aho, Sethi,
+// Ullman p. 117 says: "The DFA uses its state to keep track of all possible
+// states the ATN can be in after reading each input symbol. That is to say,
+// after reading input a1a2..an, the DFA is in a state that represents the
+// subset T of the states of the ATN that are reachable from the ATN's start
+// state along some path labeled a1a2..an." In conventional NFA-to-DFA
+// conversion, therefore, the subset T would be a bitset representing the set of
+// states the ATN could be in. We need to track the alt predicted by each state
+// as well, however. More importantly, we need to maintain a stack of states,
+// tracking the closure operations as they jump from rule to rule, emulating
+// rule invocations (method calls). I have to add a stack to simulate the proper
+// lookahead sequences for the underlying LL grammar from which the ATN was
+// derived.
+//
+// I use a set of ATNConfig objects, not simple states. An ATNConfig is both a
+// state (ala normal conversion) and a RuleContext describing the chain of rules
+// (if any) followed to arrive at that state.
+//
+// A DFAState may have multiple references to a particular state, but with
+// different ATN contexts (with same or different alts) meaning that state was
+// reached via a different set of rule invocations.
+type DFAState struct {
+	stateNumber int
+	configs     ATNConfigSet
+
+	// edges elements point to the target of the symbol. Shift up by 1 so (-1)
+	// Token.EOF maps to the first element.
+	edges []*DFAState
+	edgesMu	sync.RWMutex
+
+	isAcceptState bool
+
+	// prediction is the ttype we match or alt we predict if the state is accept.
+	// Set to ATN.INVALID_ALT_NUMBER when predicates != nil or
+	// requiresFullContext.
+	prediction int
+
+	lexerActionExecutor *LexerActionExecutor
+
+	// requiresFullContext indicates it was created during an SLL prediction that
+	// discovered a conflict between the configurations in the state. Future
+	// ParserATNSimulator.execATN invocations immediately jump doing
+	// full context prediction if true.
+	requiresFullContext bool
+
+	// predicates is the predicates associated with the ATN configurations of the
+	// DFA state during SLL parsing. When we have predicates, requiresFullContext
+	// is false, since full context prediction evaluates predicates on-the-fly. If
+	// d is
+	// not nil, then prediction is ATN.INVALID_ALT_NUMBER.
+	//
+	// We only use these for non-requiresFullContext but conflicting states. That
+	// means we know from the context (it's $ or we don't dip into outer context)
+	// that it's an ambiguity not a conflict.
+	//
+	// This list is computed by
+	// ParserATNSimulator.predicateDFAState.
+	predicates []*PredPrediction
+}
+
+func NewDFAState(stateNumber int, configs ATNConfigSet) *DFAState {
+	if configs == nil {
+		configs = NewBaseATNConfigSet(false)
+	}
+
+	return &DFAState{configs: configs, stateNumber: stateNumber}
+}
+
+// GetAltSet gets the set of all alts mentioned by all ATN configurations in d.
+func (d *DFAState) GetAltSet() *Set {
+	alts := NewSet(nil, nil)
+
+	if d.configs != nil {
+		for _, c := range d.configs.GetItems() {
+			alts.add(c.GetAlt())
+		}
+	}
+
+	if alts.length() == 0 {
+		return nil
+	}
+
+	return alts
+}
+
+func (d *DFAState) getEdges() []*DFAState {
+	d.edgesMu.RLock()
+	defer d.edgesMu.RUnlock()
+	return d.edges
+}
+
+func (d *DFAState) numEdges() int {
+	d.edgesMu.RLock()
+	defer d.edgesMu.RUnlock()
+	return len(d.edges)
+}
+
+func (d *DFAState) getIthEdge(i int) *DFAState {
+	d.edgesMu.RLock()
+	defer d.edgesMu.RUnlock()
+	return d.edges[i]
+}
+
+func (d *DFAState) setEdges(newEdges []*DFAState) {
+	d.edgesMu.Lock()
+	defer d.edgesMu.Unlock()
+	d.edges = newEdges
+}
+
+func (d *DFAState) setIthEdge(i int, edge *DFAState) {
+	d.edgesMu.Lock()
+	defer d.edgesMu.Unlock()
+	d.edges[i] = edge
+}
+
+func (d *DFAState) setPrediction(v int) {
+	d.prediction = v
+}
+
+// equals returns whether d equals other. Two DFAStates are equal if their ATN
+// configuration sets are the same. This method is used to see if a state
+// already exists.
+//
+// Because the number of alternatives and number of ATN configurations are
+// finite, there is a finite number of DFA states that can be processed. This is
+// necessary to show that the algorithm terminates.
+//
+// Cannot test the DFA state numbers here because in
+// ParserATNSimulator.addDFAState we need to know if any other state exists that
+// has d exact set of ATN configurations. The stateNumber is irrelevant.
+func (d *DFAState) equals(other interface{}) bool {
+	if d == other {
+		return true
+	} else if _, ok := other.(*DFAState); !ok {
+		return false
+	}
+
+	return d.configs.Equals(other.(*DFAState).configs)
+}
+
+func (d *DFAState) String() string {
+	var s string
+	if d.isAcceptState {
+		if d.predicates != nil {
+			s = "=>" + fmt.Sprint(d.predicates)
+		} else {
+			s = "=>" + fmt.Sprint(d.prediction)
+		}
+	}
+
+	return fmt.Sprintf("%d:%s%s", fmt.Sprint(d.configs), s)
+}
+
+func (d *DFAState) hash() int {
+	h := murmurInit(11)
+
+	c := 1
+	if d.isAcceptState {
+		if d.predicates != nil {
+			for _, p := range d.predicates {
+				h = murmurUpdate(h, p.alt)
+				h = murmurUpdate(h, p.pred.hash())
+				c += 2
+			}
+		} else {
+			h = murmurUpdate(h, d.prediction)
+			c += 1
+		}
+	}
+
+	h = murmurUpdate(h, d.configs.hash())
+	return murmurFinish(h, c)
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/diagnostic_error_listener.go

@@ -0,0 +1,111 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"strconv"
+)
+
+//
+// This implementation of {@link ANTLRErrorListener} can be used to identify
+// certain potential correctness and performance problems in grammars. "reports"
+// are made by calling {@link Parser//NotifyErrorListeners} with the appropriate
+// message.
+//
+// <ul>
+// <li><b>Ambiguities</b>: These are cases where more than one path through the
+// grammar can Match the input.</li>
+// <li><b>Weak context sensitivity</b>: These are cases where full-context
+// prediction resolved an SLL conflict to a unique alternative which equaled the
+// minimum alternative of the SLL conflict.</li>
+// <li><b>Strong (forced) context sensitivity</b>: These are cases where the
+// full-context prediction resolved an SLL conflict to a unique alternative,
+// <em>and</em> the minimum alternative of the SLL conflict was found to not be
+// a truly viable alternative. Two-stage parsing cannot be used for inputs where
+// d situation occurs.</li>
+// </ul>
+
+type DiagnosticErrorListener struct {
+	*DefaultErrorListener
+
+	exactOnly bool
+}
+
+func NewDiagnosticErrorListener(exactOnly bool) *DiagnosticErrorListener {
+
+	n := new(DiagnosticErrorListener)
+
+	// whether all ambiguities or only exact ambiguities are Reported.
+	n.exactOnly = exactOnly
+	return n
+}
+
+func (d *DiagnosticErrorListener) ReportAmbiguity(recognizer Parser, dfa *DFA, startIndex, stopIndex int, exact bool, ambigAlts *BitSet, configs ATNConfigSet) {
+	if d.exactOnly && !exact {
+		return
+	}
+	msg := "reportAmbiguity d=" +
+		d.getDecisionDescription(recognizer, dfa) +
+		": ambigAlts=" +
+		d.getConflictingAlts(ambigAlts, configs).String() +
+		", input='" +
+		recognizer.GetTokenStream().GetTextFromInterval(NewInterval(startIndex, stopIndex)) + "'"
+	recognizer.NotifyErrorListeners(msg, nil, nil)
+}
+
+func (d *DiagnosticErrorListener) ReportAttemptingFullContext(recognizer Parser, dfa *DFA, startIndex, stopIndex int, conflictingAlts *BitSet, configs ATNConfigSet) {
+
+	msg := "reportAttemptingFullContext d=" +
+		d.getDecisionDescription(recognizer, dfa) +
+		", input='" +
+		recognizer.GetTokenStream().GetTextFromInterval(NewInterval(startIndex, stopIndex)) + "'"
+	recognizer.NotifyErrorListeners(msg, nil, nil)
+}
+
+func (d *DiagnosticErrorListener) ReportContextSensitivity(recognizer Parser, dfa *DFA, startIndex, stopIndex, prediction int, configs ATNConfigSet) {
+	msg := "reportContextSensitivity d=" +
+		d.getDecisionDescription(recognizer, dfa) +
+		", input='" +
+		recognizer.GetTokenStream().GetTextFromInterval(NewInterval(startIndex, stopIndex)) + "'"
+	recognizer.NotifyErrorListeners(msg, nil, nil)
+}
+
+func (d *DiagnosticErrorListener) getDecisionDescription(recognizer Parser, dfa *DFA) string {
+	decision := dfa.decision
+	ruleIndex := dfa.atnStartState.GetRuleIndex()
+
+	ruleNames := recognizer.GetRuleNames()
+	if ruleIndex < 0 || ruleIndex >= len(ruleNames) {
+		return strconv.Itoa(decision)
+	}
+	ruleName := ruleNames[ruleIndex]
+	if ruleName == "" {
+		return strconv.Itoa(decision)
+	}
+	return strconv.Itoa(decision) + " (" + ruleName + ")"
+}
+
+//
+// Computes the set of conflicting or ambiguous alternatives from a
+// configuration set, if that information was not already provided by the
+// parser.
+//
+// @param ReportedAlts The set of conflicting or ambiguous alternatives, as
+// Reported by the parser.
+// @param configs The conflicting or ambiguous configuration set.
+// @return Returns {@code ReportedAlts} if it is not {@code nil}, otherwise
+// returns the set of alternatives represented in {@code configs}.
+//
+func (d *DiagnosticErrorListener) getConflictingAlts(ReportedAlts *BitSet, set ATNConfigSet) *BitSet {
+	if ReportedAlts != nil {
+		return ReportedAlts
+	}
+	result := NewBitSet()
+	for _, c := range set.GetItems() {
+		result.add(c.GetAlt())
+	}
+
+	return result
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/error_listener.go

@@ -0,0 +1,108 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+)
+
+// Provides an empty default implementation of {@link ANTLRErrorListener}. The
+// default implementation of each method does nothing, but can be overridden as
+// necessary.
+
+type ErrorListener interface {
+	SyntaxError(recognizer Recognizer, offendingSymbol interface{}, line, column int, msg string, e RecognitionException)
+	ReportAmbiguity(recognizer Parser, dfa *DFA, startIndex, stopIndex int, exact bool, ambigAlts *BitSet, configs ATNConfigSet)
+	ReportAttemptingFullContext(recognizer Parser, dfa *DFA, startIndex, stopIndex int, conflictingAlts *BitSet, configs ATNConfigSet)
+	ReportContextSensitivity(recognizer Parser, dfa *DFA, startIndex, stopIndex, prediction int, configs ATNConfigSet)
+}
+
+type DefaultErrorListener struct {
+}
+
+func NewDefaultErrorListener() *DefaultErrorListener {
+	return new(DefaultErrorListener)
+}
+
+func (d *DefaultErrorListener) SyntaxError(recognizer Recognizer, offendingSymbol interface{}, line, column int, msg string, e RecognitionException) {
+}
+
+func (d *DefaultErrorListener) ReportAmbiguity(recognizer Parser, dfa *DFA, startIndex, stopIndex int, exact bool, ambigAlts *BitSet, configs ATNConfigSet) {
+}
+
+func (d *DefaultErrorListener) ReportAttemptingFullContext(recognizer Parser, dfa *DFA, startIndex, stopIndex int, conflictingAlts *BitSet, configs ATNConfigSet) {
+}
+
+func (d *DefaultErrorListener) ReportContextSensitivity(recognizer Parser, dfa *DFA, startIndex, stopIndex, prediction int, configs ATNConfigSet) {
+}
+
+type ConsoleErrorListener struct {
+	*DefaultErrorListener
+}
+
+func NewConsoleErrorListener() *ConsoleErrorListener {
+	return new(ConsoleErrorListener)
+}
+
+//
+// Provides a default instance of {@link ConsoleErrorListener}.
+//
+var ConsoleErrorListenerINSTANCE = NewConsoleErrorListener()
+
+//
+// {@inheritDoc}
+//
+// <p>
+// This implementation prints messages to {@link System//err} containing the
+// values of {@code line}, {@code charPositionInLine}, and {@code msg} using
+// the following format.</p>
+//
+// <pre>
+// line <em>line</em>:<em>charPositionInLine</em> <em>msg</em>
+// </pre>
+//
+func (c *ConsoleErrorListener) SyntaxError(recognizer Recognizer, offendingSymbol interface{}, line, column int, msg string, e RecognitionException) {
+	fmt.Fprintln(os.Stderr, "line "+strconv.Itoa(line)+":"+strconv.Itoa(column)+" "+msg)
+}
+
+type ProxyErrorListener struct {
+	*DefaultErrorListener
+	delegates []ErrorListener
+}
+
+func NewProxyErrorListener(delegates []ErrorListener) *ProxyErrorListener {
+	if delegates == nil {
+		panic("delegates is not provided")
+	}
+	l := new(ProxyErrorListener)
+	l.delegates = delegates
+	return l
+}
+
+func (p *ProxyErrorListener) SyntaxError(recognizer Recognizer, offendingSymbol interface{}, line, column int, msg string, e RecognitionException) {
+	for _, d := range p.delegates {
+		d.SyntaxError(recognizer, offendingSymbol, line, column, msg, e)
+	}
+}
+
+func (p *ProxyErrorListener) ReportAmbiguity(recognizer Parser, dfa *DFA, startIndex, stopIndex int, exact bool, ambigAlts *BitSet, configs ATNConfigSet) {
+	for _, d := range p.delegates {
+		d.ReportAmbiguity(recognizer, dfa, startIndex, stopIndex, exact, ambigAlts, configs)
+	}
+}
+
+func (p *ProxyErrorListener) ReportAttemptingFullContext(recognizer Parser, dfa *DFA, startIndex, stopIndex int, conflictingAlts *BitSet, configs ATNConfigSet) {
+	for _, d := range p.delegates {
+		d.ReportAttemptingFullContext(recognizer, dfa, startIndex, stopIndex, conflictingAlts, configs)
+	}
+}
+
+func (p *ProxyErrorListener) ReportContextSensitivity(recognizer Parser, dfa *DFA, startIndex, stopIndex, prediction int, configs ATNConfigSet) {
+	for _, d := range p.delegates {
+		d.ReportContextSensitivity(recognizer, dfa, startIndex, stopIndex, prediction, configs)
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/error_strategy.go

@@ -0,0 +1,758 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+)
+
+type ErrorStrategy interface {
+	reset(Parser)
+	RecoverInline(Parser) Token
+	Recover(Parser, RecognitionException)
+	Sync(Parser)
+	inErrorRecoveryMode(Parser) bool
+	ReportError(Parser, RecognitionException)
+	ReportMatch(Parser)
+}
+
+// This is the default implementation of {@link ANTLRErrorStrategy} used for
+// error Reporting and recovery in ANTLR parsers.
+//
+type DefaultErrorStrategy struct {
+	errorRecoveryMode bool
+	lastErrorIndex    int
+	lastErrorStates   *IntervalSet
+}
+
+var _ ErrorStrategy = &DefaultErrorStrategy{}
+
+func NewDefaultErrorStrategy() *DefaultErrorStrategy {
+
+	d := new(DefaultErrorStrategy)
+
+	// Indicates whether the error strategy is currently "recovering from an
+	// error". This is used to suppress Reporting multiple error messages while
+	// attempting to recover from a detected syntax error.
+	//
+	// @see //inErrorRecoveryMode
+	//
+	d.errorRecoveryMode = false
+
+	// The index into the input stream where the last error occurred.
+	// This is used to prevent infinite loops where an error is found
+	// but no token is consumed during recovery...another error is found,
+	// ad nauseum. This is a failsafe mechanism to guarantee that at least
+	// one token/tree node is consumed for two errors.
+	//
+	d.lastErrorIndex = -1
+	d.lastErrorStates = nil
+	return d
+}
+
+// <p>The default implementation simply calls {@link //endErrorCondition} to
+// ensure that the handler is not in error recovery mode.</p>
+func (d *DefaultErrorStrategy) reset(recognizer Parser) {
+	d.endErrorCondition(recognizer)
+}
+
+//
+// This method is called to enter error recovery mode when a recognition
+// exception is Reported.
+//
+// @param recognizer the parser instance
+//
+func (d *DefaultErrorStrategy) beginErrorCondition(recognizer Parser) {
+	d.errorRecoveryMode = true
+}
+
+func (d *DefaultErrorStrategy) inErrorRecoveryMode(recognizer Parser) bool {
+	return d.errorRecoveryMode
+}
+
+//
+// This method is called to leave error recovery mode after recovering from
+// a recognition exception.
+//
+// @param recognizer
+//
+func (d *DefaultErrorStrategy) endErrorCondition(recognizer Parser) {
+	d.errorRecoveryMode = false
+	d.lastErrorStates = nil
+	d.lastErrorIndex = -1
+}
+
+//
+// {@inheritDoc}
+//
+// <p>The default implementation simply calls {@link //endErrorCondition}.</p>
+//
+func (d *DefaultErrorStrategy) ReportMatch(recognizer Parser) {
+	d.endErrorCondition(recognizer)
+}
+
+//
+// {@inheritDoc}
+//
+// <p>The default implementation returns immediately if the handler is already
+// in error recovery mode. Otherwise, it calls {@link //beginErrorCondition}
+// and dispatches the Reporting task based on the runtime type of {@code e}
+// according to the following table.</p>
+//
+// <ul>
+// <li>{@link NoViableAltException}: Dispatches the call to
+// {@link //ReportNoViableAlternative}</li>
+// <li>{@link InputMisMatchException}: Dispatches the call to
+// {@link //ReportInputMisMatch}</li>
+// <li>{@link FailedPredicateException}: Dispatches the call to
+// {@link //ReportFailedPredicate}</li>
+// <li>All other types: calls {@link Parser//NotifyErrorListeners} to Report
+// the exception</li>
+// </ul>
+//
+func (d *DefaultErrorStrategy) ReportError(recognizer Parser, e RecognitionException) {
+	// if we've already Reported an error and have not Matched a token
+	// yet successfully, don't Report any errors.
+	if d.inErrorRecoveryMode(recognizer) {
+		return // don't Report spurious errors
+	}
+	d.beginErrorCondition(recognizer)
+
+	switch t := e.(type) {
+	default:
+		fmt.Println("unknown recognition error type: " + reflect.TypeOf(e).Name())
+		//            fmt.Println(e.stack)
+		recognizer.NotifyErrorListeners(e.GetMessage(), e.GetOffendingToken(), e)
+	case *NoViableAltException:
+		d.ReportNoViableAlternative(recognizer, t)
+	case *InputMisMatchException:
+		d.ReportInputMisMatch(recognizer, t)
+	case *FailedPredicateException:
+		d.ReportFailedPredicate(recognizer, t)
+	}
+}
+
+// {@inheritDoc}
+//
+// <p>The default implementation reSynchronizes the parser by consuming tokens
+// until we find one in the reSynchronization set--loosely the set of tokens
+// that can follow the current rule.</p>
+//
+func (d *DefaultErrorStrategy) Recover(recognizer Parser, e RecognitionException) {
+
+	if d.lastErrorIndex == recognizer.GetInputStream().Index() &&
+		d.lastErrorStates != nil && d.lastErrorStates.contains(recognizer.GetState()) {
+		// uh oh, another error at same token index and previously-Visited
+		// state in ATN must be a case where LT(1) is in the recovery
+		// token set so nothing got consumed. Consume a single token
+		// at least to prevent an infinite loop d is a failsafe.
+		recognizer.Consume()
+	}
+	d.lastErrorIndex = recognizer.GetInputStream().Index()
+	if d.lastErrorStates == nil {
+		d.lastErrorStates = NewIntervalSet()
+	}
+	d.lastErrorStates.addOne(recognizer.GetState())
+	followSet := d.getErrorRecoverySet(recognizer)
+	d.consumeUntil(recognizer, followSet)
+}
+
+// The default implementation of {@link ANTLRErrorStrategy//Sync} makes sure
+// that the current lookahead symbol is consistent with what were expecting
+// at d point in the ATN. You can call d anytime but ANTLR only
+// generates code to check before subrules/loops and each iteration.
+//
+// <p>Implements Jim Idle's magic Sync mechanism in closures and optional
+// subrules. E.g.,</p>
+//
+// <pre>
+// a : Sync ( stuff Sync )*
+// Sync : {consume to what can follow Sync}
+// </pre>
+//
+// At the start of a sub rule upon error, {@link //Sync} performs single
+// token deletion, if possible. If it can't do that, it bails on the current
+// rule and uses the default error recovery, which consumes until the
+// reSynchronization set of the current rule.
+//
+// <p>If the sub rule is optional ({@code (...)?}, {@code (...)*}, or block
+// with an empty alternative), then the expected set includes what follows
+// the subrule.</p>
+//
+// <p>During loop iteration, it consumes until it sees a token that can start a
+// sub rule or what follows loop. Yes, that is pretty aggressive. We opt to
+// stay in the loop as long as possible.</p>
+//
+// <p><strong>ORIGINS</strong></p>
+//
+// <p>Previous versions of ANTLR did a poor job of their recovery within loops.
+// A single mismatch token or missing token would force the parser to bail
+// out of the entire rules surrounding the loop. So, for rule</p>
+//
+// <pre>
+// classfunc : 'class' ID '{' member* '}'
+// </pre>
+//
+// input with an extra token between members would force the parser to
+// consume until it found the next class definition rather than the next
+// member definition of the current class.
+//
+// <p>This functionality cost a little bit of effort because the parser has to
+// compare token set at the start of the loop and at each iteration. If for
+// some reason speed is suffering for you, you can turn off d
+// functionality by simply overriding d method as a blank { }.</p>
+//
+func (d *DefaultErrorStrategy) Sync(recognizer Parser) {
+	// If already recovering, don't try to Sync
+	if d.inErrorRecoveryMode(recognizer) {
+		return
+	}
+
+	s := recognizer.GetInterpreter().atn.states[recognizer.GetState()]
+	la := recognizer.GetTokenStream().LA(1)
+
+	// try cheaper subset first might get lucky. seems to shave a wee bit off
+	nextTokens := recognizer.GetATN().NextTokens(s, nil)
+	if nextTokens.contains(TokenEpsilon) || nextTokens.contains(la) {
+		return
+	}
+
+	switch s.GetStateType() {
+	case ATNStateBlockStart, ATNStateStarBlockStart, ATNStatePlusBlockStart, ATNStateStarLoopEntry:
+		// Report error and recover if possible
+		if d.SingleTokenDeletion(recognizer) != nil {
+			return
+		}
+		panic(NewInputMisMatchException(recognizer))
+	case ATNStatePlusLoopBack, ATNStateStarLoopBack:
+		d.ReportUnwantedToken(recognizer)
+		expecting := NewIntervalSet()
+		expecting.addSet(recognizer.GetExpectedTokens())
+		whatFollowsLoopIterationOrRule := expecting.addSet(d.getErrorRecoverySet(recognizer))
+		d.consumeUntil(recognizer, whatFollowsLoopIterationOrRule)
+	default:
+		// do nothing if we can't identify the exact kind of ATN state
+	}
+}
+
+// This is called by {@link //ReportError} when the exception is a
+// {@link NoViableAltException}.
+//
+// @see //ReportError
+//
+// @param recognizer the parser instance
+// @param e the recognition exception
+//
+func (d *DefaultErrorStrategy) ReportNoViableAlternative(recognizer Parser, e *NoViableAltException) {
+	tokens := recognizer.GetTokenStream()
+	var input string
+	if tokens != nil {
+		if e.startToken.GetTokenType() == TokenEOF {
+			input = "<EOF>"
+		} else {
+			input = tokens.GetTextFromTokens(e.startToken, e.offendingToken)
+		}
+	} else {
+		input = "<unknown input>"
+	}
+	msg := "no viable alternative at input " + d.escapeWSAndQuote(input)
+	recognizer.NotifyErrorListeners(msg, e.offendingToken, e)
+}
+
+//
+// This is called by {@link //ReportError} when the exception is an
+// {@link InputMisMatchException}.
+//
+// @see //ReportError
+//
+// @param recognizer the parser instance
+// @param e the recognition exception
+//
+func (this *DefaultErrorStrategy) ReportInputMisMatch(recognizer Parser, e *InputMisMatchException) {
+	msg := "mismatched input " + this.GetTokenErrorDisplay(e.offendingToken) +
+		" expecting " + e.getExpectedTokens().StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false)
+	recognizer.NotifyErrorListeners(msg, e.offendingToken, e)
+}
+
+//
+// This is called by {@link //ReportError} when the exception is a
+// {@link FailedPredicateException}.
+//
+// @see //ReportError
+//
+// @param recognizer the parser instance
+// @param e the recognition exception
+//
+func (d *DefaultErrorStrategy) ReportFailedPredicate(recognizer Parser, e *FailedPredicateException) {
+	ruleName := recognizer.GetRuleNames()[recognizer.GetParserRuleContext().GetRuleIndex()]
+	msg := "rule " + ruleName + " " + e.message
+	recognizer.NotifyErrorListeners(msg, e.offendingToken, e)
+}
+
+// This method is called to Report a syntax error which requires the removal
+// of a token from the input stream. At the time d method is called, the
+// erroneous symbol is current {@code LT(1)} symbol and has not yet been
+// removed from the input stream. When d method returns,
+// {@code recognizer} is in error recovery mode.
+//
+// <p>This method is called when {@link //singleTokenDeletion} identifies
+// single-token deletion as a viable recovery strategy for a mismatched
+// input error.</p>
+//
+// <p>The default implementation simply returns if the handler is already in
+// error recovery mode. Otherwise, it calls {@link //beginErrorCondition} to
+// enter error recovery mode, followed by calling
+// {@link Parser//NotifyErrorListeners}.</p>
+//
+// @param recognizer the parser instance
+//
+func (d *DefaultErrorStrategy) ReportUnwantedToken(recognizer Parser) {
+	if d.inErrorRecoveryMode(recognizer) {
+		return
+	}
+	d.beginErrorCondition(recognizer)
+	t := recognizer.GetCurrentToken()
+	tokenName := d.GetTokenErrorDisplay(t)
+	expecting := d.GetExpectedTokens(recognizer)
+	msg := "extraneous input " + tokenName + " expecting " +
+		expecting.StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false)
+	recognizer.NotifyErrorListeners(msg, t, nil)
+}
+
+// This method is called to Report a syntax error which requires the
+// insertion of a missing token into the input stream. At the time d
+// method is called, the missing token has not yet been inserted. When d
+// method returns, {@code recognizer} is in error recovery mode.
+//
+// <p>This method is called when {@link //singleTokenInsertion} identifies
+// single-token insertion as a viable recovery strategy for a mismatched
+// input error.</p>
+//
+// <p>The default implementation simply returns if the handler is already in
+// error recovery mode. Otherwise, it calls {@link //beginErrorCondition} to
+// enter error recovery mode, followed by calling
+// {@link Parser//NotifyErrorListeners}.</p>
+//
+// @param recognizer the parser instance
+//
+func (d *DefaultErrorStrategy) ReportMissingToken(recognizer Parser) {
+	if d.inErrorRecoveryMode(recognizer) {
+		return
+	}
+	d.beginErrorCondition(recognizer)
+	t := recognizer.GetCurrentToken()
+	expecting := d.GetExpectedTokens(recognizer)
+	msg := "missing " + expecting.StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false) +
+		" at " + d.GetTokenErrorDisplay(t)
+	recognizer.NotifyErrorListeners(msg, t, nil)
+}
+
+// <p>The default implementation attempts to recover from the mismatched input
+// by using single token insertion and deletion as described below. If the
+// recovery attempt fails, d method panics an
+// {@link InputMisMatchException}.</p>
+//
+// <p><strong>EXTRA TOKEN</strong> (single token deletion)</p>
+//
+// <p>{@code LA(1)} is not what we are looking for. If {@code LA(2)} has the
+// right token, however, then assume {@code LA(1)} is some extra spurious
+// token and delete it. Then consume and return the next token (which was
+// the {@code LA(2)} token) as the successful result of the Match operation.</p>
+//
+// <p>This recovery strategy is implemented by {@link
+// //singleTokenDeletion}.</p>
+//
+// <p><strong>MISSING TOKEN</strong> (single token insertion)</p>
+//
+// <p>If current token (at {@code LA(1)}) is consistent with what could come
+// after the expected {@code LA(1)} token, then assume the token is missing
+// and use the parser's {@link TokenFactory} to create it on the fly. The
+// "insertion" is performed by returning the created token as the successful
+// result of the Match operation.</p>
+//
+// <p>This recovery strategy is implemented by {@link
+// //singleTokenInsertion}.</p>
+//
+// <p><strong>EXAMPLE</strong></p>
+//
+// <p>For example, Input {@code i=(3} is clearly missing the {@code ')'}. When
+// the parser returns from the nested call to {@code expr}, it will have
+// call chain:</p>
+//
+// <pre>
+// stat &rarr expr &rarr atom
+// </pre>
+//
+// and it will be trying to Match the {@code ')'} at d point in the
+// derivation:
+//
+// <pre>
+// =&gt ID '=' '(' INT ')' ('+' atom)* ''
+// ^
+// </pre>
+//
+// The attempt to Match {@code ')'} will fail when it sees {@code ''} and
+// call {@link //recoverInline}. To recover, it sees that {@code LA(1)==''}
+// is in the set of tokens that can follow the {@code ')'} token reference
+// in rule {@code atom}. It can assume that you forgot the {@code ')'}.
+//
+func (d *DefaultErrorStrategy) RecoverInline(recognizer Parser) Token {
+	// SINGLE TOKEN DELETION
+	MatchedSymbol := d.SingleTokenDeletion(recognizer)
+	if MatchedSymbol != nil {
+		// we have deleted the extra token.
+		// now, move past ttype token as if all were ok
+		recognizer.Consume()
+		return MatchedSymbol
+	}
+	// SINGLE TOKEN INSERTION
+	if d.SingleTokenInsertion(recognizer) {
+		return d.GetMissingSymbol(recognizer)
+	}
+	// even that didn't work must panic the exception
+	panic(NewInputMisMatchException(recognizer))
+}
+
+//
+// This method implements the single-token insertion inline error recovery
+// strategy. It is called by {@link //recoverInline} if the single-token
+// deletion strategy fails to recover from the mismatched input. If this
+// method returns {@code true}, {@code recognizer} will be in error recovery
+// mode.
+//
+// <p>This method determines whether or not single-token insertion is viable by
+// checking if the {@code LA(1)} input symbol could be successfully Matched
+// if it were instead the {@code LA(2)} symbol. If d method returns
+// {@code true}, the caller is responsible for creating and inserting a
+// token with the correct type to produce d behavior.</p>
+//
+// @param recognizer the parser instance
+// @return {@code true} if single-token insertion is a viable recovery
+// strategy for the current mismatched input, otherwise {@code false}
+//
+func (d *DefaultErrorStrategy) SingleTokenInsertion(recognizer Parser) bool {
+	currentSymbolType := recognizer.GetTokenStream().LA(1)
+	// if current token is consistent with what could come after current
+	// ATN state, then we know we're missing a token error recovery
+	// is free to conjure up and insert the missing token
+	atn := recognizer.GetInterpreter().atn
+	currentState := atn.states[recognizer.GetState()]
+	next := currentState.GetTransitions()[0].getTarget()
+	expectingAtLL2 := atn.NextTokens(next, recognizer.GetParserRuleContext())
+	if expectingAtLL2.contains(currentSymbolType) {
+		d.ReportMissingToken(recognizer)
+		return true
+	}
+
+	return false
+}
+
+// This method implements the single-token deletion inline error recovery
+// strategy. It is called by {@link //recoverInline} to attempt to recover
+// from mismatched input. If this method returns nil, the parser and error
+// handler state will not have changed. If this method returns non-nil,
+// {@code recognizer} will <em>not</em> be in error recovery mode since the
+// returned token was a successful Match.
+//
+// <p>If the single-token deletion is successful, d method calls
+// {@link //ReportUnwantedToken} to Report the error, followed by
+// {@link Parser//consume} to actually "delete" the extraneous token. Then,
+// before returning {@link //ReportMatch} is called to signal a successful
+// Match.</p>
+//
+// @param recognizer the parser instance
+// @return the successfully Matched {@link Token} instance if single-token
+// deletion successfully recovers from the mismatched input, otherwise
+// {@code nil}
+//
+func (d *DefaultErrorStrategy) SingleTokenDeletion(recognizer Parser) Token {
+	NextTokenType := recognizer.GetTokenStream().LA(2)
+	expecting := d.GetExpectedTokens(recognizer)
+	if expecting.contains(NextTokenType) {
+		d.ReportUnwantedToken(recognizer)
+		// print("recoverFromMisMatchedToken deleting " \
+		// + str(recognizer.GetTokenStream().LT(1)) \
+		// + " since " + str(recognizer.GetTokenStream().LT(2)) \
+		// + " is what we want", file=sys.stderr)
+		recognizer.Consume() // simply delete extra token
+		// we want to return the token we're actually Matching
+		MatchedSymbol := recognizer.GetCurrentToken()
+		d.ReportMatch(recognizer) // we know current token is correct
+		return MatchedSymbol
+	}
+
+	return nil
+}
+
+// Conjure up a missing token during error recovery.
+//
+// The recognizer attempts to recover from single missing
+// symbols. But, actions might refer to that missing symbol.
+// For example, x=ID {f($x)}. The action clearly assumes
+// that there has been an identifier Matched previously and that
+// $x points at that token. If that token is missing, but
+// the next token in the stream is what we want we assume that
+// d token is missing and we keep going. Because we
+// have to return some token to replace the missing token,
+// we have to conjure one up. This method gives the user control
+// over the tokens returned for missing tokens. Mostly,
+// you will want to create something special for identifier
+// tokens. For literals such as '{' and ',', the default
+// action in the parser or tree parser works. It simply creates
+// a CommonToken of the appropriate type. The text will be the token.
+// If you change what tokens must be created by the lexer,
+// override d method to create the appropriate tokens.
+//
+func (d *DefaultErrorStrategy) GetMissingSymbol(recognizer Parser) Token {
+	currentSymbol := recognizer.GetCurrentToken()
+	expecting := d.GetExpectedTokens(recognizer)
+	expectedTokenType := expecting.first()
+	var tokenText string
+
+	if expectedTokenType == TokenEOF {
+		tokenText = "<missing EOF>"
+	} else {
+		ln := recognizer.GetLiteralNames()
+		if expectedTokenType > 0 && expectedTokenType < len(ln) {
+			tokenText = "<missing " + recognizer.GetLiteralNames()[expectedTokenType] + ">"
+		} else {
+			tokenText = "<missing undefined>" // TODO matches the JS impl
+		}
+	}
+	current := currentSymbol
+	lookback := recognizer.GetTokenStream().LT(-1)
+	if current.GetTokenType() == TokenEOF && lookback != nil {
+		current = lookback
+	}
+
+	tf := recognizer.GetTokenFactory()
+
+	return tf.Create(current.GetSource(), expectedTokenType, tokenText, TokenDefaultChannel, -1, -1, current.GetLine(), current.GetColumn())
+}
+
+func (d *DefaultErrorStrategy) GetExpectedTokens(recognizer Parser) *IntervalSet {
+	return recognizer.GetExpectedTokens()
+}
+
+// How should a token be displayed in an error message? The default
+// is to display just the text, but during development you might
+// want to have a lot of information spit out. Override in that case
+// to use t.String() (which, for CommonToken, dumps everything about
+// the token). This is better than forcing you to override a method in
+// your token objects because you don't have to go modify your lexer
+// so that it creates a NewJava type.
+//
+func (d *DefaultErrorStrategy) GetTokenErrorDisplay(t Token) string {
+	if t == nil {
+		return "<no token>"
+	}
+	s := t.GetText()
+	if s == "" {
+		if t.GetTokenType() == TokenEOF {
+			s = "<EOF>"
+		} else {
+			s = "<" + strconv.Itoa(t.GetTokenType()) + ">"
+		}
+	}
+	return d.escapeWSAndQuote(s)
+}
+
+func (d *DefaultErrorStrategy) escapeWSAndQuote(s string) string {
+	s = strings.Replace(s, "\t", "\\t", -1)
+	s = strings.Replace(s, "\n", "\\n", -1)
+	s = strings.Replace(s, "\r", "\\r", -1)
+	return "'" + s + "'"
+}
+
+// Compute the error recovery set for the current rule. During
+// rule invocation, the parser pushes the set of tokens that can
+// follow that rule reference on the stack d amounts to
+// computing FIRST of what follows the rule reference in the
+// enclosing rule. See LinearApproximator.FIRST().
+// This local follow set only includes tokens
+// from within the rule i.e., the FIRST computation done by
+// ANTLR stops at the end of a rule.
+//
+// EXAMPLE
+//
+// When you find a "no viable alt exception", the input is not
+// consistent with any of the alternatives for rule r. The best
+// thing to do is to consume tokens until you see something that
+// can legally follow a call to r//or* any rule that called r.
+// You don't want the exact set of viable next tokens because the
+// input might just be missing a token--you might consume the
+// rest of the input looking for one of the missing tokens.
+//
+// Consider grammar:
+//
+// a : '[' b ']'
+// | '(' b ')'
+//
+// b : c '^' INT
+// c : ID
+// | INT
+//
+//
+// At each rule invocation, the set of tokens that could follow
+// that rule is pushed on a stack. Here are the various
+// context-sensitive follow sets:
+//
+// FOLLOW(b1_in_a) = FIRST(']') = ']'
+// FOLLOW(b2_in_a) = FIRST(')') = ')'
+// FOLLOW(c_in_b) = FIRST('^') = '^'
+//
+// Upon erroneous input "[]", the call chain is
+//
+// a -> b -> c
+//
+// and, hence, the follow context stack is:
+//
+// depth follow set start of rule execution
+// 0 <EOF> a (from main())
+// 1 ']' b
+// 2 '^' c
+//
+// Notice that ')' is not included, because b would have to have
+// been called from a different context in rule a for ')' to be
+// included.
+//
+// For error recovery, we cannot consider FOLLOW(c)
+// (context-sensitive or otherwise). We need the combined set of
+// all context-sensitive FOLLOW sets--the set of all tokens that
+// could follow any reference in the call chain. We need to
+// reSync to one of those tokens. Note that FOLLOW(c)='^' and if
+// we reSync'd to that token, we'd consume until EOF. We need to
+// Sync to context-sensitive FOLLOWs for a, b, and c: {']','^'}.
+// In this case, for input "[]", LA(1) is ']' and in the set, so we would
+// not consume anything. After printing an error, rule c would
+// return normally. Rule b would not find the required '^' though.
+// At this point, it gets a mismatched token error and panics an
+// exception (since LA(1) is not in the viable following token
+// set). The rule exception handler tries to recover, but finds
+// the same recovery set and doesn't consume anything. Rule b
+// exits normally returning to rule a. Now it finds the ']' (and
+// with the successful Match exits errorRecovery mode).
+//
+// So, you can see that the parser walks up the call chain looking
+// for the token that was a member of the recovery set.
+//
+// Errors are not generated in errorRecovery mode.
+//
+// ANTLR's error recovery mechanism is based upon original ideas:
+//
+// "Algorithms + Data Structures = Programs" by Niklaus Wirth
+//
+// and
+//
+// "A note on error recovery in recursive descent parsers":
+// http://portal.acm.org/citation.cfm?id=947902.947905
+//
+// Later, Josef Grosch had some good ideas:
+//
+// "Efficient and Comfortable Error Recovery in Recursive Descent
+// Parsers":
+// ftp://www.cocolab.com/products/cocktail/doca4.ps/ell.ps.zip
+//
+// Like Grosch I implement context-sensitive FOLLOW sets that are combined
+// at run-time upon error to avoid overhead during parsing.
+//
+func (d *DefaultErrorStrategy) getErrorRecoverySet(recognizer Parser) *IntervalSet {
+	atn := recognizer.GetInterpreter().atn
+	ctx := recognizer.GetParserRuleContext()
+	recoverSet := NewIntervalSet()
+	for ctx != nil && ctx.GetInvokingState() >= 0 {
+		// compute what follows who invoked us
+		invokingState := atn.states[ctx.GetInvokingState()]
+		rt := invokingState.GetTransitions()[0]
+		follow := atn.NextTokens(rt.(*RuleTransition).followState, nil)
+		recoverSet.addSet(follow)
+		ctx = ctx.GetParent().(ParserRuleContext)
+	}
+	recoverSet.removeOne(TokenEpsilon)
+	return recoverSet
+}
+
+// Consume tokens until one Matches the given token set.//
+func (d *DefaultErrorStrategy) consumeUntil(recognizer Parser, set *IntervalSet) {
+	ttype := recognizer.GetTokenStream().LA(1)
+	for ttype != TokenEOF && !set.contains(ttype) {
+		recognizer.Consume()
+		ttype = recognizer.GetTokenStream().LA(1)
+	}
+}
+
+//
+// This implementation of {@link ANTLRErrorStrategy} responds to syntax errors
+// by immediately canceling the parse operation with a
+// {@link ParseCancellationException}. The implementation ensures that the
+// {@link ParserRuleContext//exception} field is set for all parse tree nodes
+// that were not completed prior to encountering the error.
+//
+// <p>
+// This error strategy is useful in the following scenarios.</p>
+//
+// <ul>
+// <li><strong>Two-stage parsing:</strong> This error strategy allows the first
+// stage of two-stage parsing to immediately terminate if an error is
+// encountered, and immediately fall back to the second stage. In addition to
+// avoiding wasted work by attempting to recover from errors here, the empty
+// implementation of {@link BailErrorStrategy//Sync} improves the performance of
+// the first stage.</li>
+// <li><strong>Silent validation:</strong> When syntax errors are not being
+// Reported or logged, and the parse result is simply ignored if errors occur,
+// the {@link BailErrorStrategy} avoids wasting work on recovering from errors
+// when the result will be ignored either way.</li>
+// </ul>
+//
+// <p>
+// {@code myparser.setErrorHandler(NewBailErrorStrategy())}</p>
+//
+// @see Parser//setErrorHandler(ANTLRErrorStrategy)
+
+type BailErrorStrategy struct {
+	*DefaultErrorStrategy
+}
+
+var _ ErrorStrategy = &BailErrorStrategy{}
+
+func NewBailErrorStrategy() *BailErrorStrategy {
+
+	b := new(BailErrorStrategy)
+
+	b.DefaultErrorStrategy = NewDefaultErrorStrategy()
+
+	return b
+}
+
+// Instead of recovering from exception {@code e}, re-panic it wrapped
+// in a {@link ParseCancellationException} so it is not caught by the
+// rule func catches. Use {@link Exception//getCause()} to get the
+// original {@link RecognitionException}.
+//
+func (b *BailErrorStrategy) Recover(recognizer Parser, e RecognitionException) {
+	context := recognizer.GetParserRuleContext()
+	for context != nil {
+		context.SetException(e)
+		context = context.GetParent().(ParserRuleContext)
+	}
+	panic(NewParseCancellationException()) // TODO we don't emit e properly
+}
+
+// Make sure we don't attempt to recover inline if the parser
+// successfully recovers, it won't panic an exception.
+//
+func (b *BailErrorStrategy) RecoverInline(recognizer Parser) Token {
+	b.Recover(recognizer, NewInputMisMatchException(recognizer))
+
+	return nil
+}
+
+// Make sure we don't attempt to recover from problems in subrules.//
+func (b *BailErrorStrategy) Sync(recognizer Parser) {
+	// pass
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/errors.go

