mirror of
https://github.com/microsoft/regorus.git
synced 2026-08-05 02:16:11 +00:00
3a3bbcdb7d
Only scalars, composites and comprehensions containing scalars are supported. This will be changed as OPA fixes bug with default values Signed-off-by: Anand Krishnamoorthi <anakrish@microsoft.com>
1719 lines
59 KiB
Rust
1719 lines
59 KiB
Rust
// Copyright (c) Microsoft Corporation.
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// Licensed under the MIT License.
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use crate::ast::*;
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use crate::builtins;
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use crate::lexer::Span;
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use crate::parser::Parser;
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use crate::value::*;
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use anyhow::{anyhow, bail, Result};
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use log::info;
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use std::collections::{hash_map::Entry, BTreeMap, BTreeSet, HashMap};
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use std::rc::Rc;
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type Scope = BTreeMap<String, Variable>;
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pub struct Interpreter<'source> {
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modules: Vec<&'source Module<'source>>,
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module: Option<&'source Module<'source>>,
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current_module_path: String,
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input: Value,
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data: Value,
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scopes: Vec<Scope>,
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// TODO: handle recursive calls where same expr could have different values.
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loop_var_values: BTreeMap<&'source Expr<'source>, Value>,
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contexts: Vec<Context<'source>>,
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functions: HashMap<String, &'source Rule<'source>>,
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rules: HashMap<String, Vec<&'source Rule<'source>>>,
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default_rules: HashMap<String, Vec<(&'source Rule<'source>, Option<String>)>>,
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processed: BTreeSet<&'source Rule<'source>>,
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active_rules: Vec<&'source Rule<'source>>,
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}
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#[derive(Debug)]
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struct Variable {
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value: Value,
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partial: bool,
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_has_default: bool,
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}
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#[derive(Debug, Clone)]
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struct Context<'source> {
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key_expr: Option<&'source Expr<'source>>,
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output_expr: Option<&'source Expr<'source>>,
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value: Value,
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}
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#[derive(Debug)]
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struct LoopExpr<'source> {
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span: &'source Span<'source>,
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expr: &'source Expr<'source>,
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value: &'source Expr<'source>,
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}
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impl<'source> Interpreter<'source> {
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pub fn new(modules: Vec<&'source Module<'source>>) -> Result<Interpreter<'source>> {
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Ok(Interpreter {
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modules,
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module: None,
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current_module_path: String::default(),
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input: Value::new_object(),
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data: Value::new_object(),
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scopes: vec![Scope::new()],
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contexts: vec![],
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loop_var_values: BTreeMap::new(),
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functions: HashMap::new(),
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rules: HashMap::new(),
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default_rules: HashMap::new(),
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processed: BTreeSet::new(),
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active_rules: vec![],
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})
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}
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fn current_module(&self) -> Result<&'source Module<'source>> {
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match &self.module {
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Some(m) => Ok(m),
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_ => bail!("internal error: current module not set"),
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}
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}
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#[inline(always)]
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fn add_variable(
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&mut self,
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name: &str,
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partial: bool,
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default: Option<Value>,
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) -> Result<(String, Value)> {
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let name = name.to_string();
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// Only add the variable if the key is not "_"
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let value = if name != "_" {
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let (value, _has_default) = if let Some(default) = default {
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(default, true)
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} else {
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(Value::Undefined, false)
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};
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let variable = Variable {
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value: value.clone(),
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partial,
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_has_default,
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};
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match self.scopes.last_mut() {
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Some(scope) => {
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scope.insert(name.to_string(), variable);
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}
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_ => bail!("internal error: no active scope"),
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}
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value
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} else {
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Value::Undefined
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};
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Ok((name, value))
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}
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fn add_variable_or(
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&mut self,
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name: &str,
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partial: bool,
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default: Option<Value>,
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) -> Result<(String, Value, bool)> {
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for scope in self.scopes.iter().rev() {
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if let Some(variable) = scope.get(&name.to_string()) {
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return Ok((name.to_string(), variable.value.clone(), variable.partial));
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}
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}
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let (name, value) = self.add_variable(name, partial, default)?;
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Ok((name, value, partial))
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}
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// TODO: optimize this
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fn variables_assignment(&mut self, name: &str, value: &Value) -> Result<()> {
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match self.scopes.last_mut() {
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Some(scope) => {
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if let Some(variable) = scope.get_mut(name) {
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variable.value = value.clone();
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} else {
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return Err(anyhow!("variable {} is undefined", name));
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}
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}
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_ => bail!("internal error: no active scope"),
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}
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Ok(())
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}
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fn eval_chained_ref_dot_or_brack(&mut self, mut expr: &'source Expr<'source>) -> Result<Value> {
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// Collect a chaing of '.field' or '["field"]'
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let mut path = vec![];
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loop {
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match expr {
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// Stop path collection upon encountering the leading variable.
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Expr::Var(v) => {
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path.reverse();
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return self.lookup_var(v.text(), &path[..]);
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}
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// Accumulate chained . field accesses.
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Expr::RefDot { refr, field, .. } => {
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expr = refr;
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path.push(field.text());
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}
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Expr::RefBrack { refr, index, .. } => match index.as_ref() {
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// refr["field"] is the same as refr.field
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Expr::String(s) => {
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expr = refr;
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path.push(s.text());
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}
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// Handle other forms of refr.
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// Note, we have the choice to evaluate a non-string index
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_ => {
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path.reverse();
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let obj = self.eval_expr(refr)?;
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let index = self.eval_expr(index)?;
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return Ok(Self::get_value_chained(obj[&index].clone(), &path[..]));
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}
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},
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_ => {
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path.reverse();
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return Ok(Self::get_value_chained(self.eval_expr(expr)?, &path[..]));
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}
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}
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}
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}
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fn is_loop_var(&self, ident: &str) -> bool {
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// TODO: check for vars that are declared using some-vars
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// TODO: check for vars that are not declared and dont exist in any scope including global.
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ident == "_"
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}
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fn hoist_loops_impl(&self, expr: &'source Expr<'source>, loops: &mut Vec<LoopExpr<'source>>) {
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use Expr::*;
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match expr {
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RefBrack { refr, index, span } => {
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// First hoist any loops in refr
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self.hoist_loops_impl(refr, loops);
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// Then hoist the current bracket operation.
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match index.as_ref() {
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Var(ident) if self.is_loop_var(ident.text()) => loops.push(LoopExpr {
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span,
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expr,
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//var: ident.text(),
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value: refr,
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}),
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_ => {
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// hoist any loops in index expression.
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self.hoist_loops_impl(index, loops);
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}
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}
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}
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// Primitives
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String(_) | RawString(_) | Number(_) | True(_) | False(_) | Null(_) | Var(_) => (),
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// Recurse into expressions in other variants.
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Array { items, .. } | Set { items, .. } | Call { params: items, .. } => {
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for item in items {
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self.hoist_loops_impl(item, loops);
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}
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}
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Object { fields, .. } => {
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for (_, key, value) in fields {
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self.hoist_loops_impl(key, loops);
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self.hoist_loops_impl(value, loops);
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}
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}
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RefDot { refr: expr, .. } | UnaryExpr { expr, .. } => {
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self.hoist_loops_impl(expr, loops)
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}
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BinExpr { lhs, rhs, .. }
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| BoolExpr { lhs, rhs, .. }
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| ArithExpr { lhs, rhs, .. }
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| AssignExpr { lhs, rhs, .. } => {
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self.hoist_loops_impl(lhs, loops);
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self.hoist_loops_impl(rhs, loops);
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}
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Membership {
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key,
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value,
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collection,
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..
