887 lines
28 KiB
Rust
887 lines
28 KiB
Rust
//! Module defining script statements.
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use super::{ASTFlags, ASTNode, BinaryExpr, Expr, FnCallExpr, Ident};
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use crate::engine::KEYWORD_EVAL;
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use crate::tokenizer::{Span, Token};
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use crate::{calc_fn_hash, Position, StaticVec, INT};
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#[cfg(feature = "no_std")]
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use std::prelude::v1::*;
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use std::{
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collections::BTreeMap,
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fmt,
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hash::Hash,
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mem,
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num::NonZeroUsize,
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ops::{Deref, DerefMut},
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};
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/// _(internals)_ An op-assignment operator.
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/// Exported under the `internals` feature only.
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///
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/// This type may hold a straight assignment (i.e. not an op-assignment).
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#[derive(Clone, Copy, Eq, PartialEq, Hash)]
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pub struct OpAssignment {
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/// Hash of the op-assignment call.
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pub hash_op_assign: u64,
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/// Hash of the underlying operator call (for fallback).
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pub hash_op: u64,
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/// Op-assignment operator.
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pub op_assign: &'static str,
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/// Underlying operator.
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pub op: &'static str,
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/// [Position] of the op-assignment operator.
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pub pos: Position,
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}
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impl OpAssignment {
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/// Create a new [`OpAssignment`] that is only a straight assignment.
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#[must_use]
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#[inline(always)]
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pub const fn new_assignment(pos: Position) -> Self {
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Self {
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hash_op_assign: 0,
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hash_op: 0,
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op_assign: "=",
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op: "=",
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pos,
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}
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}
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/// Is this an op-assignment?
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#[must_use]
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#[inline(always)]
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pub const fn is_op_assignment(&self) -> bool {
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self.hash_op_assign != 0 || self.hash_op != 0
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}
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/// Create a new [`OpAssignment`].
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///
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/// # Panics
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///
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/// Panics if the name is not an op-assignment operator.
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#[must_use]
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#[inline(always)]
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pub fn new_op_assignment(name: &str, pos: Position) -> Self {
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Self::new_op_assignment_from_token(Token::lookup_from_syntax(name).expect("operator"), pos)
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}
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/// Create a new [`OpAssignment`] from a [`Token`].
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///
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/// # Panics
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///
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/// Panics if the token is not an op-assignment operator.
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#[must_use]
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pub fn new_op_assignment_from_token(op: Token, pos: Position) -> Self {
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let op_raw = op
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.get_base_op_from_assignment()
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.expect("op-assignment operator")
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.literal_syntax();
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Self {
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hash_op_assign: calc_fn_hash(op.literal_syntax(), 2),
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hash_op: calc_fn_hash(op_raw, 2),
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op_assign: op.literal_syntax(),
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op: op_raw,
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pos,
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}
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}
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/// Create a new [`OpAssignment`] from a base operator.
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///
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/// # Panics
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///
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/// Panics if the name is not an operator that can be converted into an op-operator.
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#[must_use]
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#[inline(always)]
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pub fn new_op_assignment_from_base(name: &str, pos: Position) -> Self {
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Self::new_op_assignment_from_base_token(
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Token::lookup_from_syntax(name).expect("operator"),
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pos,
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)
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}
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/// Convert a [`Token`] into a new [`OpAssignment`].
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///
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/// # Panics
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///
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/// Panics if the token is cannot be converted into an op-assignment operator.
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#[inline(always)]
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#[must_use]
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pub fn new_op_assignment_from_base_token(op: Token, pos: Position) -> Self {
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Self::new_op_assignment_from_token(op.convert_to_op_assignment().expect("operator"), pos)
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}
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}
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impl fmt::Debug for OpAssignment {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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if self.is_op_assignment() {
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f.debug_struct("OpAssignment")
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.field("hash_op_assign", &self.hash_op_assign)
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.field("hash_op", &self.hash_op)
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.field("op_assign", &self.op_assign)
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.field("op", &self.op)
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.field("pos", &self.pos)
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.finish()
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} else {
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fmt::Debug::fmt(&self.pos, f)
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}
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}
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}
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/// A statements block with a condition.