@@ -0,0 +1,241 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// The root of the ANTLR exception hierarchy. In general, ANTLR tracks just
+//  3 kinds of errors: prediction errors, failed predicate errors, and
+//  mismatched input errors. In each case, the parser knows where it is
+//  in the input, where it is in the ATN, the rule invocation stack,
+//  and what kind of problem occurred.
+
+type RecognitionException interface {
+	GetOffendingToken() Token
+	GetMessage() string
+	GetInputStream() IntStream
+}
+
+type BaseRecognitionException struct {
+	message        string
+	recognizer     Recognizer
+	offendingToken Token
+	offendingState int
+	ctx            RuleContext
+	input          IntStream
+}
+
+func NewBaseRecognitionException(message string, recognizer Recognizer, input IntStream, ctx RuleContext) *BaseRecognitionException {
+
+	// todo
+	//	Error.call(this)
+	//
+	//	if (!!Error.captureStackTrace) {
+	//        Error.captureStackTrace(this, RecognitionException)
+	//	} else {
+	//		stack := NewError().stack
+	//	}
+	// TODO may be able to use - "runtime" func Stack(buf []byte, all bool) int
+
+	t := new(BaseRecognitionException)
+
+	t.message = message
+	t.recognizer = recognizer
+	t.input = input
+	t.ctx = ctx
+	// The current {@link Token} when an error occurred. Since not all streams
+	// support accessing symbols by index, we have to track the {@link Token}
+	// instance itself.
+	t.offendingToken = nil
+	// Get the ATN state number the parser was in at the time the error
+	// occurred. For {@link NoViableAltException} and
+	// {@link LexerNoViableAltException} exceptions, this is the
+	// {@link DecisionState} number. For others, it is the state whose outgoing
+	// edge we couldn't Match.
+	t.offendingState = -1
+	if t.recognizer != nil {
+		t.offendingState = t.recognizer.GetState()
+	}
+
+	return t
+}
+
+func (b *BaseRecognitionException) GetMessage() string {
+	return b.message
+}
+
+func (b *BaseRecognitionException) GetOffendingToken() Token {
+	return b.offendingToken
+}
+
+func (b *BaseRecognitionException) GetInputStream() IntStream {
+	return b.input
+}
+
+// <p>If the state number is not known, b method returns -1.</p>
+
+//
+// Gets the set of input symbols which could potentially follow the
+// previously Matched symbol at the time b exception was panicn.
+//
+// <p>If the set of expected tokens is not known and could not be computed,
+// b method returns {@code nil}.</p>
+//
+// @return The set of token types that could potentially follow the current
+// state in the ATN, or {@code nil} if the information is not available.
+// /
+func (b *BaseRecognitionException) getExpectedTokens() *IntervalSet {
+	if b.recognizer != nil {
+		return b.recognizer.GetATN().getExpectedTokens(b.offendingState, b.ctx)
+	}
+
+	return nil
+}
+
+func (b *BaseRecognitionException) String() string {
+	return b.message
+}
+
+type LexerNoViableAltException struct {
+	*BaseRecognitionException
+
+	startIndex     int
+	deadEndConfigs ATNConfigSet
+}
+
+func NewLexerNoViableAltException(lexer Lexer, input CharStream, startIndex int, deadEndConfigs ATNConfigSet) *LexerNoViableAltException {
+
+	l := new(LexerNoViableAltException)
+
+	l.BaseRecognitionException = NewBaseRecognitionException("", lexer, input, nil)
+
+	l.startIndex = startIndex
+	l.deadEndConfigs = deadEndConfigs
+
+	return l
+}
+
+func (l *LexerNoViableAltException) String() string {
+	symbol := ""
+	if l.startIndex >= 0 && l.startIndex < l.input.Size() {
+		symbol = l.input.(CharStream).GetTextFromInterval(NewInterval(l.startIndex, l.startIndex))
+	}
+	return "LexerNoViableAltException" + symbol
+}
+
+type NoViableAltException struct {
+	*BaseRecognitionException
+
+	startToken     Token
+	offendingToken Token
+	ctx            ParserRuleContext
+	deadEndConfigs ATNConfigSet
+}
+
+// Indicates that the parser could not decide which of two or more paths
+// to take based upon the remaining input. It tracks the starting token
+// of the offending input and also knows where the parser was
+// in the various paths when the error. Reported by ReportNoViableAlternative()
+//
+func NewNoViableAltException(recognizer Parser, input TokenStream, startToken Token, offendingToken Token, deadEndConfigs ATNConfigSet, ctx ParserRuleContext) *NoViableAltException {
+
+	if ctx == nil {
+		ctx = recognizer.GetParserRuleContext()
+	}
+
+	if offendingToken == nil {
+		offendingToken = recognizer.GetCurrentToken()
+	}
+
+	if startToken == nil {
+		startToken = recognizer.GetCurrentToken()
+	}
+
+	if input == nil {
+		input = recognizer.GetInputStream().(TokenStream)
+	}
+
+	n := new(NoViableAltException)
+	n.BaseRecognitionException = NewBaseRecognitionException("", recognizer, input, ctx)
+
+	// Which configurations did we try at input.Index() that couldn't Match
+	// input.LT(1)?//
+	n.deadEndConfigs = deadEndConfigs
+	// The token object at the start index the input stream might
+	// not be buffering tokens so get a reference to it. (At the
+	// time the error occurred, of course the stream needs to keep a
+	// buffer all of the tokens but later we might not have access to those.)
+	n.startToken = startToken
+	n.offendingToken = offendingToken
+
+	return n
+}
+
+type InputMisMatchException struct {
+	*BaseRecognitionException
+}
+
+// This signifies any kind of mismatched input exceptions such as
+// when the current input does not Match the expected token.
+//
+func NewInputMisMatchException(recognizer Parser) *InputMisMatchException {
+
+	i := new(InputMisMatchException)
+	i.BaseRecognitionException = NewBaseRecognitionException("", recognizer, recognizer.GetInputStream(), recognizer.GetParserRuleContext())
+
+	i.offendingToken = recognizer.GetCurrentToken()
+
+	return i
+
+}
+
+// A semantic predicate failed during validation. Validation of predicates
+// occurs when normally parsing the alternative just like Matching a token.
+// Disambiguating predicate evaluation occurs when we test a predicate during
+// prediction.
+
+type FailedPredicateException struct {
+	*BaseRecognitionException
+
+	ruleIndex      int
+	predicateIndex int
+	predicate      string
+}
+
+func NewFailedPredicateException(recognizer Parser, predicate string, message string) *FailedPredicateException {
+
+	f := new(FailedPredicateException)
+
+	f.BaseRecognitionException = NewBaseRecognitionException(f.formatMessage(predicate, message), recognizer, recognizer.GetInputStream(), recognizer.GetParserRuleContext())
+
+	s := recognizer.GetInterpreter().atn.states[recognizer.GetState()]
+	trans := s.GetTransitions()[0]
+	if trans2, ok := trans.(*PredicateTransition); ok {
+		f.ruleIndex = trans2.ruleIndex
+		f.predicateIndex = trans2.predIndex
+	} else {
+		f.ruleIndex = 0
+		f.predicateIndex = 0
+	}
+	f.predicate = predicate
+	f.offendingToken = recognizer.GetCurrentToken()
+
+	return f
+}
+
+func (f *FailedPredicateException) formatMessage(predicate, message string) string {
+	if message != "" {
+		return message
+	}
+
+	return "failed predicate: {" + predicate + "}?"
+}
+
+type ParseCancellationException struct {
+}
+
+func NewParseCancellationException() *ParseCancellationException {
+	//	Error.call(this)
+	//	Error.captureStackTrace(this, ParseCancellationException)
+	return new(ParseCancellationException)
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/file_stream.go

@@ -0,0 +1,49 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"bytes"
+	"io"
+	"os"
+)
+
+//  This is an InputStream that is loaded from a file all at once
+//  when you construct the object.
+
+type FileStream struct {
+	*InputStream
+
+	filename string
+}
+
+func NewFileStream(fileName string) (*FileStream, error) {
+
+	buf := bytes.NewBuffer(nil)
+
+	f, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	_, err = io.Copy(buf, f)
+	if err != nil {
+		return nil, err
+	}
+
+	fs := new(FileStream)
+
+	fs.filename = fileName
+	s := string(buf.Bytes())
+
+	fs.InputStream = NewInputStream(s)
+
+	return fs, nil
+
+}
+
+func (f *FileStream) GetSourceName() string {
+	return f.filename
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/go.mod

@@ -0,0 +1,3 @@
+module github.com/antlr/antlr4/runtime/Go/antlr
+
+go 1.16

vendor/github.com/antlr/antlr4/runtime/Go/antlr/input_stream.go

@@ -0,0 +1,113 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+type InputStream struct {
+	name  string
+	index int
+	data  []rune
+	size  int
+}
+
+func NewInputStream(data string) *InputStream {
+
+	is := new(InputStream)
+
+	is.name = "<empty>"
+	is.index = 0
+	is.data = []rune(data)
+	is.size = len(is.data) // number of runes
+
+	return is
+}
+
+func (is *InputStream) reset() {
+	is.index = 0
+}
+
+func (is *InputStream) Consume() {
+	if is.index >= is.size {
+		// assert is.LA(1) == TokenEOF
+		panic("cannot consume EOF")
+	}
+	is.index++
+}
+
+func (is *InputStream) LA(offset int) int {
+
+	if offset == 0 {
+		return 0 // nil
+	}
+	if offset < 0 {
+		offset++ // e.g., translate LA(-1) to use offset=0
+	}
+	pos := is.index + offset - 1
+
+	if pos < 0 || pos >= is.size { // invalid
+		return TokenEOF
+	}
+
+	return int(is.data[pos])
+}
+
+func (is *InputStream) LT(offset int) int {
+	return is.LA(offset)
+}
+
+func (is *InputStream) Index() int {
+	return is.index
+}
+
+func (is *InputStream) Size() int {
+	return is.size
+}
+
+// mark/release do nothing we have entire buffer
+func (is *InputStream) Mark() int {
+	return -1
+}
+
+func (is *InputStream) Release(marker int) {
+}
+
+func (is *InputStream) Seek(index int) {
+	if index <= is.index {
+		is.index = index // just jump don't update stream state (line,...)
+		return
+	}
+	// seek forward
+	is.index = intMin(index, is.size)
+}
+
+func (is *InputStream) GetText(start int, stop int) string {
+	if stop >= is.size {
+		stop = is.size - 1
+	}
+	if start >= is.size {
+		return ""
+	}
+
+	return string(is.data[start : stop+1])
+}
+
+func (is *InputStream) GetTextFromTokens(start, stop Token) string {
+	if start != nil && stop != nil {
+		return is.GetTextFromInterval(NewInterval(start.GetTokenIndex(), stop.GetTokenIndex()))
+	}
+
+	return ""
+}
+
+func (is *InputStream) GetTextFromInterval(i *Interval) string {
+	return is.GetText(i.Start, i.Stop)
+}
+
+func (*InputStream) GetSourceName() string {
+	return "Obtained from string"
+}
+
+func (is *InputStream) String() string {
+	return string(is.data)
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/int_stream.go

@@ -0,0 +1,16 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+type IntStream interface {
+	Consume()
+	LA(int) int
+	Mark() int
+	Release(marker int)
+	Index() int
+	Seek(index int)
+	Size() int
+	GetSourceName() string
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/interval_set.go

@@ -0,0 +1,296 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"strconv"
+	"strings"
+)
+
+type Interval struct {
+	Start int
+	Stop  int
+}
+
+/* stop is not included! */
+func NewInterval(start, stop int) *Interval {
+	i := new(Interval)
+
+	i.Start = start
+	i.Stop = stop
+	return i
+}
+
+func (i *Interval) Contains(item int) bool {
+	return item >= i.Start && item < i.Stop
+}
+
+func (i *Interval) String() string {
+	if i.Start == i.Stop-1 {
+		return strconv.Itoa(i.Start)
+	}
+
+	return strconv.Itoa(i.Start) + ".." + strconv.Itoa(i.Stop-1)
+}
+
+func (i *Interval) length() int {
+	return i.Stop - i.Start
+}
+
+type IntervalSet struct {
+	intervals []*Interval
+	readOnly  bool
+}
+
+func NewIntervalSet() *IntervalSet {
+
+	i := new(IntervalSet)
+
+	i.intervals = nil
+	i.readOnly = false
+
+	return i
+}
+
+func (i *IntervalSet) first() int {
+	if len(i.intervals) == 0 {
+		return TokenInvalidType
+	}
+
+	return i.intervals[0].Start
+}
+
+func (i *IntervalSet) addOne(v int) {
+	i.addInterval(NewInterval(v, v+1))
+}
+
+func (i *IntervalSet) addRange(l, h int) {
+	i.addInterval(NewInterval(l, h+1))
+}
+
+func (i *IntervalSet) addInterval(v *Interval) {
+	if i.intervals == nil {
+		i.intervals = make([]*Interval, 0)
+		i.intervals = append(i.intervals, v)
+	} else {
+		// find insert pos
+		for k, interval := range i.intervals {
+			// distinct range -> insert
+			if v.Stop < interval.Start {
+				i.intervals = append(i.intervals[0:k], append([]*Interval{v}, i.intervals[k:]...)...)
+				return
+			} else if v.Stop == interval.Start {
+				i.intervals[k].Start = v.Start
+				return
+			} else if v.Start <= interval.Stop {
+				i.intervals[k] = NewInterval(intMin(interval.Start, v.Start), intMax(interval.Stop, v.Stop))
+
+				// if not applying to end, merge potential overlaps
+				if k < len(i.intervals)-1 {
+					l := i.intervals[k]
+					r := i.intervals[k+1]
+					// if r contained in l
+					if l.Stop >= r.Stop {
+						i.intervals = append(i.intervals[0:k+1], i.intervals[k+2:]...)
+					} else if l.Stop >= r.Start { // partial overlap
+						i.intervals[k] = NewInterval(l.Start, r.Stop)
+						i.intervals = append(i.intervals[0:k+1], i.intervals[k+2:]...)
+					}
+				}
+				return
+			}
+		}
+		// greater than any exiting
+		i.intervals = append(i.intervals, v)
+	}
+}
+
+func (i *IntervalSet) addSet(other *IntervalSet) *IntervalSet {
+	if other.intervals != nil {
+		for k := 0; k < len(other.intervals); k++ {
+			i2 := other.intervals[k]
+			i.addInterval(NewInterval(i2.Start, i2.Stop))
+		}
+	}
+	return i
+}
+
+func (i *IntervalSet) complement(start int, stop int) *IntervalSet {
+	result := NewIntervalSet()
+	result.addInterval(NewInterval(start, stop+1))
+	for j := 0; j < len(i.intervals); j++ {
+		result.removeRange(i.intervals[j])
+	}
+	return result
+}
+
+func (i *IntervalSet) contains(item int) bool {
+	if i.intervals == nil {
+		return false
+	}
+	for k := 0; k < len(i.intervals); k++ {
+		if i.intervals[k].Contains(item) {
+			return true
+		}
+	}
+	return false
+}
+
+func (i *IntervalSet) length() int {
+	len := 0
+
+	for _, v := range i.intervals {
+		len += v.length()
+	}
+
+	return len
+}
+
+func (i *IntervalSet) removeRange(v *Interval) {
+	if v.Start == v.Stop-1 {
+		i.removeOne(v.Start)
+	} else if i.intervals != nil {
+		k := 0
+		for n := 0; n < len(i.intervals); n++ {
+			ni := i.intervals[k]
+			// intervals are ordered
+			if v.Stop <= ni.Start {
+				return
+			} else if v.Start > ni.Start && v.Stop < ni.Stop {
+				i.intervals[k] = NewInterval(ni.Start, v.Start)
+				x := NewInterval(v.Stop, ni.Stop)
+				// i.intervals.splice(k, 0, x)
+				i.intervals = append(i.intervals[0:k], append([]*Interval{x}, i.intervals[k:]...)...)
+				return
+			} else if v.Start <= ni.Start && v.Stop >= ni.Stop {
+				//                i.intervals.splice(k, 1)
+				i.intervals = append(i.intervals[0:k], i.intervals[k+1:]...)
+				k = k - 1 // need another pass
+			} else if v.Start < ni.Stop {
+				i.intervals[k] = NewInterval(ni.Start, v.Start)
+			} else if v.Stop < ni.Stop {
+				i.intervals[k] = NewInterval(v.Stop, ni.Stop)
+			}
+			k++
+		}
+	}
+}
+
+func (i *IntervalSet) removeOne(v int) {
+	if i.intervals != nil {
+		for k := 0; k < len(i.intervals); k++ {
+			ki := i.intervals[k]
+			// intervals i ordered
+			if v < ki.Start {
+				return
+			} else if v == ki.Start && v == ki.Stop-1 {
+				//				i.intervals.splice(k, 1)
+				i.intervals = append(i.intervals[0:k], i.intervals[k+1:]...)
+				return
+			} else if v == ki.Start {
+				i.intervals[k] = NewInterval(ki.Start+1, ki.Stop)
+				return
+			} else if v == ki.Stop-1 {
+				i.intervals[k] = NewInterval(ki.Start, ki.Stop-1)
+				return
+			} else if v < ki.Stop-1 {
+				x := NewInterval(ki.Start, v)
+				ki.Start = v + 1
+				//				i.intervals.splice(k, 0, x)
+				i.intervals = append(i.intervals[0:k], append([]*Interval{x}, i.intervals[k:]...)...)
+				return
+			}
+		}
+	}
+}
+
+func (i *IntervalSet) String() string {
+	return i.StringVerbose(nil, nil, false)
+}
+
+func (i *IntervalSet) StringVerbose(literalNames []string, symbolicNames []string, elemsAreChar bool) string {
+
+	if i.intervals == nil {
+		return "{}"
+	} else if literalNames != nil || symbolicNames != nil {
+		return i.toTokenString(literalNames, symbolicNames)
+	} else if elemsAreChar {
+		return i.toCharString()
+	}
+
+	return i.toIndexString()
+}
+
+func (i *IntervalSet) toCharString() string {
+	names := make([]string, len(i.intervals))
+
+	for j := 0; j < len(i.intervals); j++ {
+		v := i.intervals[j]
+		if v.Stop == v.Start+1 {
+			if v.Start == TokenEOF {
+				names = append(names, "<EOF>")
+			} else {
+				names = append(names, ("'" + string(v.Start) + "'"))
+			}
+		} else {
+			names = append(names, "'"+string(v.Start)+"'..'"+string(v.Stop-1)+"'")
+		}
+	}
+	if len(names) > 1 {
+		return "{" + strings.Join(names, ", ") + "}"
+	}
+
+	return names[0]
+}
+
+func (i *IntervalSet) toIndexString() string {
+
+	names := make([]string, 0)
+	for j := 0; j < len(i.intervals); j++ {
+		v := i.intervals[j]
+		if v.Stop == v.Start+1 {
+			if v.Start == TokenEOF {
+				names = append(names, "<EOF>")
+			} else {
+				names = append(names, strconv.Itoa(v.Start))
+			}
+		} else {
+			names = append(names, strconv.Itoa(v.Start)+".."+strconv.Itoa(v.Stop-1))
+		}
+	}
+	if len(names) > 1 {
+		return "{" + strings.Join(names, ", ") + "}"
+	}
+
+	return names[0]
+}
+
+func (i *IntervalSet) toTokenString(literalNames []string, symbolicNames []string) string {
+	names := make([]string, 0)
+	for _, v := range i.intervals {
+		for j := v.Start; j < v.Stop; j++ {
+			names = append(names, i.elementName(literalNames, symbolicNames, j))
+		}
+	}
+	if len(names) > 1 {
+		return "{" + strings.Join(names, ", ") + "}"
+	}
+
+	return names[0]
+}
+
+func (i *IntervalSet) elementName(literalNames []string, symbolicNames []string, a int) string {
+	if a == TokenEOF {
+		return "<EOF>"
+	} else if a == TokenEpsilon {
+		return "<EPSILON>"
+	} else {
+		if a < len(literalNames) && literalNames[a] != "" {
+			return literalNames[a]
+		}
+
+		return symbolicNames[a]
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/lexer.go

@@ -0,0 +1,418 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// A lexer is recognizer that draws input symbols from a character stream.
+//  lexer grammars result in a subclass of this object. A Lexer object
+//  uses simplified Match() and error recovery mechanisms in the interest
+//  of speed.
+///
+
+type Lexer interface {
+	TokenSource
+	Recognizer
+
+	Emit() Token
+
+	SetChannel(int)
+	PushMode(int)
+	PopMode() int
+	SetType(int)
+	SetMode(int)
+}
+
+type BaseLexer struct {
+	*BaseRecognizer
+
+	Interpreter         ILexerATNSimulator
+	TokenStartCharIndex int
+	TokenStartLine      int
+	TokenStartColumn    int
+	ActionType          int
+	Virt                Lexer // The most derived lexer implementation. Allows virtual method calls.
+
+	input                  CharStream
+	factory                TokenFactory
+	tokenFactorySourcePair *TokenSourceCharStreamPair
+	token                  Token
+	hitEOF                 bool
+	channel                int
+	thetype                int
+	modeStack              IntStack
+	mode                   int
+	text                   string
+}
+
+func NewBaseLexer(input CharStream) *BaseLexer {
+
+	lexer := new(BaseLexer)
+
+	lexer.BaseRecognizer = NewBaseRecognizer()
+
+	lexer.input = input
+	lexer.factory = CommonTokenFactoryDEFAULT
+	lexer.tokenFactorySourcePair = &TokenSourceCharStreamPair{lexer, input}
+
+	lexer.Virt = lexer
+
+	lexer.Interpreter = nil // child classes must populate it
+
+	// The goal of all lexer rules/methods is to create a token object.
+	// l is an instance variable as multiple rules may collaborate to
+	// create a single token. NextToken will return l object after
+	// Matching lexer rule(s). If you subclass to allow multiple token
+	// emissions, then set l to the last token to be Matched or
+	// something nonnil so that the auto token emit mechanism will not
+	// emit another token.
+	lexer.token = nil
+
+	// What character index in the stream did the current token start at?
+	// Needed, for example, to get the text for current token. Set at
+	// the start of NextToken.
+	lexer.TokenStartCharIndex = -1
+
+	// The line on which the first character of the token resides///
+	lexer.TokenStartLine = -1
+
+	// The character position of first character within the line///
+	lexer.TokenStartColumn = -1
+
+	// Once we see EOF on char stream, next token will be EOF.
+	// If you have DONE : EOF  then you see DONE EOF.
+	lexer.hitEOF = false
+
+	// The channel number for the current token///
+	lexer.channel = TokenDefaultChannel
+
+	// The token type for the current token///
+	lexer.thetype = TokenInvalidType
+
+	lexer.modeStack = make([]int, 0)
+	lexer.mode = LexerDefaultMode
+
+	// You can set the text for the current token to override what is in
+	// the input char buffer. Use setText() or can set l instance var.
+	// /
+	lexer.text = ""
+
+	return lexer
+}
+
+const (
+	LexerDefaultMode = 0
+	LexerMore        = -2
+	LexerSkip        = -3
+)
+
+const (
+	LexerDefaultTokenChannel = TokenDefaultChannel
+	LexerHidden              = TokenHiddenChannel
+	LexerMinCharValue        = 0x0000
+	LexerMaxCharValue        = 0x10FFFF
+)
+
+func (b *BaseLexer) reset() {
+	// wack Lexer state variables
+	if b.input != nil {
+		b.input.Seek(0) // rewind the input
+	}
+	b.token = nil
+	b.thetype = TokenInvalidType
+	b.channel = TokenDefaultChannel
+	b.TokenStartCharIndex = -1
+	b.TokenStartColumn = -1
+	b.TokenStartLine = -1
+	b.text = ""
+
+	b.hitEOF = false
+	b.mode = LexerDefaultMode
+	b.modeStack = make([]int, 0)
+
+	b.Interpreter.reset()
+}
+
+func (b *BaseLexer) GetInterpreter() ILexerATNSimulator {
+	return b.Interpreter
+}
+
+func (b *BaseLexer) GetInputStream() CharStream {
+	return b.input
+}
+
+func (b *BaseLexer) GetSourceName() string {
+	return b.GrammarFileName
+}
+
+func (b *BaseLexer) SetChannel(v int) {
+	b.channel = v
+}
+
+func (b *BaseLexer) GetTokenFactory() TokenFactory {
+	return b.factory
+}
+
+func (b *BaseLexer) setTokenFactory(f TokenFactory) {
+	b.factory = f
+}
+
+func (b *BaseLexer) safeMatch() (ret int) {
+	defer func() {
+		if e := recover(); e != nil {
+			if re, ok := e.(RecognitionException); ok {
+				b.notifyListeners(re) // Report error
+				b.Recover(re)
+				ret = LexerSkip // default
+			}
+		}
+	}()
+
+	return b.Interpreter.Match(b.input, b.mode)
+}
+
+// Return a token from l source i.e., Match a token on the char stream.
+func (b *BaseLexer) NextToken() Token {
+	if b.input == nil {
+		panic("NextToken requires a non-nil input stream.")
+	}
+
+	tokenStartMarker := b.input.Mark()
+
+	// previously in finally block
+	defer func() {
+		// make sure we release marker after Match or
+		// unbuffered char stream will keep buffering
+		b.input.Release(tokenStartMarker)
+	}()
+
+	for {
+		if b.hitEOF {
+			b.EmitEOF()
+			return b.token
+		}
+		b.token = nil
+		b.channel = TokenDefaultChannel
+		b.TokenStartCharIndex = b.input.Index()
+		b.TokenStartColumn = b.Interpreter.GetCharPositionInLine()
+		b.TokenStartLine = b.Interpreter.GetLine()
+		b.text = ""
+		continueOuter := false
+		for {
+			b.thetype = TokenInvalidType
+			ttype := LexerSkip
+
+			ttype = b.safeMatch()
+
+			if b.input.LA(1) == TokenEOF {
+				b.hitEOF = true
+			}
+			if b.thetype == TokenInvalidType {
+				b.thetype = ttype
+			}
+			if b.thetype == LexerSkip {
+				continueOuter = true
+				break
+			}
+			if b.thetype != LexerMore {
+				break
+			}
+		}
+
+		if continueOuter {
+			continue
+		}
+		if b.token == nil {
+			b.Virt.Emit()
+		}
+		return b.token
+	}
+
+	return nil
+}
+
+// Instruct the lexer to Skip creating a token for current lexer rule
+// and look for another token. NextToken() knows to keep looking when
+// a lexer rule finishes with token set to SKIPTOKEN. Recall that
+// if token==nil at end of any token rule, it creates one for you
+// and emits it.
+// /
+func (b *BaseLexer) Skip() {
+	b.thetype = LexerSkip
+}
+
+func (b *BaseLexer) More() {
+	b.thetype = LexerMore
+}
+
+func (b *BaseLexer) SetMode(m int) {
+	b.mode = m
+}
+
+func (b *BaseLexer) PushMode(m int) {
+	if LexerATNSimulatorDebug {
+		fmt.Println("pushMode " + strconv.Itoa(m))
+	}
+	b.modeStack.Push(b.mode)
+	b.mode = m
+}
+
+func (b *BaseLexer) PopMode() int {
+	if len(b.modeStack) == 0 {
+		panic("Empty Stack")
+	}
+	if LexerATNSimulatorDebug {
+		fmt.Println("popMode back to " + fmt.Sprint(b.modeStack[0:len(b.modeStack)-1]))
+	}
+	i, _ := b.modeStack.Pop()
+	b.mode = i
+	return b.mode
+}
+
+func (b *BaseLexer) inputStream() CharStream {
+	return b.input
+}
+
+// SetInputStream resets the lexer input stream and associated lexer state.
+func (b *BaseLexer) SetInputStream(input CharStream) {
+	b.input = nil
+	b.tokenFactorySourcePair = &TokenSourceCharStreamPair{b, b.input}
+	b.reset()
+	b.input = input
+	b.tokenFactorySourcePair = &TokenSourceCharStreamPair{b, b.input}
+}
+
+func (b *BaseLexer) GetTokenSourceCharStreamPair() *TokenSourceCharStreamPair {
+	return b.tokenFactorySourcePair
+}
+
+// By default does not support multiple emits per NextToken invocation
+// for efficiency reasons. Subclass and override l method, NextToken,
+// and GetToken (to push tokens into a list and pull from that list
+// rather than a single variable as l implementation does).
+// /
+func (b *BaseLexer) EmitToken(token Token) {
+	b.token = token
+}
+
+// The standard method called to automatically emit a token at the
+// outermost lexical rule. The token object should point into the
+// char buffer start..stop. If there is a text override in 'text',
+// use that to set the token's text. Override l method to emit
+// custom Token objects or provide a Newfactory.
+// /
+func (b *BaseLexer) Emit() Token {
+	t := b.factory.Create(b.tokenFactorySourcePair, b.thetype, b.text, b.channel, b.TokenStartCharIndex, b.GetCharIndex()-1, b.TokenStartLine, b.TokenStartColumn)
+	b.EmitToken(t)
+	return t
+}
+
+func (b *BaseLexer) EmitEOF() Token {
+	cpos := b.GetCharPositionInLine()
+	lpos := b.GetLine()
+	eof := b.factory.Create(b.tokenFactorySourcePair, TokenEOF, "", TokenDefaultChannel, b.input.Index(), b.input.Index()-1, lpos, cpos)
+	b.EmitToken(eof)
+	return eof
+}
+
+func (b *BaseLexer) GetCharPositionInLine() int {
+	return b.Interpreter.GetCharPositionInLine()
+}
+
+func (b *BaseLexer) GetLine() int {
+	return b.Interpreter.GetLine()
+}
+
+func (b *BaseLexer) GetType() int {
+	return b.thetype
+}
+
+func (b *BaseLexer) SetType(t int) {
+	b.thetype = t
+}
+
+// What is the index of the current character of lookahead?///
+func (b *BaseLexer) GetCharIndex() int {
+	return b.input.Index()
+}
+
+// Return the text Matched so far for the current token or any text override.
+//Set the complete text of l token it wipes any previous changes to the text.
+func (b *BaseLexer) GetText() string {
+	if b.text != "" {
+		return b.text
+	}
+
+	return b.Interpreter.GetText(b.input)
+}
+
+func (b *BaseLexer) SetText(text string) {
+	b.text = text
+}
+
+func (b *BaseLexer) GetATN() *ATN {
+	return b.Interpreter.ATN()
+}
+
+// Return a list of all Token objects in input char stream.
+// Forces load of all tokens. Does not include EOF token.
+// /
+func (b *BaseLexer) GetAllTokens() []Token {
+	vl := b.Virt
+	tokens := make([]Token, 0)
+	t := vl.NextToken()
+	for t.GetTokenType() != TokenEOF {
+		tokens = append(tokens, t)
+		t = vl.NextToken()
+	}
+	return tokens
+}
+
+func (b *BaseLexer) notifyListeners(e RecognitionException) {
+	start := b.TokenStartCharIndex
+	stop := b.input.Index()
+	text := b.input.GetTextFromInterval(NewInterval(start, stop))
+	msg := "token recognition error at: '" + text + "'"
+	listener := b.GetErrorListenerDispatch()
+	listener.SyntaxError(b, nil, b.TokenStartLine, b.TokenStartColumn, msg, e)
+}
+
+func (b *BaseLexer) getErrorDisplayForChar(c rune) string {
+	if c == TokenEOF {
+		return "<EOF>"
+	} else if c == '\n' {
+		return "\\n"
+	} else if c == '\t' {
+		return "\\t"
+	} else if c == '\r' {
+		return "\\r"
+	} else {
+		return string(c)
+	}
+}
+
+func (b *BaseLexer) getCharErrorDisplay(c rune) string {
+	return "'" + b.getErrorDisplayForChar(c) + "'"
+}
+
+// Lexers can normally Match any char in it's vocabulary after Matching
+// a token, so do the easy thing and just kill a character and hope
+// it all works out. You can instead use the rule invocation stack
+// to do sophisticated error recovery if you are in a fragment rule.
+// /
+func (b *BaseLexer) Recover(re RecognitionException) {
+	if b.input.LA(1) != TokenEOF {
+		if _, ok := re.(*LexerNoViableAltException); ok {
+			// Skip a char and try again
+			b.Interpreter.Consume(b.input)
+		} else {
+			// TODO: Do we lose character or line position information?
+			b.input.Consume()
+		}
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/lexer_action.go

