Syntax directed translation

gistfile1.java

// Example of computing attributes in Rats!
AssignStmt assignStmt = l : expr COLONEQ r : expr { yyValue = new AssignStmt(l, r) }

// class that represents an assignment statement node.
class AssignStmt extends Stmt {
    Expression _lhs, _rhs; // children
    public AssignStmt(Expression l, Expression r) {
        _lhs = l;
        _rhs = l;
    }
}