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

vendor/github.com/google/cel-go/interpreter/evalstate.go

@@ -0,0 +1,75 @@
+// Copyright 2018 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package interpreter
+
+import (
+	"github.com/google/cel-go/common/types/ref"
+)
+
+// EvalState tracks the values associated with expression ids during execution.
+type EvalState interface {
+	// IDs returns the list of ids with recorded values.
+	IDs() []int64
+
+	// Value returns the observed value of the given expression id if found, and a nil false
+	// result if not.
+	Value(int64) (ref.Val, bool)
+
+	// SetValue sets the observed value of the expression id.
+	SetValue(int64, ref.Val)
+
+	// Reset clears the previously recorded expression values.
+	Reset()
+}
+
+// evalState permits the mutation of evaluation state for a given expression id.
+type evalState struct {
+	values map[int64]ref.Val
+}
+
+// NewEvalState returns an EvalState instanced used to observe the intermediate
+// evaluations of an expression.
+func NewEvalState() EvalState {
+	return &evalState{
+		values: make(map[int64]ref.Val),
+	}
+}
+
+// IDs implements the EvalState interface method.
+func (s *evalState) IDs() []int64 {
+	var ids []int64
+	for k, v := range s.values {
+		if v != nil {
+			ids = append(ids, k)
+		}
+	}
+	return ids
+}
+
+// Value is an implementation of the EvalState interface method.
+func (s *evalState) Value(exprID int64) (ref.Val, bool) {
+	val, found := s.values[exprID]
+	return val, found
+}
+
+// SetValue is an implementation of the EvalState interface method.
+func (s *evalState) SetValue(exprID int64, val ref.Val) {
+	s.values[exprID] = val
+}
+
+// Reset implements the EvalState interface method.
+func (s *evalState) Reset() {
+	s.values = map[int64]ref.Val{}
+}