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04f587190e
YEAST (YEAST Elaborates Abstract Syntax Trees) is a framework for
transforming tree-sitter parse trees before CodeQL extraction.
Core components:
- shared/yeast/ — Ast, Node, Schema, query matching engine, captures,
FreshScope, BuildCtx
- shared/yeast-macros/ — proc macros: query!, tree!, trees!, rule!
The query language is inspired by tree-sitter queries:
(assignment left: (_) @lhs right: (_) @rhs)
Templates support embedded Rust ({expr}), splicing ({..expr}),
computed literals (#{expr}), and fresh identifiers ($name).
The rule! macro combines query and transform:
rule!((for pattern: (_) @pat ...) => (call receiver: {val} ...))
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
44 lines
1.2 KiB
Rust
44 lines
1.2 KiB
Rust
use std::cell::Cell;
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use std::collections::BTreeMap;
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/// Tracks fresh identifier generation during a single tree-building operation.
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/// All occurrences of the same `$name` within one build share the same generated value.
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pub struct FreshScope {
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counter: Cell<u32>,
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resolved: std::cell::RefCell<BTreeMap<String, String>>,
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}
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impl Default for FreshScope {
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fn default() -> Self {
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Self::new()
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}
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}
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impl FreshScope {
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pub fn new() -> Self {
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Self {
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counter: Cell::new(0),
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resolved: std::cell::RefCell::new(BTreeMap::new()),
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}
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}
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pub fn resolve(&self, name: &str) -> String {
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self.resolved
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.borrow_mut()
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.entry(name.to_string())
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.or_insert_with(|| {
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let id = self.counter.get();
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self.counter.set(id + 1);
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format!("${name}-{id}")
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})
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.clone()
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}
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/// Clear resolved names but keep the counter. Called between rule
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/// applications so that `$tmp` in different rules gets different values
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/// while the counter increases monotonically.
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pub fn next_scope(&self) {
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self.resolved.borrow_mut().clear();
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}
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}
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