@@ -0,0 +1,431 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import "strconv"
+
+const (
+	LexerActionTypeChannel  = 0 //The type of a {@link LexerChannelAction} action.
+	LexerActionTypeCustom   = 1 //The type of a {@link LexerCustomAction} action.
+	LexerActionTypeMode     = 2 //The type of a {@link LexerModeAction} action.
+	LexerActionTypeMore     = 3 //The type of a {@link LexerMoreAction} action.
+	LexerActionTypePopMode  = 4 //The type of a {@link LexerPopModeAction} action.
+	LexerActionTypePushMode = 5 //The type of a {@link LexerPushModeAction} action.
+	LexerActionTypeSkip     = 6 //The type of a {@link LexerSkipAction} action.
+	LexerActionTypeType     = 7 //The type of a {@link LexerTypeAction} action.
+)
+
+type LexerAction interface {
+	getActionType() int
+	getIsPositionDependent() bool
+	execute(lexer Lexer)
+	hash() int
+	equals(other LexerAction) bool
+}
+
+type BaseLexerAction struct {
+	actionType          int
+	isPositionDependent bool
+}
+
+func NewBaseLexerAction(action int) *BaseLexerAction {
+	la := new(BaseLexerAction)
+
+	la.actionType = action
+	la.isPositionDependent = false
+
+	return la
+}
+
+func (b *BaseLexerAction) execute(lexer Lexer) {
+	panic("Not implemented")
+}
+
+func (b *BaseLexerAction) getActionType() int {
+	return b.actionType
+}
+
+func (b *BaseLexerAction) getIsPositionDependent() bool {
+	return b.isPositionDependent
+}
+
+func (b *BaseLexerAction) hash() int {
+	return b.actionType
+}
+
+func (b *BaseLexerAction) equals(other LexerAction) bool {
+	return b == other
+}
+
+//
+// Implements the {@code Skip} lexer action by calling {@link Lexer//Skip}.
+//
+// <p>The {@code Skip} command does not have any parameters, so l action is
+// implemented as a singleton instance exposed by {@link //INSTANCE}.</p>
+type LexerSkipAction struct {
+	*BaseLexerAction
+}
+
+func NewLexerSkipAction() *LexerSkipAction {
+	la := new(LexerSkipAction)
+	la.BaseLexerAction = NewBaseLexerAction(LexerActionTypeSkip)
+	return la
+}
+
+// Provides a singleton instance of l parameterless lexer action.
+var LexerSkipActionINSTANCE = NewLexerSkipAction()
+
+func (l *LexerSkipAction) execute(lexer Lexer) {
+	lexer.Skip()
+}
+
+func (l *LexerSkipAction) String() string {
+	return "skip"
+}
+
+//  Implements the {@code type} lexer action by calling {@link Lexer//setType}
+// with the assigned type.
+type LexerTypeAction struct {
+	*BaseLexerAction
+
+	thetype int
+}
+
+func NewLexerTypeAction(thetype int) *LexerTypeAction {
+	l := new(LexerTypeAction)
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeType)
+	l.thetype = thetype
+	return l
+}
+
+func (l *LexerTypeAction) execute(lexer Lexer) {
+	lexer.SetType(l.thetype)
+}
+
+func (l *LexerTypeAction) hash() int {
+	h := murmurInit(0)
+	h = murmurUpdate(h, l.actionType)
+	h = murmurUpdate(h, l.thetype)
+	return murmurFinish(h, 2)
+}
+
+func (l *LexerTypeAction) equals(other LexerAction) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerTypeAction); !ok {
+		return false
+	} else {
+		return l.thetype == other.(*LexerTypeAction).thetype
+	}
+}
+
+func (l *LexerTypeAction) String() string {
+	return "actionType(" + strconv.Itoa(l.thetype) + ")"
+}
+
+// Implements the {@code pushMode} lexer action by calling
+// {@link Lexer//pushMode} with the assigned mode.
+type LexerPushModeAction struct {
+	*BaseLexerAction
+
+	mode int
+}
+
+func NewLexerPushModeAction(mode int) *LexerPushModeAction {
+
+	l := new(LexerPushModeAction)
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypePushMode)
+
+	l.mode = mode
+	return l
+}
+
+// <p>This action is implemented by calling {@link Lexer//pushMode} with the
+// value provided by {@link //getMode}.</p>
+func (l *LexerPushModeAction) execute(lexer Lexer) {
+	lexer.PushMode(l.mode)
+}
+
+func (l *LexerPushModeAction) hash() int {
+	h := murmurInit(0)
+	h = murmurUpdate(h, l.actionType)
+	h = murmurUpdate(h, l.mode)
+	return murmurFinish(h, 2)
+}
+
+func (l *LexerPushModeAction) equals(other LexerAction) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerPushModeAction); !ok {
+		return false
+	} else {
+		return l.mode == other.(*LexerPushModeAction).mode
+	}
+}
+
+func (l *LexerPushModeAction) String() string {
+	return "pushMode(" + strconv.Itoa(l.mode) + ")"
+}
+
+// Implements the {@code popMode} lexer action by calling {@link Lexer//popMode}.
+//
+// <p>The {@code popMode} command does not have any parameters, so l action is
+// implemented as a singleton instance exposed by {@link //INSTANCE}.</p>
+type LexerPopModeAction struct {
+	*BaseLexerAction
+}
+
+func NewLexerPopModeAction() *LexerPopModeAction {
+
+	l := new(LexerPopModeAction)
+
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypePopMode)
+
+	return l
+}
+
+var LexerPopModeActionINSTANCE = NewLexerPopModeAction()
+
+// <p>This action is implemented by calling {@link Lexer//popMode}.</p>
+func (l *LexerPopModeAction) execute(lexer Lexer) {
+	lexer.PopMode()
+}
+
+func (l *LexerPopModeAction) String() string {
+	return "popMode"
+}
+
+// Implements the {@code more} lexer action by calling {@link Lexer//more}.
+//
+// <p>The {@code more} command does not have any parameters, so l action is
+// implemented as a singleton instance exposed by {@link //INSTANCE}.</p>
+
+type LexerMoreAction struct {
+	*BaseLexerAction
+}
+
+func NewLexerMoreAction() *LexerMoreAction {
+	l := new(LexerMoreAction)
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeMore)
+
+	return l
+}
+
+var LexerMoreActionINSTANCE = NewLexerMoreAction()
+
+// <p>This action is implemented by calling {@link Lexer//popMode}.</p>
+func (l *LexerMoreAction) execute(lexer Lexer) {
+	lexer.More()
+}
+
+func (l *LexerMoreAction) String() string {
+	return "more"
+}
+
+// Implements the {@code mode} lexer action by calling {@link Lexer//mode} with
+// the assigned mode.
+type LexerModeAction struct {
+	*BaseLexerAction
+
+	mode int
+}
+
+func NewLexerModeAction(mode int) *LexerModeAction {
+	l := new(LexerModeAction)
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeMode)
+	l.mode = mode
+	return l
+}
+
+// <p>This action is implemented by calling {@link Lexer//mode} with the
+// value provided by {@link //getMode}.</p>
+func (l *LexerModeAction) execute(lexer Lexer) {
+	lexer.SetMode(l.mode)
+}
+
+func (l *LexerModeAction) hash() int {
+	h := murmurInit(0)
+	h = murmurUpdate(h, l.actionType)
+	h = murmurUpdate(h, l.mode)
+	return murmurFinish(h, 2)
+}
+
+func (l *LexerModeAction) equals(other LexerAction) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerModeAction); !ok {
+		return false
+	} else {
+		return l.mode == other.(*LexerModeAction).mode
+	}
+}
+
+func (l *LexerModeAction) String() string {
+	return "mode(" + strconv.Itoa(l.mode) + ")"
+}
+
+// Executes a custom lexer action by calling {@link Recognizer//action} with the
+// rule and action indexes assigned to the custom action. The implementation of
+// a custom action is added to the generated code for the lexer in an override
+// of {@link Recognizer//action} when the grammar is compiled.
+//
+// <p>This class may represent embedded actions created with the <code>{...}</code>
+// syntax in ANTLR 4, as well as actions created for lexer commands where the
+// command argument could not be evaluated when the grammar was compiled.</p>
+
+// Constructs a custom lexer action with the specified rule and action
+// indexes.
+//
+// @param ruleIndex The rule index to use for calls to
+// {@link Recognizer//action}.
+// @param actionIndex The action index to use for calls to
+// {@link Recognizer//action}.
+
+type LexerCustomAction struct {
+	*BaseLexerAction
+	ruleIndex, actionIndex int
+}
+
+func NewLexerCustomAction(ruleIndex, actionIndex int) *LexerCustomAction {
+	l := new(LexerCustomAction)
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeCustom)
+	l.ruleIndex = ruleIndex
+	l.actionIndex = actionIndex
+	l.isPositionDependent = true
+	return l
+}
+
+// <p>Custom actions are implemented by calling {@link Lexer//action} with the
+// appropriate rule and action indexes.</p>
+func (l *LexerCustomAction) execute(lexer Lexer) {
+	lexer.Action(nil, l.ruleIndex, l.actionIndex)
+}
+
+func (l *LexerCustomAction) hash() int {
+	h := murmurInit(0)
+	h = murmurUpdate(h, l.actionType)
+	h = murmurUpdate(h, l.ruleIndex)
+	h = murmurUpdate(h, l.actionIndex)
+	return murmurFinish(h, 3)
+}
+
+func (l *LexerCustomAction) equals(other LexerAction) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerCustomAction); !ok {
+		return false
+	} else {
+		return l.ruleIndex == other.(*LexerCustomAction).ruleIndex && l.actionIndex == other.(*LexerCustomAction).actionIndex
+	}
+}
+
+// Implements the {@code channel} lexer action by calling
+// {@link Lexer//setChannel} with the assigned channel.
+// Constructs a New{@code channel} action with the specified channel value.
+// @param channel The channel value to pass to {@link Lexer//setChannel}.
+type LexerChannelAction struct {
+	*BaseLexerAction
+
+	channel int
+}
+
+func NewLexerChannelAction(channel int) *LexerChannelAction {
+	l := new(LexerChannelAction)
+	l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeChannel)
+	l.channel = channel
+	return l
+}
+
+// <p>This action is implemented by calling {@link Lexer//setChannel} with the
+// value provided by {@link //getChannel}.</p>
+func (l *LexerChannelAction) execute(lexer Lexer) {
+	lexer.SetChannel(l.channel)
+}
+
+func (l *LexerChannelAction) hash() int {
+	h := murmurInit(0)
+	h = murmurUpdate(h, l.actionType)
+	h = murmurUpdate(h, l.channel)
+	return murmurFinish(h, 2)
+}
+
+func (l *LexerChannelAction) equals(other LexerAction) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerChannelAction); !ok {
+		return false
+	} else {
+		return l.channel == other.(*LexerChannelAction).channel
+	}
+}
+
+func (l *LexerChannelAction) String() string {
+	return "channel(" + strconv.Itoa(l.channel) + ")"
+}
+
+// This implementation of {@link LexerAction} is used for tracking input offsets
+// for position-dependent actions within a {@link LexerActionExecutor}.
+//
+// <p>This action is not serialized as part of the ATN, and is only required for
+// position-dependent lexer actions which appear at a location other than the
+// end of a rule. For more information about DFA optimizations employed for
+// lexer actions, see {@link LexerActionExecutor//append} and
+// {@link LexerActionExecutor//fixOffsetBeforeMatch}.</p>
+
+// Constructs a Newindexed custom action by associating a character offset
+// with a {@link LexerAction}.
+//
+// <p>Note: This class is only required for lexer actions for which
+// {@link LexerAction//isPositionDependent} returns {@code true}.</p>
+//
+// @param offset The offset into the input {@link CharStream}, relative to
+// the token start index, at which the specified lexer action should be
+// executed.
+// @param action The lexer action to execute at a particular offset in the
+// input {@link CharStream}.
+type LexerIndexedCustomAction struct {
+	*BaseLexerAction
+
+	offset              int
+	lexerAction         LexerAction
+	isPositionDependent bool
+}
+
+func NewLexerIndexedCustomAction(offset int, lexerAction LexerAction) *LexerIndexedCustomAction {
+
+	l := new(LexerIndexedCustomAction)
+	l.BaseLexerAction = NewBaseLexerAction(lexerAction.getActionType())
+
+	l.offset = offset
+	l.lexerAction = lexerAction
+	l.isPositionDependent = true
+
+	return l
+}
+
+// <p>This method calls {@link //execute} on the result of {@link //getAction}
+// using the provided {@code lexer}.</p>
+func (l *LexerIndexedCustomAction) execute(lexer Lexer) {
+	// assume the input stream position was properly set by the calling code
+	l.lexerAction.execute(lexer)
+}
+
+func (l *LexerIndexedCustomAction) hash() int {
+	h := murmurInit(0)
+	h = murmurUpdate(h, l.actionType)
+	h = murmurUpdate(h, l.offset)
+	h = murmurUpdate(h, l.lexerAction.hash())
+	return murmurFinish(h, 3)
+}
+
+func (l *LexerIndexedCustomAction) equals(other LexerAction) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerIndexedCustomAction); !ok {
+		return false
+	} else {
+		return l.offset == other.(*LexerIndexedCustomAction).offset && l.lexerAction == other.(*LexerIndexedCustomAction).lexerAction
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/lexer_action_executor.go

@@ -0,0 +1,170 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// Represents an executor for a sequence of lexer actions which traversed during
+// the Matching operation of a lexer rule (token).
+//
+// <p>The executor tracks position information for position-dependent lexer actions
+// efficiently, ensuring that actions appearing only at the end of the rule do
+// not cause bloating of the {@link DFA} created for the lexer.</p>
+
+type LexerActionExecutor struct {
+	lexerActions     []LexerAction
+	cachedHash       int
+}
+
+func NewLexerActionExecutor(lexerActions []LexerAction) *LexerActionExecutor {
+
+	if lexerActions == nil {
+		lexerActions = make([]LexerAction, 0)
+	}
+
+	l := new(LexerActionExecutor)
+
+	l.lexerActions = lexerActions
+
+	// Caches the result of {@link //hashCode} since the hash code is an element
+	// of the performance-critical {@link LexerATNConfig//hashCode} operation.
+	l.cachedHash = murmurInit(57)
+	for _, a := range lexerActions {
+		l.cachedHash = murmurUpdate(l.cachedHash, a.hash())
+	}
+
+	return l
+}
+
+// Creates a {@link LexerActionExecutor} which executes the actions for
+// the input {@code lexerActionExecutor} followed by a specified
+// {@code lexerAction}.
+//
+// @param lexerActionExecutor The executor for actions already traversed by
+// the lexer while Matching a token within a particular
+// {@link LexerATNConfig}. If this is {@code nil}, the method behaves as
+// though it were an empty executor.
+// @param lexerAction The lexer action to execute after the actions
+// specified in {@code lexerActionExecutor}.
+//
+// @return A {@link LexerActionExecutor} for executing the combine actions
+// of {@code lexerActionExecutor} and {@code lexerAction}.
+func LexerActionExecutorappend(lexerActionExecutor *LexerActionExecutor, lexerAction LexerAction) *LexerActionExecutor {
+	if lexerActionExecutor == nil {
+		return NewLexerActionExecutor([]LexerAction{lexerAction})
+	}
+
+	return NewLexerActionExecutor(append(lexerActionExecutor.lexerActions, lexerAction))
+}
+
+// Creates a {@link LexerActionExecutor} which encodes the current offset
+// for position-dependent lexer actions.
+//
+// <p>Normally, when the executor encounters lexer actions where
+// {@link LexerAction//isPositionDependent} returns {@code true}, it calls
+// {@link IntStream//seek} on the input {@link CharStream} to set the input
+// position to the <em>end</em> of the current token. This behavior provides
+// for efficient DFA representation of lexer actions which appear at the end
+// of a lexer rule, even when the lexer rule Matches a variable number of
+// characters.</p>
+//
+// <p>Prior to traversing a Match transition in the ATN, the current offset
+// from the token start index is assigned to all position-dependent lexer
+// actions which have not already been assigned a fixed offset. By storing
+// the offsets relative to the token start index, the DFA representation of
+// lexer actions which appear in the middle of tokens remains efficient due
+// to sharing among tokens of the same length, regardless of their absolute
+// position in the input stream.</p>
+//
+// <p>If the current executor already has offsets assigned to all
+// position-dependent lexer actions, the method returns {@code this}.</p>
+//
+// @param offset The current offset to assign to all position-dependent
+// lexer actions which do not already have offsets assigned.
+//
+// @return A {@link LexerActionExecutor} which stores input stream offsets
+// for all position-dependent lexer actions.
+// /
+func (l *LexerActionExecutor) fixOffsetBeforeMatch(offset int) *LexerActionExecutor {
+	var updatedLexerActions []LexerAction
+	for i := 0; i < len(l.lexerActions); i++ {
+		_, ok := l.lexerActions[i].(*LexerIndexedCustomAction)
+		if l.lexerActions[i].getIsPositionDependent() && !ok {
+			if updatedLexerActions == nil {
+				updatedLexerActions = make([]LexerAction, 0)
+
+				for _, a := range l.lexerActions {
+					updatedLexerActions = append(updatedLexerActions, a)
+				}
+			}
+
+			updatedLexerActions[i] = NewLexerIndexedCustomAction(offset, l.lexerActions[i])
+		}
+	}
+	if updatedLexerActions == nil {
+		return l
+	}
+
+	return NewLexerActionExecutor(updatedLexerActions)
+}
+
+// Execute the actions encapsulated by l executor within the context of a
+// particular {@link Lexer}.
+//
+// <p>This method calls {@link IntStream//seek} to set the position of the
+// {@code input} {@link CharStream} prior to calling
+// {@link LexerAction//execute} on a position-dependent action. Before the
+// method returns, the input position will be restored to the same position
+// it was in when the method was invoked.</p>
+//
+// @param lexer The lexer instance.
+// @param input The input stream which is the source for the current token.
+// When l method is called, the current {@link IntStream//index} for
+// {@code input} should be the start of the following token, i.e. 1
+// character past the end of the current token.
+// @param startIndex The token start index. This value may be passed to
+// {@link IntStream//seek} to set the {@code input} position to the beginning
+// of the token.
+// /
+func (l *LexerActionExecutor) execute(lexer Lexer, input CharStream, startIndex int) {
+	requiresSeek := false
+	stopIndex := input.Index()
+
+	defer func() {
+		if requiresSeek {
+			input.Seek(stopIndex)
+		}
+	}()
+
+	for i := 0; i < len(l.lexerActions); i++ {
+		lexerAction := l.lexerActions[i]
+		if la, ok := lexerAction.(*LexerIndexedCustomAction); ok {
+			offset := la.offset
+			input.Seek(startIndex + offset)
+			lexerAction = la.lexerAction
+			requiresSeek = (startIndex + offset) != stopIndex
+		} else if lexerAction.getIsPositionDependent() {
+			input.Seek(stopIndex)
+			requiresSeek = false
+		}
+		lexerAction.execute(lexer)
+	}
+}
+
+func (l *LexerActionExecutor) hash() int {
+	if l == nil {
+		return 61
+	}
+	return l.cachedHash
+}
+
+func (l *LexerActionExecutor) equals(other interface{}) bool {
+	if l == other {
+		return true
+	} else if _, ok := other.(*LexerActionExecutor); !ok {
+		return false
+	} else {
+		return l.cachedHash == other.(*LexerActionExecutor).cachedHash &&
+			&l.lexerActions == &other.(*LexerActionExecutor).lexerActions
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/lexer_atn_simulator.go

@@ -0,0 +1,658 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strconv"
+)
+
+var (
+	LexerATNSimulatorDebug    = false
+	LexerATNSimulatorDFADebug = false
+
+	LexerATNSimulatorMinDFAEdge = 0
+	LexerATNSimulatorMaxDFAEdge = 127 // forces unicode to stay in ATN
+
+	LexerATNSimulatorMatchCalls = 0
+)
+
+type ILexerATNSimulator interface {
+	IATNSimulator
+
+	reset()
+	Match(input CharStream, mode int) int
+	GetCharPositionInLine() int
+	GetLine() int
+	GetText(input CharStream) string
+	Consume(input CharStream)
+}
+
+type LexerATNSimulator struct {
+	*BaseATNSimulator
+
+	recog              Lexer
+	predictionMode     int
+	mergeCache         DoubleDict
+	startIndex         int
+	Line               int
+	CharPositionInLine int
+	mode               int
+	prevAccept         *SimState
+	MatchCalls         int
+}
+
+func NewLexerATNSimulator(recog Lexer, atn *ATN, decisionToDFA []*DFA, sharedContextCache *PredictionContextCache) *LexerATNSimulator {
+	l := new(LexerATNSimulator)
+
+	l.BaseATNSimulator = NewBaseATNSimulator(atn, sharedContextCache)
+
+	l.decisionToDFA = decisionToDFA
+	l.recog = recog
+	// The current token's starting index into the character stream.
+	// Shared across DFA to ATN simulation in case the ATN fails and the
+	// DFA did not have a previous accept state. In l case, we use the
+	// ATN-generated exception object.
+	l.startIndex = -1
+	// line number 1..n within the input///
+	l.Line = 1
+	// The index of the character relative to the beginning of the line
+	// 0..n-1///
+	l.CharPositionInLine = 0
+	l.mode = LexerDefaultMode
+	// Used during DFA/ATN exec to record the most recent accept configuration
+	// info
+	l.prevAccept = NewSimState()
+	// done
+	return l
+}
+
+func (l *LexerATNSimulator) copyState(simulator *LexerATNSimulator) {
+	l.CharPositionInLine = simulator.CharPositionInLine
+	l.Line = simulator.Line
+	l.mode = simulator.mode
+	l.startIndex = simulator.startIndex
+}
+
+func (l *LexerATNSimulator) Match(input CharStream, mode int) int {
+	l.MatchCalls++
+	l.mode = mode
+	mark := input.Mark()
+
+	defer func() {
+		input.Release(mark)
+	}()
+
+	l.startIndex = input.Index()
+	l.prevAccept.reset()
+
+	dfa := l.decisionToDFA[mode]
+
+	if dfa.getS0() == nil {
+		return l.MatchATN(input)
+	}
+
+	return l.execATN(input, dfa.getS0())
+}
+
+func (l *LexerATNSimulator) reset() {
+	l.prevAccept.reset()
+	l.startIndex = -1
+	l.Line = 1
+	l.CharPositionInLine = 0
+	l.mode = LexerDefaultMode
+}
+
+func (l *LexerATNSimulator) MatchATN(input CharStream) int {
+	startState := l.atn.modeToStartState[l.mode]
+
+	if LexerATNSimulatorDebug {
+		fmt.Println("MatchATN mode " + strconv.Itoa(l.mode) + " start: " + startState.String())
+	}
+	oldMode := l.mode
+	s0Closure := l.computeStartState(input, startState)
+	suppressEdge := s0Closure.hasSemanticContext
+	s0Closure.hasSemanticContext = false
+
+	next := l.addDFAState(s0Closure)
+
+	if !suppressEdge {
+		l.decisionToDFA[l.mode].setS0(next)
+	}
+
+	predict := l.execATN(input, next)
+
+	if LexerATNSimulatorDebug {
+		fmt.Println("DFA after MatchATN: " + l.decisionToDFA[oldMode].ToLexerString())
+	}
+	return predict
+}
+
+func (l *LexerATNSimulator) execATN(input CharStream, ds0 *DFAState) int {
+
+	if LexerATNSimulatorDebug {
+		fmt.Println("start state closure=" + ds0.configs.String())
+	}
+	if ds0.isAcceptState {
+		// allow zero-length tokens
+		l.captureSimState(l.prevAccept, input, ds0)
+	}
+	t := input.LA(1)
+	s := ds0 // s is current/from DFA state
+
+	for { // while more work
+		if LexerATNSimulatorDebug {
+			fmt.Println("execATN loop starting closure: " + s.configs.String())
+		}
+
+		// As we move src->trg, src->trg, we keep track of the previous trg to
+		// avoid looking up the DFA state again, which is expensive.
+		// If the previous target was already part of the DFA, we might
+		// be able to avoid doing a reach operation upon t. If s!=nil,
+		// it means that semantic predicates didn't prevent us from
+		// creating a DFA state. Once we know s!=nil, we check to see if
+		// the DFA state has an edge already for t. If so, we can just reuse
+		// it's configuration set there's no point in re-computing it.
+		// This is kind of like doing DFA simulation within the ATN
+		// simulation because DFA simulation is really just a way to avoid
+		// computing reach/closure sets. Technically, once we know that
+		// we have a previously added DFA state, we could jump over to
+		// the DFA simulator. But, that would mean popping back and forth
+		// a lot and making things more complicated algorithmically.
+		// This optimization makes a lot of sense for loops within DFA.
+		// A character will take us back to an existing DFA state
+		// that already has lots of edges out of it. e.g., .* in comments.
+		target := l.getExistingTargetState(s, t)
+		if target == nil {
+			target = l.computeTargetState(input, s, t)
+			// print("Computed:" + str(target))
+		}
+		if target == ATNSimulatorError {
+			break
+		}
+		// If l is a consumable input element, make sure to consume before
+		// capturing the accept state so the input index, line, and char
+		// position accurately reflect the state of the interpreter at the
+		// end of the token.
+		if t != TokenEOF {
+			l.Consume(input)
+		}
+		if target.isAcceptState {
+			l.captureSimState(l.prevAccept, input, target)
+			if t == TokenEOF {
+				break
+			}
+		}
+		t = input.LA(1)
+		s = target // flip current DFA target becomes Newsrc/from state
+	}
+
+	return l.failOrAccept(l.prevAccept, input, s.configs, t)
+}
+
+// Get an existing target state for an edge in the DFA. If the target state
+// for the edge has not yet been computed or is otherwise not available,
+// l method returns {@code nil}.
+//
+// @param s The current DFA state
+// @param t The next input symbol
+// @return The existing target DFA state for the given input symbol
+// {@code t}, or {@code nil} if the target state for l edge is not
+// already cached
+func (l *LexerATNSimulator) getExistingTargetState(s *DFAState, t int) *DFAState {
+	if s.getEdges() == nil || t < LexerATNSimulatorMinDFAEdge || t > LexerATNSimulatorMaxDFAEdge {
+		return nil
+	}
+
+	target := s.getIthEdge(t-LexerATNSimulatorMinDFAEdge)
+	if LexerATNSimulatorDebug && target != nil {
+		fmt.Println("reuse state " + strconv.Itoa(s.stateNumber) + " edge to " + strconv.Itoa(target.stateNumber))
+	}
+	return target
+}
+
+// Compute a target state for an edge in the DFA, and attempt to add the
+// computed state and corresponding edge to the DFA.
+//
+// @param input The input stream
+// @param s The current DFA state
+// @param t The next input symbol
+//
+// @return The computed target DFA state for the given input symbol
+// {@code t}. If {@code t} does not lead to a valid DFA state, l method
+// returns {@link //ERROR}.
+func (l *LexerATNSimulator) computeTargetState(input CharStream, s *DFAState, t int) *DFAState {
+	reach := NewOrderedATNConfigSet()
+
+	// if we don't find an existing DFA state
+	// Fill reach starting from closure, following t transitions
+	l.getReachableConfigSet(input, s.configs, reach.BaseATNConfigSet, t)
+
+	if len(reach.configs) == 0 { // we got nowhere on t from s
+		if !reach.hasSemanticContext {
+			// we got nowhere on t, don't panic out l knowledge it'd
+			// cause a failover from DFA later.
+			l.addDFAEdge(s, t, ATNSimulatorError, nil)
+		}
+		// stop when we can't Match any more char
+		return ATNSimulatorError
+	}
+	// Add an edge from s to target DFA found/created for reach
+	return l.addDFAEdge(s, t, nil, reach.BaseATNConfigSet)
+}
+
+func (l *LexerATNSimulator) failOrAccept(prevAccept *SimState, input CharStream, reach ATNConfigSet, t int) int {
+	if l.prevAccept.dfaState != nil {
+		lexerActionExecutor := prevAccept.dfaState.lexerActionExecutor
+		l.accept(input, lexerActionExecutor, l.startIndex, prevAccept.index, prevAccept.line, prevAccept.column)
+		return prevAccept.dfaState.prediction
+	}
+
+	// if no accept and EOF is first char, return EOF
+	if t == TokenEOF && input.Index() == l.startIndex {
+		return TokenEOF
+	}
+
+	panic(NewLexerNoViableAltException(l.recog, input, l.startIndex, reach))
+}
+
+// Given a starting configuration set, figure out all ATN configurations
+// we can reach upon input {@code t}. Parameter {@code reach} is a return
+// parameter.
+func (l *LexerATNSimulator) getReachableConfigSet(input CharStream, closure ATNConfigSet, reach ATNConfigSet, t int) {
+	// l is used to Skip processing for configs which have a lower priority
+	// than a config that already reached an accept state for the same rule
+	SkipAlt := ATNInvalidAltNumber
+
+	for _, cfg := range closure.GetItems() {
+		currentAltReachedAcceptState := (cfg.GetAlt() == SkipAlt)
+		if currentAltReachedAcceptState && cfg.(*LexerATNConfig).passedThroughNonGreedyDecision {
+			continue
+		}
+
+		if LexerATNSimulatorDebug {
+
+			fmt.Printf("testing %s at %s\n", l.GetTokenName(t), cfg.String()) // l.recog, true))
+		}
+
+		for _, trans := range cfg.GetState().GetTransitions() {
+			target := l.getReachableTarget(trans, t)
+			if target != nil {
+				lexerActionExecutor := cfg.(*LexerATNConfig).lexerActionExecutor
+				if lexerActionExecutor != nil {
+					lexerActionExecutor = lexerActionExecutor.fixOffsetBeforeMatch(input.Index() - l.startIndex)
+				}
+				treatEOFAsEpsilon := (t == TokenEOF)
+				config := NewLexerATNConfig3(cfg.(*LexerATNConfig), target, lexerActionExecutor)
+				if l.closure(input, config, reach,
+					currentAltReachedAcceptState, true, treatEOFAsEpsilon) {
+					// any remaining configs for l alt have a lower priority
+					// than the one that just reached an accept state.
+					SkipAlt = cfg.GetAlt()
+				}
+			}
+		}
+	}
+}
+
+func (l *LexerATNSimulator) accept(input CharStream, lexerActionExecutor *LexerActionExecutor, startIndex, index, line, charPos int) {
+	if LexerATNSimulatorDebug {
+		fmt.Printf("ACTION %s\n", lexerActionExecutor)
+	}
+	// seek to after last char in token
+	input.Seek(index)
+	l.Line = line
+	l.CharPositionInLine = charPos
+	if lexerActionExecutor != nil && l.recog != nil {
+		lexerActionExecutor.execute(l.recog, input, startIndex)
+	}
+}
+
+func (l *LexerATNSimulator) getReachableTarget(trans Transition, t int) ATNState {
+	if trans.Matches(t, 0, LexerMaxCharValue) {
+		return trans.getTarget()
+	}
+
+	return nil
+}
+
+func (l *LexerATNSimulator) computeStartState(input CharStream, p ATNState) *OrderedATNConfigSet {
+	configs := NewOrderedATNConfigSet()
+	for i := 0; i < len(p.GetTransitions()); i++ {
+		target := p.GetTransitions()[i].getTarget()
+		cfg := NewLexerATNConfig6(target, i+1, BasePredictionContextEMPTY)
+		l.closure(input, cfg, configs, false, false, false)
+	}
+
+	return configs
+}
+
+// Since the alternatives within any lexer decision are ordered by
+// preference, l method stops pursuing the closure as soon as an accept
+// state is reached. After the first accept state is reached by depth-first
+// search from {@code config}, all other (potentially reachable) states for
+// l rule would have a lower priority.
+//
+// @return {@code true} if an accept state is reached, otherwise
+// {@code false}.
+func (l *LexerATNSimulator) closure(input CharStream, config *LexerATNConfig, configs ATNConfigSet,
+	currentAltReachedAcceptState, speculative, treatEOFAsEpsilon bool) bool {
+
+	if LexerATNSimulatorDebug {
+		fmt.Println("closure(" + config.String() + ")") // config.String(l.recog, true) + ")")
+	}
+
+	_, ok := config.state.(*RuleStopState)
+	if ok {
+
+		if LexerATNSimulatorDebug {
+			if l.recog != nil {
+				fmt.Printf("closure at %s rule stop %s\n", l.recog.GetRuleNames()[config.state.GetRuleIndex()], config)
+			} else {
+				fmt.Printf("closure at rule stop %s\n", config)
+			}
+		}
+
+		if config.context == nil || config.context.hasEmptyPath() {
+			if config.context == nil || config.context.isEmpty() {
+				configs.Add(config, nil)
+				return true
+			}
+
+			configs.Add(NewLexerATNConfig2(config, config.state, BasePredictionContextEMPTY), nil)
+			currentAltReachedAcceptState = true
+		}
+		if config.context != nil && !config.context.isEmpty() {
+			for i := 0; i < config.context.length(); i++ {
+				if config.context.getReturnState(i) != BasePredictionContextEmptyReturnState {
+					newContext := config.context.GetParent(i) // "pop" return state
+					returnState := l.atn.states[config.context.getReturnState(i)]
+					cfg := NewLexerATNConfig2(config, returnState, newContext)
+					currentAltReachedAcceptState = l.closure(input, cfg, configs, currentAltReachedAcceptState, speculative, treatEOFAsEpsilon)
+				}
+			}
+		}
+		return currentAltReachedAcceptState
+	}
+	// optimization
+	if !config.state.GetEpsilonOnlyTransitions() {
+		if !currentAltReachedAcceptState || !config.passedThroughNonGreedyDecision {
+			configs.Add(config, nil)
+		}
+	}
+	for j := 0; j < len(config.state.GetTransitions()); j++ {
+		trans := config.state.GetTransitions()[j]
+		cfg := l.getEpsilonTarget(input, config, trans, configs, speculative, treatEOFAsEpsilon)
+		if cfg != nil {
+			currentAltReachedAcceptState = l.closure(input, cfg, configs,
+				currentAltReachedAcceptState, speculative, treatEOFAsEpsilon)
+		}
+	}
+	return currentAltReachedAcceptState
+}
+
+// side-effect: can alter configs.hasSemanticContext
+func (l *LexerATNSimulator) getEpsilonTarget(input CharStream, config *LexerATNConfig, trans Transition,
+	configs ATNConfigSet, speculative, treatEOFAsEpsilon bool) *LexerATNConfig {
+
+	var cfg *LexerATNConfig
+
+	if trans.getSerializationType() == TransitionRULE {
+
+		rt := trans.(*RuleTransition)
+		newContext := SingletonBasePredictionContextCreate(config.context, rt.followState.GetStateNumber())
+		cfg = NewLexerATNConfig2(config, trans.getTarget(), newContext)
+
+	} else if trans.getSerializationType() == TransitionPRECEDENCE {
+		panic("Precedence predicates are not supported in lexers.")
+	} else if trans.getSerializationType() == TransitionPREDICATE {
+		// Track traversing semantic predicates. If we traverse,
+		// we cannot add a DFA state for l "reach" computation
+		// because the DFA would not test the predicate again in the
+		// future. Rather than creating collections of semantic predicates
+		// like v3 and testing them on prediction, v4 will test them on the
+		// fly all the time using the ATN not the DFA. This is slower but
+		// semantically it's not used that often. One of the key elements to
+		// l predicate mechanism is not adding DFA states that see
+		// predicates immediately afterwards in the ATN. For example,
+
+		// a : ID {p1}? | ID {p2}?
+
+		// should create the start state for rule 'a' (to save start state
+		// competition), but should not create target of ID state. The
+		// collection of ATN states the following ID references includes
+		// states reached by traversing predicates. Since l is when we
+		// test them, we cannot cash the DFA state target of ID.
+
+		pt := trans.(*PredicateTransition)
+
+		if LexerATNSimulatorDebug {
+			fmt.Println("EVAL rule " + strconv.Itoa(trans.(*PredicateTransition).ruleIndex) + ":" + strconv.Itoa(pt.predIndex))
+		}
+		configs.SetHasSemanticContext(true)
+		if l.evaluatePredicate(input, pt.ruleIndex, pt.predIndex, speculative) {
+			cfg = NewLexerATNConfig4(config, trans.getTarget())
+		}
+	} else if trans.getSerializationType() == TransitionACTION {
+		if config.context == nil || config.context.hasEmptyPath() {
+			// execute actions anywhere in the start rule for a token.
+			//
+			// TODO: if the entry rule is invoked recursively, some
+			// actions may be executed during the recursive call. The
+			// problem can appear when hasEmptyPath() is true but
+			// isEmpty() is false. In l case, the config needs to be
+			// split into two contexts - one with just the empty path
+			// and another with everything but the empty path.
+			// Unfortunately, the current algorithm does not allow
+			// getEpsilonTarget to return two configurations, so
+			// additional modifications are needed before we can support
+			// the split operation.
+			lexerActionExecutor := LexerActionExecutorappend(config.lexerActionExecutor, l.atn.lexerActions[trans.(*ActionTransition).actionIndex])
+			cfg = NewLexerATNConfig3(config, trans.getTarget(), lexerActionExecutor)
+		} else {
+			// ignore actions in referenced rules
+			cfg = NewLexerATNConfig4(config, trans.getTarget())
+		}
+	} else if trans.getSerializationType() == TransitionEPSILON {
+		cfg = NewLexerATNConfig4(config, trans.getTarget())
+	} else if trans.getSerializationType() == TransitionATOM ||
+		trans.getSerializationType() == TransitionRANGE ||
+		trans.getSerializationType() == TransitionSET {
+		if treatEOFAsEpsilon {
+			if trans.Matches(TokenEOF, 0, LexerMaxCharValue) {
+				cfg = NewLexerATNConfig4(config, trans.getTarget())
+			}
+		}
+	}
+	return cfg
+}
+
+// Evaluate a predicate specified in the lexer.
+//
+// <p>If {@code speculative} is {@code true}, l method was called before
+// {@link //consume} for the Matched character. This method should call
+// {@link //consume} before evaluating the predicate to ensure position
+// sensitive values, including {@link Lexer//GetText}, {@link Lexer//GetLine},
+// and {@link Lexer//getcolumn}, properly reflect the current
+// lexer state. This method should restore {@code input} and the simulator
+// to the original state before returning (i.e. undo the actions made by the
+// call to {@link //consume}.</p>
+//
+// @param input The input stream.
+// @param ruleIndex The rule containing the predicate.
+// @param predIndex The index of the predicate within the rule.
+// @param speculative {@code true} if the current index in {@code input} is
+// one character before the predicate's location.
+//
+// @return {@code true} if the specified predicate evaluates to
+// {@code true}.
+// /
+func (l *LexerATNSimulator) evaluatePredicate(input CharStream, ruleIndex, predIndex int, speculative bool) bool {
+	// assume true if no recognizer was provided
+	if l.recog == nil {
+		return true
+	}
+	if !speculative {
+		return l.recog.Sempred(nil, ruleIndex, predIndex)
+	}
+	savedcolumn := l.CharPositionInLine
+	savedLine := l.Line
+	index := input.Index()
+	marker := input.Mark()
+
+	defer func() {
+		l.CharPositionInLine = savedcolumn
+		l.Line = savedLine
+		input.Seek(index)
+		input.Release(marker)
+	}()
+
+	l.Consume(input)
+	return l.recog.Sempred(nil, ruleIndex, predIndex)
+}
+
+func (l *LexerATNSimulator) captureSimState(settings *SimState, input CharStream, dfaState *DFAState) {
+	settings.index = input.Index()
+	settings.line = l.Line
+	settings.column = l.CharPositionInLine
+	settings.dfaState = dfaState
+}
+
+func (l *LexerATNSimulator) addDFAEdge(from *DFAState, tk int, to *DFAState, cfgs ATNConfigSet) *DFAState {
+	if to == nil && cfgs != nil {
+		// leading to l call, ATNConfigSet.hasSemanticContext is used as a
+		// marker indicating dynamic predicate evaluation makes l edge
+		// dependent on the specific input sequence, so the static edge in the
+		// DFA should be omitted. The target DFAState is still created since
+		// execATN has the ability to reSynchronize with the DFA state cache
+		// following the predicate evaluation step.
+		//
+		// TJP notes: next time through the DFA, we see a pred again and eval.
+		// If that gets us to a previously created (but dangling) DFA
+		// state, we can continue in pure DFA mode from there.
+		// /
+		suppressEdge := cfgs.HasSemanticContext()
+		cfgs.SetHasSemanticContext(false)
+
+		to = l.addDFAState(cfgs)
+
+		if suppressEdge {
+			return to
+		}
+	}
+	// add the edge
+	if tk < LexerATNSimulatorMinDFAEdge || tk > LexerATNSimulatorMaxDFAEdge {
+		// Only track edges within the DFA bounds
+		return to
+	}
+	if LexerATNSimulatorDebug {
+		fmt.Println("EDGE " + from.String() + " -> " + to.String() + " upon " + strconv.Itoa(tk))
+	}
+	if from.getEdges() == nil {
+		// make room for tokens 1..n and -1 masquerading as index 0
+		from.setEdges(make([]*DFAState, LexerATNSimulatorMaxDFAEdge-LexerATNSimulatorMinDFAEdge+1))
+	}
+	from.setIthEdge(tk-LexerATNSimulatorMinDFAEdge, to) // connect
+
+	return to
+}
+
+// Add a NewDFA state if there isn't one with l set of
+// configurations already. This method also detects the first
+// configuration containing an ATN rule stop state. Later, when
+// traversing the DFA, we will know which rule to accept.
+func (l *LexerATNSimulator) addDFAState(configs ATNConfigSet) *DFAState {
+
+	proposed := NewDFAState(-1, configs)
+	var firstConfigWithRuleStopState ATNConfig
+
+	for _, cfg := range configs.GetItems() {
+
+		_, ok := cfg.GetState().(*RuleStopState)
+
+		if ok {
+			firstConfigWithRuleStopState = cfg
+			break
+		}
+	}
+	if firstConfigWithRuleStopState != nil {
+		proposed.isAcceptState = true
+		proposed.lexerActionExecutor = firstConfigWithRuleStopState.(*LexerATNConfig).lexerActionExecutor
+		proposed.setPrediction(l.atn.ruleToTokenType[firstConfigWithRuleStopState.GetState().GetRuleIndex()])
+	}
+	hash := proposed.hash()
+	dfa := l.decisionToDFA[l.mode]
+	existing, ok := dfa.getState(hash)
+	if ok {
+		return existing
+	}
+	newState := proposed
+	newState.stateNumber = dfa.numStates()
+	configs.SetReadOnly(true)
+	newState.configs = configs
+	dfa.setState(hash, newState)
+	return newState
+}
+
+func (l *LexerATNSimulator) getDFA(mode int) *DFA {
+	return l.decisionToDFA[mode]
+}
+
+// Get the text Matched so far for the current token.
+func (l *LexerATNSimulator) GetText(input CharStream) string {
+	// index is first lookahead char, don't include.
+	return input.GetTextFromInterval(NewInterval(l.startIndex, input.Index()-1))
+}
+
+func (l *LexerATNSimulator) Consume(input CharStream) {
+	curChar := input.LA(1)
+	if curChar == int('\n') {
+		l.Line++
+		l.CharPositionInLine = 0
+	} else {
+		l.CharPositionInLine++
+	}
+	input.Consume()
+}
+
+func (l *LexerATNSimulator) GetCharPositionInLine() int {
+	return l.CharPositionInLine
+}
+
+func (l *LexerATNSimulator) GetLine() int {
+	return l.Line
+}
+
+func (l *LexerATNSimulator) GetTokenName(tt int) string {
+	if tt == -1 {
+		return "EOF"
+	}
+
+	return "'" + string(tt) + "'"
+}
+
+func resetSimState(sim *SimState) {
+	sim.index = -1
+	sim.line = 0
+	sim.column = -1
+	sim.dfaState = nil
+}
+
+type SimState struct {
+	index    int
+	line     int
+	column   int
+	dfaState *DFAState
+}
+
+func NewSimState() *SimState {
+	s := new(SimState)
+	resetSimState(s)
+	return s
+}
+
+func (s *SimState) reset() {
+	resetSimState(s)
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/ll1_analyzer.go

