1.1 --- a/src/SemanticAnalysis.cpp	Mon Jul 30 22:24:57 2012 -0700
     1.2 +++ b/src/SemanticAnalysis.cpp	Mon Jul 30 22:30:38 2012 -0700
     1.3 @@ -58,6 +58,19 @@
     1.4      }
     1.5  }
     1.6  
     1.7 +static inline bool
     1.8 +EvaluateUnaryOperation(TokenKind kind, const BoxedPrimitive &inner, BoxedPrimitive *out)
     1.9 +{
    1.10 +  switch (kind) {
    1.11 +    case TOK_MINUS:
    1.12 +      *out = BoxedPrimitive::Int(-inner.toInt());
    1.13 +      return true;
    1.14 +
    1.15 +    default:
    1.16 +      return false;
    1.17 +  }
    1.18 +}
    1.19 +
    1.20  static bool
    1.21  EvaluateForConstant(Expression *expression, BoxedPrimitive *out)
    1.22  {
    1.23 @@ -75,6 +88,15 @@
    1.24          return EvaluateBinaryOperation(b->token(), left, right, out);
    1.25        }
    1.26  
    1.27 +      case AstNode::kUnaryExpression:
    1.28 +      {
    1.29 +        BoxedPrimitive inner;
    1.30 +        UnaryExpression *u = expression->toUnaryExpression();
    1.31 +        if (!EvaluateForConstant(u->expression(), &inner))
    1.32 +            return false;
    1.33 +        return EvaluateUnaryOperation(u->token(), inner, out);
    1.34 +      }
    1.35 +
    1.36        case AstNode::kNameProxy:
    1.37        {
    1.38          NameProxy *proxy = expression->toNameProxy();