Fixing string compile-time constant evaluation

frog/gen.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * Top level generator object for writing code and keeping track of
  * dependencies.
  *
  * Should have two compilation models, but only one implemented so far.
  *
@@ skipping 1738 matching lines @@
         var value = (kind == TokenKind.AND)
             ? x.actualValue && y.actualValue : x.actualValue || y.actualValue;
         return new EvaluatedValue(world.nonNullBool, value, '$value',
             node.span);
       }
       return new Value(world.nonNullBool, code, node.span);
     } else if (kind == TokenKind.EQ_STRICT || kind == TokenKind.NE_STRICT) {
       var x = visitValue(node.x);
       var y = visitValue(node.y);
       if (x.isConst && y.isConst) {
-        var value = kind == TokenKind.EQ_STRICT
-            // Note: it is ok to use == and not === here since all of these
-            // constant comparisons are applied to doubles, bool, or strings.
-            // We need it for the compile-time evaluator because
-            // (9).toDouble() === 9.0 is false in dartvm.
-            ? x.actualValue == y.actualValue : x.actualValue != y.actualValue;
+        var xVal = x.actualValue;
+        var yVal = y.actualValue;
+
+        // cannonicalize strings if they are using different quote chars:
+        if (x.type.isString && y.type.isString
+            && xVal[0] != yVal[0]) {

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

does this need to handle multiline strings too?

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

Thankfully no, we do normalize those.

+          if (xVal[0] == '"') {
+            xVal = xVal.substring(1, xVal.length - 1);
+            yVal = toDoubleQuote(yVal.substring(1, yVal.length - 1));
+          } else {
+            xVal = toDoubleQuote(xVal.substring(1, xVal.length - 1));
+            yVal = yVal.substring(1, yVal.length - 1);
+          }
+        }
+        print("$xVal vs $yVal");

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

remove

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

oops. thanks.

+
+        // Note: it is ok to use == and not === here since all of these
+        // constant comparisons are applied to doubles, bool, or strings.
+        // We need it for the compile-time evaluator because
+        // (9).toDouble() === 9.0 is false in dartvm.
+        var value = kind == TokenKind.EQ_STRICT ? xVal == yVal : xVal != yVal;
         return new EvaluatedValue(world.nonNullBool, value, "$value",
             node.span);
       }
       if (x.code == 'null' || y.code == 'null') {
         // Switching to == ensures that null and undefined are interchangable.
         final op = node.op.toString().substring(0,2);
         return new Value(world.nonNullBool, '${x.code} $op ${y.code}',
             node.span);
       } else {
         // TODO(jimhug): Resolve issue with undefined and null here.
@@ skipping 500 matching lines @@
     // TODO(jimhug): Confirm that only strings need possible translation
     if (type.isString) {
       if (text.startsWith('@')) {
         text = _escapeString(parseStringLiteral(text));
         text = '"$text"';
       } else if (isMultilineString(text)) {
         // convert multi-line strings into single-line
         text = parseStringLiteral(text);
         // TODO(jimhug): What about \r?
         text = text.replaceAll('\n', '\\n');
-        text = text.replaceAll('"', '\\"');
+        text = toDoubleQuote(text);
         text = '"$text"';
       }
       if (text !== node.text) {
         node.value = text;
         node.text = text;
       }
     }
 
     // TODO(jimhug): Should pass node.span - but that breaks something...
     return new EvaluatedValue(type, node.value, node.text, null);
@@ skipping 113 matching lines @@
       result.add(new Value(world.varType, '\$$i', null, /*needsTemp:*/false));
     }
     for (int i = bareCount; i < length; i++) {
       var name = getName(i);
       if (name == null) name = '\$$i';
       result.add(new Value(world.varType, name, null, /*needsTemp:*/false));
     }
     return new Arguments(nodes, result);
   }
 }