@@ -0,0 +1,212 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+type LL1Analyzer struct {
+	atn *ATN
+}
+
+func NewLL1Analyzer(atn *ATN) *LL1Analyzer {
+	la := new(LL1Analyzer)
+	la.atn = atn
+	return la
+}
+
+//* Special value added to the lookahead sets to indicate that we hit
+//  a predicate during analysis if {@code seeThruPreds==false}.
+///
+const (
+	LL1AnalyzerHitPred = TokenInvalidType
+)
+
+//*
+// Calculates the SLL(1) expected lookahead set for each outgoing transition
+// of an {@link ATNState}. The returned array has one element for each
+// outgoing transition in {@code s}. If the closure from transition
+// <em>i</em> leads to a semantic predicate before Matching a symbol, the
+// element at index <em>i</em> of the result will be {@code nil}.
+//
+// @param s the ATN state
+// @return the expected symbols for each outgoing transition of {@code s}.
+func (la *LL1Analyzer) getDecisionLookahead(s ATNState) []*IntervalSet {
+	if s == nil {
+		return nil
+	}
+	count := len(s.GetTransitions())
+	look := make([]*IntervalSet, count)
+	for alt := 0; alt < count; alt++ {
+		look[alt] = NewIntervalSet()
+		lookBusy := NewSet(nil, nil)
+		seeThruPreds := false // fail to get lookahead upon pred
+		la.look1(s.GetTransitions()[alt].getTarget(), nil, BasePredictionContextEMPTY, look[alt], lookBusy, NewBitSet(), seeThruPreds, false)
+		// Wipe out lookahead for la alternative if we found nothing
+		// or we had a predicate when we !seeThruPreds
+		if look[alt].length() == 0 || look[alt].contains(LL1AnalyzerHitPred) {
+			look[alt] = nil
+		}
+	}
+	return look
+}
+
+//*
+// Compute set of tokens that can follow {@code s} in the ATN in the
+// specified {@code ctx}.
+//
+// <p>If {@code ctx} is {@code nil} and the end of the rule containing
+// {@code s} is reached, {@link Token//EPSILON} is added to the result set.
+// If {@code ctx} is not {@code nil} and the end of the outermost rule is
+// reached, {@link Token//EOF} is added to the result set.</p>
+//
+// @param s the ATN state
+// @param stopState the ATN state to stop at. This can be a
+// {@link BlockEndState} to detect epsilon paths through a closure.
+// @param ctx the complete parser context, or {@code nil} if the context
+// should be ignored
+//
+// @return The set of tokens that can follow {@code s} in the ATN in the
+// specified {@code ctx}.
+///
+func (la *LL1Analyzer) Look(s, stopState ATNState, ctx RuleContext) *IntervalSet {
+	r := NewIntervalSet()
+	seeThruPreds := true // ignore preds get all lookahead
+	var lookContext PredictionContext
+	if ctx != nil {
+		lookContext = predictionContextFromRuleContext(s.GetATN(), ctx)
+	}
+	la.look1(s, stopState, lookContext, r, NewSet(nil, nil), NewBitSet(), seeThruPreds, true)
+	return r
+}
+
+//*
+// Compute set of tokens that can follow {@code s} in the ATN in the
+// specified {@code ctx}.
+//
+// <p>If {@code ctx} is {@code nil} and {@code stopState} or the end of the
+// rule containing {@code s} is reached, {@link Token//EPSILON} is added to
+// the result set. If {@code ctx} is not {@code nil} and {@code addEOF} is
+// {@code true} and {@code stopState} or the end of the outermost rule is
+// reached, {@link Token//EOF} is added to the result set.</p>
+//
+// @param s the ATN state.
+// @param stopState the ATN state to stop at. This can be a
+// {@link BlockEndState} to detect epsilon paths through a closure.
+// @param ctx The outer context, or {@code nil} if the outer context should
+// not be used.
+// @param look The result lookahead set.
+// @param lookBusy A set used for preventing epsilon closures in the ATN
+// from causing a stack overflow. Outside code should pass
+// {@code NewSet<ATNConfig>} for la argument.
+// @param calledRuleStack A set used for preventing left recursion in the
+// ATN from causing a stack overflow. Outside code should pass
+// {@code NewBitSet()} for la argument.
+// @param seeThruPreds {@code true} to true semantic predicates as
+// implicitly {@code true} and "see through them", otherwise {@code false}
+// to treat semantic predicates as opaque and add {@link //HitPred} to the
+// result if one is encountered.
+// @param addEOF Add {@link Token//EOF} to the result if the end of the
+// outermost context is reached. This parameter has no effect if {@code ctx}
+// is {@code nil}.
+
+func (la *LL1Analyzer) look2(s, stopState ATNState, ctx PredictionContext, look *IntervalSet, lookBusy *Set, calledRuleStack *BitSet, seeThruPreds, addEOF bool, i int) {
+
+	returnState := la.atn.states[ctx.getReturnState(i)]
+	la.look1(returnState, stopState, ctx.GetParent(i), look, lookBusy, calledRuleStack, seeThruPreds, addEOF)
+
+}
+
+func (la *LL1Analyzer) look1(s, stopState ATNState, ctx PredictionContext, look *IntervalSet, lookBusy *Set, calledRuleStack *BitSet, seeThruPreds, addEOF bool) {
+
+	c := NewBaseATNConfig6(s, 0, ctx)
+
+	if lookBusy.contains(c) {
+		return
+	}
+
+	lookBusy.add(c)
+
+	if s == stopState {
+		if ctx == nil {
+			look.addOne(TokenEpsilon)
+			return
+		} else if ctx.isEmpty() && addEOF {
+			look.addOne(TokenEOF)
+			return
+		}
+	}
+
+	_, ok := s.(*RuleStopState)
+
+	if ok {
+		if ctx == nil {
+			look.addOne(TokenEpsilon)
+			return
+		} else if ctx.isEmpty() && addEOF {
+			look.addOne(TokenEOF)
+			return
+		}
+
+		if ctx != BasePredictionContextEMPTY {
+	        removed := calledRuleStack.contains(s.GetRuleIndex())
+            defer func() {
+                if removed {
+                    calledRuleStack.add(s.GetRuleIndex())
+                }
+            }()
+        	calledRuleStack.remove(s.GetRuleIndex())
+			// run thru all possible stack tops in ctx
+			for i := 0; i < ctx.length(); i++ {
+				returnState := la.atn.states[ctx.getReturnState(i)]
+				la.look2(returnState, stopState, ctx, look, lookBusy, calledRuleStack, seeThruPreds, addEOF, i)
+			}
+			return
+		}
+	}
+
+	n := len(s.GetTransitions())
+
+	for i := 0; i < n; i++ {
+		t := s.GetTransitions()[i]
+
+		if t1, ok := t.(*RuleTransition); ok {
+			if calledRuleStack.contains(t1.getTarget().GetRuleIndex()) {
+				continue
+			}
+
+			newContext := SingletonBasePredictionContextCreate(ctx, t1.followState.GetStateNumber())
+			la.look3(stopState, newContext, look, lookBusy, calledRuleStack, seeThruPreds, addEOF, t1)
+		} else if t2, ok := t.(AbstractPredicateTransition); ok {
+			if seeThruPreds {
+				la.look1(t2.getTarget(), stopState, ctx, look, lookBusy, calledRuleStack, seeThruPreds, addEOF)
+			} else {
+				look.addOne(LL1AnalyzerHitPred)
+			}
+		} else if t.getIsEpsilon() {
+			la.look1(t.getTarget(), stopState, ctx, look, lookBusy, calledRuleStack, seeThruPreds, addEOF)
+		} else if _, ok := t.(*WildcardTransition); ok {
+			look.addRange(TokenMinUserTokenType, la.atn.maxTokenType)
+		} else {
+			set := t.getLabel()
+			if set != nil {
+				if _, ok := t.(*NotSetTransition); ok {
+					set = set.complement(TokenMinUserTokenType, la.atn.maxTokenType)
+				}
+				look.addSet(set)
+			}
+		}
+	}
+}
+
+func (la *LL1Analyzer) look3(stopState ATNState, ctx PredictionContext, look *IntervalSet, lookBusy *Set, calledRuleStack *BitSet, seeThruPreds, addEOF bool, t1 *RuleTransition) {
+
+	newContext := SingletonBasePredictionContextCreate(ctx, t1.followState.GetStateNumber())
+
+	defer func() {
+		calledRuleStack.remove(t1.getTarget().GetRuleIndex())
+	}()
+
+	calledRuleStack.add(t1.getTarget().GetRuleIndex())
+	la.look1(t1.getTarget(), stopState, newContext, look, lookBusy, calledRuleStack, seeThruPreds, addEOF)
+
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/parser.go

@@ -0,0 +1,718 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type Parser interface {
+	Recognizer
+
+	GetInterpreter() *ParserATNSimulator
+
+	GetTokenStream() TokenStream
+	GetTokenFactory() TokenFactory
+	GetParserRuleContext() ParserRuleContext
+	SetParserRuleContext(ParserRuleContext)
+	Consume() Token
+	GetParseListeners() []ParseTreeListener
+
+	GetErrorHandler() ErrorStrategy
+	SetErrorHandler(ErrorStrategy)
+	GetInputStream() IntStream
+	GetCurrentToken() Token
+	GetExpectedTokens() *IntervalSet
+	NotifyErrorListeners(string, Token, RecognitionException)
+	IsExpectedToken(int) bool
+	GetPrecedence() int
+	GetRuleInvocationStack(ParserRuleContext) []string
+}
+
+type BaseParser struct {
+	*BaseRecognizer
+
+	Interpreter     *ParserATNSimulator
+	BuildParseTrees bool
+
+	input           TokenStream
+	errHandler      ErrorStrategy
+	precedenceStack IntStack
+	ctx             ParserRuleContext
+
+	tracer         *TraceListener
+	parseListeners []ParseTreeListener
+	_SyntaxErrors  int
+}
+
+// p.is all the parsing support code essentially most of it is error
+// recovery stuff.//
+func NewBaseParser(input TokenStream) *BaseParser {
+
+	p := new(BaseParser)
+
+	p.BaseRecognizer = NewBaseRecognizer()
+
+	// The input stream.
+	p.input = nil
+	// The error handling strategy for the parser. The default value is a new
+	// instance of {@link DefaultErrorStrategy}.
+	p.errHandler = NewDefaultErrorStrategy()
+	p.precedenceStack = make([]int, 0)
+	p.precedenceStack.Push(0)
+	// The {@link ParserRuleContext} object for the currently executing rule.
+	// p.is always non-nil during the parsing process.
+	p.ctx = nil
+	// Specifies whether or not the parser should construct a parse tree during
+	// the parsing process. The default value is {@code true}.
+	p.BuildParseTrees = true
+	// When {@link //setTrace}{@code (true)} is called, a reference to the
+	// {@link TraceListener} is stored here so it can be easily removed in a
+	// later call to {@link //setTrace}{@code (false)}. The listener itself is
+	// implemented as a parser listener so p.field is not directly used by
+	// other parser methods.
+	p.tracer = nil
+	// The list of {@link ParseTreeListener} listeners registered to receive
+	// events during the parse.
+	p.parseListeners = nil
+	// The number of syntax errors Reported during parsing. p.value is
+	// incremented each time {@link //NotifyErrorListeners} is called.
+	p._SyntaxErrors = 0
+	p.SetInputStream(input)
+
+	return p
+}
+
+// p.field maps from the serialized ATN string to the deserialized {@link
+// ATN} with
+// bypass alternatives.
+//
+// @see ATNDeserializationOptions//isGenerateRuleBypassTransitions()
+//
+var bypassAltsAtnCache = make(map[string]int)
+
+// reset the parser's state//
+func (p *BaseParser) reset() {
+	if p.input != nil {
+		p.input.Seek(0)
+	}
+	p.errHandler.reset(p)
+	p.ctx = nil
+	p._SyntaxErrors = 0
+	p.SetTrace(nil)
+	p.precedenceStack = make([]int, 0)
+	p.precedenceStack.Push(0)
+	if p.Interpreter != nil {
+		p.Interpreter.reset()
+	}
+}
+
+func (p *BaseParser) GetErrorHandler() ErrorStrategy {
+	return p.errHandler
+}
+
+func (p *BaseParser) SetErrorHandler(e ErrorStrategy) {
+	p.errHandler = e
+}
+
+// Match current input symbol against {@code ttype}. If the symbol type
+// Matches, {@link ANTLRErrorStrategy//ReportMatch} and {@link //consume} are
+// called to complete the Match process.
+//
+// <p>If the symbol type does not Match,
+// {@link ANTLRErrorStrategy//recoverInline} is called on the current error
+// strategy to attempt recovery. If {@link //getBuildParseTree} is
+// {@code true} and the token index of the symbol returned by
+// {@link ANTLRErrorStrategy//recoverInline} is -1, the symbol is added to
+// the parse tree by calling {@link ParserRuleContext//addErrorNode}.</p>
+//
+// @param ttype the token type to Match
+// @return the Matched symbol
+// @panics RecognitionException if the current input symbol did not Match
+// {@code ttype} and the error strategy could not recover from the
+// mismatched symbol
+
+func (p *BaseParser) Match(ttype int) Token {
+
+	t := p.GetCurrentToken()
+
+	if t.GetTokenType() == ttype {
+		p.errHandler.ReportMatch(p)
+		p.Consume()
+	} else {
+		t = p.errHandler.RecoverInline(p)
+		if p.BuildParseTrees && t.GetTokenIndex() == -1 {
+			// we must have conjured up a Newtoken during single token
+			// insertion
+			// if it's not the current symbol
+			p.ctx.AddErrorNode(t)
+		}
+	}
+
+	return t
+}
+
+// Match current input symbol as a wildcard. If the symbol type Matches
+// (i.e. has a value greater than 0), {@link ANTLRErrorStrategy//ReportMatch}
+// and {@link //consume} are called to complete the Match process.
+//
+// <p>If the symbol type does not Match,
+// {@link ANTLRErrorStrategy//recoverInline} is called on the current error
+// strategy to attempt recovery. If {@link //getBuildParseTree} is
+// {@code true} and the token index of the symbol returned by
+// {@link ANTLRErrorStrategy//recoverInline} is -1, the symbol is added to
+// the parse tree by calling {@link ParserRuleContext//addErrorNode}.</p>
+//
+// @return the Matched symbol
+// @panics RecognitionException if the current input symbol did not Match
+// a wildcard and the error strategy could not recover from the mismatched
+// symbol
+
+func (p *BaseParser) MatchWildcard() Token {
+	t := p.GetCurrentToken()
+	if t.GetTokenType() > 0 {
+		p.errHandler.ReportMatch(p)
+		p.Consume()
+	} else {
+		t = p.errHandler.RecoverInline(p)
+		if p.BuildParseTrees && t.GetTokenIndex() == -1 {
+			// we must have conjured up a Newtoken during single token
+			// insertion
+			// if it's not the current symbol
+			p.ctx.AddErrorNode(t)
+		}
+	}
+	return t
+}
+
+func (p *BaseParser) GetParserRuleContext() ParserRuleContext {
+	return p.ctx
+}
+
+func (p *BaseParser) SetParserRuleContext(v ParserRuleContext) {
+	p.ctx = v
+}
+
+func (p *BaseParser) GetParseListeners() []ParseTreeListener {
+	if p.parseListeners == nil {
+		return make([]ParseTreeListener, 0)
+	}
+	return p.parseListeners
+}
+
+// Registers {@code listener} to receive events during the parsing process.
+//
+// <p>To support output-preserving grammar transformations (including but not
+// limited to left-recursion removal, automated left-factoring, and
+// optimized code generation), calls to listener methods during the parse
+// may differ substantially from calls made by
+// {@link ParseTreeWalker//DEFAULT} used after the parse is complete. In
+// particular, rule entry and exit events may occur in a different order
+// during the parse than after the parser. In addition, calls to certain
+// rule entry methods may be omitted.</p>
+//
+// <p>With the following specific exceptions, calls to listener events are
+// <em>deterministic</em>, i.e. for identical input the calls to listener
+// methods will be the same.</p>
+//
+// <ul>
+// <li>Alterations to the grammar used to generate code may change the
+// behavior of the listener calls.</li>
+// <li>Alterations to the command line options passed to ANTLR 4 when
+// generating the parser may change the behavior of the listener calls.</li>
+// <li>Changing the version of the ANTLR Tool used to generate the parser
+// may change the behavior of the listener calls.</li>
+// </ul>
+//
+// @param listener the listener to add
+//
+// @panics nilPointerException if {@code} listener is {@code nil}
+//
+func (p *BaseParser) AddParseListener(listener ParseTreeListener) {
+	if listener == nil {
+		panic("listener")
+	}
+	if p.parseListeners == nil {
+		p.parseListeners = make([]ParseTreeListener, 0)
+	}
+	p.parseListeners = append(p.parseListeners, listener)
+}
+
+//
+// Remove {@code listener} from the list of parse listeners.
+//
+// <p>If {@code listener} is {@code nil} or has not been added as a parse
+// listener, p.method does nothing.</p>
+// @param listener the listener to remove
+//
+func (p *BaseParser) RemoveParseListener(listener ParseTreeListener) {
+
+	if p.parseListeners != nil {
+
+		idx := -1
+		for i, v := range p.parseListeners {
+			if v == listener {
+				idx = i
+				break
+			}
+		}
+
+		if idx == -1 {
+			return
+		}
+
+		// remove the listener from the slice
+		p.parseListeners = append(p.parseListeners[0:idx], p.parseListeners[idx+1:]...)
+
+		if len(p.parseListeners) == 0 {
+			p.parseListeners = nil
+		}
+	}
+}
+
+// Remove all parse listeners.
+func (p *BaseParser) removeParseListeners() {
+	p.parseListeners = nil
+}
+
+// Notify any parse listeners of an enter rule event.
+func (p *BaseParser) TriggerEnterRuleEvent() {
+	if p.parseListeners != nil {
+		ctx := p.ctx
+		for _, listener := range p.parseListeners {
+			listener.EnterEveryRule(ctx)
+			ctx.EnterRule(listener)
+		}
+	}
+}
+
+//
+// Notify any parse listeners of an exit rule event.
+//
+// @see //addParseListener
+//
+func (p *BaseParser) TriggerExitRuleEvent() {
+	if p.parseListeners != nil {
+		// reverse order walk of listeners
+		ctx := p.ctx
+		l := len(p.parseListeners) - 1
+
+		for i := range p.parseListeners {
+			listener := p.parseListeners[l-i]
+			ctx.ExitRule(listener)
+			listener.ExitEveryRule(ctx)
+		}
+	}
+}
+
+func (p *BaseParser) GetInterpreter() *ParserATNSimulator {
+	return p.Interpreter
+}
+
+func (p *BaseParser) GetATN() *ATN {
+	return p.Interpreter.atn
+}
+
+func (p *BaseParser) GetTokenFactory() TokenFactory {
+	return p.input.GetTokenSource().GetTokenFactory()
+}
+
+// Tell our token source and error strategy about a Newway to create tokens.//
+func (p *BaseParser) setTokenFactory(factory TokenFactory) {
+	p.input.GetTokenSource().setTokenFactory(factory)
+}
+
+// The ATN with bypass alternatives is expensive to create so we create it
+// lazily.
+//
+// @panics UnsupportedOperationException if the current parser does not
+// implement the {@link //getSerializedATN()} method.
+//
+func (p *BaseParser) GetATNWithBypassAlts() {
+
+	// TODO
+	panic("Not implemented!")
+
+	//	serializedAtn := p.getSerializedATN()
+	//	if (serializedAtn == nil) {
+	//		panic("The current parser does not support an ATN with bypass alternatives.")
+	//	}
+	//	result := p.bypassAltsAtnCache[serializedAtn]
+	//	if (result == nil) {
+	//		deserializationOptions := NewATNDeserializationOptions(nil)
+	//		deserializationOptions.generateRuleBypassTransitions = true
+	//		result = NewATNDeserializer(deserializationOptions).deserialize(serializedAtn)
+	//		p.bypassAltsAtnCache[serializedAtn] = result
+	//	}
+	//	return result
+}
+
+// The preferred method of getting a tree pattern. For example, here's a
+// sample use:
+//
+// <pre>
+// ParseTree t = parser.expr()
+// ParseTreePattern p = parser.compileParseTreePattern("&ltID&gt+0",
+// MyParser.RULE_expr)
+// ParseTreeMatch m = p.Match(t)
+// String id = m.Get("ID")
+// </pre>
+
+func (p *BaseParser) compileParseTreePattern(pattern, patternRuleIndex, lexer Lexer) {
+
+	panic("NewParseTreePatternMatcher not implemented!")
+	//
+	//	if (lexer == nil) {
+	//		if (p.GetTokenStream() != nil) {
+	//			tokenSource := p.GetTokenStream().GetTokenSource()
+	//			if _, ok := tokenSource.(ILexer); ok {
+	//				lexer = tokenSource
+	//			}
+	//		}
+	//	}
+	//	if (lexer == nil) {
+	//		panic("Parser can't discover a lexer to use")
+	//	}
+
+	//	m := NewParseTreePatternMatcher(lexer, p)
+	//	return m.compile(pattern, patternRuleIndex)
+}
+
+func (p *BaseParser) GetInputStream() IntStream {
+	return p.GetTokenStream()
+}
+
+func (p *BaseParser) SetInputStream(input TokenStream) {
+	p.SetTokenStream(input)
+}
+
+func (p *BaseParser) GetTokenStream() TokenStream {
+	return p.input
+}
+
+// Set the token stream and reset the parser.//
+func (p *BaseParser) SetTokenStream(input TokenStream) {
+	p.input = nil
+	p.reset()
+	p.input = input
+}
+
+// Match needs to return the current input symbol, which gets put
+// into the label for the associated token ref e.g., x=ID.
+//
+func (p *BaseParser) GetCurrentToken() Token {
+	return p.input.LT(1)
+}
+
+func (p *BaseParser) NotifyErrorListeners(msg string, offendingToken Token, err RecognitionException) {
+	if offendingToken == nil {
+		offendingToken = p.GetCurrentToken()
+	}
+	p._SyntaxErrors++
+	line := offendingToken.GetLine()
+	column := offendingToken.GetColumn()
+	listener := p.GetErrorListenerDispatch()
+	listener.SyntaxError(p, offendingToken, line, column, msg, err)
+}
+
+func (p *BaseParser) Consume() Token {
+	o := p.GetCurrentToken()
+	if o.GetTokenType() != TokenEOF {
+		p.GetInputStream().Consume()
+	}
+	hasListener := p.parseListeners != nil && len(p.parseListeners) > 0
+	if p.BuildParseTrees || hasListener {
+		if p.errHandler.inErrorRecoveryMode(p) {
+			node := p.ctx.AddErrorNode(o)
+			if p.parseListeners != nil {
+				for _, l := range p.parseListeners {
+					l.VisitErrorNode(node)
+				}
+			}
+
+		} else {
+			node := p.ctx.AddTokenNode(o)
+			if p.parseListeners != nil {
+				for _, l := range p.parseListeners {
+					l.VisitTerminal(node)
+				}
+			}
+		}
+		//        node.invokingState = p.state
+	}
+
+	return o
+}
+
+func (p *BaseParser) addContextToParseTree() {
+	// add current context to parent if we have a parent
+	if p.ctx.GetParent() != nil {
+		p.ctx.GetParent().(ParserRuleContext).AddChild(p.ctx)
+	}
+}
+
+func (p *BaseParser) EnterRule(localctx ParserRuleContext, state, ruleIndex int) {
+	p.SetState(state)
+	p.ctx = localctx
+	p.ctx.SetStart(p.input.LT(1))
+	if p.BuildParseTrees {
+		p.addContextToParseTree()
+	}
+	if p.parseListeners != nil {
+		p.TriggerEnterRuleEvent()
+	}
+}
+
+func (p *BaseParser) ExitRule() {
+	p.ctx.SetStop(p.input.LT(-1))
+	// trigger event on ctx, before it reverts to parent
+	if p.parseListeners != nil {
+		p.TriggerExitRuleEvent()
+	}
+	p.SetState(p.ctx.GetInvokingState())
+	if p.ctx.GetParent() != nil {
+		p.ctx = p.ctx.GetParent().(ParserRuleContext)
+	} else {
+		p.ctx = nil
+	}
+}
+
+func (p *BaseParser) EnterOuterAlt(localctx ParserRuleContext, altNum int) {
+	localctx.SetAltNumber(altNum)
+	// if we have Newlocalctx, make sure we replace existing ctx
+	// that is previous child of parse tree
+	if p.BuildParseTrees && p.ctx != localctx {
+		if p.ctx.GetParent() != nil {
+			p.ctx.GetParent().(ParserRuleContext).RemoveLastChild()
+			p.ctx.GetParent().(ParserRuleContext).AddChild(localctx)
+		}
+	}
+	p.ctx = localctx
+}
+
+// Get the precedence level for the top-most precedence rule.
+//
+// @return The precedence level for the top-most precedence rule, or -1 if
+// the parser context is not nested within a precedence rule.
+
+func (p *BaseParser) GetPrecedence() int {
+	if len(p.precedenceStack) == 0 {
+		return -1
+	}
+
+	return p.precedenceStack[len(p.precedenceStack)-1]
+}
+
+func (p *BaseParser) EnterRecursionRule(localctx ParserRuleContext, state, ruleIndex, precedence int) {
+	p.SetState(state)
+	p.precedenceStack.Push(precedence)
+	p.ctx = localctx
+	p.ctx.SetStart(p.input.LT(1))
+	if p.parseListeners != nil {
+		p.TriggerEnterRuleEvent() // simulates rule entry for
+		// left-recursive rules
+	}
+}
+
+//
+// Like {@link //EnterRule} but for recursive rules.
+
+func (p *BaseParser) PushNewRecursionContext(localctx ParserRuleContext, state, ruleIndex int) {
+	previous := p.ctx
+	previous.SetParent(localctx)
+	previous.SetInvokingState(state)
+	previous.SetStop(p.input.LT(-1))
+
+	p.ctx = localctx
+	p.ctx.SetStart(previous.GetStart())
+	if p.BuildParseTrees {
+		p.ctx.AddChild(previous)
+	}
+	if p.parseListeners != nil {
+		p.TriggerEnterRuleEvent() // simulates rule entry for
+		// left-recursive rules
+	}
+}
+
+func (p *BaseParser) UnrollRecursionContexts(parentCtx ParserRuleContext) {
+	p.precedenceStack.Pop()
+	p.ctx.SetStop(p.input.LT(-1))
+	retCtx := p.ctx // save current ctx (return value)
+	// unroll so ctx is as it was before call to recursive method
+	if p.parseListeners != nil {
+		for p.ctx != parentCtx {
+			p.TriggerExitRuleEvent()
+			p.ctx = p.ctx.GetParent().(ParserRuleContext)
+		}
+	} else {
+		p.ctx = parentCtx
+	}
+	// hook into tree
+	retCtx.SetParent(parentCtx)
+	if p.BuildParseTrees && parentCtx != nil {
+		// add return ctx into invoking rule's tree
+		parentCtx.AddChild(retCtx)
+	}
+}
+
+func (p *BaseParser) GetInvokingContext(ruleIndex int) ParserRuleContext {
+	ctx := p.ctx
+	for ctx != nil {
+		if ctx.GetRuleIndex() == ruleIndex {
+			return ctx
+		}
+		ctx = ctx.GetParent().(ParserRuleContext)
+	}
+	return nil
+}
+
+func (p *BaseParser) Precpred(localctx RuleContext, precedence int) bool {
+	return precedence >= p.precedenceStack[len(p.precedenceStack)-1]
+}
+
+func (p *BaseParser) inContext(context ParserRuleContext) bool {
+	// TODO: useful in parser?
+	return false
+}
+
+//
+// Checks whether or not {@code symbol} can follow the current state in the
+// ATN. The behavior of p.method is equivalent to the following, but is
+// implemented such that the complete context-sensitive follow set does not
+// need to be explicitly constructed.
+//
+// <pre>
+// return getExpectedTokens().contains(symbol)
+// </pre>
+//
+// @param symbol the symbol type to check
+// @return {@code true} if {@code symbol} can follow the current state in
+// the ATN, otherwise {@code false}.
+
+func (p *BaseParser) IsExpectedToken(symbol int) bool {
+	atn := p.Interpreter.atn
+	ctx := p.ctx
+	s := atn.states[p.state]
+	following := atn.NextTokens(s, nil)
+	if following.contains(symbol) {
+		return true
+	}
+	if !following.contains(TokenEpsilon) {
+		return false
+	}
+	for ctx != nil && ctx.GetInvokingState() >= 0 && following.contains(TokenEpsilon) {
+		invokingState := atn.states[ctx.GetInvokingState()]
+		rt := invokingState.GetTransitions()[0]
+		following = atn.NextTokens(rt.(*RuleTransition).followState, nil)
+		if following.contains(symbol) {
+			return true
+		}
+		ctx = ctx.GetParent().(ParserRuleContext)
+	}
+	if following.contains(TokenEpsilon) && symbol == TokenEOF {
+		return true
+	}
+
+	return false
+}
+
+// Computes the set of input symbols which could follow the current parser
+// state and context, as given by {@link //GetState} and {@link //GetContext},
+// respectively.
+//
+// @see ATN//getExpectedTokens(int, RuleContext)
+//
+func (p *BaseParser) GetExpectedTokens() *IntervalSet {
+	return p.Interpreter.atn.getExpectedTokens(p.state, p.ctx)
+}
+
+func (p *BaseParser) GetExpectedTokensWithinCurrentRule() *IntervalSet {
+	atn := p.Interpreter.atn
+	s := atn.states[p.state]
+	return atn.NextTokens(s, nil)
+}
+
+// Get a rule's index (i.e., {@code RULE_ruleName} field) or -1 if not found.//
+func (p *BaseParser) GetRuleIndex(ruleName string) int {
+	var ruleIndex, ok = p.GetRuleIndexMap()[ruleName]
+	if ok {
+		return ruleIndex
+	}
+
+	return -1
+}
+
+// Return List&ltString&gt of the rule names in your parser instance
+// leading up to a call to the current rule. You could override if
+// you want more details such as the file/line info of where
+// in the ATN a rule is invoked.
+//
+// this very useful for error messages.
+
+func (p *BaseParser) GetRuleInvocationStack(c ParserRuleContext) []string {
+	if c == nil {
+		c = p.ctx
+	}
+	stack := make([]string, 0)
+	for c != nil {
+		// compute what follows who invoked us
+		ruleIndex := c.GetRuleIndex()
+		if ruleIndex < 0 {
+			stack = append(stack, "n/a")
+		} else {
+			stack = append(stack, p.GetRuleNames()[ruleIndex])
+		}
+
+		vp := c.GetParent()
+
+		if vp == nil {
+			break
+		}
+
+		c = vp.(ParserRuleContext)
+	}
+	return stack
+}
+
+// For debugging and other purposes.//
+func (p *BaseParser) GetDFAStrings() string {
+	return fmt.Sprint(p.Interpreter.decisionToDFA)
+}
+
+// For debugging and other purposes.//
+func (p *BaseParser) DumpDFA() {
+	seenOne := false
+	for _, dfa := range p.Interpreter.decisionToDFA {
+		if dfa.numStates() > 0 {
+			if seenOne {
+				fmt.Println()
+			}
+			fmt.Println("Decision " + strconv.Itoa(dfa.decision) + ":")
+			fmt.Print(dfa.String(p.LiteralNames, p.SymbolicNames))
+			seenOne = true
+		}
+	}
+}
+
+func (p *BaseParser) GetSourceName() string {
+	return p.GrammarFileName
+}
+
+// During a parse is sometimes useful to listen in on the rule entry and exit
+// events as well as token Matches. p.is for quick and dirty debugging.
+//
+func (p *BaseParser) SetTrace(trace *TraceListener) {
+	if trace == nil {
+		p.RemoveParseListener(p.tracer)
+		p.tracer = nil
+	} else {
+		if p.tracer != nil {
+			p.RemoveParseListener(p.tracer)
+		}
+		p.tracer = NewTraceListener(p)
+		p.AddParseListener(p.tracer)
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/parser_rule_context.go