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///
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/// The condition may simply be [`Expr::BoolConstant`] with `true` if there is actually no condition.
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#[derive(Debug, Clone, Hash)]
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pub struct ConditionalStmtBlock {
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/// Condition.
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pub condition: Expr,
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/// Statements block.
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pub statements: StmtBlock,
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}
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impl<B: Into<StmtBlock>> From<B> for ConditionalStmtBlock {
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#[inline(always)]
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fn from(value: B) -> Self {
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Self {
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condition: Expr::BoolConstant(true, Position::NONE),
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statements: value.into(),
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}
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}
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}
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impl<B: Into<StmtBlock>> From<(Expr, B)> for ConditionalStmtBlock {
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#[inline(always)]
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fn from(value: (Expr, B)) -> Self {
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Self {
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condition: value.0,
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statements: value.1.into(),
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}
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}
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}
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/// _(internals)_ A type containing all cases for a `switch` statement.
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/// Exported under the `internals` feature only.
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#[derive(Debug, Clone, Hash)]
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pub struct SwitchCases {
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/// Dictionary mapping value hashes to [`ConditionalStmtBlock`]'s.
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pub cases: BTreeMap<u64, Box<ConditionalStmtBlock>>,
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/// Statements block for the default case (there can be no condition for the default case).
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pub def_case: Box<StmtBlock>,
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/// List of range cases.
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pub ranges: StaticVec<(INT, INT, bool, Box<ConditionalStmtBlock>)>,
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}
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/// _(internals)_ A `try-catch` block.
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/// Exported under the `internals` feature only.
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#[derive(Debug, Clone, Hash)]
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pub struct TryCatchBlock {
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/// `try` block.
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pub try_block: StmtBlock,
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/// `catch` variable, if any.
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pub catch_var: Ident,
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/// `catch` block.
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pub catch_block: StmtBlock,
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}
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/// _(internals)_ The underlying container type for [`StmtBlock`].
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/// Exported under the `internals` feature only.
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///
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/// A [`SmallVec`](https://crates.io/crates/smallvec) containing up to 8 items inline is used to
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/// hold a statements block, with the assumption that most program blocks would container fewer than
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/// 8 statements, and those that do have a lot more statements.
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#[cfg(not(feature = "no_std"))]
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pub type StmtBlockContainer = smallvec::SmallVec<[Stmt; 8]>;
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/// _(internals)_ The underlying container type for [`StmtBlock`].
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/// Exported under the `internals` feature only.
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#[cfg(feature = "no_std")]
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pub type StmtBlockContainer = StaticVec<Stmt>;
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/// _(internals)_ A scoped block of statements.
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/// Exported under the `internals` feature only.
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#[derive(Clone, Hash, Default)]
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pub struct StmtBlock {
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block: StmtBlockContainer,
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span: Span,
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}
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impl StmtBlock {
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/// A [`StmtBlock`] that does not exist.
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pub const NONE: Self = Self::empty(Position::NONE);
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/// Create a new [`StmtBlock`].
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#[inline(always)]
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#[must_use]
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pub fn new(
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statements: impl IntoIterator<Item = Stmt>,
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start_pos: Position,
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end_pos: Position,
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) -> Self {
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Self::new_with_span(statements, Span::new(start_pos, end_pos))
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}
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/// Create a new [`StmtBlock`].
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#[must_use]
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pub fn new_with_span(statements: impl IntoIterator<Item = Stmt>, span: Span) -> Self {
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let mut statements: smallvec::SmallVec<_> = statements.into_iter().collect();
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statements.shrink_to_fit();
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Self {
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block: statements,
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span,
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}
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}
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/// Create an empty [`StmtBlock`].
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#[inline(always)]
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#[must_use]
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pub const fn empty(pos: Position) -> Self {
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Self {
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block: StmtBlockContainer::new_const(),
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span: Span::new(pos, pos),
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}
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}
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/// Is this statements block empty?
