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 leftResult = left.evaluate(table);
  final rightResult = right.evaluate(table);

  //cant be array
  if (leftResult.type is ArrayType || rightResult.type is ArrayType) {
    throw Exception("Cannot apply binary operator to array");
  }

  if (leftResult.type.primitiveType != PrimitiveTypes.int ||
      rightResult.type.primitiveType != PrimitiveTypes.int) {
    throw Exception("BoolBinOp can only be applied to int");
  }
  //should always return 0 or 1 in i64
  switch (nodeValue) {
    case BoolOperator.and:
      Node.addIrLine(
          "%and.$id = and i64 ${leftResult.regName}, ${rightResult.regName}");
      Node.addIrLine("%logic.$id = icmp ne i64 %and.$id, 0");
      Node.addIrLine("%boolBinOp.$id = zext i1 %logic.$id to i64");

      break;
    case BoolOperator.or:
      Node.addIrLine(
          "%and.$id = or i64 ${leftResult.regName}, ${rightResult.regName}");
      Node.addIrLine("%logic.$id = icmp ne i64 %and.$id, 0");
      Node.addIrLine("%boolBinOp.$id = zext i1 %logic.$id to i64");
      break;
    default:
      throw Exception("Unknown operator: $nodeValue");
  }
  return LangVal("%boolBinOp.$id", const PrimitiveType(PrimitiveTypes.int));
}