Make string interpolations be compile-time-constants.

frog/leg/compile_time_constants.dart

Index: frog/leg/compile_time_constants.dart
diff --git a/frog/leg/compile_time_constants.dart b/frog/leg/compile_time_constants.dart
index cefe2f5f2a70f8d0f44862a181f09597555c33cf..053a79affc00f9ce31880b09bb4337a733f7f89e 100644
--- a/frog/leg/compile_time_constants.dart
+++ b/frog/leg/compile_time_constants.dart
@@ -333,9 +333,9 @@ class MapConstant extends ObjectConstant {
           buffer.add("$isolatePrototype.$name");
         } else {
           value.writeJsCode(buffer, handler);
-        }      
+        }
       }
-      buffer.add("}");      
+      buffer.add("}");
     }
 
     void badFieldCountError() {
@@ -768,6 +768,36 @@ class CompileTimeConstantEvaluator extends AbstractVisitor {
     return new StringConstant(node.dartString);
   }
 
+  Constant visitStringJuxtapostion(StringJuxtaposition node) {
+    if (node.dartString !== null) {

[ngeoffray, 2012/03/15 08:09:41]

!node.isInterpolation

[Lasse Reichstein Nielsen, 2012/03/15 08:39:09]

For consistency :)

+      return new StringConstant(node.dartString);
+    }
+    StringConstant left = evaluate(node.left);
+    StringConstant right = evaluate(node.right);
+    return new StringConstant(new DartString.concat(left.value, right.value));
+  }
+
+  Constant visitStringInterpolation(StringInterpolation node) {
+    StringConstant initialString = evaluate(node.string);
+    DartString accumulator = initialString.value;
+    for (StringInterpolationPart part in node.parts) {
+      Constant expression = evaluate(part.expression);
+      DartString expressionString;
+      if (expression.isNum() || expression.isBool()) {
+        Object value = expression.value;
+        expressionString = new DartString.literal(value.toString());
+      } else if (expression.isString()) {
+        expressionString = expression.value;
+      } else {
+        error(part.expression);
+      }
+      accumulator = new DartString.concat(accumulator, expressionString);
+      StringConstant partString = evaluate(part.string);
+      accumulator = new DartString.concat(accumulator, partString.value);
+    };

[ngeoffray, 2012/03/15 08:09:41]

extra ';'

[Lasse Reichstein Nielsen, 2012/03/15 08:39:09]

well spotted.

+    return new StringConstant(accumulator);
+  }
+
   // TODO(floitsch): provide better error-messages.
   Constant visitSend(Send send) {
     Element element = elements[send];