Inserted string validation as separate task in compiler.

frog/leg/warnings.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.
 
 class MessageKind {
   final String template;
   const MessageKind(this.template);
 
   static final GENERIC = const MessageKind('#{1}');
 
@@ skipping 68 matching lines @@
   static final FIELD_PARAMETER_NOT_ALLOWED = const MessageKind(
       'A field parameter is only allowed in generative constructors');
   static final INVALID_PARAMETER = const MessageKind(
       "Cannot resolve parameter");
   static final NOT_INSTANCE_FIELD = const MessageKind(
       '#{1} is not an instance field');
 
   static final NOT_A_COMPILE_TIME_CONSTANT = const MessageKind(
       '#{1} cannot be used as compile-time constant');
 
+  static final INVALID_STRING_ESCAPE = const MessageKind(
+      'Unexpected character or end-of-string in string escape at index #{1}');

[ahe, 2012/01/25 08:39:44]

I'm not a big fan of telling the user: I'm not sure what happened, but it was
either this or that. So if you think it is important to distinguish between
"unexpected character" and "end-of-string" (I don't ;-), please make two error
codes. But I'd just write:

"unexpected character in string escape"

[ahe, 2012/01/25 08:39:44]

"Unexpected" should be lowercase to be consistent with other messages (except
the inconsistent ones :-)

[ahe, 2012/01/25 08:39:44]

" at index #{1}" should be removed. Instead this position should be reported by
the diagnostic system.

[Lasse Reichstein Nielsen, 2012/01/26 10:14:20]

I'm removing all of these, since I'm not using them any more.

+  static final INVALID_SINGLE_LINE_STRING = const MessageKind(
+      'Line terminator in single-line string at index #{1}');

[ahe, 2012/01/25 08:39:44]

Lowercase and remove "at index #{1}".

+  static final INVALID_UNICODE_SCALAR = const MessageKind(
+      'Invalid character U+#{2} in string escape at index #{1}');

[ahe, 2012/01/25 08:39:44]

Lowercase and remove "at index #{1}".

+
+
   toString() => template;
 }
 
 class Message {
   final kind;
   final List arguments;
   String message;
 
   Message(this.kind, this.arguments);
 
@@ skipping 38 matching lines @@
   String toString() => message.toString();
 }
 
 class CompileTimeConstantError {
   final Message message;
   CompileTimeConstantError.message(this.message);
   CompileTimeConstantError(MessageKind kind, List<Type> arguments)
     : message = new Message(kind, arguments);
   String toString() => message.toString();  
 }