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#[inline(always)]
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#[must_use]
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pub fn is_empty(&self) -> bool {
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self.block.is_empty()
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}
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/// Number of statements in this statements block.
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#[inline(always)]
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#[must_use]
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pub fn len(&self) -> usize {
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self.block.len()
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}
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/// Get the statements of this statements block.
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#[inline(always)]
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#[must_use]
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pub fn statements(&self) -> &[Stmt] {
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&self.block
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}
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/// Extract the statements.
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#[inline(always)]
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#[must_use]
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pub(crate) fn take_statements(&mut self) -> StmtBlockContainer {
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mem::take(&mut self.block)
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}
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/// Get an iterator over the statements of this statements block.
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#[inline(always)]
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#[must_use]
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pub fn iter(&self) -> impl Iterator<Item = &Stmt> {
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self.block.iter()
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}
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/// Get the start position (location of the beginning `{`) of this statements block.
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#[inline(always)]
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#[must_use]
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pub const fn position(&self) -> Position {
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(self.span).start()
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}
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/// Get the end position (location of the ending `}`) of this statements block.
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#[inline(always)]
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#[must_use]
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pub const fn end_position(&self) -> Position {
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(self.span).end()
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}
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/// Get the positions (locations of the beginning `{` and ending `}`) of this statements block.
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#[inline(always)]
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#[must_use]
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pub const fn span(&self) -> Span {
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self.span
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}
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/// Get the positions (locations of the beginning `{` and ending `}`) of this statements block
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/// or a default.
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#[inline(always)]
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#[must_use]
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pub const fn span_or_else(&self, def_start_pos: Position, def_end_pos: Position) -> Span {
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Span::new(
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(self.span).start().or_else(def_start_pos),
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(self.span).end().or_else(def_end_pos),
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)
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}
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/// Set the positions of this statements block.
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#[inline(always)]
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pub fn set_position(&mut self, start_pos: Position, end_pos: Position) {
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self.span = Span::new(start_pos, end_pos);
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}
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}
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impl Deref for StmtBlock {
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type Target = StmtBlockContainer;
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#[inline(always)]
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fn deref(&self) -> &Self::Target {
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&self.block
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}
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}
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impl DerefMut for StmtBlock {
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#[inline(always)]
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fn deref_mut(&mut self) -> &mut Self::Target {
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&mut self.block
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}
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}
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impl AsRef<[Stmt]> for StmtBlock {
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#[inline(always)]
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fn as_ref(&self) -> &[Stmt] {
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&self.block
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}
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}
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impl AsMut<[Stmt]> for StmtBlock {
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#[inline(always)]
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fn as_mut(&mut self) -> &mut [Stmt] {
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&mut self.block
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}
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}
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impl fmt::Debug for StmtBlock {
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fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
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f.write_str("Block")?;
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fmt::Debug::fmt(&self.block, f)?;
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if !self.span.is_none() {
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write!(f, " @ {:?}", self.span())?;
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}
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Ok(())
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}
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}
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impl From<Stmt> for StmtBlock {
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#[inline]
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fn from(stmt: Stmt) -> Self {
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match stmt {
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Stmt::Block(block) => *block,
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Stmt::Noop(pos) => Self {
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block: StmtBlockContainer::new_const(),
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span: Span::new(pos, pos),
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},
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_ => {
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let pos = stmt.position();
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Self {
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block: vec![stmt].into(),
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span: Span::new(pos, Position::NONE),
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}
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}
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}
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}
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}
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impl IntoIterator for StmtBlock {
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type Item = Stmt;
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#[cfg(not(feature = "no_std"))]
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type IntoIter = smallvec::IntoIter<[Stmt; 8]>;
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#[cfg(feature = "no_std")]
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type IntoIter = smallvec::IntoIter<[Stmt; 3]>;
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#[inline(always)]
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fn into_iter(self) -> Self::IntoIter {
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self.block.into_iter()
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}
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}
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impl Extend<Stmt> for StmtBlock {
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#[inline(always)]
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fn extend<T: IntoIterator<Item = Stmt>>(&mut self, iter: T) {
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self.block.extend(iter)
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}
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}
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/// _(internals)_ A statement.
