First implementation of top-level fields without initializers.

frog/leg/scanner/listener.dart

Index: frog/leg/scanner/listener.dart
===================================================================
--- frog/leg/scanner/listener.dart	(revision 2339)
+++ frog/leg/scanner/listener.dart	(working copy)
@@ -462,7 +462,16 @@
   }
 
   void endTopLevelFields(int count, Token beginToken, Token endToken) {
-    canceler.cancel("Cannot handle fields", token: beginToken);
+    List<Identifier> names = <Identifier>[];

[ahe, 2011/12/12 14:56:57]

Please use Link or LinkBuilder.

[ngeoffray, 2011/12/12 15:52:08]

Done.

+    for (int i = 0; i < count; i++) {
+      names.add(popNode());
+    }
+    Element fields = new PartialFieldListElement(beginToken, endToken);

[ahe, 2011/12/12 14:56:57]

FieldList -> Fields?

[ngeoffray, 2011/12/12 15:52:08]

As discussed, maintained FieldList according to the names in the grammar.

+
+    // Push in source order.

[ahe, 2011/12/12 14:56:57]

Normally the order is reversed, isn't it?

[ngeoffray, 2011/12/12 15:52:08]

Yes.

+    for (int i = count - 1; i >= 0; i--) {
+      pushElement(new PartialFieldElement(names[i].source, fields));
+    }
   }
 
   void handleIdentifier(Token token) {
@@ -1016,6 +1025,46 @@
   }
 }
 
+class PartialFieldElement extends Element {
+  final Element variables;
+
+  PartialFieldElement(SourceString name,
+                      Element this.variables,
+                      [Element enclosing = null])
+    : super(name, ElementKind.FIELD, enclosing);
+
+  Node parseNode(Canceler canceler, Logger logger)
+    => variables.parseNode(canceler, logger);

[ahe, 2011/12/12 14:56:57]

I prefer using { return ... } when it doesn't fit on one line.

[ngeoffray, 2011/12/12 15:52:08]

Done.

+
+  Type computeType(Compiler compiler, Type types)

[ahe, 2011/12/12 14:56:57]

This method doesn't belong in this library.

[ngeoffray, 2011/12/12 15:52:08]

Done.

+    => variables.computeType(compiler, types);

[ahe, 2011/12/12 14:56:57]

Ditto for { return ... }.

[ngeoffray, 2011/12/12 15:52:08]

Done.

+
+  Type get type() => variables.type;
+}
+
+class PartialFieldListElement extends Element {

[karlklose, 2011/12/12 15:09:48]

Can you add a short comment on what this element represents?

[ngeoffray, 2011/12/12 15:52:08]

Done.

+  final Token beginToken;
+  final Token endToken;
+  Node node;

[karlklose, 2011/12/12 15:09:48]

Or perhaps adding a more precise type for the Node would make it more obvious? 

[ngeoffray, 2011/12/12 15:52:08]

Done.

+  Type type;
+
+  PartialFieldListElement(Token this.beginToken, Token this.endToken)
+    : super(null, ElementKind.VARIABLE_LIST, null);
+
+  Node parseNode(Canceler canceler, Logger logger) {
+    if (node != null) return node;
+    node = parse(canceler, logger,
+        (p) => p.parseVariablesDeclaration(beginToken));
+    return node;
+  }
+
+  Type computeType(Compiler compiler, Type types) {

[ahe, 2011/12/12 14:56:57]

This method doesn't belong in this library.

[ngeoffray, 2011/12/12 15:52:08]

Done.

+    if (type != null) return type;
+    type = getType(parseNode(compiler, compiler).type, compiler, types);
+    return type;
+  }
+}
+
 Node parse(Canceler canceler, Logger logger, doParse(Parser parser)) {
   NodeListener listener = new NodeListener(canceler, logger);
   doParse(new Parser(listener));