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} => {
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self.hoist_loops_impl(key, loops);
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if let Some(value) = value.as_ref() {
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self.hoist_loops_impl(value, loops);
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}
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self.hoist_loops_impl(collection, loops);
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}
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// The output expressions of comprehensions must be subject to hoisting
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// only after evaluating the body of the comprehensions since the output
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// expressions may depend on variables defined within the body.
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ArrayCompr { .. } | SetCompr { .. } | ObjectCompr { .. } => (),
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}
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}
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fn hoist_loops(&self, literal: &'source Literal<'source>) -> Vec<LoopExpr<'source>> {
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let mut loops = vec![];
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use Literal::*;
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match literal {
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SomeVars { .. } => (),
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SomeIn {
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key,
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value,
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collection,
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..
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} => {
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self.hoist_loops_impl(key, &mut loops);
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if let Some(value) = value {
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self.hoist_loops_impl(value, &mut loops);
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}
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self.hoist_loops_impl(collection, &mut loops);
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}
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Every {
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domain: collection, ..
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} => self.hoist_loops_impl(collection, &mut loops),
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Expr { expr, .. } | NotExpr { expr, .. } => self.hoist_loops_impl(expr, &mut loops),
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}
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loops
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}
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fn eval_bool_expr(
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&mut self,
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op: &BoolOp,
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lhs_expr: &'source Expr<'source>,
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rhs_expr: &'source Expr<'source>,
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) -> Result<Value> {
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let lhs = self.eval_expr(lhs_expr)?;
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let rhs = self.eval_expr(rhs_expr)?;
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Ok(builtins::compare(op, &lhs, &rhs))
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}
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fn eval_bin_expr(
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&mut self,
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op: &BinOp,
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lhs: &'source Expr<'source>,
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rhs: &'source Expr<'source>,
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) -> Result<Value> {
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let lhs = self.eval_expr(lhs)?;
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let rhs = self.eval_expr(rhs)?;
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let lhs = if let Value::Set(set) = lhs {
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set
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} else {
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return Err(anyhow!("expect {:?} to be a set", lhs));
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};
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let rhs = if let Value::Set(set) = rhs {
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set
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} else {
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return Err(anyhow!("expect {:?} to be a set", rhs));
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};
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info!(
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"eval_bin_expr, op: {:?}, lhs: {:?}, rhs: {:?}",
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op, lhs, rhs
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);
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Ok(Value::from_set(match op {
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BinOp::Or => lhs.union(&rhs).cloned().collect(),
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BinOp::And => lhs.intersection(&rhs).cloned().collect(),
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}))
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}
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fn eval_arith_expr(
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&mut self,
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op: &ArithOp,
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lhs: &'source Expr<'source>,
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rhs: &'source Expr<'source>,
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) -> Result<Value> {
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let lhs = self.eval_expr(lhs)?;
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let rhs = self.eval_expr(rhs)?;
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// Handle special case for set difference.
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if let (Value::Set(lhs), ArithOp::Sub, Value::Set(rhs)) = (&lhs, op, &rhs) {
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return Ok(Value::from_set(lhs.difference(rhs).cloned().collect()));
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}
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let lhs = if let Value::Number(number) = lhs {
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number.0
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} else {
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return Err(anyhow!("expect {:?} to be a number", lhs));
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};
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let rhs = if let Value::Number(number) = rhs {
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number.0
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} else {
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return Err(anyhow!("expect {:?} to be a number", rhs));
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};
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let result = match op {
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ArithOp::Add => lhs + rhs,
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ArithOp::Sub => lhs - rhs,
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ArithOp::Mul => lhs * rhs,
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ArithOp::Div => lhs / rhs,
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};
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info!(
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"eval_arith_expr, op: {:?}, lhs: {:?}, rhs: {:?}",
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op, lhs, rhs
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);
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Ok(Value::Number(Number(result)))
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}
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fn eval_assign_expr(
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&mut self,
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op: &AssignOp,
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lhs: &'source Expr<'source>,
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rhs: &'source Expr<'source>,
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) -> Result<Value> {
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let lhs = if let Expr::Var(span) = lhs {
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span.text()
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} else {
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return Err(anyhow!("expect a variable, got: {:?}", lhs));
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};
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let (_, variable, _) = self.add_variable_or(lhs, false, None)?;
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let rhs = self.eval_expr(rhs)?;
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// TODO: handle iterations
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if variable[0] != Value::Undefined {
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return Err(anyhow!("Redefinition for variable {:?}", lhs));
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}
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// TODO: optimize this
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self.variables_assignment(lhs, &rhs)?;
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info!(
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"eval_assign_expr before, op: {:?}, lhs: {:?}, rhs: {:?}",
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op, lhs, rhs
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);
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Ok(Value::Bool(true))
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}
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fn eval_stmt(&mut self, stmt: &'source LiteralStmt<'source>) -> Result<bool> {
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let mut to_restore = vec![];
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for wm in &stmt.with_mods {
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// Evaluate value and ref
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let value = self.eval_expr(&wm.r#as)?;
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let path = Parser::get_path_ref_components(&wm.refr)?;
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let mut path: Vec<&str> = path.iter().map(|s| s.text()).collect();
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// TODO: multiple modules and qualified path
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if path.len() > 2 && format!("{}.{}", path[0], path[1]) == self.current_module_path {
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path = path[1..].to_vec();
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}
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// Set new values in modifications table
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let mut saved = false;
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for (i, _) in path.iter().enumerate() {
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let vref = Self::make_or_get_value_mut(&mut self.data, &path[0..i])?;
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if vref == &Value::Undefined {
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to_restore.push((path[0..i].to_vec(), vref.clone()));
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saved = false;
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break;
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}
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}
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// TODO: input
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let vref = Self::make_or_get_value_mut(&mut self.data, &path[..])?;
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if !saved {
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to_restore.push((path, vref.clone()));
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}
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*vref = value;
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}
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let r = Ok(match &stmt.literal {
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Literal::Expr { expr, .. } => {
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let value = self.eval_expr(expr)?;
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if let Value::Bool(bool) = value {
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bool
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} else {
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// panic!();
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// TODO: confirm this
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// For non-booleans, treat anything other than undefined as true
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value != Value::Undefined
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}
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}
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Literal::SomeVars { vars, .. } => {
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for var in vars {
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let name = var.text();
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if let Ok((_, variable, _)) = self.add_variable_or(name, false, None) {
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if variable != Value::Undefined {
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return Err(anyhow!(
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"duplicated definition of local variable {}",
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name
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));
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}
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}
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}
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true
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}
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Literal::SomeIn {
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key,
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value,
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collection,
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..
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} => {
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let value = self.eval_membership(key, value, collection)?;
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if let Value::Bool(bool) = value {
|
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bool
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} else {
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panic!();
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}
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}
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Literal::NotExpr { expr, .. } => matches!(self.eval_expr(expr)?, Value::Bool(false)),
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_ => unimplemented!(),
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});
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|
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for (path, value) in to_restore.into_iter().rev() {
|
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if value == Value::Undefined {
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unimplemented!("handle undefined restore");
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} else {
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let vref = Self::make_or_get_value_mut(&mut self.data, &path[..])?;
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*vref = value;
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}
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}
|
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r
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}
|
|
|
|
fn eval_stmts_in_loop(
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|
&mut self,
|
|
stmts: &'source [LiteralStmt<'source>],
|
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loops: &[LoopExpr<'source>],
|
|
) -> Result<bool> {
|
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if loops.is_empty() {
|
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if !stmts.is_empty() {
|
|
// Evaluate the current statement whose loop expressions have been hoisted.
|
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if !self.eval_stmt(&stmts[0])? {
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return Ok(false);
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}
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self.eval_stmts(&stmts[1..])
