Build script tags.

dart/frog/leg/elements/elements.dart

Index: dart/frog/leg/elements/elements.dart
diff --git a/dart/frog/leg/elements/elements.dart b/dart/frog/leg/elements/elements.dart
index 72fd376866d0b19decfb39bc815b5f247b635a3b..d4f91d9b081c277eea8d048a9027418bff5b82ab 100644
--- a/dart/frog/leg/elements/elements.dart
+++ b/dart/frog/leg/elements/elements.dart
@@ -50,7 +50,6 @@ class Element implements Hashable {
   final Element enclosingElement;
   Modifiers get modifiers() => null;
 
-
   Node parseNode(Canceler canceler, Logger logger) {
     canceler.cancel("Internal Error: Element.parseNode");
   }
@@ -87,13 +86,38 @@ class Element implements Hashable {
   toString() => '$kind($name)';
 }
 
-class CompilationUnitElement extends Element {
+class EnclosingElement extends Element {

[ngeoffray, 2012/01/25 09:04:59]

EnclosingElement -> ContainerElement?

Because other elements can be enclosing (eg a method), calling this class
EnclosingElement makes things confusing.

[ahe, 2012/01/25 09:18:53]

I was planning on making the other elements subclasses of EnclosingElement. But
now I'm not sure that is a good idea. addMember is not an integral property of
what it means to be an EnclosingElement.

[ahe, 2012/01/25 09:28:53]

Done.

+  EnclosingElement(name, kind, enclosingElement) :
+    super(name, kind, enclosingElement);
+
+  abstract void addMember(Element element, Canceler canceler);
+}
+
+class CompilationUnitElement extends EnclosingElement {
   final Script script;
+  Link<Element> topLevelElements = const EmptyLink<Element>();
+  Link<ScriptTag> tags = const EmptyLink<ScriptTag>();
+  final Map<SourceString, Element> scope;
+
   CompilationUnitElement(Script script, Element enclosing)
     : super(new SourceString(script.name),
             ElementKind.COMPILATION_UNIT,
             enclosing),
-      this.script = script;
+      this.script = script,
+      this.scope = new Map<SourceString, Element>();
+
+  void addMember(Element element, Canceler canceler) {
+    topLevelElements = topLevelElements.prepend(element);
+    Element existing = scope.putIfAbsent(element.name, ()=>element);

[ngeoffray, 2012/01/25 09:04:59]

spaces around => ?

+    if (existing !== element) {

[ngeoffray, 2012/01/25 09:04:59]

Is this the right place to do it? Do we want a per-compilation unit error, or a
per-library error? It looks to me that the library will have to create the scope
and run through the topLevelElements of its compilation units, in order to
report duplicates.

[ahe, 2012/01/25 09:18:53]

You're right, there is not much value in reporting duplicates at this point. I
should remove the scope from compilation unit.

[ahe, 2012/01/25 09:28:53]

Done.

+      canceler.cancel('duplicate definition', token: element.position());
+      canceler.cancel('existing definition', token: existing.position());
+    }
+  }
+
+  void addTag(ScriptTag tag) {
+    tags = tags.prepend(tag);
+  }
 }
 
 class VariableElement extends Element {
@@ -329,7 +353,7 @@ class SynthesizedConstructorElement extends FunctionElement {
   Token position() => null;
 }
 
-class ClassElement extends Element {
+class ClassElement extends EnclosingElement {
   Type type;
   Type supertype;
   Link<Element> members = const EmptyLink<Element>();
@@ -347,7 +371,7 @@ class ClassElement extends Element {
       constructors = new Map<SourceString, Element>(),
       super(name, ElementKind.CLASS, enclosing);
 
-  void addMember(Element element) {
+  void addMember(Element element, Canceler canceler) {
     members = members.prepend(element);
     if (element.kind == ElementKind.GENERATIVE_CONSTRUCTOR ||
         element.modifiers.isFactory()) {