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/// Exported under the `internals` feature only.
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#[derive(Debug, Clone, Hash)]
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#[non_exhaustive]
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pub enum Stmt {
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/// No-op.
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Noop(Position),
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/// `if` expr `{` stmt `}` `else` `{` stmt `}`
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If(Box<(Expr, StmtBlock, StmtBlock)>, Position),
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/// `switch` expr `{` literal or range or _ `if` condition `=>` stmt `,` ... `}`
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///
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/// ### Data Structure
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///
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/// 0) Hash table for (condition, block)
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/// 1) Default block
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/// 2) List of ranges: (start, end, inclusive, condition, statement)
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Switch(Box<(Expr, SwitchCases)>, Position),
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/// `while` expr `{` stmt `}` | `loop` `{` stmt `}`
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///
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/// If the guard expression is [`UNIT`][Expr::Unit], then it is a `loop` statement.
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While(Box<(Expr, StmtBlock)>, Position),
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/// `do` `{` stmt `}` `while`|`until` expr
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///
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/// ### Flags
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///
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/// * [`NONE`][ASTFlags::NONE] = `while`
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/// * [`NEGATED`][ASTFlags::NEGATED] = `until`
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Do(Box<(Expr, StmtBlock)>, ASTFlags, Position),
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/// `for` `(` id `,` counter `)` `in` expr `{` stmt `}`
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For(Box<(Ident, Ident, Expr, StmtBlock)>, Position),
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/// \[`export`\] `let`|`const` id `=` expr
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///
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/// ### Flags
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///
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/// * [`EXPORTED`][ASTFlags::EXPORTED] = `export`
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/// * [`CONSTANT`][ASTFlags::CONSTANT] = `const`
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Var(Box<(Ident, Expr, Option<NonZeroUsize>)>, ASTFlags, Position),
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/// expr op`=` expr
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Assignment(Box<(OpAssignment, BinaryExpr)>),
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/// func `(` expr `,` ... `)`
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///
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/// Note - this is a duplicate of [`Expr::FnCall`] to cover the very common pattern of a single
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/// function call forming one statement.
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FnCall(Box<FnCallExpr>, Position),
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/// `{` stmt`;` ... `}`
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Block(Box<StmtBlock>),
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/// `try` `{` stmt; ... `}` `catch` `(` var `)` `{` stmt; ... `}`
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TryCatch(Box<TryCatchBlock>, Position),
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/// [expression][Expr]
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Expr(Box<Expr>),
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/// `continue`/`break`
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///
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/// ### Flags
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///
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/// * [`NONE`][ASTFlags::NONE] = `continue`
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/// * [`BREAK`][ASTFlags::BREAK] = `break`
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BreakLoop(ASTFlags, Position),
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/// `return`/`throw`
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///
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/// ### Flags
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///
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/// * [`NONE`][ASTFlags::NONE] = `return`
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/// * [`BREAK`][ASTFlags::BREAK] = `throw`
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Return(Option<Box<Expr>>, ASTFlags, Position),
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/// `import` expr `as` alias
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///
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/// Not available under `no_module`.
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#[cfg(not(feature = "no_module"))]
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Import(Box<(Expr, Ident)>, Position),
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/// `export` var `as` alias
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///
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/// Not available under `no_module`.
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#[cfg(not(feature = "no_module"))]
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Export(Box<(Ident, Ident)>, Position),
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/// Convert a variable to shared.
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///
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/// Not available under `no_closure`.
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///
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/// # Notes
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///
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/// This variant does not map to any language structure. It is currently only used only to
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/// convert a normal variable into a shared variable when the variable is _captured_ by a closure.