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} else {
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self.eval_stmts(stmts)
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}
|
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} else {
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let loop_expr = &loops[0];
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let mut result = false;
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match self.eval_expr(loop_expr.value)? {
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Value::Array(items) => {
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for v in items.iter() {
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self.loop_var_values.insert(loop_expr.expr, v.clone());
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result = self.eval_stmts_in_loop(stmts, &loops[1..])? || result;
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}
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}
|
|
Value::Set(items) => {
|
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for v in items.iter() {
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self.loop_var_values.insert(loop_expr.expr, v.clone());
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result = self.eval_stmts_in_loop(stmts, &loops[1..])? || result;
|
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}
|
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}
|
|
Value::Object(obj) => {
|
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for (_, v) in obj.iter() {
|
|
self.loop_var_values.insert(loop_expr.expr, v.clone());
|
|
result = self.eval_stmts_in_loop(stmts, &loops[1..])? || result;
|
|
}
|
|
}
|
|
_ => {
|
|
return Err(loop_expr.span.source.error(
|
|
loop_expr.span.line,
|
|
loop_expr.span.col,
|
|
"item cannot be indexed",
|
|
));
|
|
}
|
|
}
|
|
self.loop_var_values.remove(loop_expr.expr);
|
|
// Return true if at least on iteration returned true
|
|
Ok(result)
|
|
}
|
|
}
|
|
|
|
fn eval_output_expr_in_loop(&mut self, loops: &[LoopExpr<'source>]) -> Result<bool> {
|
|
if loops.is_empty() {
|
|
let (key_expr, output_expr) = self.get_exprs_from_context()?;
|
|
|
|
match (key_expr, output_expr) {
|
|
(Some(ke), Some(oe)) => {
|
|
let key = self.eval_expr(ke)?;
|
|
let value = self.eval_expr(oe)?;
|
|
|
|
let ctx = self.contexts.last_mut().unwrap();
|
|
if key != Value::Undefined && value != Value::Undefined {
|
|
let map = ctx.value.as_object_mut()?;
|
|
match map.get(&key) {
|
|
Some(pv) if *pv != value => {
|
|
let span = ke.span();
|
|
return Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
format!(
|
|
"value for key `{}` generated multiple times: `{}` and `{}`",
|
|
serde_json::to_string_pretty(&key)?,
|
|
serde_json::to_string_pretty(&pv)?,
|
|
serde_json::to_string_pretty(&value)?,
|
|
)
|
|
.as_str(),
|
|
));
|
|
}
|
|
_ => map.insert(key, value),
|
|
};
|
|
} else {
|
|
ctx.value = Value::Undefined;
|
|
};
|
|
}
|
|
(None, Some(oe)) => {
|
|
let output = self.eval_expr(oe)?;
|
|
let ctx = self.contexts.last_mut().unwrap();
|
|
if output != Value::Undefined {
|
|
match &mut ctx.value {
|
|
Value::Array(a) => {
|
|
Rc::make_mut(a).push(output);
|
|
}
|
|
Value::Set(ref mut s) => {
|
|
Rc::make_mut(s).insert(output);
|
|
}
|
|
_ => bail!("internal error: invalid context value"),
|
|
}
|
|
} else {
|
|
ctx.value = Value::Undefined;
|
|
}
|
|
}
|
|
// No output expression.
|
|
// TODO: should we just push a Bool(true)?
|
|
_ => (),
|
|
}
|
|
|
|
// Push the context back so that it is available to the caller.
|
|
// self.contexts.push(ctx);
|
|
return Ok(true);
|
|
}
|
|
|
|
// Try out values in current loop expr.
|
|
let loop_expr = &loops[0];
|
|
let mut result = false;
|
|
match self.eval_expr(loop_expr.value)? {
|
|
Value::Array(items) => {
|
|
for v in items.iter() {
|
|
self.loop_var_values.insert(loop_expr.expr, v.clone());
|
|
result = self.eval_output_expr_in_loop(&loops[1..])? || result;
|
|
}
|
|
}
|
|
Value::Set(items) => {
|
|
for v in items.iter() {
|
|
self.loop_var_values.insert(loop_expr.expr, v.clone());
|
|
result = self.eval_output_expr_in_loop(&loops[1..])? || result;
|
|
}
|
|
}
|
|
Value::Object(obj) => {
|
|
for (_, v) in obj.iter() {
|
|
self.loop_var_values.insert(loop_expr.expr, v.clone());
|
|
result = self.eval_output_expr_in_loop(&loops[1..])? || result;
|
|
}
|
|
}
|
|
_ => {
|
|
return Err(loop_expr.span.source.error(
|
|
loop_expr.span.line,
|
|
loop_expr.span.col,
|
|
"item cannot be indexed",
|
|
));
|
|
}
|
|
}
|
|
self.loop_var_values.remove(loop_expr.expr);
|
|
Ok(result)
|
|
}
|
|
|
|
fn get_current_context(&self) -> Result<&Context<'source>> {
|
|
match self.contexts.last() {
|
|
Some(ctx) => Ok(ctx),
|
|
_ => bail!("internal error: no active context found"),
|
|
}
|
|
}
|
|
|
|
fn get_exprs_from_context(
|
|
&self,
|
|
) -> Result<(
|
|
Option<&'source Expr<'source>>,
|
|
Option<&'source Expr<'source>>,
|
|
)> {
|
|
let ctx = self.get_current_context()?;
|
|
Ok((ctx.key_expr, ctx.output_expr))
|
|
}
|
|
|
|
fn eval_output_expr(&mut self) -> Result<bool> {
|
|
// Evaluate output expression after all the statements have been executed.
|
|
|
|
let (key_expr, output_expr) = self.get_exprs_from_context()?;
|
|
let mut loops = vec![];
|
|
|
|
if let Some(ke) = &key_expr {
|
|
self.hoist_loops_impl(ke, &mut loops);
|
|
}
|
|
if let Some(oe) = &output_expr {
|
|
self.hoist_loops_impl(oe, &mut loops);
|
|
}
|
|
|
|
self.eval_output_expr_in_loop(&loops[..])?;
|
|
|
|
let ctx = self.get_current_context()?;
|
|
if let Some(_oe) = ctx.output_expr {
|
|
// Ensure that at least one output was generated.
|
|
Ok(ctx.value != Value::Undefined)
|
|
} else {
|
|
Ok(true)
|
|
}
|
|
}
|
|
|
|
fn eval_stmts(&mut self, stmts: &'source [LiteralStmt<'source>]) -> Result<bool> {
|
|
let mut result = true;
|
|
|
|
for (idx, stmt) in stmts.iter().enumerate() {
|
|
if !result {
|
|
break;
|
|
}
|
|
|
|
let loop_exprs = self.hoist_loops(&stmt.literal);
|
|
if !loop_exprs.is_empty() {
|
|
// If there are hoisted loop expressions, execute subsequent statements
|
|
// within loops.
