evaluate method

  1. @override
LangVal<LangType> evaluate(
  1. SymbolTable table
)
override

Evaluates this AST node and generates corresponding LLVM IR code.

This is the main method that each AST node must implement to:

  1. Perform semantic analysis (type checking, symbol resolution)
  2. Generate LLVM IR instructions for the node's operation
  3. Return the result value (if this is an expression)

Parameters:

  • table: The current symbol table for variable and function lookups

Returns: The result of evaluating this node (type depends on node type)

Throws:

  • Exception for semantic errors (undefined variables, type mismatches, etc.)
  • Various specific exceptions for different error conditions

Note: The base implementation throws "Not implemented" - concrete subclasses must override this method with their specific evaluation logic.

Implementation

@override
LangVal evaluate(SymbolTable table) {
  final childResult = child.evaluate(table);
  //cant be array
  if (childResult.type is ArrayType) {
    throw Exception("Cannot apply unary operator to array");
  }

  switch (nodeValue) {
    case MathOp.add:
      return childResult;
    case MathOp.sub:
      Node.addIrLine(
          "%unOp.$id = sub ${childResult.type.irType} 0, ${childResult.regName}");
      return LangVal("%unOp.$id", childResult.type);
    default:
      throw Exception("Unknown operator: $nodeValue");
  }
}