# HG changeset patch
# User David Anderson <dvander@alliedmods.net>
# Date 1343712638 25200
# Node ID a8735148dcf03df153d93436e4be037587477a57
# Parent  393f1b8ac8c39e952adbb4f3dd807b6453e40a0b
Support -x as a constant expression.

diff -r 393f1b8ac8c3 -r a8735148dcf0 src/SemanticAnalysis.cpp
--- a/src/SemanticAnalysis.cpp	Mon Jul 30 22:24:57 2012 -0700
+++ b/src/SemanticAnalysis.cpp	Mon Jul 30 22:30:38 2012 -0700
@@ -58,6 +58,19 @@
     }
 }
 
+static inline bool
+EvaluateUnaryOperation(TokenKind kind, const BoxedPrimitive &inner, BoxedPrimitive *out)
+{
+  switch (kind) {
+    case TOK_MINUS:
+      *out = BoxedPrimitive::Int(-inner.toInt());
+      return true;
+
+    default:
+      return false;
+  }
+}
+
 static bool
 EvaluateForConstant(Expression *expression, BoxedPrimitive *out)
 {
@@ -75,6 +88,15 @@
         return EvaluateBinaryOperation(b->token(), left, right, out);
       }
 
+      case AstNode::kUnaryExpression:
+      {
+        BoxedPrimitive inner;
+        UnaryExpression *u = expression->toUnaryExpression();
+        if (!EvaluateForConstant(u->expression(), &inner))
+            return false;
+        return EvaluateUnaryOperation(u->token(), inner, out);
+      }
+
       case AstNode::kNameProxy:
       {
         NameProxy *proxy = expression->toNameProxy();