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#[cfg(not(feature = "no_closure"))]
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Share(Box<crate::Identifier>, Position),
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}
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impl Default for Stmt {
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#[inline(always)]
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fn default() -> Self {
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Self::Noop(Position::NONE)
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}
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}
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impl From<StmtBlock> for Stmt {
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#[inline(always)]
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fn from(block: StmtBlock) -> Self {
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Self::Block(block.into())
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}
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}
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impl<T: IntoIterator<Item = Stmt>> From<(T, Position, Position)> for Stmt {
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#[inline(always)]
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fn from(value: (T, Position, Position)) -> Self {
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StmtBlock::new(value.0, value.1, value.2).into()
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}
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}
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impl<T: IntoIterator<Item = Stmt>> From<(T, Span)> for Stmt {
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#[inline(always)]
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fn from(value: (T, Span)) -> Self {
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StmtBlock::new_with_span(value.0, value.1).into()
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}
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}
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impl Stmt {
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/// Is this statement [`Noop`][Stmt::Noop]?
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#[inline(always)]
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#[must_use]
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pub const fn is_noop(&self) -> bool {
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matches!(self, Self::Noop(..))
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}
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/// Get the [position][Position] of this statement.
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#[must_use]
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pub fn position(&self) -> Position {
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match self {
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Self::Noop(pos)
|
|
| Self::BreakLoop(.., pos)
|
|
| Self::FnCall(.., pos)
|
|
| Self::If(.., pos)
|
|
| Self::Switch(.., pos)
|
|
| Self::While(.., pos)
|
|
| Self::Do(.., pos)
|
|
| Self::For(.., pos)
|
|
| Self::Return(.., pos)
|
|
| Self::Var(.., pos)
|
|
| Self::TryCatch(.., pos) => *pos,
|
|
|
|
Self::Assignment(x) => x.0.pos,
|
|
|
|
Self::Block(x) => x.position(),
|
|
|
|
Self::Expr(x) => x.start_position(),
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(.., pos) => *pos,
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Export(.., pos) => *pos,
|
|
|
|
#[cfg(not(feature = "no_closure"))]
|
|
Self::Share(.., pos) => *pos,
|
|
}
|
|
}
|
|
/// Override the [position][Position] of this statement.
|
|
pub fn set_position(&mut self, new_pos: Position) -> &mut Self {
|
|
match self {
|
|
Self::Noop(pos)
|
|
| Self::BreakLoop(.., pos)
|
|
| Self::FnCall(.., pos)
|
|
| Self::If(.., pos)
|
|
| Self::Switch(.., pos)
|
|
| Self::While(.., pos)
|
|
| Self::Do(.., pos)
|
|
| Self::For(.., pos)
|
|
| Self::Return(.., pos)
|
|
| Self::Var(.., pos)
|
|
| Self::TryCatch(.., pos) => *pos = new_pos,
|
|
|
|
Self::Assignment(x) => x.0.pos = new_pos,
|
|
|
|
Self::Block(x) => x.set_position(new_pos, x.end_position()),
|
|
|
|
Self::Expr(x) => {
|
|
x.set_position(new_pos);
|
|
}
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(.., pos) => *pos = new_pos,
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Export(.., pos) => *pos = new_pos,
|
|
|
|
#[cfg(not(feature = "no_closure"))]
|
|
Self::Share(.., pos) => *pos = new_pos,
|
|
}
|
|
|
|
self
|
|
}
|
|
/// Does this statement return a value?
|
|
#[must_use]
|
|
pub const fn returns_value(&self) -> bool {
|
|
match self {
|
|
Self::If(..)
|
|
| Self::Switch(..)
|
|
| Self::Block(..)
|
|
| Self::Expr(..)
|
|
| Self::FnCall(..) => true,
|
|
|
|
Self::Noop(..)
|
|
| Self::While(..)
|
|
| Self::Do(..)
|
|
| Self::For(..)
|
|
| Self::TryCatch(..) => false,
|
|
|
|
Self::Var(..) | Self::Assignment(..) | Self::BreakLoop(..) | Self::Return(..) => false,
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(..) | Self::Export(..) => false,
|
|
|
|
#[cfg(not(feature = "no_closure"))]
|
|
Self::Share(..) => false,
|
|
}
|
|
}
|
|
/// Is this statement self-terminated (i.e. no need for a semicolon terminator)?
