Module meta_var 

Meta-variable Environment and Utilities

This module provides types and functions for handling meta-variables in AST pattern matching. Meta-variables allow patterns to flexibly match and capture code fragments, supporting single and multi-capture semantics.

Key Components

• MetaVarEnv: Stores meta-variable instantiations during pattern matching.
• MetaVariable: Enum representing different meta-variable forms (single, multi, dropped).
• extract_meta_var: Utility to parse meta-variable strings.
• Insertion, retrieval, and transformation APIs for meta-variable environments.

Example

use thread_ast_engine::meta_var::{MetaVarEnv, MetaVariable, extract_meta_var};

let mut env = MetaVarEnv::new();
env.insert("$A", node);
let meta = extract_meta_var("$A", '$');

See MetaVarEnv for details on usage in AST matching and rewriting.

Structs

MetaVarEnv

a dictionary that stores metavariable instantiation const a = 123 matched with const a = $A will produce env: $A => 123

Enums

MetaVariable

Type Aliases

MetaVariableID

Interned string type for meta-variable identifiers.

Underlying