|
|
return self.eval_stmts_in_loop(&stmts[idx..], &loop_exprs[..]);
|
|
}
|
|
result = self.eval_stmt(stmt)?;
|
|
}
|
|
|
|
if result {
|
|
result = self.eval_output_expr()?;
|
|
}
|
|
Ok(result)
|
|
}
|
|
|
|
fn eval_query(&mut self, query: &'source Query<'source>) -> Result<bool> {
|
|
// Execute the query in a new scope
|
|
self.scopes.push(Scope::new());
|
|
let r = self.eval_stmts(&query.stmts);
|
|
self.scopes.pop();
|
|
r
|
|
}
|
|
|
|
fn eval_array(&mut self, items: &'source Vec<Expr<'source>>) -> Result<Value> {
|
|
let mut array = Vec::new();
|
|
|
|
for item in items {
|
|
let term = self.eval_expr(item)?;
|
|
if term == Value::Undefined {
|
|
return Ok(Value::Undefined);
|
|
}
|
|
|
|
array.push(term);
|
|
}
|
|
|
|
Ok(Value::from_array(array))
|
|
}
|
|
|
|
fn eval_object(&mut self, fields: &'source Vec<(Span, Expr, Expr)>) -> Result<Value> {
|
|
let mut object = BTreeMap::new();
|
|
|
|
for (_, key, value) in fields {
|
|
// TODO: check this
|
|
// While the grammar defines a object-item as
|
|
// ( scalar | ref | var ) ":" term, the OPA
|
|
// implementation is more like expr ":" expr
|
|
let key = self.eval_expr(key)?;
|
|
let value = self.eval_expr(value)?;
|
|
object.insert(key, value);
|
|
}
|
|
|
|
Ok(Value::from_map(object))
|
|
}
|
|
|
|
fn eval_set(&mut self, items: &'source Vec<Expr<'source>>) -> Result<Value> {
|
|
let mut set = BTreeSet::new();
|
|
|
|
for item in items {
|
|
let term = self.eval_expr(item)?;
|
|
if term == Value::Undefined {
|
|
return Ok(Value::Undefined);
|
|
}
|
|
set.insert(term);
|
|
}
|
|
|
|
Ok(Value::from_set(set))
|
|
}
|
|
|
|
fn eval_membership(
|
|
&mut self,
|
|
key: &'source Expr<'source>,
|
|
value: &'source Option<Expr<'source>>,
|
|
collection: &'source Expr<'source>,
|
|
) -> Result<Value> {
|
|
let key = self.eval_expr(key)?;
|
|
|
|
let collection = self.eval_expr(collection)?;
|
|
|
|
let result = match &collection {
|
|
Value::Array(array) => {
|
|
if let Some(value) = value {
|
|
let value = self.eval_expr(value)?;
|
|
collection[&key] == value
|
|
} else {
|
|
array.iter().any(|item| *item == key)
|
|
}
|
|
}
|
|
Value::Object(object) => {
|
|
if let Some(value) = value {
|
|
let value = self.eval_expr(value)?;
|
|
collection[&key] == value
|
|
} else {
|
|
object.values().into_iter().any(|item| *item == key)
|
|
}
|
|
}
|
|
Value::Set(set) => {
|
|
if value.is_some() {
|
|
false
|
|
//return Err(anyhow!("key-value pair is not supported for set"));
|
|
} else {
|
|
set.contains(&key)
|
|
}
|
|
}
|
|
_ => {
|
|
return Err(anyhow!("\"{}\" must be array, object, or set", collection));
|
|
}
|
|
};
|
|
|
|
Ok(Value::Bool(result))
|
|
}
|
|
|
|
fn eval_array_compr(
|
|
&mut self,
|
|
term: &'source Expr<'source>,
|
|
query: &'source Query<'source>,
|
|
) -> Result<Value> {
|
|
// Push new context
|
|
self.contexts.push(Context {
|
|
key_expr: None,
|
|
output_expr: Some(term),
|
|
value: Value::new_array(),
|
|
});
|
|
|
|
// Evaluate body first.
|
|
self.eval_query(query)?;
|
|
|
|
match self.contexts.pop() {
|
|
Some(ctx) => Ok(ctx.value),
|
|
None => bail!("internal error: context already popped"),
|
|
}
|
|
}
|
|
|
|
fn eval_set_compr(
|
|
&mut self,
|
|
term: &'source Expr<'source>,
|
|
query: &'source Query<'source>,
|
|
) -> Result<Value> {
|
|
// Push new context
|
|
self.contexts.push(Context {
|
|
key_expr: None,
|
|
output_expr: Some(term),
|
|
value: Value::new_set(),
|
|
});
|
|
|
|
self.eval_query(query)?;
|
|
|
|
match self.contexts.pop() {
|
|
Some(ctx) => Ok(ctx.value),
|
|
None => bail!("internal error: context already popped"),
|
|
}
|
|
}
|
|
|
|
fn eval_object_compr(
|
|
&mut self,
|
|
key: &'source Expr<'source>,
|
|
value: &'source Expr<'source>,
|
|
query: &'source Query<'source>,
|
|
) -> Result<Value> {
|
|
// Push new context
|
|
self.contexts.push(Context {
|
|
key_expr: Some(key),
|
|
output_expr: Some(value),
|
|
value: Value::new_object(),
|
|
});
|
|
|
|
self.eval_query(query)?;
|
|
|
|
match self.contexts.pop() {
|
|
Some(ctx) => Ok(ctx.value),
|
|
None => bail!("internal error: context already popped"),
|
|
}
|
|
}
|
|
|
|
fn lookup_function(&self, fcn: &'source Expr<'source>) -> Result<&'source Rule<'source>> {
|
|
let mut path = Self::get_path_string(fcn, None)?;
|
|
if !path.starts_with("data.") {
|
|
path = self.current_module_path.clone() + "." + &path;
|
|
}
|
|
|
|
match self.functions.get(&path) {
|
|
Some(r) => Ok(r),
|
|
_ => {
|
|
bail!("function not found")
|
|
}
|
|
}
|
|
}
|
|
|
|
fn eval_call(
|
|
&mut self,
|
|
span: &'source Span<'source>,
|
|
fcn: &'source Expr<'source>,
|
|
params: &'source Vec<Expr<'source>>,
|
|
) -> Result<Value> {
|
|
let fcn_rule = match self.lookup_function(fcn) {
|
|
Ok(r) => r,
|
|
_ => {
|
|
return Err(span
|
|
.source
|
|
.error(span.line, span.col, "could not find function"))
|
|
}
|
|
};
|
|
|
|
let (args, output_expr, bodies) = match fcn_rule {
|
|
Rule::Spec {
|
|
head: RuleHead::Func { args, assign, .. },
|
|
bodies,
|
|
..
|
|
} => (args, assign.as_ref().map(|a| &a.value), bodies),
|
|
_ => bail!("internal error not a function"),
|
|
};
|
|
|
|
if args.len() != params.len() {
|
|
return Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
format!(
|
|
"mismatch in number of arguments. supplied {}, expected {}",
|
|
params.len(),
|
|
args.len()
|
|
)
|
|
.as_str(),
|
|
));
|
|
}
|
|
|
|
let mut args_scope = Scope::new();
|
|
for (idx, a) in args.iter().enumerate() {
|
|
let a = match a {
|
|
Expr::Var(s) => s.text(),
|
|
_ => unimplemented!("destructuring function arguments"),
|
|
};
|
|
//TODO: check call in params
|
|
args_scope.insert(
|
|
a.to_string(),
|
|
Variable {
|
|
value: self.eval_expr(¶ms[idx])?,
|
|
partial: false,
|
|
_has_default: false,
|
|
},
|
|
);
|
|
}
|
|
|
|
let ctx = Context {
|
|
key_expr: None,
|
|
output_expr,
|
|
value: Value::new_set(),
|
|
};
|
|
|
|
// Back up local variables of current function and empty
|
|
// the local variables of callee function.