|
|
#[must_use]
|
|
pub const fn is_self_terminated(&self) -> bool {
|
|
match self {
|
|
Self::If(..)
|
|
| Self::Switch(..)
|
|
| Self::While(..)
|
|
| Self::For(..)
|
|
| Self::Block(..)
|
|
| Self::TryCatch(..) => true,
|
|
|
|
// A No-op requires a semicolon in order to know it is an empty statement!
|
|
Self::Noop(..) => false,
|
|
|
|
Self::Expr(e) => match &**e {
|
|
Expr::Custom(x, ..) if x.is_self_terminated() => true,
|
|
_ => false,
|
|
},
|
|
|
|
Self::Var(..)
|
|
| Self::Assignment(..)
|
|
| Self::FnCall(..)
|
|
| Self::Do(..)
|
|
| Self::BreakLoop(..)
|
|
| Self::Return(..) => false,
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(..) | Self::Export(..) => false,
|
|
|
|
#[cfg(not(feature = "no_closure"))]
|
|
Self::Share(..) => false,
|
|
}
|
|
}
|
|
/// Is this statement _pure_?
|
|
///
|
|
/// A pure statement has no side effects.
|
|
#[must_use]
|
|
pub fn is_pure(&self) -> bool {
|
|
match self {
|
|
Self::Noop(..) => true,
|
|
Self::Expr(expr) => expr.is_pure(),
|
|
Self::If(x, ..) => {
|
|
x.0.is_pure() && x.1.iter().all(Stmt::is_pure) && x.2.iter().all(Stmt::is_pure)
|
|
}
|
|
Self::Switch(x, ..) => {
|
|
x.0.is_pure()
|
|
&& x.1.cases.values().all(|block| {
|
|
block.condition.is_pure() && block.statements.iter().all(Stmt::is_pure)
|
|
})
|
|
&& x.1.ranges.iter().all(|(.., block)| {
|
|
block.condition.is_pure() && block.statements.iter().all(Stmt::is_pure)
|
|
})
|
|
&& x.1.def_case.iter().all(Stmt::is_pure)
|
|
}
|
|
|
|
// Loops that exit can be pure because it can never be infinite.
|
|
Self::While(x, ..) if matches!(x.0, Expr::BoolConstant(false, ..)) => true,
|
|
Self::Do(x, options, ..) if matches!(x.0, Expr::BoolConstant(..)) => match x.0 {
|
|
Expr::BoolConstant(cond, ..) if cond == options.contains(ASTFlags::NEGATED) => {
|
|
x.1.iter().all(Stmt::is_pure)
|
|
}
|
|
_ => false,
|
|
},
|
|
|
|
// Loops are never pure since they can be infinite - and that's a side effect.
|
|
Self::While(..) | Self::Do(..) => false,
|
|
|
|
// For loops can be pure because if the iterable is pure, it is finite,
|
|
// so infinite loops can never occur.
|
|
Self::For(x, ..) => x.2.is_pure() && x.3.iter().all(Stmt::is_pure),
|
|
|
|
Self::Var(..) | Self::Assignment(..) | Self::FnCall(..) => false,
|
|
Self::Block(block, ..) => block.iter().all(|stmt| stmt.is_pure()),
|
|
Self::BreakLoop(..) | Self::Return(..) => false,
|
|
Self::TryCatch(x, ..) => {
|
|
x.try_block.iter().all(Stmt::is_pure) && x.catch_block.iter().all(Stmt::is_pure)
|
|
}
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(..) => false,
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Export(..) => false,
|
|
|
|
#[cfg(not(feature = "no_closure"))]
|
|
Self::Share(..) => false,
|
|
}
|
|
}
|
|
/// Does this statement's behavior depend on its containing block?
|
|
///
|
|
/// A statement that depends on its containing block behaves differently when promoted to an
|
|
/// upper block.
|
|
///
|
|
/// Currently only variable definitions (i.e. `let` and `const`), `import`/`export` statements,
|
|
/// and `eval` calls (which may in turn define variables) fall under this category.
