Fixing string compile-time constant evaluation

frog/member.dart

Index: frog/member.dart
diff --git a/frog/member.dart b/frog/member.dart
index 2793de4153de8014d3f6b665dd6fd38bbc33c4af..6161b823a2f60074ef590e1b1db90da0e27d4e80 100644
--- a/frog/member.dart
+++ b/frog/member.dart
@@ -1177,13 +1177,29 @@ class MethodMember extends Member {
       } else if (name == '\$add') {
         if (allConst) {
           var val0 = target.dynamic.actualValue;
+          var quote0 = val0[0];
           val0 = val0.substring(1, val0.length - 1);
           var val1 = args.values[0].dynamic.actualValue;
+          var quote1 = null;
           if (args.values[0].type.isString) {
+            quote1 = val1[0];
             val1 = val1.substring(1, val1.length - 1);
           }
-          var value = '${val0}${val1}';
-          value = '"' + value.replaceAll('"', '\\"') + '"';
+          // ensure that both strings use the same quote char:

[Jennifer Messerly, 2011/11/29 18:55:48]

it'd be really nice if this was pulled out into its own function

[Siggi Cherem (dart-lang), 2011/11/29 19:09:26]

Done.

+          var value;
+          if (quote0 == quote1 || quote1 == null) {
+            // if both strings use the same quote, then merge them together
+            value = '$quote0${val0}${val1}$quote0';
+          } else if (quote0 == '"') {
+            // if they are different, escape the single-quote to be double-quote
+            // the choice of single vs double is arbitrary, but choosing one
+            // ensures that we only do this escaping once on a string portion.
+            assert(quote1 == "'");
+            value = '$quote0${val0}${toDoubleQuote(val1)}$quote0';
+          } else {
+            assert(quote1 == '"');
+            value = '$quote1${toDoubleQuote(val0)}${val1}$quote1';
+          }
           return new EvaluatedValue(world.stringType, value, value, node.span);
         }