|
|
let scopes = std::mem::take(&mut self.scopes);
|
|
|
|
// Set the arguments scope.
|
|
self.scopes.push(args_scope);
|
|
let value = self.eval_rule_bodies(ctx, span, bodies)?;
|
|
let result = match &value {
|
|
Value::Set(s) if s.len() == 1 => Ok(s.iter().next().unwrap().clone()),
|
|
Value::Set(s) if !s.is_empty() => Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
format!("function produced multiple outputs {value:?}").as_str(),
|
|
)),
|
|
// If the function successfully executed, but did not return any value, then return true.
|
|
Value::Set(s) if s.is_empty() && output_expr.is_none() => Ok(Value::Bool(true)),
|
|
|
|
// If the function execution resulted in undefined, then propagate it.
|
|
Value::Undefined => Ok(Value::Undefined),
|
|
_ => bail!("internal error: function did not return set {value:?}"),
|
|
};
|
|
|
|
// Restore local variables for current context.
|
|
self.scopes = scopes;
|
|
result
|
|
}
|
|
|
|
fn get_var_value(&self, name: &str) -> Option<Value> {
|
|
// Lookup local variables and arguments.
|
|
for scope in self.scopes.iter().rev() {
|
|
if let Some(v) = scope.get(name) {
|
|
return Some(v.value.clone());
|
|
}
|
|
}
|
|
None
|
|
}
|
|
|
|
fn ensure_rule_evaluated(&mut self, path: String) -> Result<()> {
|
|
if let Some(rules) = self.rules.get(&path) {
|
|
for r in rules.clone() {
|
|
if !self.processed.contains(r) {
|
|
let module = self.get_rule_module(r)?;
|
|
self.eval_rule(module, r)?;
|
|
}
|
|
}
|
|
}
|
|
// Evaluate the associated default rules after non-default rules
|
|
if let Some(rules) = self.default_rules.get(&path) {
|
|
for (r, _) in rules.clone() {
|
|
if !self.processed.contains(r) {
|
|
let module = self.get_rule_module(r)?;
|
|
let prev_module = self.set_current_module(Some(module))?;
|
|
self.eval_default_rule(r)?;
|
|
self.set_current_module(prev_module)?;
|
|
}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
fn lookup_var(&mut self, name: &str, fields: &[&str]) -> Result<Value> {
|
|
// Return local variable/argument.
|
|
if let Some(v) = self.get_var_value(name) {
|
|
return Ok(Self::get_value_chained(v, fields));
|
|
}
|
|
|
|
// Handle input.
|
|
if name == "input" {
|
|
return Ok(Self::get_value_chained(self.input.clone(), fields));
|
|
}
|
|
|
|
// Ensure that rules are evaluated
|
|
if name == "data" {
|
|
// Evaluate rule corresponding to longest matching path.
|
|
for i in (1..fields.len() + 1).rev() {
|
|
let path = "data.".to_owned() + &fields[0..i].join(".");
|
|
if self.rules.get(&path).is_some() || self.default_rules.get(&path).is_some() {
|
|
self.ensure_rule_evaluated(path)?;
|
|
break;
|
|
}
|
|
}
|
|
Ok(Self::get_value_chained(self.data.clone(), fields))
|
|
} else {
|
|
// Add module prefix and ensure that any matching rule is evaluated.
|
|
let module_path =
|
|
Self::get_path_string(&self.current_module()?.package.refr, Some("data"))?;
|
|
let path = module_path + "." + name;
|
|
self.ensure_rule_evaluated(path)?;
|
|
|
|
let mut path: Vec<&str> =
|
|
Parser::get_path_ref_components(&self.module.unwrap().package.refr)?
|
|
.iter()
|
|
.map(|s| s.text())
|
|
.collect();
|
|
path.push(name);
|
|
|
|
let value = Self::get_value_chained(self.data.clone(), &path[..]);
|
|
Ok(Self::get_value_chained(value, fields))
|
|
}
|
|
}
|
|
|
|
fn eval_expr(&mut self, expr: &'source Expr<'source>) -> Result<Value> {
|
|
match expr {
|
|
Expr::Null(_) => Ok(Value::Null),
|
|
Expr::True(_) => Ok(Value::Bool(true)),
|
|
Expr::False(_) => Ok(Value::Bool(false)),
|
|
Expr::Number(span) => match serde_json::from_str::<Value>(span.text()) {
|
|
Ok(v) => Ok(v),
|
|
Err(e) => Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
format!("could not parse number. {e}").as_str(),
|
|
)),
|
|
},
|
|
// TODO: Handle string vs rawstring
|
|
Expr::String(span) => Ok(Value::String(span.text().to_string())),
|
|
Expr::RawString(span) => Ok(Value::String(span.text().to_string())),
|
|
|
|
// TODO: Handle undefined variables
|
|
Expr::Var(_) => self.eval_chained_ref_dot_or_brack(expr),
|
|
Expr::RefDot { .. } => self.eval_chained_ref_dot_or_brack(expr),
|
|
Expr::RefBrack { .. } => match self.loop_var_values.get(expr) {
|
|
Some(v) => Ok(v.clone()),
|
|
_ => self.eval_chained_ref_dot_or_brack(expr),
|
|
},
|
|
|
|
// Expressions with operators
|
|
Expr::ArithExpr { op, lhs, rhs, .. } => self.eval_arith_expr(op, lhs, rhs),
|
|
Expr::AssignExpr { op, lhs, rhs, .. } => self.eval_assign_expr(op, lhs, rhs),
|
|
Expr::BinExpr { op, lhs, rhs, .. } => self.eval_bin_expr(op, lhs, rhs),
|
|
Expr::BoolExpr { op, lhs, rhs, .. } => self.eval_bool_expr(op, lhs, rhs),
|
|
Expr::Membership {
|
|
key,
|
|
value,
|
|
collection,
|
|
..
|
|
} => self.eval_membership(key, value, collection),
|
|
|
|
// Creation expression
|
|
Expr::Array { items, .. } => self.eval_array(items),
|
|
Expr::Object { fields, .. } => self.eval_object(fields),
|
|
Expr::Set { items, .. } => self.eval_set(items),
|
|
|
|
// Comprehensions
|
|
Expr::ArrayCompr { term, query, .. } => self.eval_array_compr(term, query),
|
|
Expr::ObjectCompr {
|
|
key, value, query, ..
|
|
} => self.eval_object_compr(key, value, query),
|
|
Expr::SetCompr { term, query, .. } => self.eval_set_compr(term, query),
|
|
Expr::UnaryExpr { .. } => unimplemented!("unar expr is umplemented"),
|
|
Expr::Call { span, fcn, params } => self.eval_call(span, fcn, params),
|
|
}
|
|
}
|
|
|
|
fn make_rule_context(
|
|
&self,
|
|
head: &'source RuleHead<'source>,
|
|
) -> Result<(Context<'source>, Vec<Span<'source>>)> {
|
|
//TODO: include "data" ?