|
|
#[inline]
|
|
#[must_use]
|
|
pub fn is_block_dependent(&self) -> bool {
|
|
match self {
|
|
Self::Var(..) => true,
|
|
|
|
Self::Expr(e) => match &**e {
|
|
Expr::Stmt(s) => s.iter().all(Stmt::is_block_dependent),
|
|
Expr::FnCall(x, ..) => !x.is_qualified() && x.name == KEYWORD_EVAL,
|
|
_ => false,
|
|
},
|
|
|
|
Self::FnCall(x, ..) => !x.is_qualified() && x.name == KEYWORD_EVAL,
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(..) | Self::Export(..) => true,
|
|
|
|
_ => false,
|
|
}
|
|
}
|
|
/// Is this statement _pure_ within the containing block?
|
|
///
|
|
/// An internally pure statement only has side effects that disappear outside the block.
|
|
///
|
|
/// Currently only variable definitions (i.e. `let` and `const`) and `import`/`export`
|
|
/// statements are internally pure, other than pure expressions.
|
|
#[inline]
|
|
#[must_use]
|
|
pub fn is_internally_pure(&self) -> bool {
|
|
match self {
|
|
Self::Var(x, ..) => x.1.is_pure(),
|
|
|
|
Self::Expr(e) => match e.as_ref() {
|
|
Expr::Stmt(s) => s.iter().all(Stmt::is_internally_pure),
|
|
_ => self.is_pure(),
|
|
},
|
|
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(x, ..) => x.0.is_pure(),
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Export(..) => true,
|
|
|
|
_ => self.is_pure(),
|
|
}
|
|
}
|
|
/// Does this statement break the current control flow through the containing block?
|
|
///
|
|
/// Currently this is only true for `return`, `throw`, `break` and `continue`.
|
|
///
|
|
/// All statements following this statement will essentially be dead code.
|
|
#[inline]
|
|
#[must_use]
|
|
pub const fn is_control_flow_break(&self) -> bool {
|
|
match self {
|
|
Self::Return(..) | Self::BreakLoop(..) => true,
|
|
_ => false,
|
|
}
|
|
}
|
|
/// Recursively walk this statement.
|
|
/// Return `false` from the callback to terminate the walk.
|
|
pub fn walk<'a>(
|
|
&'a self,
|
|
path: &mut Vec<ASTNode<'a>>,
|
|
on_node: &mut impl FnMut(&[ASTNode]) -> bool,
|
|
) -> bool {
|
|
// Push the current node onto the path
|
|
path.push(self.into());
|
|
|
|
if !on_node(path) {
|
|
return false;
|
|
}
|
|
|
|
match self {
|
|
Self::Var(x, ..) => {
|
|
if !x.1.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
Self::If(x, ..) => {
|
|
if !x.0.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
for s in x.1.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
for s in x.2.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::Switch(x, ..) => {
|
|
if !x.0.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
for b in x.1.cases.values() {
|
|
if !b.condition.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
for s in b.statements.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
for (.., b) in &x.1.ranges {
|
|
if !b.condition.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
for s in b.statements.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
for s in x.1.def_case.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::While(x, ..) | Self::Do(x, ..) => {
|
|
if !x.0.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
for s in x.1.statements() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::For(x, ..) => {
|
|
if !x.2.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
for s in x.3.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::Assignment(x, ..) => {
|
|
if !x.1.lhs.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
if !x.1.rhs.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
Self::FnCall(x, ..) => {
|
|
for s in &x.args {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::Block(x, ..) => {
|
|
for s in x.statements() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::TryCatch(x, ..) => {
|
|
for s in x.try_block.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
for s in x.catch_block.iter() {
|
|
if !s.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
Self::Expr(e) => {
|
|
if !e.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
Self::Return(Some(e), ..) => {
|
|
if !e.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
#[cfg(not(feature = "no_module"))]
|
|
Self::Import(x, ..) => {
|
|
if !x.0.walk(path, on_node) {
|
|
return false;
|
|
}
|
|
}
|
|
_ => (),
|
|
}
|
|
|
|
path.pop().unwrap();
|
|
|
|
true
|
|
}
|
|
}
|