@@ -0,0 +1,362 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"reflect"
+	"strconv"
+)
+
+type ParserRuleContext interface {
+	RuleContext
+
+	SetException(RecognitionException)
+
+	AddTokenNode(token Token) *TerminalNodeImpl
+	AddErrorNode(badToken Token) *ErrorNodeImpl
+
+	EnterRule(listener ParseTreeListener)
+	ExitRule(listener ParseTreeListener)
+
+	SetStart(Token)
+	GetStart() Token
+
+	SetStop(Token)
+	GetStop() Token
+
+	AddChild(child RuleContext) RuleContext
+	RemoveLastChild()
+}
+
+type BaseParserRuleContext struct {
+	*BaseRuleContext
+
+	start, stop Token
+	exception   RecognitionException
+	children    []Tree
+}
+
+func NewBaseParserRuleContext(parent ParserRuleContext, invokingStateNumber int) *BaseParserRuleContext {
+	prc := new(BaseParserRuleContext)
+
+	prc.BaseRuleContext = NewBaseRuleContext(parent, invokingStateNumber)
+
+	prc.RuleIndex = -1
+	// * If we are debugging or building a parse tree for a Visitor,
+	// we need to track all of the tokens and rule invocations associated
+	// with prc rule's context. This is empty for parsing w/o tree constr.
+	// operation because we don't the need to track the details about
+	// how we parse prc rule.
+	// /
+	prc.children = nil
+	prc.start = nil
+	prc.stop = nil
+	// The exception that forced prc rule to return. If the rule successfully
+	// completed, prc is {@code nil}.
+	prc.exception = nil
+
+	return prc
+}
+
+func (prc *BaseParserRuleContext) SetException(e RecognitionException) {
+	prc.exception = e
+}
+
+func (prc *BaseParserRuleContext) GetChildren() []Tree {
+	return prc.children
+}
+
+func (prc *BaseParserRuleContext) CopyFrom(ctx *BaseParserRuleContext) {
+	// from RuleContext
+	prc.parentCtx = ctx.parentCtx
+	prc.invokingState = ctx.invokingState
+	prc.children = nil
+	prc.start = ctx.start
+	prc.stop = ctx.stop
+}
+
+func (prc *BaseParserRuleContext) GetText() string {
+	if prc.GetChildCount() == 0 {
+		return ""
+	}
+
+	var s string
+	for _, child := range prc.children {
+		s += child.(ParseTree).GetText()
+	}
+
+	return s
+}
+
+// Double dispatch methods for listeners
+func (prc *BaseParserRuleContext) EnterRule(listener ParseTreeListener) {
+}
+
+func (prc *BaseParserRuleContext) ExitRule(listener ParseTreeListener) {
+}
+
+// * Does not set parent link other add methods do that///
+func (prc *BaseParserRuleContext) addTerminalNodeChild(child TerminalNode) TerminalNode {
+	if prc.children == nil {
+		prc.children = make([]Tree, 0)
+	}
+	if child == nil {
+		panic("Child may not be null")
+	}
+	prc.children = append(prc.children, child)
+	return child
+}
+
+func (prc *BaseParserRuleContext) AddChild(child RuleContext) RuleContext {
+	if prc.children == nil {
+		prc.children = make([]Tree, 0)
+	}
+	if child == nil {
+		panic("Child may not be null")
+	}
+	prc.children = append(prc.children, child)
+	return child
+}
+
+// * Used by EnterOuterAlt to toss out a RuleContext previously added as
+// we entered a rule. If we have // label, we will need to remove
+// generic ruleContext object.
+// /
+func (prc *BaseParserRuleContext) RemoveLastChild() {
+	if prc.children != nil && len(prc.children) > 0 {
+		prc.children = prc.children[0 : len(prc.children)-1]
+	}
+}
+
+func (prc *BaseParserRuleContext) AddTokenNode(token Token) *TerminalNodeImpl {
+
+	node := NewTerminalNodeImpl(token)
+	prc.addTerminalNodeChild(node)
+	node.parentCtx = prc
+	return node
+
+}
+
+func (prc *BaseParserRuleContext) AddErrorNode(badToken Token) *ErrorNodeImpl {
+	node := NewErrorNodeImpl(badToken)
+	prc.addTerminalNodeChild(node)
+	node.parentCtx = prc
+	return node
+}
+
+func (prc *BaseParserRuleContext) GetChild(i int) Tree {
+	if prc.children != nil && len(prc.children) >= i {
+		return prc.children[i]
+	}
+
+	return nil
+}
+
+func (prc *BaseParserRuleContext) GetChildOfType(i int, childType reflect.Type) RuleContext {
+	if childType == nil {
+		return prc.GetChild(i).(RuleContext)
+	}
+
+	for j := 0; j < len(prc.children); j++ {
+		child := prc.children[j]
+		if reflect.TypeOf(child) == childType {
+			if i == 0 {
+				return child.(RuleContext)
+			}
+
+			i--
+		}
+	}
+
+	return nil
+}
+
+func (prc *BaseParserRuleContext) ToStringTree(ruleNames []string, recog Recognizer) string {
+	return TreesStringTree(prc, ruleNames, recog)
+}
+
+func (prc *BaseParserRuleContext) GetRuleContext() RuleContext {
+	return prc
+}
+
+func (prc *BaseParserRuleContext) Accept(visitor ParseTreeVisitor) interface{} {
+	return visitor.VisitChildren(prc)
+}
+
+func (prc *BaseParserRuleContext) SetStart(t Token) {
+	prc.start = t
+}
+
+func (prc *BaseParserRuleContext) GetStart() Token {
+	return prc.start
+}
+
+func (prc *BaseParserRuleContext) SetStop(t Token) {
+	prc.stop = t
+}
+
+func (prc *BaseParserRuleContext) GetStop() Token {
+	return prc.stop
+}
+
+func (prc *BaseParserRuleContext) GetToken(ttype int, i int) TerminalNode {
+
+	for j := 0; j < len(prc.children); j++ {
+		child := prc.children[j]
+		if c2, ok := child.(TerminalNode); ok {
+			if c2.GetSymbol().GetTokenType() == ttype {
+				if i == 0 {
+					return c2
+				}
+
+				i--
+			}
+		}
+	}
+	return nil
+}
+
+func (prc *BaseParserRuleContext) GetTokens(ttype int) []TerminalNode {
+	if prc.children == nil {
+		return make([]TerminalNode, 0)
+	}
+
+	tokens := make([]TerminalNode, 0)
+
+	for j := 0; j < len(prc.children); j++ {
+		child := prc.children[j]
+		if tchild, ok := child.(TerminalNode); ok {
+			if tchild.GetSymbol().GetTokenType() == ttype {
+				tokens = append(tokens, tchild)
+			}
+		}
+	}
+
+	return tokens
+}
+
+func (prc *BaseParserRuleContext) GetPayload() interface{} {
+	return prc
+}
+
+func (prc *BaseParserRuleContext) getChild(ctxType reflect.Type, i int) RuleContext {
+	if prc.children == nil || i < 0 || i >= len(prc.children) {
+		return nil
+	}
+
+	j := -1 // what element have we found with ctxType?
+	for _, o := range prc.children {
+
+		childType := reflect.TypeOf(o)
+
+		if childType.Implements(ctxType) {
+			j++
+			if j == i {
+				return o.(RuleContext)
+			}
+		}
+	}
+	return nil
+}
+
+// Go lacks generics, so it's not possible for us to return the child with the correct type, but we do
+// check for convertibility
+
+func (prc *BaseParserRuleContext) GetTypedRuleContext(ctxType reflect.Type, i int) RuleContext {
+	return prc.getChild(ctxType, i)
+}
+
+func (prc *BaseParserRuleContext) GetTypedRuleContexts(ctxType reflect.Type) []RuleContext {
+	if prc.children == nil {
+		return make([]RuleContext, 0)
+	}
+
+	contexts := make([]RuleContext, 0)
+
+	for _, child := range prc.children {
+		childType := reflect.TypeOf(child)
+
+		if childType.ConvertibleTo(ctxType) {
+			contexts = append(contexts, child.(RuleContext))
+		}
+	}
+	return contexts
+}
+
+func (prc *BaseParserRuleContext) GetChildCount() int {
+	if prc.children == nil {
+		return 0
+	}
+
+	return len(prc.children)
+}
+
+func (prc *BaseParserRuleContext) GetSourceInterval() *Interval {
+	if prc.start == nil || prc.stop == nil {
+		return TreeInvalidInterval
+	}
+
+	return NewInterval(prc.start.GetTokenIndex(), prc.stop.GetTokenIndex())
+}
+
+//need to manage circular dependencies, so export now
+
+// Print out a whole tree, not just a node, in LISP format
+// (root child1 .. childN). Print just a node if b is a leaf.
+//
+
+func (prc *BaseParserRuleContext) String(ruleNames []string, stop RuleContext) string {
+
+	var p ParserRuleContext = prc
+	s := "["
+	for p != nil && p != stop {
+		if ruleNames == nil {
+			if !p.IsEmpty() {
+				s += strconv.Itoa(p.GetInvokingState())
+			}
+		} else {
+			ri := p.GetRuleIndex()
+			var ruleName string
+			if ri >= 0 && ri < len(ruleNames) {
+				ruleName = ruleNames[ri]
+			} else {
+				ruleName = strconv.Itoa(ri)
+			}
+			s += ruleName
+		}
+		if p.GetParent() != nil && (ruleNames != nil || !p.GetParent().(ParserRuleContext).IsEmpty()) {
+			s += " "
+		}
+		pi := p.GetParent()
+		if pi != nil {
+			p = pi.(ParserRuleContext)
+		} else {
+			p = nil
+		}
+	}
+	s += "]"
+	return s
+}
+
+var RuleContextEmpty = NewBaseParserRuleContext(nil, -1)
+
+type InterpreterRuleContext interface {
+	ParserRuleContext
+}
+
+type BaseInterpreterRuleContext struct {
+	*BaseParserRuleContext
+}
+
+func NewBaseInterpreterRuleContext(parent BaseInterpreterRuleContext, invokingStateNumber, ruleIndex int) *BaseInterpreterRuleContext {
+
+	prc := new(BaseInterpreterRuleContext)
+
+	prc.BaseParserRuleContext = NewBaseParserRuleContext(parent, invokingStateNumber)
+
+	prc.RuleIndex = ruleIndex
+
+	return prc
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/prediction_context.go

@@ -0,0 +1,756 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"strconv"
+)
+
+// Represents {@code $} in local context prediction, which means wildcard.
+// {@code//+x =//}.
+// /
+const (
+	BasePredictionContextEmptyReturnState = 0x7FFFFFFF
+)
+
+// Represents {@code $} in an array in full context mode, when {@code $}
+// doesn't mean wildcard: {@code $ + x = [$,x]}. Here,
+// {@code $} = {@link //EmptyReturnState}.
+// /
+
+var (
+	BasePredictionContextglobalNodeCount = 1
+	BasePredictionContextid              = BasePredictionContextglobalNodeCount
+)
+
+type PredictionContext interface {
+	hash() int
+	GetParent(int) PredictionContext
+	getReturnState(int) int
+	equals(PredictionContext) bool
+	length() int
+	isEmpty() bool
+	hasEmptyPath() bool
+	String() string
+}
+
+type BasePredictionContext struct {
+	cachedHash int
+}
+
+func NewBasePredictionContext(cachedHash int) *BasePredictionContext {
+	pc := new(BasePredictionContext)
+	pc.cachedHash = cachedHash
+
+	return pc
+}
+
+func (b *BasePredictionContext) isEmpty() bool {
+	return false
+}
+
+func calculateHash(parent PredictionContext, returnState int) int {
+	h := murmurInit(1)
+	h = murmurUpdate(h, parent.hash())
+	h = murmurUpdate(h, returnState)
+	return murmurFinish(h, 2)
+}
+
+func calculateEmptyHash() int {
+	h := murmurInit(1)
+	return murmurFinish(h, 0)
+}
+
+// Used to cache {@link BasePredictionContext} objects. Its used for the shared
+// context cash associated with contexts in DFA states. This cache
+// can be used for both lexers and parsers.
+
+type PredictionContextCache struct {
+	cache map[PredictionContext]PredictionContext
+}
+
+func NewPredictionContextCache() *PredictionContextCache {
+	t := new(PredictionContextCache)
+	t.cache = make(map[PredictionContext]PredictionContext)
+	return t
+}
+
+// Add a context to the cache and return it. If the context already exists,
+// return that one instead and do not add a Newcontext to the cache.
+// Protect shared cache from unsafe thread access.
+//
+func (p *PredictionContextCache) add(ctx PredictionContext) PredictionContext {
+	if ctx == BasePredictionContextEMPTY {
+		return BasePredictionContextEMPTY
+	}
+	existing := p.cache[ctx]
+	if existing != nil {
+		return existing
+	}
+	p.cache[ctx] = ctx
+	return ctx
+}
+
+func (p *PredictionContextCache) Get(ctx PredictionContext) PredictionContext {
+	return p.cache[ctx]
+}
+
+func (p *PredictionContextCache) length() int {
+	return len(p.cache)
+}
+
+type SingletonPredictionContext interface {
+	PredictionContext
+}
+
+type BaseSingletonPredictionContext struct {
+	*BasePredictionContext
+
+	parentCtx   PredictionContext
+	returnState int
+}
+
+func NewBaseSingletonPredictionContext(parent PredictionContext, returnState int) *BaseSingletonPredictionContext {
+
+	s := new(BaseSingletonPredictionContext)
+	s.BasePredictionContext = NewBasePredictionContext(37)
+
+	if parent != nil {
+		s.cachedHash = calculateHash(parent, returnState)
+	} else {
+		s.cachedHash = calculateEmptyHash()
+	}
+
+	s.parentCtx = parent
+	s.returnState = returnState
+
+	return s
+}
+
+func SingletonBasePredictionContextCreate(parent PredictionContext, returnState int) PredictionContext {
+	if returnState == BasePredictionContextEmptyReturnState && parent == nil {
+		// someone can pass in the bits of an array ctx that mean $
+		return BasePredictionContextEMPTY
+	}
+
+	return NewBaseSingletonPredictionContext(parent, returnState)
+}
+
+func (b *BaseSingletonPredictionContext) length() int {
+	return 1
+}
+
+func (b *BaseSingletonPredictionContext) GetParent(index int) PredictionContext {
+	return b.parentCtx
+}
+
+func (b *BaseSingletonPredictionContext) getReturnState(index int) int {
+	return b.returnState
+}
+
+func (b *BaseSingletonPredictionContext) hasEmptyPath() bool {
+	return b.returnState == BasePredictionContextEmptyReturnState
+}
+
+func (b *BaseSingletonPredictionContext) equals(other PredictionContext) bool {
+	if b == other {
+		return true
+	} else if _, ok := other.(*BaseSingletonPredictionContext); !ok {
+		return false
+	} else if b.hash() != other.hash() {
+		return false // can't be same if hash is different
+	}
+
+	otherP := other.(*BaseSingletonPredictionContext)
+
+	if b.returnState != other.getReturnState(0) {
+		return false
+	} else if b.parentCtx == nil {
+		return otherP.parentCtx == nil
+	}
+
+	return b.parentCtx.equals(otherP.parentCtx)
+}
+
+func (b *BaseSingletonPredictionContext) hash() int {
+	h := murmurInit(1)
+
+	if b.parentCtx == nil {
+		return murmurFinish(h, 0)
+	}
+
+	h = murmurUpdate(h, b.parentCtx.hash())
+	h = murmurUpdate(h, b.returnState)
+	return murmurFinish(h, 2)
+}
+
+func (b *BaseSingletonPredictionContext) String() string {
+	var up string
+
+	if b.parentCtx == nil {
+		up = ""
+	} else {
+		up = b.parentCtx.String()
+	}
+
+	if len(up) == 0 {
+		if b.returnState == BasePredictionContextEmptyReturnState {
+			return "$"
+		}
+
+		return strconv.Itoa(b.returnState)
+	}
+
+	return strconv.Itoa(b.returnState) + " " + up
+}
+
+var BasePredictionContextEMPTY = NewEmptyPredictionContext()
+
+type EmptyPredictionContext struct {
+	*BaseSingletonPredictionContext
+}
+
+func NewEmptyPredictionContext() *EmptyPredictionContext {
+
+	p := new(EmptyPredictionContext)
+
+	p.BaseSingletonPredictionContext = NewBaseSingletonPredictionContext(nil, BasePredictionContextEmptyReturnState)
+
+	return p
+}
+
+func (e *EmptyPredictionContext) isEmpty() bool {
+	return true
+}
+
+func (e *EmptyPredictionContext) GetParent(index int) PredictionContext {
+	return nil
+}
+
+func (e *EmptyPredictionContext) getReturnState(index int) int {
+	return e.returnState
+}
+
+func (e *EmptyPredictionContext) equals(other PredictionContext) bool {
+	return e == other
+}
+
+func (e *EmptyPredictionContext) String() string {
+	return "$"
+}
+
+type ArrayPredictionContext struct {
+	*BasePredictionContext
+
+	parents      []PredictionContext
+	returnStates []int
+}
+
+func NewArrayPredictionContext(parents []PredictionContext, returnStates []int) *ArrayPredictionContext {
+	// Parent can be nil only if full ctx mode and we make an array
+	// from {@link //EMPTY} and non-empty. We merge {@link //EMPTY} by using
+	// nil parent and
+	// returnState == {@link //EmptyReturnState}.
+
+	c := new(ArrayPredictionContext)
+	c.BasePredictionContext = NewBasePredictionContext(37)
+
+	for i := range parents {
+		c.cachedHash += calculateHash(parents[i], returnStates[i])
+	}
+
+	c.parents = parents
+	c.returnStates = returnStates
+
+	return c
+}
+
+func (a *ArrayPredictionContext) GetReturnStates() []int {
+	return a.returnStates
+}
+
+func (a *ArrayPredictionContext) hasEmptyPath() bool {
+	return a.getReturnState(a.length()-1) == BasePredictionContextEmptyReturnState
+}
+
+func (a *ArrayPredictionContext) isEmpty() bool {
+	// since EmptyReturnState can only appear in the last position, we
+	// don't need to verify that size==1
+	return a.returnStates[0] == BasePredictionContextEmptyReturnState
+}
+
+func (a *ArrayPredictionContext) length() int {
+	return len(a.returnStates)
+}
+
+func (a *ArrayPredictionContext) GetParent(index int) PredictionContext {
+	return a.parents[index]
+}
+
+func (a *ArrayPredictionContext) getReturnState(index int) int {
+	return a.returnStates[index]
+}
+
+func (a *ArrayPredictionContext) equals(other PredictionContext) bool {
+	if _, ok := other.(*ArrayPredictionContext); !ok {
+		return false
+	} else if a.cachedHash != other.hash() {
+		return false // can't be same if hash is different
+	} else {
+		otherP := other.(*ArrayPredictionContext)
+		return &a.returnStates == &otherP.returnStates && &a.parents == &otherP.parents
+	}
+}
+
+func (a *ArrayPredictionContext) hash() int {
+	h := murmurInit(1)
+
+	for _, p := range a.parents {
+		h = murmurUpdate(h, p.hash())
+	}
+
+	for _, r := range a.returnStates {
+		h = murmurUpdate(h, r)
+	}
+
+	return murmurFinish(h, 2 * len(a.parents))
+}
+
+func (a *ArrayPredictionContext) String() string {
+	if a.isEmpty() {
+		return "[]"
+	}
+
+	s := "["
+	for i := 0; i < len(a.returnStates); i++ {
+		if i > 0 {
+			s = s + ", "
+		}
+		if a.returnStates[i] == BasePredictionContextEmptyReturnState {
+			s = s + "$"
+			continue
+		}
+		s = s + strconv.Itoa(a.returnStates[i])
+		if a.parents[i] != nil {
+			s = s + " " + a.parents[i].String()
+		} else {
+			s = s + "nil"
+		}
+	}
+
+	return s + "]"
+}
+
+// Convert a {@link RuleContext} tree to a {@link BasePredictionContext} graph.
+// Return {@link //EMPTY} if {@code outerContext} is empty or nil.
+// /
+func predictionContextFromRuleContext(a *ATN, outerContext RuleContext) PredictionContext {
+	if outerContext == nil {
+		outerContext = RuleContextEmpty
+	}
+	// if we are in RuleContext of start rule, s, then BasePredictionContext
+	// is EMPTY. Nobody called us. (if we are empty, return empty)
+	if outerContext.GetParent() == nil || outerContext == RuleContextEmpty {
+		return BasePredictionContextEMPTY
+	}
+	// If we have a parent, convert it to a BasePredictionContext graph
+	parent := predictionContextFromRuleContext(a, outerContext.GetParent().(RuleContext))
+	state := a.states[outerContext.GetInvokingState()]
+	transition := state.GetTransitions()[0]
+
+	return SingletonBasePredictionContextCreate(parent, transition.(*RuleTransition).followState.GetStateNumber())
+}
+
+func merge(a, b PredictionContext, rootIsWildcard bool, mergeCache *DoubleDict) PredictionContext {
+	// share same graph if both same
+	if a == b {
+		return a
+	}
+
+	ac, ok1 := a.(*BaseSingletonPredictionContext)
+	bc, ok2 := b.(*BaseSingletonPredictionContext)
+
+	if ok1 && ok2 {
+		return mergeSingletons(ac, bc, rootIsWildcard, mergeCache)
+	}
+	// At least one of a or b is array
+	// If one is $ and rootIsWildcard, return $ as// wildcard
+	if rootIsWildcard {
+		if _, ok := a.(*EmptyPredictionContext); ok {
+			return a
+		}
+		if _, ok := b.(*EmptyPredictionContext); ok {
+			return b
+		}
+	}
+	// convert singleton so both are arrays to normalize
+	if _, ok := a.(*BaseSingletonPredictionContext); ok {
+		a = NewArrayPredictionContext([]PredictionContext{a.GetParent(0)}, []int{a.getReturnState(0)})
+	}
+	if _, ok := b.(*BaseSingletonPredictionContext); ok {
+		b = NewArrayPredictionContext([]PredictionContext{b.GetParent(0)}, []int{b.getReturnState(0)})
+	}
+	return mergeArrays(a.(*ArrayPredictionContext), b.(*ArrayPredictionContext), rootIsWildcard, mergeCache)
+}
+
+//
+// Merge two {@link SingletonBasePredictionContext} instances.
+//
+// <p>Stack tops equal, parents merge is same return left graph.<br>
+// <embed src="images/SingletonMerge_SameRootSamePar.svg"
+// type="image/svg+xml"/></p>
+//
+// <p>Same stack top, parents differ merge parents giving array node, then
+// remainders of those graphs. A Newroot node is created to point to the
+// merged parents.<br>
+// <embed src="images/SingletonMerge_SameRootDiffPar.svg"
+// type="image/svg+xml"/></p>
+//
+// <p>Different stack tops pointing to same parent. Make array node for the
+// root where both element in the root point to the same (original)
+// parent.<br>
+// <embed src="images/SingletonMerge_DiffRootSamePar.svg"
+// type="image/svg+xml"/></p>
+//
+// <p>Different stack tops pointing to different parents. Make array node for
+// the root where each element points to the corresponding original
+// parent.<br>
+// <embed src="images/SingletonMerge_DiffRootDiffPar.svg"
+// type="image/svg+xml"/></p>
+//
+// @param a the first {@link SingletonBasePredictionContext}
+// @param b the second {@link SingletonBasePredictionContext}
+// @param rootIsWildcard {@code true} if this is a local-context merge,
+// otherwise false to indicate a full-context merge
+// @param mergeCache
+// /
+func mergeSingletons(a, b *BaseSingletonPredictionContext, rootIsWildcard bool, mergeCache *DoubleDict) PredictionContext {
+	if mergeCache != nil {
+		previous := mergeCache.Get(a.hash(), b.hash())
+		if previous != nil {
+			return previous.(PredictionContext)
+		}
+		previous = mergeCache.Get(b.hash(), a.hash())
+		if previous != nil {
+			return previous.(PredictionContext)
+		}
+	}
+
+	rootMerge := mergeRoot(a, b, rootIsWildcard)
+	if rootMerge != nil {
+		if mergeCache != nil {
+			mergeCache.set(a.hash(), b.hash(), rootMerge)
+		}
+		return rootMerge
+	}
+	if a.returnState == b.returnState {
+		parent := merge(a.parentCtx, b.parentCtx, rootIsWildcard, mergeCache)
+		// if parent is same as existing a or b parent or reduced to a parent,
+		// return it
+		if parent == a.parentCtx {
+			return a // ax + bx = ax, if a=b
+		}
+		if parent == b.parentCtx {
+			return b // ax + bx = bx, if a=b
+		}
+		// else: ax + ay = a'[x,y]
+		// merge parents x and y, giving array node with x,y then remainders
+		// of those graphs. dup a, a' points at merged array
+		// Newjoined parent so create Newsingleton pointing to it, a'
+		spc := SingletonBasePredictionContextCreate(parent, a.returnState)
+		if mergeCache != nil {
+			mergeCache.set(a.hash(), b.hash(), spc)
+		}
+		return spc
+	}
+	// a != b payloads differ
+	// see if we can collapse parents due to $+x parents if local ctx
+	var singleParent PredictionContext
+	if a == b || (a.parentCtx != nil && a.parentCtx == b.parentCtx) { // ax +
+		// bx =
+		// [a,b]x
+		singleParent = a.parentCtx
+	}
+	if singleParent != nil { // parents are same
+		// sort payloads and use same parent
+		payloads := []int{a.returnState, b.returnState}
+		if a.returnState > b.returnState {
+			payloads[0] = b.returnState
+			payloads[1] = a.returnState
+		}
+		parents := []PredictionContext{singleParent, singleParent}
+		apc := NewArrayPredictionContext(parents, payloads)
+		if mergeCache != nil {
+			mergeCache.set(a.hash(), b.hash(), apc)
+		}
+		return apc
+	}
+	// parents differ and can't merge them. Just pack together
+	// into array can't merge.
+	// ax + by = [ax,by]
+	payloads := []int{a.returnState, b.returnState}
+	parents := []PredictionContext{a.parentCtx, b.parentCtx}
+	if a.returnState > b.returnState { // sort by payload
+		payloads[0] = b.returnState
+		payloads[1] = a.returnState
+		parents = []PredictionContext{b.parentCtx, a.parentCtx}
+	}
+	apc := NewArrayPredictionContext(parents, payloads)
+	if mergeCache != nil {
+		mergeCache.set(a.hash(), b.hash(), apc)
+	}
+	return apc
+}
+
+//
+// Handle case where at least one of {@code a} or {@code b} is
+// {@link //EMPTY}. In the following diagrams, the symbol {@code $} is used
+// to represent {@link //EMPTY}.
+//
+// <h2>Local-Context Merges</h2>
+//
+// <p>These local-context merge operations are used when {@code rootIsWildcard}
+// is true.</p>
+//
+// <p>{@link //EMPTY} is superset of any graph return {@link //EMPTY}.<br>
+// <embed src="images/LocalMerge_EmptyRoot.svg" type="image/svg+xml"/></p>
+//
+// <p>{@link //EMPTY} and anything is {@code //EMPTY}, so merged parent is
+// {@code //EMPTY} return left graph.<br>
+// <embed src="images/LocalMerge_EmptyParent.svg" type="image/svg+xml"/></p>
+//
+// <p>Special case of last merge if local context.<br>
+// <embed src="images/LocalMerge_DiffRoots.svg" type="image/svg+xml"/></p>
+//
+// <h2>Full-Context Merges</h2>
+//
+// <p>These full-context merge operations are used when {@code rootIsWildcard}
+// is false.</p>
+//
+// <p><embed src="images/FullMerge_EmptyRoots.svg" type="image/svg+xml"/></p>
+//
+// <p>Must keep all contexts {@link //EMPTY} in array is a special value (and
+// nil parent).<br>
+// <embed src="images/FullMerge_EmptyRoot.svg" type="image/svg+xml"/></p>
+//
+// <p><embed src="images/FullMerge_SameRoot.svg" type="image/svg+xml"/></p>
+//
+// @param a the first {@link SingletonBasePredictionContext}
+// @param b the second {@link SingletonBasePredictionContext}
+// @param rootIsWildcard {@code true} if this is a local-context merge,
+// otherwise false to indicate a full-context merge
+// /
+func mergeRoot(a, b SingletonPredictionContext, rootIsWildcard bool) PredictionContext {
+	if rootIsWildcard {
+		if a == BasePredictionContextEMPTY {
+			return BasePredictionContextEMPTY // // + b =//
+		}
+		if b == BasePredictionContextEMPTY {
+			return BasePredictionContextEMPTY // a +// =//
+		}
+	} else {
+		if a == BasePredictionContextEMPTY && b == BasePredictionContextEMPTY {
+			return BasePredictionContextEMPTY // $ + $ = $
+		} else if a == BasePredictionContextEMPTY { // $ + x = [$,x]
+			payloads := []int{b.getReturnState(-1), BasePredictionContextEmptyReturnState}
+			parents := []PredictionContext{b.GetParent(-1), nil}
+			return NewArrayPredictionContext(parents, payloads)
+		} else if b == BasePredictionContextEMPTY { // x + $ = [$,x] ($ is always first if present)
+			payloads := []int{a.getReturnState(-1), BasePredictionContextEmptyReturnState}
+			parents := []PredictionContext{a.GetParent(-1), nil}
+			return NewArrayPredictionContext(parents, payloads)
+		}
+	}
+	return nil
+}
+
+//
+// Merge two {@link ArrayBasePredictionContext} instances.
+//
+// <p>Different tops, different parents.<br>
+// <embed src="images/ArrayMerge_DiffTopDiffPar.svg" type="image/svg+xml"/></p>
+//
+// <p>Shared top, same parents.<br>
+// <embed src="images/ArrayMerge_ShareTopSamePar.svg" type="image/svg+xml"/></p>
+//
+// <p>Shared top, different parents.<br>
+// <embed src="images/ArrayMerge_ShareTopDiffPar.svg" type="image/svg+xml"/></p>
+//
+// <p>Shared top, all shared parents.<br>
+// <embed src="images/ArrayMerge_ShareTopSharePar.svg"
+// type="image/svg+xml"/></p>
+//
+// <p>Equal tops, merge parents and reduce top to
+// {@link SingletonBasePredictionContext}.<br>
+// <embed src="images/ArrayMerge_EqualTop.svg" type="image/svg+xml"/></p>
+// /
+func mergeArrays(a, b *ArrayPredictionContext, rootIsWildcard bool, mergeCache *DoubleDict) PredictionContext {
+	if mergeCache != nil {
+		previous := mergeCache.Get(a.hash(), b.hash())
+		if previous != nil {
+			return previous.(PredictionContext)
+		}
+		previous = mergeCache.Get(b.hash(), a.hash())
+		if previous != nil {
+			return previous.(PredictionContext)
+		}
+	}
+	// merge sorted payloads a + b => M
+	i := 0 // walks a
+	j := 0 // walks b
+	k := 0 // walks target M array
+
+	mergedReturnStates := make([]int, len(a.returnStates)+len(b.returnStates))
+	mergedParents := make([]PredictionContext, len(a.returnStates)+len(b.returnStates))
+	// walk and merge to yield mergedParents, mergedReturnStates
+	for i < len(a.returnStates) && j < len(b.returnStates) {
+		aParent := a.parents[i]
+		bParent := b.parents[j]
+		if a.returnStates[i] == b.returnStates[j] {
+			// same payload (stack tops are equal), must yield merged singleton
+			payload := a.returnStates[i]
+			// $+$ = $
+			bothDollars := payload == BasePredictionContextEmptyReturnState && aParent == nil && bParent == nil
+			axAX := (aParent != nil && bParent != nil && aParent == bParent) // ax+ax
+			// ->
+			// ax
+			if bothDollars || axAX {
+				mergedParents[k] = aParent // choose left
+				mergedReturnStates[k] = payload
+			} else { // ax+ay -> a'[x,y]
+				mergedParent := merge(aParent, bParent, rootIsWildcard, mergeCache)
+				mergedParents[k] = mergedParent
+				mergedReturnStates[k] = payload
+			}
+			i++ // hop over left one as usual
+			j++ // but also Skip one in right side since we merge
+		} else if a.returnStates[i] < b.returnStates[j] { // copy a[i] to M
+			mergedParents[k] = aParent
+			mergedReturnStates[k] = a.returnStates[i]
+			i++
+		} else { // b > a, copy b[j] to M
+			mergedParents[k] = bParent
+			mergedReturnStates[k] = b.returnStates[j]
+			j++
+		}
+		k++
+	}
+	// copy over any payloads remaining in either array
+	if i < len(a.returnStates) {
+		for p := i; p < len(a.returnStates); p++ {
+			mergedParents[k] = a.parents[p]
+			mergedReturnStates[k] = a.returnStates[p]
+			k++
+		}
+	} else {
+		for p := j; p < len(b.returnStates); p++ {
+			mergedParents[k] = b.parents[p]
+			mergedReturnStates[k] = b.returnStates[p]
+			k++
+		}
+	}
+	// trim merged if we combined a few that had same stack tops
+	if k < len(mergedParents) { // write index < last position trim
+		if k == 1 { // for just one merged element, return singleton top
+			pc := SingletonBasePredictionContextCreate(mergedParents[0], mergedReturnStates[0])
+			if mergeCache != nil {
+				mergeCache.set(a.hash(), b.hash(), pc)
+			}
+			return pc
+		}
+		mergedParents = mergedParents[0:k]
+		mergedReturnStates = mergedReturnStates[0:k]
+	}
+
+	M := NewArrayPredictionContext(mergedParents, mergedReturnStates)
+
+	// if we created same array as a or b, return that instead
+	// TODO: track whether this is possible above during merge sort for speed
+	if M == a {
+		if mergeCache != nil {
+			mergeCache.set(a.hash(), b.hash(), a)
+		}
+		return a
+	}
+	if M == b {
+		if mergeCache != nil {
+			mergeCache.set(a.hash(), b.hash(), b)
+		}
+		return b
+	}
+	combineCommonParents(mergedParents)
+
+	if mergeCache != nil {
+		mergeCache.set(a.hash(), b.hash(), M)
+	}
+	return M
+}
+
+//
+// Make pass over all <em>M</em> {@code parents} merge any {@code equals()}
+// ones.
+// /
+func combineCommonParents(parents []PredictionContext) {
+	uniqueParents := make(map[PredictionContext]PredictionContext)
+
+	for p := 0; p < len(parents); p++ {
+		parent := parents[p]
+		if uniqueParents[parent] == nil {
+			uniqueParents[parent] = parent
+		}
+	}
+	for q := 0; q < len(parents); q++ {
+		parents[q] = uniqueParents[parents[q]]
+	}
+}
+
+func getCachedBasePredictionContext(context PredictionContext, contextCache *PredictionContextCache, visited map[PredictionContext]PredictionContext) PredictionContext {
+
+	if context.isEmpty() {
+		return context
+	}
+	existing := visited[context]
+	if existing != nil {
+		return existing
+	}
+	existing = contextCache.Get(context)
+	if existing != nil {
+		visited[context] = existing
+		return existing
+	}
+	changed := false
+	parents := make([]PredictionContext, context.length())
+	for i := 0; i < len(parents); i++ {
+		parent := getCachedBasePredictionContext(context.GetParent(i), contextCache, visited)
+		if changed || parent != context.GetParent(i) {
+			if !changed {
+				parents = make([]PredictionContext, context.length())
+				for j := 0; j < context.length(); j++ {
+					parents[j] = context.GetParent(j)
+				}
+				changed = true
+			}
+			parents[i] = parent
+		}
+	}
+	if !changed {
+		contextCache.add(context)
+		visited[context] = context
+		return context
+	}
+	var updated PredictionContext
+	if len(parents) == 0 {
+		updated = BasePredictionContextEMPTY
+	} else if len(parents) == 1 {
+		updated = SingletonBasePredictionContextCreate(parents[0], context.getReturnState(0))
+	} else {
+		updated = NewArrayPredictionContext(parents, context.(*ArrayPredictionContext).GetReturnStates())
+	}
+	contextCache.add(updated)
+	visited[updated] = updated
+	visited[context] = updated
+
+	return updated
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/prediction_mode.go