|
|
let mut path = Parser::get_path_ref_components(&self.module.unwrap().package.refr)?;
|
|
|
|
match head {
|
|
RuleHead::Compr { refr, assign, .. } => {
|
|
let output_expr = assign.as_ref().map(|assign| &assign.value);
|
|
let (refr, key_expr, value) = match refr {
|
|
Expr::RefBrack { refr, index, .. } => {
|
|
(refr.as_ref(), Some(index.as_ref()), Value::new_object())
|
|
}
|
|
_ => (refr, None, Value::new_array()),
|
|
};
|
|
|
|
Parser::get_path_ref_components_into(refr, &mut path)?;
|
|
|
|
Ok((
|
|
Context {
|
|
key_expr,
|
|
output_expr,
|
|
value,
|
|
},
|
|
path,
|
|
))
|
|
}
|
|
RuleHead::Set { refr, key, .. } => {
|
|
Parser::get_path_ref_components_into(refr, &mut path)?;
|
|
Ok((
|
|
Context {
|
|
key_expr: None,
|
|
output_expr: key.as_ref(),
|
|
value: Value::new_set(),
|
|
},
|
|
path,
|
|
))
|
|
}
|
|
_ => unimplemented!("unhandled rule ref type"),
|
|
}
|
|
}
|
|
|
|
fn get_rule_module(&self, rule: &'source Rule<'source>) -> Result<&'source Module<'source>> {
|
|
for m in &self.modules {
|
|
if m.policy.contains(rule) {
|
|
return Ok(m);
|
|
}
|
|
}
|
|
bail!("internal error: could not find module for rule");
|
|
}
|
|
|
|
fn eval_rule_bodies(
|
|
&mut self,
|
|
ctx: Context<'source>,
|
|
span: &'source Span<'source>,
|
|
bodies: &'source Vec<RuleBody<'source>>,
|
|
) -> Result<Value> {
|
|
let mut result = true;
|
|
self.scopes.push(Scope::new());
|
|
|
|
if bodies.is_empty() {
|
|
self.contexts.push(ctx.clone());
|
|
result = self.eval_output_expr()?;
|
|
} else {
|
|
for body in bodies {
|
|
self.contexts.push(ctx.clone());
|
|
result = self.eval_query(&body.query)?;
|
|
|
|
// The body evaluated successfully.
|
|
if result {
|
|
break;
|
|
}
|
|
|
|
if bodies.len() > 1 {
|
|
unimplemented!("else bodies");
|
|
}
|
|
}
|
|
}
|
|
|
|
let ctx = match self.contexts.pop() {
|
|
Some(ctx) => ctx,
|
|
_ => bail!("internal error: rule's context already popped"),
|
|
};
|
|
|
|
// Drop local variables and leave the local scope
|
|
self.scopes.pop();
|
|
|
|
Ok(match result {
|
|
true => match &ctx.value {
|
|
Value::Object(_) => ctx.value,
|
|
Value::Array(a) if a.len() == 1 => a[0].clone(),
|
|
Value::Array(a) if a.is_empty() => Value::Bool(true),
|
|
Value::Array(_) => {
|
|
return Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
"complete rules should not produce multiple outputs",
|
|
))
|
|
}
|
|
Value::Set(_) => ctx.value,
|
|
_ => unimplemented!("todo fix this"),
|
|
},
|
|
false => Value::Undefined,
|
|
})
|
|
}
|
|
|
|
fn get_value_chained(mut obj: Value, path: &[&str]) -> Value {
|
|
for p in path {
|
|
obj = obj[&Value::String(p.to_string())].clone();
|
|
}
|
|
obj
|
|
}
|
|
|
|
#[inline]
|
|
fn make_or_get_value_mut<'a>(obj: &'a mut Value, paths: &[&str]) -> Result<&'a mut Value> {
|
|
if paths.is_empty() {
|
|
return Ok(obj);
|
|
}
|
|
|
|
let key = Value::String(paths[0].to_owned());
|
|
if obj == &Value::Undefined {
|
|
*obj = Value::new_object();
|
|
}
|
|
if let Value::Object(map) = obj {
|
|
if map.get(&key).is_none() {
|
|
Rc::make_mut(map).insert(key.clone(), Value::Undefined);
|
|
}
|
|
}
|
|
|
|
match obj {
|
|
Value::Object(map) => match Rc::make_mut(map).get_mut(&key) {
|
|
Some(v) if paths.len() == 1 => Ok(v),
|
|
Some(v) => Self::make_or_get_value_mut(v, &paths[1..]),
|
|
_ => bail!("internal error: unexpected"),
|
|
},
|
|
Value::Undefined if paths.len() > 1 => {
|
|
*obj = Value::new_object();
|
|
Self::make_or_get_value_mut(obj, paths)
|
|
}
|
|
Value::Undefined => Ok(obj),
|
|
_ => bail!("make: not an object {obj:?}"),
|
|
}
|
|
}
|
|
|
|
pub fn merge_value(span: &Span<'source>, value: &mut Value, mut new: Value) -> Result<()> {
|
|
match (value, &mut new) {
|
|
(v @ Value::Undefined, _) => *v = new,
|
|
(Value::Set(ref mut set), Value::Set(new)) => {
|
|
Rc::make_mut(set).append(Rc::make_mut(new))
|
|
}
|
|
(Value::Object(map), Value::Object(new)) => {
|
|
for (k, v) in new.iter() {
|
|
match map.get(k) {
|
|
Some(pv) if *pv != *v => {
|
|
return Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
format!(
|
|
"value for key `{}` generated multiple times: `{}` and `{}`",
|
|
serde_json::to_string_pretty(&k)?,
|
|
serde_json::to_string_pretty(&pv)?,
|
|
serde_json::to_string_pretty(&v)?,
|
|
)
|
|
.as_str(),
|
|
));
|
|
}
|
|
_ => Rc::make_mut(map).insert(k.clone(), v.clone()),
|
|
};
|
|
}
|
|
}
|
|
_ => bail!("could not merge value"),
|
|
};
|
|
Ok(())
|
|
}
|
|
|
|
pub fn get_path_string(refr: &Expr, document: Option<&str>) -> Result<String> {
|
|
let mut comps = vec![];
|
|
let mut expr = Some(refr);
|
|
while expr.is_some() {
|
|
match expr {
|
|
Some(Expr::RefDot { refr, field, .. }) => {
|
|
comps.push(field.text());
|
|
expr = Some(refr);
|
|
}
|
|
Some(Expr::RefBrack { refr, index, .. })
|
|
if matches!(index.as_ref(), Expr::String(_)) =>
|
|
{
|
|
if let Expr::String(s) = index.as_ref() {
|
|
comps.push(s.text());
|
|
expr = Some(refr);
|
|
}
|
|
}
|
|
Some(Expr::Var(v)) => {
|
|
comps.push(v.text());
|
|
expr = None;
|
|
}
|
|
_ => bail!("not a simple ref"),
|
|
}
|
|
}
|
|
if let Some(d) = document {
|
|
comps.push(d);
|
|
};
|
|
comps.reverse();
|
|
Ok(comps.join("."))
|
|
}
|
|
|
|
fn set_current_module(
|
|
&mut self,
|
|
module: Option<&'source Module<'source>>,
|
|
) -> Result<Option<&'source Module<'source>>> {
|
|
let m = self.module;
|
|
if let Some(m) = module {
|
|
self.current_module_path = Self::get_path_string(&m.package.refr, Some("data"))?;
|
|
}
|
|
self.module = module;
|
|
Ok(m)
|
|
}
|
|
|
|
pub fn update_function_table(&mut self) -> Result<()> {
|
|
for module in self.modules.clone() {
|
|
let prev_module = self.set_current_module(Some(module))?;
|
|
let module_path =
|
|
Self::get_path_string(&self.current_module()?.package.refr, Some("data"))?;
|
|
for rule in &module.policy {
|
|
if let Rule::Spec {
|
|
head: RuleHead::Func { refr, .. },
|
|
..
