No Symbol Table for Variable Tracking

[SAMBA8695]

Description

The compiler currently has no symbol table. As a result, variables declared using let are never stored, and identifiers cannot be resolved during later stages of compilation.

Although the parser builds AST_VAR_DECL and AST_VAR nodes, there is no data structure that tracks variable names and their associated values or IR representations.

Example Input

let x = 1;
let y = x + 2;

Current Behavior

• Variable declarations (let x = ...) do not store x anywhere
• Identifier usage (x) cannot be resolved
• IR generation ignores variable scope and lifetime
• LLVM output discards computed values
• No error is reported for undefined variables

Expected Behavior

• A symbol table should map variable names to their values or IR references
• Variable declarations should insert entries into the symbol table
• Identifier usage should look up variables in the symbol table
• Using an undefined variable should produce a clear error

Suggested Direction

• Introduce a symbol table data structure (e.g. hash map or scoped table)
• Integrate symbol table into parsing or IR generation
• Handle AST_VAR_DECL and AST_VAR using the symbol table
• Prepare for future scope support (blocks, functions)