@@ -0,0 +1,553 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// This enumeration defines the prediction modes available in ANTLR 4 along with
+// utility methods for analyzing configuration sets for conflicts and/or
+// ambiguities.
+
+const (
+	//
+	// The SLL(*) prediction mode. This prediction mode ignores the current
+	// parser context when making predictions. This is the fastest prediction
+	// mode, and provides correct results for many grammars. This prediction
+	// mode is more powerful than the prediction mode provided by ANTLR 3, but
+	// may result in syntax errors for grammar and input combinations which are
+	// not SLL.
+	//
+	// <p>
+	// When using this prediction mode, the parser will either return a correct
+	// parse tree (i.e. the same parse tree that would be returned with the
+	// {@link //LL} prediction mode), or it will Report a syntax error. If a
+	// syntax error is encountered when using the {@link //SLL} prediction mode,
+	// it may be due to either an actual syntax error in the input or indicate
+	// that the particular combination of grammar and input requires the more
+	// powerful {@link //LL} prediction abilities to complete successfully.</p>
+	//
+	// <p>
+	// This prediction mode does not provide any guarantees for prediction
+	// behavior for syntactically-incorrect inputs.</p>
+	//
+	PredictionModeSLL = 0
+	//
+	// The LL(*) prediction mode. This prediction mode allows the current parser
+	// context to be used for resolving SLL conflicts that occur during
+	// prediction. This is the fastest prediction mode that guarantees correct
+	// parse results for all combinations of grammars with syntactically correct
+	// inputs.
+	//
+	// <p>
+	// When using this prediction mode, the parser will make correct decisions
+	// for all syntactically-correct grammar and input combinations. However, in
+	// cases where the grammar is truly ambiguous this prediction mode might not
+	// Report a precise answer for <em>exactly which</em> alternatives are
+	// ambiguous.</p>
+	//
+	// <p>
+	// This prediction mode does not provide any guarantees for prediction
+	// behavior for syntactically-incorrect inputs.</p>
+	//
+	PredictionModeLL = 1
+	//
+	// The LL(*) prediction mode with exact ambiguity detection. In addition to
+	// the correctness guarantees provided by the {@link //LL} prediction mode,
+	// this prediction mode instructs the prediction algorithm to determine the
+	// complete and exact set of ambiguous alternatives for every ambiguous
+	// decision encountered while parsing.
+	//
+	// <p>
+	// This prediction mode may be used for diagnosing ambiguities during
+	// grammar development. Due to the performance overhead of calculating sets
+	// of ambiguous alternatives, this prediction mode should be avoided when
+	// the exact results are not necessary.</p>
+	//
+	// <p>
+	// This prediction mode does not provide any guarantees for prediction
+	// behavior for syntactically-incorrect inputs.</p>
+	//
+	PredictionModeLLExactAmbigDetection = 2
+)
+
+//
+// Computes the SLL prediction termination condition.
+//
+// <p>
+// This method computes the SLL prediction termination condition for both of
+// the following cases.</p>
+//
+// <ul>
+// <li>The usual SLL+LL fallback upon SLL conflict</li>
+// <li>Pure SLL without LL fallback</li>
+// </ul>
+//
+// <p><strong>COMBINED SLL+LL PARSING</strong></p>
+//
+// <p>When LL-fallback is enabled upon SLL conflict, correct predictions are
+// ensured regardless of how the termination condition is computed by this
+// method. Due to the substantially higher cost of LL prediction, the
+// prediction should only fall back to LL when the additional lookahead
+// cannot lead to a unique SLL prediction.</p>
+//
+// <p>Assuming combined SLL+LL parsing, an SLL configuration set with only
+// conflicting subsets should fall back to full LL, even if the
+// configuration sets don't resolve to the same alternative (e.g.
+// {@code {1,2}} and {@code {3,4}}. If there is at least one non-conflicting
+// configuration, SLL could continue with the hopes that more lookahead will
+// resolve via one of those non-conflicting configurations.</p>
+//
+// <p>Here's the prediction termination rule them: SLL (for SLL+LL parsing)
+// stops when it sees only conflicting configuration subsets. In contrast,
+// full LL keeps going when there is uncertainty.</p>
+//
+// <p><strong>HEURISTIC</strong></p>
+//
+// <p>As a heuristic, we stop prediction when we see any conflicting subset
+// unless we see a state that only has one alternative associated with it.
+// The single-alt-state thing lets prediction continue upon rules like
+// (otherwise, it would admit defeat too soon):</p>
+//
+// <p>{@code [12|1|[], 6|2|[], 12|2|[]]. s : (ID | ID ID?) '' }</p>
+//
+// <p>When the ATN simulation reaches the state before {@code ''}, it has a
+// DFA state that looks like: {@code [12|1|[], 6|2|[], 12|2|[]]}. Naturally
+// {@code 12|1|[]} and {@code 12|2|[]} conflict, but we cannot stop
+// processing this node because alternative to has another way to continue,
+// via {@code [6|2|[]]}.</p>
+//
+// <p>It also let's us continue for this rule:</p>
+//
+// <p>{@code [1|1|[], 1|2|[], 8|3|[]] a : A | A | A B }</p>
+//
+// <p>After Matching input A, we reach the stop state for rule A, state 1.
+// State 8 is the state right before B. Clearly alternatives 1 and 2
+// conflict and no amount of further lookahead will separate the two.
+// However, alternative 3 will be able to continue and so we do not stop
+// working on this state. In the previous example, we're concerned with
+// states associated with the conflicting alternatives. Here alt 3 is not
+// associated with the conflicting configs, but since we can continue
+// looking for input reasonably, don't declare the state done.</p>
+//
+// <p><strong>PURE SLL PARSING</strong></p>
+//
+// <p>To handle pure SLL parsing, all we have to do is make sure that we
+// combine stack contexts for configurations that differ only by semantic
+// predicate. From there, we can do the usual SLL termination heuristic.</p>
+//
+// <p><strong>PREDICATES IN SLL+LL PARSING</strong></p>
+//
+// <p>SLL decisions don't evaluate predicates until after they reach DFA stop
+// states because they need to create the DFA cache that works in all
+// semantic situations. In contrast, full LL evaluates predicates collected
+// during start state computation so it can ignore predicates thereafter.
+// This means that SLL termination detection can totally ignore semantic
+// predicates.</p>
+//
+// <p>Implementation-wise, {@link ATNConfigSet} combines stack contexts but not
+// semantic predicate contexts so we might see two configurations like the
+// following.</p>
+//
+// <p>{@code (s, 1, x, {}), (s, 1, x', {p})}</p>
+//
+// <p>Before testing these configurations against others, we have to merge
+// {@code x} and {@code x'} (without modifying the existing configurations).
+// For example, we test {@code (x+x')==x''} when looking for conflicts in
+// the following configurations.</p>
+//
+// <p>{@code (s, 1, x, {}), (s, 1, x', {p}), (s, 2, x'', {})}</p>
+//
+// <p>If the configuration set has predicates (as indicated by
+// {@link ATNConfigSet//hasSemanticContext}), this algorithm makes a copy of
+// the configurations to strip out all of the predicates so that a standard
+// {@link ATNConfigSet} will merge everything ignoring predicates.</p>
+//
+func PredictionModehasSLLConflictTerminatingPrediction(mode int, configs ATNConfigSet) bool {
+	// Configs in rule stop states indicate reaching the end of the decision
+	// rule (local context) or end of start rule (full context). If all
+	// configs meet this condition, then none of the configurations is able
+	// to Match additional input so we terminate prediction.
+	//
+	if PredictionModeallConfigsInRuleStopStates(configs) {
+		return true
+	}
+	// pure SLL mode parsing
+	if mode == PredictionModeSLL {
+		// Don't bother with combining configs from different semantic
+		// contexts if we can fail over to full LL costs more time
+		// since we'll often fail over anyway.
+		if configs.HasSemanticContext() {
+			// dup configs, tossing out semantic predicates
+			dup := NewBaseATNConfigSet(false)
+			for _, c := range configs.GetItems() {
+
+				//				NewBaseATNConfig({semanticContext:}, c)
+				c = NewBaseATNConfig2(c, SemanticContextNone)
+				dup.Add(c, nil)
+			}
+			configs = dup
+		}
+		// now we have combined contexts for configs with dissimilar preds
+	}
+	// pure SLL or combined SLL+LL mode parsing
+	altsets := PredictionModegetConflictingAltSubsets(configs)
+	return PredictionModehasConflictingAltSet(altsets) && !PredictionModehasStateAssociatedWithOneAlt(configs)
+}
+
+// Checks if any configuration in {@code configs} is in a
+// {@link RuleStopState}. Configurations meeting this condition have reached
+// the end of the decision rule (local context) or end of start rule (full
+// context).
+//
+// @param configs the configuration set to test
+// @return {@code true} if any configuration in {@code configs} is in a
+// {@link RuleStopState}, otherwise {@code false}
+func PredictionModehasConfigInRuleStopState(configs ATNConfigSet) bool {
+	for _, c := range configs.GetItems() {
+		if _, ok := c.GetState().(*RuleStopState); ok {
+			return true
+		}
+	}
+	return false
+}
+
+// Checks if all configurations in {@code configs} are in a
+// {@link RuleStopState}. Configurations meeting this condition have reached
+// the end of the decision rule (local context) or end of start rule (full
+// context).
+//
+// @param configs the configuration set to test
+// @return {@code true} if all configurations in {@code configs} are in a
+// {@link RuleStopState}, otherwise {@code false}
+func PredictionModeallConfigsInRuleStopStates(configs ATNConfigSet) bool {
+
+	for _, c := range configs.GetItems() {
+		if _, ok := c.GetState().(*RuleStopState); !ok {
+			return false
+		}
+	}
+	return true
+}
+
+//
+// Full LL prediction termination.
+//
+// <p>Can we stop looking ahead during ATN simulation or is there some
+// uncertainty as to which alternative we will ultimately pick, after
+// consuming more input? Even if there are partial conflicts, we might know
+// that everything is going to resolve to the same minimum alternative. That
+// means we can stop since no more lookahead will change that fact. On the
+// other hand, there might be multiple conflicts that resolve to different
+// minimums. That means we need more look ahead to decide which of those
+// alternatives we should predict.</p>
+//
+// <p>The basic idea is to split the set of configurations {@code C}, into
+// conflicting subsets {@code (s, _, ctx, _)} and singleton subsets with
+// non-conflicting configurations. Two configurations conflict if they have
+// identical {@link ATNConfig//state} and {@link ATNConfig//context} values
+// but different {@link ATNConfig//alt} value, e.g. {@code (s, i, ctx, _)}
+// and {@code (s, j, ctx, _)} for {@code i!=j}.</p>
+//
+// <p>Reduce these configuration subsets to the set of possible alternatives.
+// You can compute the alternative subsets in one pass as follows:</p>
+//
+// <p>{@code A_s,ctx = {i | (s, i, ctx, _)}} for each configuration in
+// {@code C} holding {@code s} and {@code ctx} fixed.</p>
+//
+// <p>Or in pseudo-code, for each configuration {@code c} in {@code C}:</p>
+//
+// <pre>
+// map[c] U= c.{@link ATNConfig//alt alt} // map hash/equals uses s and x, not
+// alt and not pred
+// </pre>
+//
+// <p>The values in {@code map} are the set of {@code A_s,ctx} sets.</p>
+//
+// <p>If {@code |A_s,ctx|=1} then there is no conflict associated with
+// {@code s} and {@code ctx}.</p>
+//
+// <p>Reduce the subsets to singletons by choosing a minimum of each subset. If
+// the union of these alternative subsets is a singleton, then no amount of
+// more lookahead will help us. We will always pick that alternative. If,
+// however, there is more than one alternative, then we are uncertain which
+// alternative to predict and must continue looking for resolution. We may
+// or may not discover an ambiguity in the future, even if there are no
+// conflicting subsets this round.</p>
+//
+// <p>The biggest sin is to terminate early because it means we've made a
+// decision but were uncertain as to the eventual outcome. We haven't used
+// enough lookahead. On the other hand, announcing a conflict too late is no
+// big deal you will still have the conflict. It's just inefficient. It
+// might even look until the end of file.</p>
+//
+// <p>No special consideration for semantic predicates is required because
+// predicates are evaluated on-the-fly for full LL prediction, ensuring that
+// no configuration contains a semantic context during the termination
+// check.</p>
+//
+// <p><strong>CONFLICTING CONFIGS</strong></p>
+//
+// <p>Two configurations {@code (s, i, x)} and {@code (s, j, x')}, conflict
+// when {@code i!=j} but {@code x=x'}. Because we merge all
+// {@code (s, i, _)} configurations together, that means that there are at
+// most {@code n} configurations associated with state {@code s} for
+// {@code n} possible alternatives in the decision. The merged stacks
+// complicate the comparison of configuration contexts {@code x} and
+// {@code x'}. Sam checks to see if one is a subset of the other by calling
+// merge and checking to see if the merged result is either {@code x} or
+// {@code x'}. If the {@code x} associated with lowest alternative {@code i}
+// is the superset, then {@code i} is the only possible prediction since the
+// others resolve to {@code min(i)} as well. However, if {@code x} is
+// associated with {@code j>i} then at least one stack configuration for
+// {@code j} is not in conflict with alternative {@code i}. The algorithm
+// should keep going, looking for more lookahead due to the uncertainty.</p>
+//
+// <p>For simplicity, I'm doing a equality check between {@code x} and
+// {@code x'} that lets the algorithm continue to consume lookahead longer
+// than necessary. The reason I like the equality is of course the
+// simplicity but also because that is the test you need to detect the
+// alternatives that are actually in conflict.</p>
+//
+// <p><strong>CONTINUE/STOP RULE</strong></p>
+//
+// <p>Continue if union of resolved alternative sets from non-conflicting and
+// conflicting alternative subsets has more than one alternative. We are
+// uncertain about which alternative to predict.</p>
+//
+// <p>The complete set of alternatives, {@code [i for (_,i,_)]}, tells us which
+// alternatives are still in the running for the amount of input we've
+// consumed at this point. The conflicting sets let us to strip away
+// configurations that won't lead to more states because we resolve
+// conflicts to the configuration with a minimum alternate for the
+// conflicting set.</p>
+//
+// <p><strong>CASES</strong></p>
+//
+// <ul>
+//
+// <li>no conflicts and more than 1 alternative in set =&gt continue</li>
+//
+// <li> {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s, 3, z)},
+// {@code (s', 1, y)}, {@code (s', 2, y)} yields non-conflicting set
+// {@code {3}} U conflicting sets {@code min({1,2})} U {@code min({1,2})} =
+// {@code {1,3}} =&gt continue
+// </li>
+//
+// <li>{@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 1, y)},
+// {@code (s', 2, y)}, {@code (s'', 1, z)} yields non-conflicting set
+// {@code {1}} U conflicting sets {@code min({1,2})} U {@code min({1,2})} =
+// {@code {1}} =&gt stop and predict 1</li>
+//
+// <li>{@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 1, y)},
+// {@code (s', 2, y)} yields conflicting, reduced sets {@code {1}} U
+// {@code {1}} = {@code {1}} =&gt stop and predict 1, can announce
+// ambiguity {@code {1,2}}</li>
+//
+// <li>{@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 2, y)},
+// {@code (s', 3, y)} yields conflicting, reduced sets {@code {1}} U
+// {@code {2}} = {@code {1,2}} =&gt continue</li>
+//
+// <li>{@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 3, y)},
+// {@code (s', 4, y)} yields conflicting, reduced sets {@code {1}} U
+// {@code {3}} = {@code {1,3}} =&gt continue</li>
+//
+// </ul>
+//
+// <p><strong>EXACT AMBIGUITY DETECTION</strong></p>
+//
+// <p>If all states Report the same conflicting set of alternatives, then we
+// know we have the exact ambiguity set.</p>
+//
+// <p><code>|A_<em>i</em>|&gt1</code> and
+// <code>A_<em>i</em> = A_<em>j</em></code> for all <em>i</em>, <em>j</em>.</p>
+//
+// <p>In other words, we continue examining lookahead until all {@code A_i}
+// have more than one alternative and all {@code A_i} are the same. If
+// {@code A={{1,2}, {1,3}}}, then regular LL prediction would terminate
+// because the resolved set is {@code {1}}. To determine what the real
+// ambiguity is, we have to know whether the ambiguity is between one and
+// two or one and three so we keep going. We can only stop prediction when
+// we need exact ambiguity detection when the sets look like
+// {@code A={{1,2}}} or {@code {{1,2},{1,2}}}, etc...</p>
+//
+func PredictionModeresolvesToJustOneViableAlt(altsets []*BitSet) int {
+	return PredictionModegetSingleViableAlt(altsets)
+}
+
+//
+// Determines if every alternative subset in {@code altsets} contains more
+// than one alternative.
+//
+// @param altsets a collection of alternative subsets
+// @return {@code true} if every {@link BitSet} in {@code altsets} has
+// {@link BitSet//cardinality cardinality} &gt 1, otherwise {@code false}
+//
+func PredictionModeallSubsetsConflict(altsets []*BitSet) bool {
+	return !PredictionModehasNonConflictingAltSet(altsets)
+}
+
+//
+// Determines if any single alternative subset in {@code altsets} contains
+// exactly one alternative.
+//
+// @param altsets a collection of alternative subsets
+// @return {@code true} if {@code altsets} contains a {@link BitSet} with
+// {@link BitSet//cardinality cardinality} 1, otherwise {@code false}
+//
+func PredictionModehasNonConflictingAltSet(altsets []*BitSet) bool {
+	for i := 0; i < len(altsets); i++ {
+		alts := altsets[i]
+		if alts.length() == 1 {
+			return true
+		}
+	}
+	return false
+}
+
+//
+// Determines if any single alternative subset in {@code altsets} contains
+// more than one alternative.
+//
+// @param altsets a collection of alternative subsets
+// @return {@code true} if {@code altsets} contains a {@link BitSet} with
+// {@link BitSet//cardinality cardinality} &gt 1, otherwise {@code false}
+//
+func PredictionModehasConflictingAltSet(altsets []*BitSet) bool {
+	for i := 0; i < len(altsets); i++ {
+		alts := altsets[i]
+		if alts.length() > 1 {
+			return true
+		}
+	}
+	return false
+}
+
+//
+// Determines if every alternative subset in {@code altsets} is equivalent.
+//
+// @param altsets a collection of alternative subsets
+// @return {@code true} if every member of {@code altsets} is equal to the
+// others, otherwise {@code false}
+//
+func PredictionModeallSubsetsEqual(altsets []*BitSet) bool {
+	var first *BitSet
+
+	for i := 0; i < len(altsets); i++ {
+		alts := altsets[i]
+		if first == nil {
+			first = alts
+		} else if alts != first {
+			return false
+		}
+	}
+
+	return true
+}
+
+//
+// Returns the unique alternative predicted by all alternative subsets in
+// {@code altsets}. If no such alternative exists, this method returns
+// {@link ATN//INVALID_ALT_NUMBER}.
+//
+// @param altsets a collection of alternative subsets
+//
+func PredictionModegetUniqueAlt(altsets []*BitSet) int {
+	all := PredictionModeGetAlts(altsets)
+	if all.length() == 1 {
+		return all.minValue()
+	}
+
+	return ATNInvalidAltNumber
+}
+
+// Gets the complete set of represented alternatives for a collection of
+// alternative subsets. This method returns the union of each {@link BitSet}
+// in {@code altsets}.
+//
+// @param altsets a collection of alternative subsets
+// @return the set of represented alternatives in {@code altsets}
+//
+func PredictionModeGetAlts(altsets []*BitSet) *BitSet {
+	all := NewBitSet()
+	for _, alts := range altsets {
+		all.or(alts)
+	}
+	return all
+}
+
+//
+// This func gets the conflicting alt subsets from a configuration set.
+// For each configuration {@code c} in {@code configs}:
+//
+// <pre>
+// map[c] U= c.{@link ATNConfig//alt alt} // map hash/equals uses s and x, not
+// alt and not pred
+// </pre>
+//
+func PredictionModegetConflictingAltSubsets(configs ATNConfigSet) []*BitSet {
+	configToAlts := make(map[int]*BitSet)
+
+	for _, c := range configs.GetItems() {
+		key := 31 * c.GetState().GetStateNumber() + c.GetContext().hash()
+
+		alts, ok := configToAlts[key]
+		if !ok {
+			alts = NewBitSet()
+			configToAlts[key] = alts
+		}
+		alts.add(c.GetAlt())
+	}
+
+	values := make([]*BitSet, 0, 10)
+	for _, v := range configToAlts {
+		values = append(values, v)
+	}
+	return values
+}
+
+//
+// Get a map from state to alt subset from a configuration set. For each
+// configuration {@code c} in {@code configs}:
+//
+// <pre>
+// map[c.{@link ATNConfig//state state}] U= c.{@link ATNConfig//alt alt}
+// </pre>
+//
+func PredictionModeGetStateToAltMap(configs ATNConfigSet) *AltDict {
+	m := NewAltDict()
+
+	for _, c := range configs.GetItems() {
+		alts := m.Get(c.GetState().String())
+		if alts == nil {
+			alts = NewBitSet()
+			m.put(c.GetState().String(), alts)
+		}
+		alts.(*BitSet).add(c.GetAlt())
+	}
+	return m
+}
+
+func PredictionModehasStateAssociatedWithOneAlt(configs ATNConfigSet) bool {
+	values := PredictionModeGetStateToAltMap(configs).values()
+	for i := 0; i < len(values); i++ {
+		if values[i].(*BitSet).length() == 1 {
+			return true
+		}
+	}
+	return false
+}
+
+func PredictionModegetSingleViableAlt(altsets []*BitSet) int {
+	result := ATNInvalidAltNumber
+
+	for i := 0; i < len(altsets); i++ {
+		alts := altsets[i]
+		minAlt := alts.minValue()
+		if result == ATNInvalidAltNumber {
+			result = minAlt
+		} else if result != minAlt { // more than 1 viable alt
+			return ATNInvalidAltNumber
+		}
+	}
+	return result
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/recognizer.go

@@ -0,0 +1,217 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strings"
+
+	"strconv"
+)
+
+type Recognizer interface {
+	GetLiteralNames() []string
+	GetSymbolicNames() []string
+	GetRuleNames() []string
+
+	Sempred(RuleContext, int, int) bool
+	Precpred(RuleContext, int) bool
+
+	GetState() int
+	SetState(int)
+	Action(RuleContext, int, int)
+	AddErrorListener(ErrorListener)
+	RemoveErrorListeners()
+	GetATN() *ATN
+	GetErrorListenerDispatch() ErrorListener
+}
+
+type BaseRecognizer struct {
+	listeners []ErrorListener
+	state     int
+
+	RuleNames       []string
+	LiteralNames    []string
+	SymbolicNames   []string
+	GrammarFileName string
+}
+
+func NewBaseRecognizer() *BaseRecognizer {
+	rec := new(BaseRecognizer)
+	rec.listeners = []ErrorListener{ConsoleErrorListenerINSTANCE}
+	rec.state = -1
+	return rec
+}
+
+var tokenTypeMapCache = make(map[string]int)
+var ruleIndexMapCache = make(map[string]int)
+
+func (b *BaseRecognizer) checkVersion(toolVersion string) {
+	runtimeVersion := "4.9.2"
+	if runtimeVersion != toolVersion {
+		fmt.Println("ANTLR runtime and generated code versions disagree: " + runtimeVersion + "!=" + toolVersion)
+	}
+}
+
+func (b *BaseRecognizer) Action(context RuleContext, ruleIndex, actionIndex int) {
+	panic("action not implemented on Recognizer!")
+}
+
+func (b *BaseRecognizer) AddErrorListener(listener ErrorListener) {
+	b.listeners = append(b.listeners, listener)
+}
+
+func (b *BaseRecognizer) RemoveErrorListeners() {
+	b.listeners = make([]ErrorListener, 0)
+}
+
+func (b *BaseRecognizer) GetRuleNames() []string {
+	return b.RuleNames
+}
+
+func (b *BaseRecognizer) GetTokenNames() []string {
+	return b.LiteralNames
+}
+
+func (b *BaseRecognizer) GetSymbolicNames() []string {
+	return b.SymbolicNames
+}
+
+func (b *BaseRecognizer) GetLiteralNames() []string {
+	return b.LiteralNames
+}
+
+func (b *BaseRecognizer) GetState() int {
+	return b.state
+}
+
+func (b *BaseRecognizer) SetState(v int) {
+	b.state = v
+}
+
+//func (b *Recognizer) GetTokenTypeMap() {
+//    var tokenNames = b.GetTokenNames()
+//    if (tokenNames==nil) {
+//        panic("The current recognizer does not provide a list of token names.")
+//    }
+//    var result = tokenTypeMapCache[tokenNames]
+//    if(result==nil) {
+//        result = tokenNames.reduce(function(o, k, i) { o[k] = i })
+//        result.EOF = TokenEOF
+//        tokenTypeMapCache[tokenNames] = result
+//    }
+//    return result
+//}
+
+// Get a map from rule names to rule indexes.
+//
+// <p>Used for XPath and tree pattern compilation.</p>
+//
+func (b *BaseRecognizer) GetRuleIndexMap() map[string]int {
+
+	panic("Method not defined!")
+	//    var ruleNames = b.GetRuleNames()
+	//    if (ruleNames==nil) {
+	//        panic("The current recognizer does not provide a list of rule names.")
+	//    }
+	//
+	//    var result = ruleIndexMapCache[ruleNames]
+	//    if(result==nil) {
+	//        result = ruleNames.reduce(function(o, k, i) { o[k] = i })
+	//        ruleIndexMapCache[ruleNames] = result
+	//    }
+	//    return result
+}
+
+func (b *BaseRecognizer) GetTokenType(tokenName string) int {
+	panic("Method not defined!")
+	//    var ttype = b.GetTokenTypeMap()[tokenName]
+	//    if (ttype !=nil) {
+	//        return ttype
+	//    } else {
+	//        return TokenInvalidType
+	//    }
+}
+
+//func (b *Recognizer) GetTokenTypeMap() map[string]int {
+//    Vocabulary vocabulary = getVocabulary()
+//
+//    Synchronized (tokenTypeMapCache) {
+//        Map<String, Integer> result = tokenTypeMapCache.Get(vocabulary)
+//        if (result == null) {
+//            result = new HashMap<String, Integer>()
+//            for (int i = 0; i < GetATN().maxTokenType; i++) {
+//                String literalName = vocabulary.getLiteralName(i)
+//                if (literalName != null) {
+//                    result.put(literalName, i)
+//                }
+//
+//                String symbolicName = vocabulary.GetSymbolicName(i)
+//                if (symbolicName != null) {
+//                    result.put(symbolicName, i)
+//                }
+//            }
+//
+//            result.put("EOF", Token.EOF)
+//            result = Collections.unmodifiableMap(result)
+//            tokenTypeMapCache.put(vocabulary, result)
+//        }
+//
+//        return result
+//    }
+//}
+
+// What is the error header, normally line/character position information?//
+func (b *BaseRecognizer) GetErrorHeader(e RecognitionException) string {
+	line := e.GetOffendingToken().GetLine()
+	column := e.GetOffendingToken().GetColumn()
+	return "line " + strconv.Itoa(line) + ":" + strconv.Itoa(column)
+}
+
+// How should a token be displayed in an error message? The default
+//  is to display just the text, but during development you might
+//  want to have a lot of information spit out.  Override in that case
+//  to use t.String() (which, for CommonToken, dumps everything about
+//  the token). This is better than forcing you to override a method in
+//  your token objects because you don't have to go modify your lexer
+//  so that it creates a NewJava type.
+//
+// @deprecated This method is not called by the ANTLR 4 Runtime. Specific
+// implementations of {@link ANTLRErrorStrategy} may provide a similar
+// feature when necessary. For example, see
+// {@link DefaultErrorStrategy//GetTokenErrorDisplay}.
+//
+func (b *BaseRecognizer) GetTokenErrorDisplay(t Token) string {
+	if t == nil {
+		return "<no token>"
+	}
+	s := t.GetText()
+	if s == "" {
+		if t.GetTokenType() == TokenEOF {
+			s = "<EOF>"
+		} else {
+			s = "<" + strconv.Itoa(t.GetTokenType()) + ">"
+		}
+	}
+	s = strings.Replace(s, "\t", "\\t", -1)
+	s = strings.Replace(s, "\n", "\\n", -1)
+	s = strings.Replace(s, "\r", "\\r", -1)
+
+	return "'" + s + "'"
+}
+
+func (b *BaseRecognizer) GetErrorListenerDispatch() ErrorListener {
+	return NewProxyErrorListener(b.listeners)
+}
+
+// subclass needs to override these if there are sempreds or actions
+// that the ATN interp needs to execute
+func (b *BaseRecognizer) Sempred(localctx RuleContext, ruleIndex int, actionIndex int) bool {
+	return true
+}
+
+func (b *BaseRecognizer) Precpred(localctx RuleContext, precedence int) bool {
+	return true
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/rule_context.go

@@ -0,0 +1,114 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+//  A rule context is a record of a single rule invocation. It knows
+//  which context invoked it, if any. If there is no parent context, then
+//  naturally the invoking state is not valid.  The parent link
+//  provides a chain upwards from the current rule invocation to the root
+//  of the invocation tree, forming a stack. We actually carry no
+//  information about the rule associated with b context (except
+//  when parsing). We keep only the state number of the invoking state from
+//  the ATN submachine that invoked b. Contrast b with the s
+//  pointer inside ParserRuleContext that tracks the current state
+//  being "executed" for the current rule.
+//
+//  The parent contexts are useful for computing lookahead sets and
+//  getting error information.
+//
+//  These objects are used during parsing and prediction.
+//  For the special case of parsers, we use the subclass
+//  ParserRuleContext.
+//
+//  @see ParserRuleContext
+//
+
+type RuleContext interface {
+	RuleNode
+
+	GetInvokingState() int
+	SetInvokingState(int)
+
+	GetRuleIndex() int
+	IsEmpty() bool
+
+	GetAltNumber() int
+	SetAltNumber(altNumber int)
+
+	String([]string, RuleContext) string
+}
+
+type BaseRuleContext struct {
+	parentCtx     RuleContext
+	invokingState int
+	RuleIndex     int
+}
+
+func NewBaseRuleContext(parent RuleContext, invokingState int) *BaseRuleContext {
+
+	rn := new(BaseRuleContext)
+
+	// What context invoked b rule?
+	rn.parentCtx = parent
+
+	// What state invoked the rule associated with b context?
+	// The "return address" is the followState of invokingState
+	// If parent is nil, b should be -1.
+	if parent == nil {
+		rn.invokingState = -1
+	} else {
+		rn.invokingState = invokingState
+	}
+
+	return rn
+}
+
+func (b *BaseRuleContext) GetBaseRuleContext() *BaseRuleContext {
+	return b
+}
+
+func (b *BaseRuleContext) SetParent(v Tree) {
+	if v == nil {
+		b.parentCtx = nil
+	} else {
+		b.parentCtx = v.(RuleContext)
+	}
+}
+
+func (b *BaseRuleContext) GetInvokingState() int {
+	return b.invokingState
+}
+
+func (b *BaseRuleContext) SetInvokingState(t int) {
+	b.invokingState = t
+}
+
+func (b *BaseRuleContext) GetRuleIndex() int {
+	return b.RuleIndex
+}
+
+func (b *BaseRuleContext) GetAltNumber() int {
+	return ATNInvalidAltNumber
+}
+
+func (b *BaseRuleContext) SetAltNumber(altNumber int) {}
+
+// A context is empty if there is no invoking state meaning nobody call
+// current context.
+func (b *BaseRuleContext) IsEmpty() bool {
+	return b.invokingState == -1
+}
+
+// Return the combined text of all child nodes. This method only considers
+// tokens which have been added to the parse tree.
+// <p>
+// Since tokens on hidden channels (e.g. whitespace or comments) are not
+// added to the parse trees, they will not appear in the output of b
+// method.
+//
+
+func (b *BaseRuleContext) GetParent() Tree {
+	return b.parentCtx
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/semantic_context.go