|
|
} = rule
|
|
{
|
|
let mut path =
|
|
Parser::get_path_ref_components(&self.current_module()?.package.refr)?;
|
|
|
|
Parser::get_path_ref_components_into(refr, &mut path)?;
|
|
let path: Vec<&str> = path.iter().map(|s| s.text()).collect();
|
|
|
|
if path.len() > 1 {
|
|
let value =
|
|
Self::make_or_get_value_mut(&mut self.data, &path[0..path.len() - 1])?;
|
|
if value == &Value::Undefined {
|
|
*value = Value::new_object();
|
|
}
|
|
}
|
|
|
|
let full_path = Self::get_path_string(refr, Some(module_path.as_str()))?;
|
|
self.functions.insert(full_path, rule);
|
|
}
|
|
}
|
|
self.set_current_module(prev_module)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
fn get_rule_refr(rule: &'source Rule<'source>) -> &'source Expr<'source> {
|
|
match rule {
|
|
Rule::Spec { head, .. } => match &head {
|
|
RuleHead::Compr { refr, .. }
|
|
| RuleHead::Set { refr, .. }
|
|
| RuleHead::Func { refr, .. } => refr,
|
|
},
|
|
Rule::Default { refr, .. } => refr,
|
|
}
|
|
}
|
|
|
|
fn check_default_value(&self, expr: &'source Expr<'source>) -> Result<()> {
|
|
use Expr::*;
|
|
let (kind, span) = match expr {
|
|
// Scalars are supported
|
|
String(_) | RawString(_) | Number(_) | True(_) | False(_) | Null(_) => return Ok(()),
|
|
|
|
// Uminus of number is treated as a single expression,
|
|
UnaryExpr { expr, .. } if matches!(expr.as_ref(), Number(_)) => return Ok(()),
|
|
|
|
Var(span) => ("var", span),
|
|
|
|
// Check each item in array/set.
|
|
Array { items, .. } | Set { items, .. } => {
|
|
for item in items {
|
|
self.check_default_value(item)?;
|
|
}
|
|
return Ok(());
|
|
}
|
|
|
|
// Check each field in object
|
|
Object { fields, .. } => {
|
|
for (_, key, value) in fields {
|
|
self.check_default_value(key)?;
|
|
self.check_default_value(value)?;
|
|
}
|
|
return Ok(());
|
|
}
|
|
|
|
// Check each statement in comprehensions
|
|
ArrayCompr { term, query, .. } | SetCompr { term, query, .. } => {
|
|
self.check_default_value(term)?;
|
|
for stmt in &query.stmts {
|
|
self.check_default_value_in_stmt(stmt)?;
|
|
}
|
|
return Ok(());
|
|
}
|
|
|
|
ObjectCompr {
|
|
key, value, query, ..
|
|
} => {
|
|
self.check_default_value(key)?;
|
|
self.check_default_value(value)?;
|
|
for stmt in &query.stmts {
|
|
self.check_default_value_in_stmt(stmt)?;
|
|
}
|
|
return Ok(());
|
|
}
|
|
|
|
Call { span, .. } => ("call", span),
|
|
UnaryExpr { span, .. } => ("unaryexpr", span),
|
|
RefDot { span, .. } => ("ref", span),
|
|
RefBrack { span, .. } => ("ref", span),
|
|
BinExpr { span, .. } => ("binexpr", span),
|
|
BoolExpr { span, .. } => ("boolexpr", span),
|
|
ArithExpr { span, .. } => ("arithexpr", span),
|
|
AssignExpr { span, .. } => ("assignexpr", span),
|
|
Membership { span, .. } => ("membership", span),
|
|
};
|
|
|
|
Err(span.error(format!("invalid `{kind}` in default value").as_str()))
|
|
}
|
|
|
|
fn check_default_value_in_stmt(&self, stmt: &'source LiteralStmt<'source>) -> Result<()> {
|
|
for m in &stmt.with_mods {
|
|
self.check_default_value(&m.refr)?;
|
|
self.check_default_value(&m.r#as)?;
|
|
}
|
|
|
|
match &stmt.literal {
|
|
Literal::SomeVars { span, .. } => {
|
|
Err(span.error("invalid `some vars` in default value"))
|
|
}
|
|
Literal::SomeIn {
|
|
key,
|
|
value,
|
|
collection,
|
|
..
|
|
} => {
|
|
self.check_default_value(key)?;
|
|
if let Some(value) = &value {
|
|
self.check_default_value(value)?;
|
|
}
|
|
self.check_default_value(collection)
|
|
}
|
|
Literal::Expr { expr, .. } | Literal::NotExpr { expr, .. } => {
|
|
self.check_default_value(expr)
|
|
}
|
|
Literal::Every { span, .. } => Err(span.error("invalid `every` in default value")),
|
|
}
|
|
}
|
|
|
|
fn check_default_rules(&self) -> Result<()> {
|
|
for module in &self.modules {
|
|
for rule in &module.policy {
|
|
if let Rule::Default { value, .. } = rule {
|
|
self.check_default_value(value)?;
|
|
}
|
|
}
|
|
}
|
|
Ok(())
|
|
}
|
|
|
|
fn eval_default_rule(&mut self, rule: &'source Rule<'source>) -> Result<()> {
|
|
// Skip reprocessing rule.
|
|
if self.processed.contains(rule) {
|
|
return Ok(());
|
|
}
|
|
|
|
match rule {
|
|
Rule::Default {
|
|
span, refr, value, ..
|
|
} => {
|
|
let mut path = Parser::get_path_ref_components(&self.module.unwrap().package.refr)?;
|
|
|
|
let (refr, index) = match refr {
|
|
Expr::RefBrack { refr, index, .. } => (refr.as_ref(), Some(index.as_ref())),
|
|
Expr::Var(_) => (refr, None),
|
|
_ => bail!("invalid token {:?} with the default keyword", refr),
|
|
};
|
|
|
|
Parser::get_path_ref_components_into(refr, &mut path)?;
|
|
let paths: Vec<&str> = path.iter().map(|s| s.text()).collect();
|
|
|
|
self.check_default_value(value)?;
|
|
let value = self.eval_expr(value)?;
|
|
|
|
// Assume at this point that all the non-default rules have been evaluated.