@@ -0,0 +1,455 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// A tree structure used to record the semantic context in which
+//  an ATN configuration is valid.  It's either a single predicate,
+//  a conjunction {@code p1&&p2}, or a sum of products {@code p1||p2}.
+//
+//  <p>I have scoped the {@link AND}, {@link OR}, and {@link Predicate} subclasses of
+//  {@link SemanticContext} within the scope of this outer class.</p>
+//
+
+type SemanticContext interface {
+	comparable
+
+	evaluate(parser Recognizer, outerContext RuleContext) bool
+	evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext
+
+	hash() int
+	String() string
+}
+
+func SemanticContextandContext(a, b SemanticContext) SemanticContext {
+	if a == nil || a == SemanticContextNone {
+		return b
+	}
+	if b == nil || b == SemanticContextNone {
+		return a
+	}
+	result := NewAND(a, b)
+	if len(result.opnds) == 1 {
+		return result.opnds[0]
+	}
+
+	return result
+}
+
+func SemanticContextorContext(a, b SemanticContext) SemanticContext {
+	if a == nil {
+		return b
+	}
+	if b == nil {
+		return a
+	}
+	if a == SemanticContextNone || b == SemanticContextNone {
+		return SemanticContextNone
+	}
+	result := NewOR(a, b)
+	if len(result.opnds) == 1 {
+		return result.opnds[0]
+	}
+
+	return result
+}
+
+type Predicate struct {
+	ruleIndex      int
+	predIndex      int
+	isCtxDependent bool
+}
+
+func NewPredicate(ruleIndex, predIndex int, isCtxDependent bool) *Predicate {
+	p := new(Predicate)
+
+	p.ruleIndex = ruleIndex
+	p.predIndex = predIndex
+	p.isCtxDependent = isCtxDependent // e.g., $i ref in pred
+	return p
+}
+
+//The default {@link SemanticContext}, which is semantically equivalent to
+//a predicate of the form {@code {true}?}.
+
+var SemanticContextNone SemanticContext = NewPredicate(-1, -1, false)
+
+func (p *Predicate) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext {
+	return p
+}
+
+func (p *Predicate) evaluate(parser Recognizer, outerContext RuleContext) bool {
+
+	var localctx RuleContext
+
+	if p.isCtxDependent {
+		localctx = outerContext
+	}
+
+	return parser.Sempred(localctx, p.ruleIndex, p.predIndex)
+}
+
+func (p *Predicate) equals(other interface{}) bool {
+	if p == other {
+		return true
+	} else if _, ok := other.(*Predicate); !ok {
+		return false
+	} else {
+		return p.ruleIndex == other.(*Predicate).ruleIndex &&
+			p.predIndex == other.(*Predicate).predIndex &&
+			p.isCtxDependent == other.(*Predicate).isCtxDependent
+	}
+}
+
+func (p *Predicate) hash() int {
+	return p.ruleIndex*43 + p.predIndex*47
+}
+
+func (p *Predicate) String() string {
+	return "{" + strconv.Itoa(p.ruleIndex) + ":" + strconv.Itoa(p.predIndex) + "}?"
+}
+
+type PrecedencePredicate struct {
+	precedence int
+}
+
+func NewPrecedencePredicate(precedence int) *PrecedencePredicate {
+
+	p := new(PrecedencePredicate)
+	p.precedence = precedence
+
+	return p
+}
+
+func (p *PrecedencePredicate) evaluate(parser Recognizer, outerContext RuleContext) bool {
+	return parser.Precpred(outerContext, p.precedence)
+}
+
+func (p *PrecedencePredicate) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext {
+	if parser.Precpred(outerContext, p.precedence) {
+		return SemanticContextNone
+	}
+
+	return nil
+}
+
+func (p *PrecedencePredicate) compareTo(other *PrecedencePredicate) int {
+	return p.precedence - other.precedence
+}
+
+func (p *PrecedencePredicate) equals(other interface{}) bool {
+	if p == other {
+		return true
+	} else if _, ok := other.(*PrecedencePredicate); !ok {
+		return false
+	} else {
+		return p.precedence == other.(*PrecedencePredicate).precedence
+	}
+}
+
+func (p *PrecedencePredicate) hash() int {
+	return p.precedence * 51
+}
+
+func (p *PrecedencePredicate) String() string {
+	return "{" + strconv.Itoa(p.precedence) + ">=prec}?"
+}
+
+func PrecedencePredicatefilterPrecedencePredicates(set *Set) []*PrecedencePredicate {
+	result := make([]*PrecedencePredicate, 0)
+
+	for _, v := range set.values() {
+		if c2, ok := v.(*PrecedencePredicate); ok {
+			result = append(result, c2)
+		}
+	}
+
+	return result
+}
+
+// A semantic context which is true whenever none of the contained contexts
+// is false.`
+
+type AND struct {
+	opnds []SemanticContext
+}
+
+func NewAND(a, b SemanticContext) *AND {
+
+	operands := NewSet(nil, nil)
+	if aa, ok := a.(*AND); ok {
+		for _, o := range aa.opnds {
+			operands.add(o)
+		}
+	} else {
+		operands.add(a)
+	}
+
+	if ba, ok := b.(*AND); ok {
+		for _, o := range ba.opnds {
+			operands.add(o)
+		}
+	} else {
+		operands.add(b)
+	}
+	precedencePredicates := PrecedencePredicatefilterPrecedencePredicates(operands)
+	if len(precedencePredicates) > 0 {
+		// interested in the transition with the lowest precedence
+		var reduced *PrecedencePredicate
+
+		for _, p := range precedencePredicates {
+			if reduced == nil || p.precedence < reduced.precedence {
+				reduced = p
+			}
+		}
+
+		operands.add(reduced)
+	}
+
+	vs := operands.values()
+	opnds := make([]SemanticContext, len(vs))
+	for i, v := range vs {
+		opnds[i] = v.(SemanticContext)
+	}
+
+	and := new(AND)
+	and.opnds = opnds
+
+	return and
+}
+
+func (a *AND) equals(other interface{}) bool {
+	if a == other {
+		return true
+	} else if _, ok := other.(*AND); !ok {
+		return false
+	} else {
+		for i, v := range other.(*AND).opnds {
+			if !a.opnds[i].equals(v) {
+				return false
+			}
+		}
+		return true
+	}
+}
+
+//
+// {@inheritDoc}
+//
+// <p>
+// The evaluation of predicates by a context is short-circuiting, but
+// unordered.</p>
+//
+func (a *AND) evaluate(parser Recognizer, outerContext RuleContext) bool {
+	for i := 0; i < len(a.opnds); i++ {
+		if !a.opnds[i].evaluate(parser, outerContext) {
+			return false
+		}
+	}
+	return true
+}
+
+func (a *AND) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext {
+	differs := false
+	operands := make([]SemanticContext, 0)
+
+	for i := 0; i < len(a.opnds); i++ {
+		context := a.opnds[i]
+		evaluated := context.evalPrecedence(parser, outerContext)
+		differs = differs || (evaluated != context)
+		if evaluated == nil {
+			// The AND context is false if any element is false
+			return nil
+		} else if evaluated != SemanticContextNone {
+			// Reduce the result by Skipping true elements
+			operands = append(operands, evaluated)
+		}
+	}
+	if !differs {
+		return a
+	}
+
+	if len(operands) == 0 {
+		// all elements were true, so the AND context is true
+		return SemanticContextNone
+	}
+
+	var result SemanticContext
+
+	for _, o := range operands {
+		if result == nil {
+			result = o
+		} else {
+			result = SemanticContextandContext(result, o)
+		}
+	}
+
+	return result
+}
+
+func (a *AND) hash() int {
+	h := murmurInit(37) // Init with a value different from OR
+	for _, op := range a.opnds {
+		h = murmurUpdate(h, op.hash())
+	}
+	return murmurFinish(h, len(a.opnds))
+}
+
+func (a *OR) hash() int {
+	h := murmurInit(41) // Init with a value different from AND
+	for _, op := range a.opnds {
+		h = murmurUpdate(h, op.hash())
+	}
+	return murmurFinish(h, len(a.opnds))
+}
+
+func (a *AND) String() string {
+	s := ""
+
+	for _, o := range a.opnds {
+		s += "&& " + fmt.Sprint(o)
+	}
+
+	if len(s) > 3 {
+		return s[0:3]
+	}
+
+	return s
+}
+
+//
+// A semantic context which is true whenever at least one of the contained
+// contexts is true.
+//
+
+type OR struct {
+	opnds []SemanticContext
+}
+
+func NewOR(a, b SemanticContext) *OR {
+
+	operands := NewSet(nil, nil)
+	if aa, ok := a.(*OR); ok {
+		for _, o := range aa.opnds {
+			operands.add(o)
+		}
+	} else {
+		operands.add(a)
+	}
+
+	if ba, ok := b.(*OR); ok {
+		for _, o := range ba.opnds {
+			operands.add(o)
+		}
+	} else {
+		operands.add(b)
+	}
+	precedencePredicates := PrecedencePredicatefilterPrecedencePredicates(operands)
+	if len(precedencePredicates) > 0 {
+		// interested in the transition with the lowest precedence
+		var reduced *PrecedencePredicate
+
+		for _, p := range precedencePredicates {
+			if reduced == nil || p.precedence > reduced.precedence {
+				reduced = p
+			}
+		}
+
+		operands.add(reduced)
+	}
+
+	vs := operands.values()
+
+	opnds := make([]SemanticContext, len(vs))
+	for i, v := range vs {
+		opnds[i] = v.(SemanticContext)
+	}
+
+	o := new(OR)
+	o.opnds = opnds
+
+	return o
+}
+
+func (o *OR) equals(other interface{}) bool {
+	if o == other {
+		return true
+	} else if _, ok := other.(*OR); !ok {
+		return false
+	} else {
+		for i, v := range other.(*OR).opnds {
+			if !o.opnds[i].equals(v) {
+				return false
+			}
+		}
+		return true
+	}
+}
+
+// <p>
+// The evaluation of predicates by o context is short-circuiting, but
+// unordered.</p>
+//
+func (o *OR) evaluate(parser Recognizer, outerContext RuleContext) bool {
+	for i := 0; i < len(o.opnds); i++ {
+		if o.opnds[i].evaluate(parser, outerContext) {
+			return true
+		}
+	}
+	return false
+}
+
+func (o *OR) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext {
+	differs := false
+	operands := make([]SemanticContext, 0)
+	for i := 0; i < len(o.opnds); i++ {
+		context := o.opnds[i]
+		evaluated := context.evalPrecedence(parser, outerContext)
+		differs = differs || (evaluated != context)
+		if evaluated == SemanticContextNone {
+			// The OR context is true if any element is true
+			return SemanticContextNone
+		} else if evaluated != nil {
+			// Reduce the result by Skipping false elements
+			operands = append(operands, evaluated)
+		}
+	}
+	if !differs {
+		return o
+	}
+	if len(operands) == 0 {
+		// all elements were false, so the OR context is false
+		return nil
+	}
+	var result SemanticContext
+
+	for _, o := range operands {
+		if result == nil {
+			result = o
+		} else {
+			result = SemanticContextorContext(result, o)
+		}
+	}
+
+	return result
+}
+
+func (o *OR) String() string {
+	s := ""
+
+	for _, o := range o.opnds {
+		s += "|| " + fmt.Sprint(o)
+	}
+
+	if len(s) > 3 {
+		return s[0:3]
+	}
+
+	return s
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/token.go

@@ -0,0 +1,210 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"strconv"
+	"strings"
+)
+
+type TokenSourceCharStreamPair struct {
+	tokenSource TokenSource
+	charStream  CharStream
+}
+
+// A token has properties: text, type, line, character position in the line
+// (so we can ignore tabs), token channel, index, and source from which
+// we obtained this token.
+
+type Token interface {
+	GetSource() *TokenSourceCharStreamPair
+	GetTokenType() int
+	GetChannel() int
+	GetStart() int
+	GetStop() int
+	GetLine() int
+	GetColumn() int
+
+	GetText() string
+	SetText(s string)
+
+	GetTokenIndex() int
+	SetTokenIndex(v int)
+
+	GetTokenSource() TokenSource
+	GetInputStream() CharStream
+}
+
+type BaseToken struct {
+	source     *TokenSourceCharStreamPair
+	tokenType  int    // token type of the token
+	channel    int    // The parser ignores everything not on DEFAULT_CHANNEL
+	start      int    // optional return -1 if not implemented.
+	stop       int    // optional return -1 if not implemented.
+	tokenIndex int    // from 0..n-1 of the token object in the input stream
+	line       int    // line=1..n of the 1st character
+	column     int    // beginning of the line at which it occurs, 0..n-1
+	text       string // text of the token.
+	readOnly   bool
+}
+
+const (
+	TokenInvalidType = 0
+
+	// During lookahead operations, this "token" signifies we hit rule end ATN state
+	// and did not follow it despite needing to.
+	TokenEpsilon = -2
+
+	TokenMinUserTokenType = 1
+
+	TokenEOF = -1
+
+	// All tokens go to the parser (unless Skip() is called in that rule)
+	// on a particular "channel". The parser tunes to a particular channel
+	// so that whitespace etc... can go to the parser on a "hidden" channel.
+
+	TokenDefaultChannel = 0
+
+	// Anything on different channel than DEFAULT_CHANNEL is not parsed
+	// by parser.
+
+	TokenHiddenChannel = 1
+)
+
+func (b *BaseToken) GetChannel() int {
+	return b.channel
+}
+
+func (b *BaseToken) GetStart() int {
+	return b.start
+}
+
+func (b *BaseToken) GetStop() int {
+	return b.stop
+}
+
+func (b *BaseToken) GetLine() int {
+	return b.line
+}
+
+func (b *BaseToken) GetColumn() int {
+	return b.column
+}
+
+func (b *BaseToken) GetTokenType() int {
+	return b.tokenType
+}
+
+func (b *BaseToken) GetSource() *TokenSourceCharStreamPair {
+	return b.source
+}
+
+func (b *BaseToken) GetTokenIndex() int {
+	return b.tokenIndex
+}
+
+func (b *BaseToken) SetTokenIndex(v int) {
+	b.tokenIndex = v
+}
+
+func (b *BaseToken) GetTokenSource() TokenSource {
+	return b.source.tokenSource
+}
+
+func (b *BaseToken) GetInputStream() CharStream {
+	return b.source.charStream
+}
+
+type CommonToken struct {
+	*BaseToken
+}
+
+func NewCommonToken(source *TokenSourceCharStreamPair, tokenType, channel, start, stop int) *CommonToken {
+
+	t := new(CommonToken)
+
+	t.BaseToken = new(BaseToken)
+
+	t.source = source
+	t.tokenType = tokenType
+	t.channel = channel
+	t.start = start
+	t.stop = stop
+	t.tokenIndex = -1
+	if t.source.tokenSource != nil {
+		t.line = source.tokenSource.GetLine()
+		t.column = source.tokenSource.GetCharPositionInLine()
+	} else {
+		t.column = -1
+	}
+	return t
+}
+
+// An empty {@link Pair} which is used as the default value of
+// {@link //source} for tokens that do not have a source.
+
+//CommonToken.EMPTY_SOURCE = [ nil, nil ]
+
+// Constructs a New{@link CommonToken} as a copy of another {@link Token}.
+//
+// <p>
+// If {@code oldToken} is also a {@link CommonToken} instance, the newly
+// constructed token will share a reference to the {@link //text} field and
+// the {@link Pair} stored in {@link //source}. Otherwise, {@link //text} will
+// be assigned the result of calling {@link //GetText}, and {@link //source}
+// will be constructed from the result of {@link Token//GetTokenSource} and
+// {@link Token//GetInputStream}.</p>
+//
+// @param oldToken The token to copy.
+//
+func (c *CommonToken) clone() *CommonToken {
+	t := NewCommonToken(c.source, c.tokenType, c.channel, c.start, c.stop)
+	t.tokenIndex = c.GetTokenIndex()
+	t.line = c.GetLine()
+	t.column = c.GetColumn()
+	t.text = c.GetText()
+	return t
+}
+
+func (c *CommonToken) GetText() string {
+	if c.text != "" {
+		return c.text
+	}
+	input := c.GetInputStream()
+	if input == nil {
+		return ""
+	}
+	n := input.Size()
+	if c.start < n && c.stop < n {
+		return input.GetTextFromInterval(NewInterval(c.start, c.stop))
+	}
+	return "<EOF>"
+}
+
+func (c *CommonToken) SetText(text string) {
+	c.text = text
+}
+
+func (c *CommonToken) String() string {
+	txt := c.GetText()
+	if txt != "" {
+		txt = strings.Replace(txt, "\n", "\\n", -1)
+		txt = strings.Replace(txt, "\r", "\\r", -1)
+		txt = strings.Replace(txt, "\t", "\\t", -1)
+	} else {
+		txt = "<no text>"
+	}
+
+	var ch string
+	if c.channel > 0 {
+		ch = ",channel=" + strconv.Itoa(c.channel)
+	} else {
+		ch = ""
+	}
+
+	return "[@" + strconv.Itoa(c.tokenIndex) + "," + strconv.Itoa(c.start) + ":" + strconv.Itoa(c.stop) + "='" +
+		txt + "',<" + strconv.Itoa(c.tokenType) + ">" +
+		ch + "," + strconv.Itoa(c.line) + ":" + strconv.Itoa(c.column) + "]"
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/token_source.go

@@ -0,0 +1,17 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+type TokenSource interface {
+	NextToken() Token
+	Skip()
+	More()
+	GetLine() int
+	GetCharPositionInLine() int
+	GetInputStream() CharStream
+	GetSourceName() string
+	setTokenFactory(factory TokenFactory)
+	GetTokenFactory() TokenFactory
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/token_stream.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+type TokenStream interface {
+	IntStream
+
+	LT(k int) Token
+
+	Get(index int) Token
+	GetTokenSource() TokenSource
+	SetTokenSource(TokenSource)
+
+	GetAllText() string
+	GetTextFromInterval(*Interval) string
+	GetTextFromRuleContext(RuleContext) string
+	GetTextFromTokens(Token, Token) string
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/tokenstream_rewriter.go

@@ -0,0 +1,649 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+package antlr
+
+import (
+"bytes"
+"fmt"
+)
+
+
+// 
+// Useful for rewriting out a buffered input token stream after doing some
+// augmentation or other manipulations on it.
+
+// <p>
+// You can insert stuff, replace, and delete chunks. Note that the operations
+// are done lazily--only if you convert the buffer to a {@link String} with
+// {@link TokenStream#getText()}. This is very efficient because you are not
+// moving data around all the time. As the buffer of tokens is converted to
+// strings, the {@link #getText()} method(s) scan the input token stream and
+// check to see if there is an operation at the current index. If so, the
+// operation is done and then normal {@link String} rendering continues on the
+// buffer. This is like having multiple Turing machine instruction streams
+// (programs) operating on a single input tape. :)</p>
+// <p>
+
+// This rewriter makes no modifications to the token stream. It does not ask the
+// stream to fill itself up nor does it advance the input cursor. The token
+// stream {@link TokenStream#index()} will return the same value before and
+// after any {@link #getText()} call.</p>
+
+// <p>
+// The rewriter only works on tokens that you have in the buffer and ignores the
+// current input cursor. If you are buffering tokens on-demand, calling
+// {@link #getText()} halfway through the input will only do rewrites for those
+// tokens in the first half of the file.</p>
+
+// <p>
+// Since the operations are done lazily at {@link #getText}-time, operations do
+// not screw up the token index values. That is, an insert operation at token
+// index {@code i} does not change the index values for tokens
+// {@code i}+1..n-1.</p>
+
+// <p>
+// Because operations never actually alter the buffer, you may always get the
+// original token stream back without undoing anything. Since the instructions
+// are queued up, you can easily simulate transactions and roll back any changes
+// if there is an error just by removing instructions. For example,</p>
+
+// <pre>
+// CharStream input = new ANTLRFileStream("input");
+// TLexer lex = new TLexer(input);
+// CommonTokenStream tokens = new CommonTokenStream(lex);
+// T parser = new T(tokens);
+// TokenStreamRewriter rewriter = new TokenStreamRewriter(tokens);
+// parser.startRule();
+// </pre>
+
+// <p>
+// Then in the rules, you can execute (assuming rewriter is visible):</p>
+
+// <pre>
+// Token t,u;
+// ...
+// rewriter.insertAfter(t, "text to put after t");}
+// rewriter.insertAfter(u, "text after u");}
+// System.out.println(rewriter.getText());
+// </pre>
+
+// <p>
+// You can also have multiple "instruction streams" and get multiple rewrites
+// from a single pass over the input. Just name the instruction streams and use
+// that name again when printing the buffer. This could be useful for generating
+// a C file and also its header file--all from the same buffer:</p>
+
+// <pre>
+// rewriter.insertAfter("pass1", t, "text to put after t");}
+// rewriter.insertAfter("pass2", u, "text after u");}
+// System.out.println(rewriter.getText("pass1"));
+// System.out.println(rewriter.getText("pass2"));
+// </pre>
+
+// <p>
+// If you don't use named rewrite streams, a "default" stream is used as the
+// first example shows.</p>
+
+
+
+const(
+	Default_Program_Name = "default"
+	Program_Init_Size = 100
+	Min_Token_Index = 0
+)
+
+// Define the rewrite operation hierarchy
+
+type RewriteOperation interface {
+	// Execute the rewrite operation by possibly adding to the buffer.
+	// Return the index of the next token to operate on.
+	Execute(buffer *bytes.Buffer)	int
+	String()			string
+	GetInstructionIndex()		int
+	GetIndex()			int
+	GetText()			string
+	GetOpName()			string
+	GetTokens()			TokenStream
+	SetInstructionIndex(val int)
+	SetIndex(int)
+	SetText(string)
+	SetOpName(string)
+	SetTokens(TokenStream)
+}
+
+type BaseRewriteOperation struct {
+	//Current index of rewrites list
+	instruction_index		int
+	//Token buffer index
+	index				int
+	//Substitution text
+	text				string
+	//Actual operation name
+	op_name				string
+	//Pointer to token steam
+	tokens				TokenStream
+}
+
+func (op *BaseRewriteOperation)GetInstructionIndex() int{
+	return op.instruction_index
+}
+
+func (op *BaseRewriteOperation)GetIndex() int{
+	return op.index
+}
+
+func (op *BaseRewriteOperation)GetText() string{
+	return op.text
+}
+
+func (op *BaseRewriteOperation)GetOpName() string{
+	return op.op_name
+}
+
+func (op *BaseRewriteOperation)GetTokens() TokenStream{
+	return op.tokens
+}
+
+func (op *BaseRewriteOperation)SetInstructionIndex(val int){
+	op.instruction_index = val
+}
+
+func (op *BaseRewriteOperation)SetIndex(val int) {
+	op.index = val
+}
+
+func (op *BaseRewriteOperation)SetText(val string){
+	op.text = val
+}
+
+func (op *BaseRewriteOperation)SetOpName(val string){
+	op.op_name = val
+}
+
+func (op *BaseRewriteOperation)SetTokens(val TokenStream)  {
+	op.tokens = val
+}
+
+
+func (op *BaseRewriteOperation) Execute(buffer *bytes.Buffer) int{
+	return op.index
+}
+
+func (op *BaseRewriteOperation) String() string  {
+	return fmt.Sprintf("<%s@%d:\"%s\">",
+		op.op_name,
+		op.tokens.Get(op.GetIndex()),
+		op.text,
+	)
+
+}
+
+
+type InsertBeforeOp struct {
+	BaseRewriteOperation
+}
+
+func NewInsertBeforeOp(index int, text string, stream TokenStream) *InsertBeforeOp{
+	return &InsertBeforeOp{BaseRewriteOperation:BaseRewriteOperation{
+		index:index,
+		text:text,
+		op_name:"InsertBeforeOp",
+		tokens:stream,
+	}}
+}
+
+func (op *InsertBeforeOp) Execute(buffer *bytes.Buffer) int{
+	buffer.WriteString(op.text)
+	if op.tokens.Get(op.index).GetTokenType() != TokenEOF{
+		buffer.WriteString(op.tokens.Get(op.index).GetText())
+	}
+	return op.index+1
+}
+
+func (op *InsertBeforeOp) String() string {
+	return op.BaseRewriteOperation.String()
+}
+
+// Distinguish between insert after/before to do the "insert afters"
+//  first and then the "insert befores" at same index. Implementation
+//  of "insert after" is "insert before index+1".
+
+type InsertAfterOp struct {
+	BaseRewriteOperation
+}
+
+func NewInsertAfterOp(index int, text string, stream TokenStream) *InsertAfterOp{
+	return &InsertAfterOp{BaseRewriteOperation:BaseRewriteOperation{
+		index:index+1,
+		text:text,
+		tokens:stream,
+	}}
+}
+
+func (op *InsertAfterOp) Execute(buffer *bytes.Buffer) int {
+	buffer.WriteString(op.text)
+	if op.tokens.Get(op.index).GetTokenType() != TokenEOF{
+		buffer.WriteString(op.tokens.Get(op.index).GetText())
+	}
+	return op.index+1
+}
+
+func (op *InsertAfterOp) String() string {
+	return op.BaseRewriteOperation.String()
+}
+
+// I'm going to try replacing range from x..y with (y-x)+1 ReplaceOp
+// instructions.
+type ReplaceOp struct{
+	BaseRewriteOperation
+	LastIndex int
+}
+
+func NewReplaceOp(from, to int, text string, stream TokenStream)*ReplaceOp {
+	return &ReplaceOp{
+		BaseRewriteOperation:BaseRewriteOperation{
+			index:from,
+			text:text,
+			op_name:"ReplaceOp",
+			tokens:stream,
+		},
+		LastIndex:to,
+	}
+}
+
+func (op *ReplaceOp)Execute(buffer *bytes.Buffer) int{
+	if op.text != ""{
+		buffer.WriteString(op.text)
+	}
+	return op.LastIndex +1
+}
+
+func (op *ReplaceOp) String() string {
+	if op.text == "" {
+		return fmt.Sprintf("<DeleteOP@%d..%d>",
+			op.tokens.Get(op.index), op.tokens.Get(op.LastIndex))
+	}
+	return fmt.Sprintf("<ReplaceOp@%d..%d:\"%s\">",
+		op.tokens.Get(op.index), op.tokens.Get(op.LastIndex), op.text)
+}
+
+
+type TokenStreamRewriter struct {
+	//Our source stream
+	tokens						TokenStream
+	// You may have multiple, named streams of rewrite operations.
+	//  I'm calling these things "programs."
+	//  Maps String (name) &rarr; rewrite (List)
+	programs					map[string][]RewriteOperation
+	last_rewrite_token_indexes	map[string]int
+}
+
+func NewTokenStreamRewriter(tokens TokenStream) *TokenStreamRewriter{
+	return &TokenStreamRewriter{
+		tokens:						tokens,
+		programs:					map[string][]RewriteOperation{
+			Default_Program_Name:make([]RewriteOperation,0, Program_Init_Size),
+		},
+		last_rewrite_token_indexes:	map[string]int{},
+	}
+}
+
+func (tsr *TokenStreamRewriter) GetTokenStream() TokenStream{
+	return tsr.tokens
+}
+
+//  Rollback the instruction stream for a program so that
+//  the indicated instruction (via instructionIndex) is no
+//  longer in the stream. UNTESTED!
+func (tsr *TokenStreamRewriter) Rollback(program_name string, instruction_index int){
+	is, ok  := tsr.programs[program_name]
+	if ok{
+		tsr.programs[program_name] = is[Min_Token_Index:instruction_index]
+	}
+}
+
+func (tsr *TokenStreamRewriter) RollbackDefault(instruction_index int){
+	tsr.Rollback(Default_Program_Name, instruction_index)
+}
+//Reset the program so that no instructions exist
+func (tsr *TokenStreamRewriter) DeleteProgram(program_name string){
+	tsr.Rollback(program_name, Min_Token_Index) //TODO: double test on that cause lower bound is not included
+}
+
+func (tsr *TokenStreamRewriter) DeleteProgramDefault(){
+	tsr.DeleteProgram(Default_Program_Name)
+}
+
+func (tsr *TokenStreamRewriter) InsertAfter(program_name string, index int, text string){
+	// to insert after, just insert before next index (even if past end)
+	var op RewriteOperation = NewInsertAfterOp(index, text, tsr.tokens)
+	rewrites := tsr.GetProgram(program_name)
+	op.SetInstructionIndex(len(rewrites))
+	tsr.AddToProgram(program_name, op)
+}
+
+func (tsr *TokenStreamRewriter) InsertAfterDefault(index int, text string){
+	tsr.InsertAfter(Default_Program_Name, index, text)
+}
+
+func (tsr *TokenStreamRewriter) InsertAfterToken(program_name string, token Token, text string){
+	tsr.InsertAfter(program_name, token.GetTokenIndex(), text)
+}
+
+func (tsr* TokenStreamRewriter) InsertBefore(program_name string, index int, text string){
+	var op RewriteOperation = NewInsertBeforeOp(index, text, tsr.tokens)
+	rewrites := tsr.GetProgram(program_name)
+	op.SetInstructionIndex(len(rewrites))
+	tsr.AddToProgram(program_name, op)
+}
+
+func (tsr *TokenStreamRewriter) InsertBeforeDefault(index int, text string){
+	tsr.InsertBefore(Default_Program_Name, index, text)
+}
+
+func (tsr *TokenStreamRewriter) InsertBeforeToken(program_name string,token Token, text string){
+	tsr.InsertBefore(program_name, token.GetTokenIndex(), text)
+}
+
+func (tsr *TokenStreamRewriter) Replace(program_name string, from, to int, text string){
+	if from > to || from < 0 || to < 0 || to >= tsr.tokens.Size(){
+		panic(fmt.Sprintf("replace: range invalid: %d..%d(size=%d)",
+			from, to, tsr.tokens.Size()))
+	}
+	var op RewriteOperation = NewReplaceOp(from, to, text, tsr.tokens)
+	rewrites := tsr.GetProgram(program_name)
+	op.SetInstructionIndex(len(rewrites))
+	tsr.AddToProgram(program_name, op)
+}
+
+func (tsr *TokenStreamRewriter)ReplaceDefault(from, to int, text string)  {
+	tsr.Replace(Default_Program_Name, from, to, text)
+}
+
+func (tsr *TokenStreamRewriter)ReplaceDefaultPos(index int, text string){
+	tsr.ReplaceDefault(index, index, text)
+}
+
+func (tsr *TokenStreamRewriter)ReplaceToken(program_name string, from, to Token, text string){
+	tsr.Replace(program_name, from.GetTokenIndex(), to.GetTokenIndex(), text)
+}
+
+func (tsr *TokenStreamRewriter)ReplaceTokenDefault(from, to Token, text string){
+	tsr.ReplaceToken(Default_Program_Name, from, to, text)
+}
+
+func (tsr *TokenStreamRewriter)ReplaceTokenDefaultPos(index Token, text string){
+	tsr.ReplaceTokenDefault(index, index, text)
+}
+
+func (tsr *TokenStreamRewriter)Delete(program_name string, from, to int){
+	tsr.Replace(program_name, from, to, "" )
+}
+
+func (tsr *TokenStreamRewriter)DeleteDefault(from, to int){
+	tsr.Delete(Default_Program_Name, from, to)
+}
+
+func (tsr *TokenStreamRewriter)DeleteDefaultPos(index int){
+	tsr.DeleteDefault(index,index)
+}
+
+func (tsr *TokenStreamRewriter)DeleteToken(program_name string, from, to Token)  {
+	tsr.ReplaceToken(program_name, from, to, "")
+}
+
+func (tsr *TokenStreamRewriter)DeleteTokenDefault(from,to Token){
+	tsr.DeleteToken(Default_Program_Name, from, to)
+}
+
+func (tsr *TokenStreamRewriter)GetLastRewriteTokenIndex(program_name string)int  {
+	i, ok := tsr.last_rewrite_token_indexes[program_name]
+	if !ok{
+		return -1
+	}
+	return i
+}
+
+func (tsr *TokenStreamRewriter)GetLastRewriteTokenIndexDefault()int{
+	return tsr.GetLastRewriteTokenIndex(Default_Program_Name)
+}
+
+func (tsr *TokenStreamRewriter)SetLastRewriteTokenIndex(program_name string, i int){
+	tsr.last_rewrite_token_indexes[program_name] = i
+}
+
+func (tsr *TokenStreamRewriter)InitializeProgram(name string)[]RewriteOperation{
+	is := make([]RewriteOperation, 0, Program_Init_Size)
+	tsr.programs[name] = is
+	return is
+}
+
+func (tsr *TokenStreamRewriter)AddToProgram(name string, op RewriteOperation){
+	is := tsr.GetProgram(name)
+	is = append(is, op)
+	tsr.programs[name] = is
+}
+
+func (tsr *TokenStreamRewriter)GetProgram(name string) []RewriteOperation  {
+	is, ok := tsr.programs[name]
+	if !ok{
+		is = tsr.InitializeProgram(name)
+	}
+	return is
+}
+//  Return the text from the original tokens altered per the
+//  instructions given to this rewriter.
+func (tsr *TokenStreamRewriter)GetTextDefault() string{
+	return tsr.GetText(
+		Default_Program_Name,
+		NewInterval(0, tsr.tokens.Size()-1))
+}
+//  Return the text from the original tokens altered per the
+//  instructions given to this rewriter.
+func (tsr *TokenStreamRewriter)GetText(program_name string, interval *Interval) string  {
+	rewrites := tsr.programs[program_name]
+	start := interval.Start
+	stop  := interval.Stop
+	// ensure start/end are in range
+	stop = min(stop, tsr.tokens.Size()-1)
+	start = max(start,0)
+	if rewrites == nil || len(rewrites) == 0{
+		return tsr.tokens.GetTextFromInterval(interval) // no instructions to execute
+	}
+	buf := bytes.Buffer{}
+	// First, optimize instruction stream
+	indexToOp := reduceToSingleOperationPerIndex(rewrites)
+	// Walk buffer, executing instructions and emitting tokens
+	for i:=start; i<=stop && i<tsr.tokens.Size();{
+		op := indexToOp[i]
+		delete(indexToOp, i)// remove so any left have index size-1
+		t := tsr.tokens.Get(i)
+		if op == nil{
+			// no operation at that index, just dump token
+			if t.GetTokenType() != TokenEOF {buf.WriteString(t.GetText())}
+			i++ // move to next token
+		}else {
+			i = op.Execute(&buf)// execute operation and skip
+		}
+	}
+	// include stuff after end if it's last index in buffer
+	// So, if they did an insertAfter(lastValidIndex, "foo"), include
+	// foo if end==lastValidIndex.
+	if stop == tsr.tokens.Size()-1{
+		// Scan any remaining operations after last token
+		// should be included (they will be inserts).
+		for _, op := range indexToOp{
+			if op.GetIndex() >= tsr.tokens.Size()-1 {buf.WriteString(op.GetText())}
+		}
+	}
+	return buf.String()
+}
+
+//  We need to combine operations and report invalid operations (like
+//  overlapping replaces that are not completed nested). Inserts to
+//  same index need to be combined etc...  Here are the cases:
+//
+//  I.i.u I.j.v								leave alone, nonoverlapping
+//  I.i.u I.i.v								combine: Iivu
+//
+//  R.i-j.u R.x-y.v	| i-j in x-y			delete first R
+//  R.i-j.u R.i-j.v							delete first R
+//  R.i-j.u R.x-y.v	| x-y in i-j			ERROR
+//  R.i-j.u R.x-y.v	| boundaries overlap	ERROR
+//
+//  Delete special case of replace (text==null):
+//  D.i-j.u D.x-y.v	| boundaries overlap	combine to max(min)..max(right)
+//
+//  I.i.u R.x-y.v | i in (x+1)-y			delete I (since insert before
+//											we're not deleting i)
+//  I.i.u R.x-y.v | i not in (x+1)-y		leave alone, nonoverlapping
+//  R.x-y.v I.i.u | i in x-y				ERROR
+//  R.x-y.v I.x.u 							R.x-y.uv (combine, delete I)
+//  R.x-y.v I.i.u | i not in x-y			leave alone, nonoverlapping
+//
+//  I.i.u = insert u before op @ index i
+//  R.x-y.u = replace x-y indexed tokens with u
+//
+//  First we need to examine replaces. For any replace op:
+//
+// 		1. wipe out any insertions before op within that range.
+//		2. Drop any replace op before that is contained completely within
+//	 	that range.
+//		3. Throw exception upon boundary overlap with any previous replace.
+//
+//  	Then we can deal with inserts:
+//
+// 		1. for any inserts to same index, combine even if not adjacent.
+// 		2. for any prior replace with same left boundary, combine this
+//	 	insert with replace and delete this replace.
+// 		3. throw exception if index in same range as previous replace
+//
+//  Don't actually delete; make op null in list. Easier to walk list.
+//  Later we can throw as we add to index &rarr; op map.
+//
+//  Note that I.2 R.2-2 will wipe out I.2 even though, technically, the
+//  inserted stuff would be before the replace range. But, if you
+//  add tokens in front of a method body '{' and then delete the method
+//  body, I think the stuff before the '{' you added should disappear too.
+//
+//  Return a map from token index to operation.
+//
+func reduceToSingleOperationPerIndex(rewrites []RewriteOperation) map[int]RewriteOperation{
+	// WALK REPLACES
+	for i:=0; i < len(rewrites); i++{
+		op := rewrites[i]
+		if op == nil{continue}
+		rop, ok := op.(*ReplaceOp)
+		if !ok{continue}
+		// Wipe prior inserts within range
+		for j:=0; j<i && j < len(rewrites); j++{
+			if iop, ok := rewrites[j].(*InsertBeforeOp);ok{
+				if iop.index == rop.index{
+					// E.g., insert before 2, delete 2..2; update replace
+					// text to include insert before, kill insert
+					rewrites[iop.instruction_index] = nil
+					if rop.text != ""{
+						rop.text = iop.text + rop.text
+					}else{
+						rop.text = iop.text
+					}
+				}else if iop.index > rop.index && iop.index <=rop.LastIndex{
+					// delete insert as it's a no-op.
+					rewrites[iop.instruction_index] = nil
+				}
+			}
+		}
+		// Drop any prior replaces contained within
+		for j:=0; j<i && j < len(rewrites); j++{
+			if prevop, ok := rewrites[j].(*ReplaceOp);ok{
+				if prevop.index>=rop.index && prevop.LastIndex <= rop.LastIndex{
+					// delete replace as it's a no-op.
+					rewrites[prevop.instruction_index] = nil
+					continue
+				}
+				// throw exception unless disjoint or identical
+				disjoint := prevop.LastIndex < rop.index || prevop.index > rop.LastIndex
+				// Delete special case of replace (text==null):
+				// D.i-j.u D.x-y.v	| boundaries overlap	combine to max(min)..max(right)
+				if prevop.text == "" && rop.text == "" && !disjoint{
+					rewrites[prevop.instruction_index] = nil
+					rop.index = min(prevop.index, rop.index)
+					rop.LastIndex = max(prevop.LastIndex, rop.LastIndex)
+					println("new rop" + rop.String()) //TODO: remove console write, taken from Java version
+				}else if !disjoint{
+					panic("replace op boundaries of " + rop.String() + " overlap with previous " + prevop.String())
+				}
+			}
+		}
+	}
+	// WALK INSERTS
+	for i:=0; i < len(rewrites); i++ {
+		op := rewrites[i]
+		if op == nil{continue}
+		//hack to replicate inheritance in composition
+		_, iok := rewrites[i].(*InsertBeforeOp)
+		_, aok := rewrites[i].(*InsertAfterOp)
+		if !iok && !aok{continue}
+		iop := rewrites[i]
+		// combine current insert with prior if any at same index
+		// deviating a bit from TokenStreamRewriter.java - hard to incorporate inheritance logic
+		for j:=0; j<i && j < len(rewrites); j++{
+			if nextIop, ok := rewrites[j].(*InsertAfterOp); ok{
+				if nextIop.index == iop.GetIndex(){
+					iop.SetText(nextIop.text + iop.GetText())
+					rewrites[j] = nil
+				}
+			}
+			if prevIop, ok := rewrites[j].(*InsertBeforeOp); ok{
+				if prevIop.index == iop.GetIndex(){
+					iop.SetText(iop.GetText() + prevIop.text)
+					rewrites[prevIop.instruction_index] = nil
+				}
+			}
+		}
+		// look for replaces where iop.index is in range; error
+		for j:=0; j<i && j < len(rewrites); j++{
+			if rop,ok := rewrites[j].(*ReplaceOp); ok{
+				if iop.GetIndex() == rop.index{
+					rop.text = iop.GetText() + rop.text
+					rewrites[i] = nil
+					continue
+				}
+				if iop.GetIndex() >= rop.index && iop.GetIndex() <= rop.LastIndex{
+					panic("insert op "+iop.String()+" within boundaries of previous "+rop.String())
+				}
+			}
+		}
+	}
+	m := map[int]RewriteOperation{}
+	for i:=0; i < len(rewrites); i++{
+		op := rewrites[i]
+		if op == nil {continue}
+		if _, ok := m[op.GetIndex()]; ok{
+			panic("should only be one op per index")
+		}
+		m[op.GetIndex()] = op
+	}
+	return m
+}
+
+
+/*
+	Quick fixing Go lack of overloads
+ */
+
+func max(a,b int)int{
+	if a>b{
+		return a
+	}else {
+		return b
+	}
+}
+func min(a,b int)int{
+	if a<b{
+		return a
+	}else {
+		return b
+	}
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/trace_listener.go

@@ -0,0 +1,32 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import "fmt"
+
+type TraceListener struct {
+	parser *BaseParser
+}
+
+func NewTraceListener(parser *BaseParser) *TraceListener {
+	tl := new(TraceListener)
+	tl.parser = parser
+	return tl
+}
+
+func (t *TraceListener) VisitErrorNode(_ ErrorNode) {
+}
+
+func (t *TraceListener) EnterEveryRule(ctx ParserRuleContext) {
+	fmt.Println("enter   " + t.parser.GetRuleNames()[ctx.GetRuleIndex()] + ", LT(1)=" + t.parser.input.LT(1).GetText())
+}
+
+func (t *TraceListener) VisitTerminal(node TerminalNode) {
+	fmt.Println("consume " + fmt.Sprint(node.GetSymbol()) + " rule " + t.parser.GetRuleNames()[t.parser.ctx.GetRuleIndex()])
+}
+
+func (t *TraceListener) ExitEveryRule(ctx ParserRuleContext) {
+	fmt.Println("exit    " + t.parser.GetRuleNames()[ctx.GetRuleIndex()] + ", LT(1)=" + t.parser.input.LT(1).GetText())
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/transition.go

@@ -0,0 +1,421 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"fmt"
+	"strconv"
+)
+
+//  atom, set, epsilon, action, predicate, rule transitions.
+//
+//  <p>This is a one way link.  It emanates from a state (usually via a list of
+//  transitions) and has a target state.</p>
+//
+//  <p>Since we never have to change the ATN transitions once we construct it,
+//  the states. We'll use the term Edge for the DFA to distinguish them from
+//  ATN transitions.</p>
+
+type Transition interface {
+	getTarget() ATNState
+	setTarget(ATNState)
+	getIsEpsilon() bool
+	getLabel() *IntervalSet
+	getSerializationType() int
+	Matches(int, int, int) bool
+}
+
+type BaseTransition struct {
+	target            ATNState
+	isEpsilon         bool
+	label             int
+	intervalSet       *IntervalSet
+	serializationType int
+}
+
+func NewBaseTransition(target ATNState) *BaseTransition {
+
+	if target == nil {
+		panic("target cannot be nil.")
+	}
+
+	t := new(BaseTransition)
+
+	t.target = target
+	// Are we epsilon, action, sempred?
+	t.isEpsilon = false
+	t.intervalSet = nil
+
+	return t
+}
+
+func (t *BaseTransition) getTarget() ATNState {
+	return t.target
+}
+
+func (t *BaseTransition) setTarget(s ATNState) {
+	t.target = s
+}
+
+func (t *BaseTransition) getIsEpsilon() bool {
+	return t.isEpsilon
+}
+
+func (t *BaseTransition) getLabel() *IntervalSet {
+	return t.intervalSet
+}
+
+func (t *BaseTransition) getSerializationType() int {
+	return t.serializationType
+}
+
+func (t *BaseTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	panic("Not implemented")
+}
+
+const (
+	TransitionEPSILON    = 1
+	TransitionRANGE      = 2
+	TransitionRULE       = 3
+	TransitionPREDICATE  = 4 // e.g., {isType(input.LT(1))}?
+	TransitionATOM       = 5
+	TransitionACTION     = 6
+	TransitionSET        = 7 // ~(A|B) or ~atom, wildcard, which convert to next 2
+	TransitionNOTSET     = 8
+	TransitionWILDCARD   = 9
+	TransitionPRECEDENCE = 10
+)
+
+var TransitionserializationNames = []string{
+	"INVALID",
+	"EPSILON",
+	"RANGE",
+	"RULE",
+	"PREDICATE",
+	"ATOM",
+	"ACTION",
+	"SET",
+	"NOT_SET",
+	"WILDCARD",
+	"PRECEDENCE",
+}
+
+//var TransitionserializationTypes struct {
+//	EpsilonTransition int
+//	RangeTransition int
+//	RuleTransition int
+//	PredicateTransition int
+//	AtomTransition int
+//	ActionTransition int
+//	SetTransition int
+//	NotSetTransition int
+//	WildcardTransition int
+//	PrecedencePredicateTransition int
+//}{
+//	TransitionEPSILON,
+//	TransitionRANGE,
+//	TransitionRULE,
+//	TransitionPREDICATE,
+//	TransitionATOM,
+//	TransitionACTION,
+//	TransitionSET,
+//	TransitionNOTSET,
+//	TransitionWILDCARD,
+//	TransitionPRECEDENCE
+//}
+
+// TODO: make all transitions sets? no, should remove set edges
+type AtomTransition struct {
+	*BaseTransition
+}
+
+func NewAtomTransition(target ATNState, intervalSet int) *AtomTransition {
+
+	t := new(AtomTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	t.label = intervalSet // The token type or character value or, signifies special intervalSet.
+	t.intervalSet = t.makeLabel()
+	t.serializationType = TransitionATOM
+
+	return t
+}
+
+func (t *AtomTransition) makeLabel() *IntervalSet {
+	s := NewIntervalSet()
+	s.addOne(t.label)
+	return s
+}
+
+func (t *AtomTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return t.label == symbol
+}
+
+func (t *AtomTransition) String() string {
+	return strconv.Itoa(t.label)
+}
+
+type RuleTransition struct {
+	*BaseTransition
+
+	followState           ATNState
+	ruleIndex, precedence int
+}
+
+func NewRuleTransition(ruleStart ATNState, ruleIndex, precedence int, followState ATNState) *RuleTransition {
+
+	t := new(RuleTransition)
+	t.BaseTransition = NewBaseTransition(ruleStart)
+
+	t.ruleIndex = ruleIndex
+	t.precedence = precedence
+	t.followState = followState
+	t.serializationType = TransitionRULE
+	t.isEpsilon = true
+
+	return t
+}
+
+func (t *RuleTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return false
+}
+
+type EpsilonTransition struct {
+	*BaseTransition
+
+	outermostPrecedenceReturn int
+}
+
+func NewEpsilonTransition(target ATNState, outermostPrecedenceReturn int) *EpsilonTransition {
+
+	t := new(EpsilonTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	t.serializationType = TransitionEPSILON
+	t.isEpsilon = true
+	t.outermostPrecedenceReturn = outermostPrecedenceReturn
+	return t
+}
+
+func (t *EpsilonTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return false
+}
+
+func (t *EpsilonTransition) String() string {
+	return "epsilon"
+}
+
+type RangeTransition struct {
+	*BaseTransition
+
+	start, stop int
+}
+
+func NewRangeTransition(target ATNState, start, stop int) *RangeTransition {
+
+	t := new(RangeTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	t.serializationType = TransitionRANGE
+	t.start = start
+	t.stop = stop
+	t.intervalSet = t.makeLabel()
+	return t
+}
+
+func (t *RangeTransition) makeLabel() *IntervalSet {
+	s := NewIntervalSet()
+	s.addRange(t.start, t.stop)
+	return s
+}
+
+func (t *RangeTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return symbol >= t.start && symbol <= t.stop
+}
+
+func (t *RangeTransition) String() string {
+	return "'" + string(t.start) + "'..'" + string(t.stop) + "'"
+}
+
+type AbstractPredicateTransition interface {
+	Transition
+	IAbstractPredicateTransitionFoo()
+}
+
+type BaseAbstractPredicateTransition struct {
+	*BaseTransition
+}
+
+func NewBasePredicateTransition(target ATNState) *BaseAbstractPredicateTransition {
+
+	t := new(BaseAbstractPredicateTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	return t
+}
+
+func (a *BaseAbstractPredicateTransition) IAbstractPredicateTransitionFoo() {}
+
+type PredicateTransition struct {
+	*BaseAbstractPredicateTransition
+
+	isCtxDependent       bool
+	ruleIndex, predIndex int
+}
+
+func NewPredicateTransition(target ATNState, ruleIndex, predIndex int, isCtxDependent bool) *PredicateTransition {
+
+	t := new(PredicateTransition)
+	t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target)
+
+	t.serializationType = TransitionPREDICATE
+	t.ruleIndex = ruleIndex
+	t.predIndex = predIndex
+	t.isCtxDependent = isCtxDependent // e.g., $i ref in pred
+	t.isEpsilon = true
+	return t
+}
+
+func (t *PredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return false
+}
+
+func (t *PredicateTransition) getPredicate() *Predicate {
+	return NewPredicate(t.ruleIndex, t.predIndex, t.isCtxDependent)
+}
+
+func (t *PredicateTransition) String() string {
+	return "pred_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.predIndex)
+}
+
+type ActionTransition struct {
+	*BaseTransition
+
+	isCtxDependent                    bool
+	ruleIndex, actionIndex, predIndex int
+}
+
+func NewActionTransition(target ATNState, ruleIndex, actionIndex int, isCtxDependent bool) *ActionTransition {
+
+	t := new(ActionTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	t.serializationType = TransitionACTION
+	t.ruleIndex = ruleIndex
+	t.actionIndex = actionIndex
+	t.isCtxDependent = isCtxDependent // e.g., $i ref in pred
+	t.isEpsilon = true
+	return t
+}
+
+func (t *ActionTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return false
+}
+
+func (t *ActionTransition) String() string {
+	return "action_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.actionIndex)
+}
+
+type SetTransition struct {
+	*BaseTransition
+}
+
+func NewSetTransition(target ATNState, set *IntervalSet) *SetTransition {
+
+	t := new(SetTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	t.serializationType = TransitionSET
+	if set != nil {
+		t.intervalSet = set
+	} else {
+		t.intervalSet = NewIntervalSet()
+		t.intervalSet.addOne(TokenInvalidType)
+	}
+
+	return t
+}
+
+func (t *SetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return t.intervalSet.contains(symbol)
+}
+
+func (t *SetTransition) String() string {
+	return t.intervalSet.String()
+}
+
+type NotSetTransition struct {
+	*SetTransition
+}
+
+func NewNotSetTransition(target ATNState, set *IntervalSet) *NotSetTransition {
+
+	t := new(NotSetTransition)
+
+	t.SetTransition = NewSetTransition(target, set)
+
+	t.serializationType = TransitionNOTSET
+
+	return t
+}
+
+func (t *NotSetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return symbol >= minVocabSymbol && symbol <= maxVocabSymbol && !t.intervalSet.contains(symbol)
+}
+
+func (t *NotSetTransition) String() string {
+	return "~" + t.intervalSet.String()
+}
+
+type WildcardTransition struct {
+	*BaseTransition
+}
+
+func NewWildcardTransition(target ATNState) *WildcardTransition {
+
+	t := new(WildcardTransition)
+	t.BaseTransition = NewBaseTransition(target)
+
+	t.serializationType = TransitionWILDCARD
+	return t
+}
+
+func (t *WildcardTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return symbol >= minVocabSymbol && symbol <= maxVocabSymbol
+}
+
+func (t *WildcardTransition) String() string {
+	return "."
+}
+
+type PrecedencePredicateTransition struct {
+	*BaseAbstractPredicateTransition
+
+	precedence int
+}
+
+func NewPrecedencePredicateTransition(target ATNState, precedence int) *PrecedencePredicateTransition {
+
+	t := new(PrecedencePredicateTransition)
+	t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target)
+
+	t.serializationType = TransitionPRECEDENCE
+	t.precedence = precedence
+	t.isEpsilon = true
+
+	return t
+}
+
+func (t *PrecedencePredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool {
+	return false
+}
+
+func (t *PrecedencePredicateTransition) getPredicate() *PrecedencePredicate {
+	return NewPrecedencePredicate(t.precedence)
+}
+
+func (t *PrecedencePredicateTransition) String() string {
+	return fmt.Sprint(t.precedence) + " >= _p"
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/tree.go

@@ -0,0 +1,256 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// The basic notion of a tree has a parent, a payload, and a list of children.
+//  It is the most abstract interface for all the trees used by ANTLR.
+///
+
+var TreeInvalidInterval = NewInterval(-1, -2)
+
+type Tree interface {
+	GetParent() Tree
+	SetParent(Tree)
+	GetPayload() interface{}
+	GetChild(i int) Tree
+	GetChildCount() int
+	GetChildren() []Tree
+}
+
+type SyntaxTree interface {
+	Tree
+
+	GetSourceInterval() *Interval
+}
+
+type ParseTree interface {
+	SyntaxTree
+
+	Accept(Visitor ParseTreeVisitor) interface{}
+	GetText() string
+
+	ToStringTree([]string, Recognizer) string
+}
+
+type RuleNode interface {
+	ParseTree
+
+	GetRuleContext() RuleContext
+	GetBaseRuleContext() *BaseRuleContext
+}
+
+type TerminalNode interface {
+	ParseTree
+
+	GetSymbol() Token
+}
+
+type ErrorNode interface {
+	TerminalNode
+
+	errorNode()
+}
+
+type ParseTreeVisitor interface {
+	Visit(tree ParseTree) interface{}
+	VisitChildren(node RuleNode) interface{}
+	VisitTerminal(node TerminalNode) interface{}
+	VisitErrorNode(node ErrorNode) interface{}
+}
+
+type BaseParseTreeVisitor struct{}
+
+var _ ParseTreeVisitor = &BaseParseTreeVisitor{}
+
+func (v *BaseParseTreeVisitor) Visit(tree ParseTree) interface{}            { return nil }
+func (v *BaseParseTreeVisitor) VisitChildren(node RuleNode) interface{}     { return nil }
+func (v *BaseParseTreeVisitor) VisitTerminal(node TerminalNode) interface{} { return nil }
+func (v *BaseParseTreeVisitor) VisitErrorNode(node ErrorNode) interface{}   { return nil }
+
+// TODO
+//func (this ParseTreeVisitor) Visit(ctx) {
+//	if (Utils.isArray(ctx)) {
+//		self := this
+//		return ctx.map(function(child) { return VisitAtom(self, child)})
+//	} else {
+//		return VisitAtom(this, ctx)
+//	}
+//}
+//
+//func VisitAtom(Visitor, ctx) {
+//	if (ctx.parser == nil) { //is terminal
+//		return
+//	}
+//
+//	name := ctx.parser.ruleNames[ctx.ruleIndex]
+//	funcName := "Visit" + Utils.titleCase(name)
+//
+//	return Visitor[funcName](ctx)
+//}
+
+type ParseTreeListener interface {
+	VisitTerminal(node TerminalNode)
+	VisitErrorNode(node ErrorNode)
+	EnterEveryRule(ctx ParserRuleContext)
+	ExitEveryRule(ctx ParserRuleContext)
+}
+
+type BaseParseTreeListener struct{}
+
+var _ ParseTreeListener = &BaseParseTreeListener{}
+
+func (l *BaseParseTreeListener) VisitTerminal(node TerminalNode)      {}
+func (l *BaseParseTreeListener) VisitErrorNode(node ErrorNode)        {}
+func (l *BaseParseTreeListener) EnterEveryRule(ctx ParserRuleContext) {}
+func (l *BaseParseTreeListener) ExitEveryRule(ctx ParserRuleContext)  {}
+
+type TerminalNodeImpl struct {
+	parentCtx RuleContext
+
+	symbol Token
+}
+
+var _ TerminalNode = &TerminalNodeImpl{}
+
+func NewTerminalNodeImpl(symbol Token) *TerminalNodeImpl {
+	tn := new(TerminalNodeImpl)
+
+	tn.parentCtx = nil
+	tn.symbol = symbol
+
+	return tn
+}
+
+func (t *TerminalNodeImpl) GetChild(i int) Tree {
+	return nil
+}
+
+func (t *TerminalNodeImpl) GetChildren() []Tree {
+	return nil
+}
+
+func (t *TerminalNodeImpl) SetChildren(tree []Tree) {
+	panic("Cannot set children on terminal node")
+}
+
+func (t *TerminalNodeImpl) GetSymbol() Token {
+	return t.symbol
+}
+
+func (t *TerminalNodeImpl) GetParent() Tree {
+	return t.parentCtx
+}
+
+func (t *TerminalNodeImpl) SetParent(tree Tree) {
+	t.parentCtx = tree.(RuleContext)
+}
+
+func (t *TerminalNodeImpl) GetPayload() interface{} {
+	return t.symbol
+}
+
+func (t *TerminalNodeImpl) GetSourceInterval() *Interval {
+	if t.symbol == nil {
+		return TreeInvalidInterval
+	}
+	tokenIndex := t.symbol.GetTokenIndex()
+	return NewInterval(tokenIndex, tokenIndex)
+}
+
+func (t *TerminalNodeImpl) GetChildCount() int {
+	return 0
+}
+
+func (t *TerminalNodeImpl) Accept(v ParseTreeVisitor) interface{} {
+	return v.VisitTerminal(t)
+}
+
+func (t *TerminalNodeImpl) GetText() string {
+	return t.symbol.GetText()
+}
+
+func (t *TerminalNodeImpl) String() string {
+	if t.symbol.GetTokenType() == TokenEOF {
+		return "<EOF>"
+	}
+
+	return t.symbol.GetText()
+}
+
+func (t *TerminalNodeImpl) ToStringTree(s []string, r Recognizer) string {
+	return t.String()
+}
+
+// Represents a token that was consumed during reSynchronization
+// rather than during a valid Match operation. For example,
+// we will create this kind of a node during single token insertion
+// and deletion as well as during "consume until error recovery set"
+// upon no viable alternative exceptions.
+
+type ErrorNodeImpl struct {
+	*TerminalNodeImpl
+}
+
+var _ ErrorNode = &ErrorNodeImpl{}
+
+func NewErrorNodeImpl(token Token) *ErrorNodeImpl {
+	en := new(ErrorNodeImpl)
+	en.TerminalNodeImpl = NewTerminalNodeImpl(token)
+	return en
+}
+
+func (e *ErrorNodeImpl) errorNode() {}
+
+func (e *ErrorNodeImpl) Accept(v ParseTreeVisitor) interface{} {
+	return v.VisitErrorNode(e)
+}
+
+type ParseTreeWalker struct {
+}
+
+func NewParseTreeWalker() *ParseTreeWalker {
+	return new(ParseTreeWalker)
+}
+
+// Performs a walk on the given parse tree starting at the root and going down recursively
+// with depth-first search. On each node, EnterRule is called before
+// recursively walking down into child nodes, then
+// ExitRule is called after the recursive call to wind up.
+func (p *ParseTreeWalker) Walk(listener ParseTreeListener, t Tree) {
+	switch tt := t.(type) {
+	case ErrorNode:
+		listener.VisitErrorNode(tt)
+	case TerminalNode:
+		listener.VisitTerminal(tt)
+	default:
+		p.EnterRule(listener, t.(RuleNode))
+		for i := 0; i < t.GetChildCount(); i++ {
+			child := t.GetChild(i)
+			p.Walk(listener, child)
+		}
+		p.ExitRule(listener, t.(RuleNode))
+	}
+}
+
+//
+// Enters a grammar rule by first triggering the generic event {@link ParseTreeListener//EnterEveryRule}
+// then by triggering the event specific to the given parse tree node
+//
+func (p *ParseTreeWalker) EnterRule(listener ParseTreeListener, r RuleNode) {
+	ctx := r.GetRuleContext().(ParserRuleContext)
+	listener.EnterEveryRule(ctx)
+	ctx.EnterRule(listener)
+}
+
+// Exits a grammar rule by first triggering the event specific to the given parse tree node
+// then by triggering the generic event {@link ParseTreeListener//ExitEveryRule}
+//
+func (p *ParseTreeWalker) ExitRule(listener ParseTreeListener, r RuleNode) {
+	ctx := r.GetRuleContext().(ParserRuleContext)
+	ctx.ExitRule(listener)
+	listener.ExitEveryRule(ctx)
+}
+
+var ParseTreeWalkerDefault = NewParseTreeWalker()

vendor/github.com/antlr/antlr4/runtime/Go/antlr/trees.go

@@ -0,0 +1,137 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import "fmt"
+
+/** A set of utility routines useful for all kinds of ANTLR trees. */
+
+// Print out a whole tree in LISP form. {@link //getNodeText} is used on the
+//  node payloads to get the text for the nodes.  Detect
+//  parse trees and extract data appropriately.
+func TreesStringTree(tree Tree, ruleNames []string, recog Recognizer) string {
+
+	if recog != nil {
+		ruleNames = recog.GetRuleNames()
+	}
+
+	s := TreesGetNodeText(tree, ruleNames, nil)
+
+	s = EscapeWhitespace(s, false)
+	c := tree.GetChildCount()
+	if c == 0 {
+		return s
+	}
+	res := "(" + s + " "
+	if c > 0 {
+		s = TreesStringTree(tree.GetChild(0), ruleNames, nil)
+		res += s
+	}
+	for i := 1; i < c; i++ {
+		s = TreesStringTree(tree.GetChild(i), ruleNames, nil)
+		res += (" " + s)
+	}
+	res += ")"
+	return res
+}
+
+func TreesGetNodeText(t Tree, ruleNames []string, recog Parser) string {
+	if recog != nil {
+		ruleNames = recog.GetRuleNames()
+	}
+
+	if ruleNames != nil {
+		switch t2 := t.(type) {
+		case RuleNode:
+			t3 := t2.GetRuleContext()
+			altNumber := t3.GetAltNumber()
+
+			if altNumber != ATNInvalidAltNumber {
+				return fmt.Sprintf("%s:%d", ruleNames[t3.GetRuleIndex()], altNumber)
+			}
+			return ruleNames[t3.GetRuleIndex()]
+		case ErrorNode:
+			return fmt.Sprint(t2)
+		case TerminalNode:
+			if t2.GetSymbol() != nil {
+				return t2.GetSymbol().GetText()
+			}
+		}
+	}
+
+	// no recog for rule names
+	payload := t.GetPayload()
+	if p2, ok := payload.(Token); ok {
+		return p2.GetText()
+	}
+
+	return fmt.Sprint(t.GetPayload())
+}
+
+// Return ordered list of all children of this node
+func TreesGetChildren(t Tree) []Tree {
+	list := make([]Tree, 0)
+	for i := 0; i < t.GetChildCount(); i++ {
+		list = append(list, t.GetChild(i))
+	}
+	return list
+}
+
+// Return a list of all ancestors of this node.  The first node of
+//  list is the root and the last is the parent of this node.
+//
+func TreesgetAncestors(t Tree) []Tree {
+	ancestors := make([]Tree, 0)
+	t = t.GetParent()
+	for t != nil {
+		f := []Tree{t}
+		ancestors = append(f, ancestors...)
+		t = t.GetParent()
+	}
+	return ancestors
+}
+
+func TreesFindAllTokenNodes(t ParseTree, ttype int) []ParseTree {
+	return TreesfindAllNodes(t, ttype, true)
+}
+
+func TreesfindAllRuleNodes(t ParseTree, ruleIndex int) []ParseTree {
+	return TreesfindAllNodes(t, ruleIndex, false)
+}
+
+func TreesfindAllNodes(t ParseTree, index int, findTokens bool) []ParseTree {
+	nodes := make([]ParseTree, 0)
+	treesFindAllNodes(t, index, findTokens, &nodes)
+	return nodes
+}
+
+func treesFindAllNodes(t ParseTree, index int, findTokens bool, nodes *[]ParseTree) {
+	// check this node (the root) first
+
+	t2, ok := t.(TerminalNode)
+	t3, ok2 := t.(ParserRuleContext)
+
+	if findTokens && ok {
+		if t2.GetSymbol().GetTokenType() == index {
+			*nodes = append(*nodes, t2)
+		}
+	} else if !findTokens && ok2 {
+		if t3.GetRuleIndex() == index {
+			*nodes = append(*nodes, t3)
+		}
+	}
+	// check children
+	for i := 0; i < t.GetChildCount(); i++ {
+		treesFindAllNodes(t.GetChild(i).(ParseTree), index, findTokens, nodes)
+	}
+}
+
+func TreesDescendants(t ParseTree) []ParseTree {
+	nodes := []ParseTree{t}
+	for i := 0; i < t.GetChildCount(); i++ {
+		nodes = append(nodes, TreesDescendants(t.GetChild(i).(ParseTree))...)
+	}
+	return nodes
+}

vendor/github.com/antlr/antlr4/runtime/Go/antlr/utils.go

@@ -0,0 +1,417 @@
+// Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+func intMin(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func intMax(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+// A simple integer stack
+
+type IntStack []int
+
+var ErrEmptyStack = errors.New("Stack is empty")
+
+func (s *IntStack) Pop() (int, error) {
+	l := len(*s) - 1
+	if l < 0 {
+		return 0, ErrEmptyStack
+	}
+	v := (*s)[l]
+	*s = (*s)[0:l]
+	return v, nil
+}
+
+func (s *IntStack) Push(e int) {
+	*s = append(*s, e)
+}
+
+type Set struct {
+	data             map[int][]interface{}
+	hashcodeFunction func(interface{}) int
+	equalsFunction   func(interface{}, interface{}) bool
+}
+
+func NewSet(
+	hashcodeFunction func(interface{}) int,
+	equalsFunction func(interface{}, interface{}) bool) *Set {
+
+	s := new(Set)
+
+	s.data = make(map[int][]interface{})
+
+	if hashcodeFunction != nil {
+		s.hashcodeFunction = hashcodeFunction
+	} else {
+		s.hashcodeFunction = standardHashFunction
+	}
+
+	if equalsFunction == nil {
+		s.equalsFunction = standardEqualsFunction
+	} else {
+		s.equalsFunction = equalsFunction
+	}
+
+	return s
+}
+
+func standardEqualsFunction(a interface{}, b interface{}) bool {
+
+	ac, oka := a.(comparable)
+	bc, okb := b.(comparable)
+
+	if !oka || !okb {
+		panic("Not Comparable")
+	}
+
+	return ac.equals(bc)
+}
+
+func standardHashFunction(a interface{}) int {
+	if h, ok := a.(hasher); ok {
+		return h.hash()
+	}
+
+	panic("Not Hasher")
+}
+
+type hasher interface {
+	hash() int
+}
+
+func (s *Set) length() int {
+	return len(s.data)
+}
+
+func (s *Set) add(value interface{}) interface{} {
+
+	key := s.hashcodeFunction(value)
+
+	values := s.data[key]
+
+	if s.data[key] != nil {
+		for i := 0; i < len(values); i++ {
+			if s.equalsFunction(value, values[i]) {
+				return values[i]
+			}
+		}
+
+		s.data[key] = append(s.data[key], value)
+		return value
+	}
+
+	v := make([]interface{}, 1, 10)
+	v[0] = value
+	s.data[key] = v
+
+	return value
+}
+
+func (s *Set) contains(value interface{}) bool {
+
+	key := s.hashcodeFunction(value)
+
+	values := s.data[key]
+
+	if s.data[key] != nil {
+		for i := 0; i < len(values); i++ {
+			if s.equalsFunction(value, values[i]) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func (s *Set) values() []interface{} {
+	var l []interface{}
+
+	for _, v := range s.data {
+		l = append(l, v...)
+	}
+
+	return l
+}
+
+func (s *Set) String() string {
+	r := ""
+
+	for _, av := range s.data {
+		for _, v := range av {
+			r += fmt.Sprint(v)
+		}
+	}
+
+	return r
+}
+
+type BitSet struct {
+	data map[int]bool
+}
+
+func NewBitSet() *BitSet {
+	b := new(BitSet)
+	b.data = make(map[int]bool)
+	return b
+}
+
+func (b *BitSet) add(value int) {
+	b.data[value] = true
+}
+
+func (b *BitSet) clear(index int) {
+	delete(b.data, index)
+}
+
+func (b *BitSet) or(set *BitSet) {
+	for k := range set.data {
+		b.add(k)
+	}
+}
+
+func (b *BitSet) remove(value int) {
+	delete(b.data, value)
+}
+
+func (b *BitSet) contains(value int) bool {
+	return b.data[value]
+}
+
+func (b *BitSet) values() []int {
+	ks := make([]int, len(b.data))
+	i := 0
+	for k := range b.data {
+		ks[i] = k
+		i++
+	}
+	sort.Ints(ks)
+	return ks
+}
+
+func (b *BitSet) minValue() int {
+	min := 2147483647
+
+	for k := range b.data {
+		if k < min {
+			min = k
+		}
+	}
+
+	return min
+}
+
+func (b *BitSet) equals(other interface{}) bool {
+	otherBitSet, ok := other.(*BitSet)
+	if !ok {
+		return false
+	}
+
+	if len(b.data) != len(otherBitSet.data) {
+		return false
+	}
+
+	for k, v := range b.data {
+		if otherBitSet.data[k] != v {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (b *BitSet) length() int {
+	return len(b.data)
+}
+
+func (b *BitSet) String() string {
+	vals := b.values()
+	valsS := make([]string, len(vals))
+
+	for i, val := range vals {
+		valsS[i] = strconv.Itoa(val)
+	}
+	return "{" + strings.Join(valsS, ", ") + "}"
+}
+
+type AltDict struct {
+	data map[string]interface{}
+}
+
+func NewAltDict() *AltDict {
+	d := new(AltDict)
+	d.data = make(map[string]interface{})
+	return d
+}
+
+func (a *AltDict) Get(key string) interface{} {
+	key = "k-" + key
+	return a.data[key]
+}
+
+func (a *AltDict) put(key string, value interface{}) {
+	key = "k-" + key
+	a.data[key] = value
+}
+
+func (a *AltDict) values() []interface{} {
+	vs := make([]interface{}, len(a.data))
+	i := 0
+	for _, v := range a.data {
+		vs[i] = v
+		i++
+	}
+	return vs
+}
+
+type DoubleDict struct {
+	data map[int]map[int]interface{}
+}
+
+func NewDoubleDict() *DoubleDict {
+	dd := new(DoubleDict)
+	dd.data = make(map[int]map[int]interface{})
+	return dd
+}
+
+func (d *DoubleDict) Get(a, b int) interface{} {
+	data := d.data[a]
+
+	if data == nil {
+		return nil
+	}
+
+	return data[b]
+}
+
+func (d *DoubleDict) set(a, b int, o interface{}) {
+	data := d.data[a]
+
+	if data == nil {
+		data = make(map[int]interface{})
+		d.data[a] = data
+	}
+
+	data[b] = o
+}
+
+func EscapeWhitespace(s string, escapeSpaces bool) string {
+
+	s = strings.Replace(s, "\t", "\\t", -1)
+	s = strings.Replace(s, "\n", "\\n", -1)
+	s = strings.Replace(s, "\r", "\\r", -1)
+	if escapeSpaces {
+		s = strings.Replace(s, " ", "\u00B7", -1)
+	}
+	return s
+}
+
+func TerminalNodeToStringArray(sa []TerminalNode) []string {
+	st := make([]string, len(sa))
+
+	for i, s := range sa {
+		st[i] = fmt.Sprintf("%v", s)
+	}
+
+	return st
+}
+
+func PrintArrayJavaStyle(sa []string) string {
+	var buffer bytes.Buffer
+
+	buffer.WriteString("[")
+
+	for i, s := range sa {
+		buffer.WriteString(s)
+		if i != len(sa)-1 {
+			buffer.WriteString(", ")
+		}
+	}
+
+	buffer.WriteString("]")
+
+	return buffer.String()
+}
+
+// The following routines were lifted from bits.rotate* available in Go 1.9.
+
+const uintSize = 32 << (^uint(0) >> 32 & 1) // 32 or 64
+
+// rotateLeft returns the value of x rotated left by (k mod UintSize) bits.
+// To rotate x right by k bits, call RotateLeft(x, -k).
+func rotateLeft(x uint, k int) uint {
+	if uintSize == 32 {
+		return uint(rotateLeft32(uint32(x), k))
+	}
+	return uint(rotateLeft64(uint64(x), k))
+}
+
+// rotateLeft32 returns the value of x rotated left by (k mod 32) bits.
+func rotateLeft32(x uint32, k int) uint32 {
+	const n = 32
+	s := uint(k) & (n - 1)
+	return x<<s | x>>(n-s)
+}
+
+// rotateLeft64 returns the value of x rotated left by (k mod 64) bits.
+func rotateLeft64(x uint64, k int) uint64 {
+	const n = 64
+	s := uint(k) & (n - 1)
+	return x<<s | x>>(n-s)
+}
+
+
+// murmur hash
+const (
+	c1_32 uint = 0xCC9E2D51
+	c2_32 uint = 0x1B873593
+	n1_32 uint = 0xE6546B64
+)
+
+func murmurInit(seed int) int {
+	return seed
+}
+
+func murmurUpdate(h1 int, k1 int) int {
+	var k1u uint
+	k1u = uint(k1) * c1_32
+	k1u = rotateLeft(k1u, 15)
+	k1u *= c2_32
+
+	var h1u = uint(h1) ^ k1u
+	k1u = rotateLeft(k1u, 13)
+	h1u = h1u*5 + 0xe6546b64
+	return int(h1u)
+}
+
+func murmurFinish(h1 int, numberOfWords int) int {
+	var h1u uint = uint(h1)
+	h1u ^= uint(numberOfWords * 4)
+	h1u ^= h1u >> 16
+	h1u *= uint(0x85ebca6b)
+	h1u ^= h1u >> 13
+	h1u *= 0xc2b2ae35
+	h1u ^= h1u >> 16
+
+	return int(h1u)
+}