|
|
// Merge the default value only if
|
|
// 1. The corresponding variable does not have value yet
|
|
// 2. The corresponding index in the object does not have value yet
|
|
if let Some(index) = index {
|
|
let index = self.eval_expr(index)?;
|
|
let mut object = Value::new_object();
|
|
object.as_object_mut()?.insert(index.clone(), value);
|
|
|
|
let vref = Self::make_or_get_value_mut(&mut self.data, &paths)?;
|
|
|
|
if let Value::Object(btree) = &vref {
|
|
if !btree.contains_key(&index) {
|
|
Self::merge_value(span, vref, object)?;
|
|
}
|
|
} else if let Value::Undefined = vref {
|
|
Self::merge_value(span, vref, object)?;
|
|
}
|
|
} else {
|
|
let vref = Self::make_or_get_value_mut(&mut self.data, &paths)?;
|
|
if let Value::Undefined = &vref {
|
|
Self::merge_value(span, vref, value)?;
|
|
}
|
|
};
|
|
|
|
self.processed.insert(rule);
|
|
}
|
|
_ => println!("not a default rule"),
|
|
}
|
|
|
|
Ok(())
|
|
}
|
|
|
|
fn eval_rule(
|
|
&mut self,
|
|
module: &'source Module<'source>,
|
|
rule: &'source Rule<'source>,
|
|
) -> Result<()> {
|
|
// Skip reprocessing rule
|
|
if self.processed.contains(rule) {
|
|
return Ok(());
|
|
}
|
|
|
|
// Skip default rules
|
|
if let Rule::Default { .. } = rule {
|
|
return Ok(());
|
|
}
|
|
|
|
self.active_rules.push(rule);
|
|
if self.active_rules.iter().filter(|&r| r == &rule).count() == 2 {
|
|
let mut msg = String::default();
|
|
for r in &self.active_rules {
|
|
let refr = Self::get_rule_refr(r);
|
|
let span = refr.span();
|
|
msg += span
|
|
.source
|
|
.message(span.line, span.col, "depends on", "")
|
|
.as_str();
|
|
}
|
|
msg += "cyclic evaluation";
|
|
let refr = Self::get_rule_refr(rule);
|
|
let span = refr.span();
|
|
return Err(span.source.error(
|
|
span.line,
|
|
span.col,
|
|
format!("recursion detected when evaluating rule:{msg}").as_str(),
|
|
));
|
|
}
|
|
|
|
let prev_module = self.set_current_module(Some(module))?;
|
|
match rule {
|
|
Rule::Spec {
|
|
span,
|
|
head: rule_head,
|
|
bodies: rule_body,
|
|
} => {
|
|
if matches!(rule_head, RuleHead::Func { .. }) {
|
|
return Ok(());
|
|
}
|
|
|
|
let (ctx, mut path) = self.make_rule_context(rule_head)?;
|
|
let special_set = matches!((ctx.output_expr, &ctx.value), (None, Value::Set(_)));
|
|
let value = match self.eval_rule_bodies(ctx, span, rule_body)? {
|
|
Value::Set(_) if special_set => {
|
|
let entry = path[path.len() - 1].text();
|
|
let mut s = BTreeSet::new();
|
|
s.insert(Value::String(entry.to_owned()));
|
|
path = path[0..path.len() - 1].to_vec();
|
|
Value::from_set(s)
|
|
}
|
|
v => v,
|
|
};
|
|
|
|
if value != Value::Undefined {
|
|
let paths: Vec<&str> = path.iter().map(|s| s.text()).collect();
|
|
let vref = Self::make_or_get_value_mut(&mut self.data, &paths[..])?;
|
|
Self::merge_value(span, vref, value)?;
|
|
}
|
|
}
|
|
_ => bail!("internal error: unexpected"),
|
|
}
|
|
self.set_current_module(prev_module)?;
|
|
self.processed.insert(rule);
|
|
match self.active_rules.pop() {
|
|
Some(r) if r == rule => Ok(()),
|
|
_ => bail!("internal error: current rule not active"),
|
|
}
|
|
}
|
|
|
|
pub fn eval(&mut self, data: &Option<Value>, input: &Option<Value>) -> Result<Value> {
|
|
if let Some(input) = input {
|
|
self.input = input.clone();
|
|
|
|
info!("input: {:#?}", self.input);
|
|
}
|
|
if let Some(data) = data {
|
|
self.data = data.clone();
|
|
}
|
|
|
|
self.check_default_rules()?;
|
|
self.update_function_table()?;
|
|
self.gather_rules()?;
|
|
|
|
for module in self.modules.clone() {
|
|
for rule in &module.policy {
|
|
self.eval_rule(module, rule)?;
|
|
}
|
|
}
|
|
|
|
// Defer the evaluation of the default rules to here
|
|
for module in self.modules.clone() {
|
|
let prev_module = self.set_current_module(Some(module))?;
|
|
for rule in &module.policy {
|
|
self.eval_default_rule(rule)?;
|
|
}
|
|
self.set_current_module(prev_module)?;
|
|
}
|
|
|
|
Ok(self.data.clone())
|
|
}
|
|
|
|
pub fn eval_query_snippet(&mut self, snippet: &'source Expr<'source>) -> Result<Value> {
|
|
// Create a new scope for evaluating the expression.
|
|
self.scopes.push(Scope::new());
|
|
let prev_module = self.set_current_module(self.modules.last().copied())?;
|
|
let value = self.eval_expr(snippet)?;
|
|
// Pop the scope.
|
|
let scope = self.scopes.pop();
|
|
let r = match snippet {
|
|
Expr::AssignExpr { .. } => {
|
|
if let Some(scope) = scope {
|
|
let mut r = Value::new_object();
|
|
let map = r.as_object_mut()?;
|
|
// Capture each binding.
|
|
for (name, v) in scope {
|
|
map.insert(Value::String(name), v.value);
|
|
}
|
|
Ok(r)
|
|
} else {
|
|
bail!("internal error: expression scope not found");
|
|
}
|
|
}
|
|
_ => Ok(value),
|
|
};
|
|
self.set_current_module(prev_module)?;
|
|
r
|
|
}
|
|
|
|
fn gather_rules(&mut self) -> Result<()> {
|
|
for module in self.modules.clone() {
|
|
let prev_module = self.set_current_module(Some(module))?;
|
|
for rule in &module.policy {
|
|
let refr = Self::get_rule_refr(rule);
|
|
if let Rule::Spec { .. } = rule {
|
|
// Adjust refr to ensure simple ref.
|
|
// TODO: refactor.
|
|
let refr = match refr {
|
|
Expr::RefBrack { index, .. }
|
|
if matches!(index.as_ref(), Expr::String(_)) =>
|
|
{
|
|
refr
|
|
}
|
|
Expr::RefBrack { refr, .. } => refr,
|
|
_ => refr,
|
|
};
|
|
let path = Self::get_path_string(refr, None)?;
|
|
let path = self.current_module_path.clone() + "." + &path;
|
|
match self.rules.entry(path) {
|
|
Entry::Occupied(o) => {
|
|
o.into_mut().push(rule);
|
|
}
|
|
Entry::Vacant(v) => {
|
|
v.insert(vec![rule]);
|
|
}
|
|
}
|
|
} else if let Rule::Default { .. } = rule {
|
|
let (refr, index) = match refr {
|
|
// TODO: Validate the index
|
|
Expr::RefBrack { refr, index, .. } => {
|
|
if !matches!(
|
|
index.as_ref(),
|
|
Expr::True(_) | Expr::False(_) | Expr::Number(_) | Expr::String(_)
|
|
) {
|
|
// OPA's behavior is ignoring the non-scalar index
|
|
bail!("index is not a scalar value");
|
|
}
|
|
|
|
let index = self.eval_expr(index)?;
|
|
|
|
(refr.as_ref(), Some(index.to_string()))
|
|
}
|
|
_ => (refr, None),
|
|
};
|
|
|
|
let path = Self::get_path_string(refr, None)?;
|
|
let path = self.current_module_path.clone() + "." + &path;
|
|
match self.default_rules.entry(path) {
|
|
Entry::Occupied(o) => {
|
|
for (_, i) in o.get() {
|
|
if index.is_some() && i.is_some() {
|
|
let old = i.as_ref().unwrap();
|
|
let new = index.as_ref().unwrap();
|
|
if old == new {
|
|
bail!("multiple default rules for the variable with the same index");
|
|
}
|
|
} else {
|
|
bail!("conflict type with the default rules");
|
|
}
|
|
}
|
|
o.into_mut().push((rule, index));
|
|
}
|
|
Entry::Vacant(v) => {
|
|
v.insert(vec![(rule, index)]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
self.set_current_module(prev_module)?;
|
|
}
|
|
Ok(())
|
|
}
|
|
}
|