Implement script tags.

dart/frog/leg/elements/elements.dart

 // Copyright (c) 2012, 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.
 
 #library('elements');
 
 #import('../tree/tree.dart');
 #import('../scanner/scannerlib.dart');
 #import('../leg.dart');  // TODO(karlklose): we only need type.
 #import('../util/util.dart');
@@ skipping 14 matching lines @@
   static final ElementKind VARIABLE_LIST = const ElementKind('variable_list');
   static final ElementKind FIELD_LIST = const ElementKind('field_list');
   static final ElementKind GENERATIVE_CONSTRUCTOR_BODY =
       const ElementKind('generative_constructor_body');
   static final ElementKind COMPILATION_UNIT =
       const ElementKind('compilation_unit');
   static final ElementKind GETTER = const ElementKind('getter');
   static final ElementKind SETTER = const ElementKind('setter');
   static final ElementKind ABSTRACT_FIELD = const ElementKind('abstract_field');
   static final ElementKind LIBRARY = const ElementKind('library');
+  static final ElementKind PREFIX = const ElementKind('prefix');
 
   toString() => id;
 }
 
 class Element implements Hashable {
   final SourceString name;
   final ElementKind kind;
   final Element enclosingElement;
   Modifiers get modifiers() => null;
 
@@ skipping 125 matching lines @@
     return elements[name];
   }
 
   Element lookupLocalMember(SourceString name) {
     Element element = find(name);
     if (element === null) return null;
     return (this === element.getLibrary()) ? element : null;
   }
 }
 
+class PrefixElement extends Element {
+  final LiteralString prefix;
+  final LibraryElement library;
+
+  PrefixElement(LiteralString prefix,
+                LibraryElement this.library,
+                Element enclosing)
+    : this.prefix = prefix,
+      super(prefix.dartString.source, ElementKind.PREFIX, enclosing);
+}
+
 class VariableElement extends Element {
   final VariableListElement variables;
   Expression cachedNode; // The send or the identifier in the variables list.
 
   Modifiers get modifiers() => variables.modifiers;
 
   VariableElement(SourceString name,
                   VariableListElement this.variables,
                   ElementKind kind,
                   Element enclosing,
@@ skipping 462 matching lines @@
     else if (str === '>=') str = 'ge';
     else if (str === '>') str = 'gt';
     else if (str === '<=') str = 'le';
     else if (str === '<') str = 'lt';
     else if (str === '&' || str === '&=') str = 'and';
     else if (str === '^' || str === '^=') str = 'xor';
     else if (str === '|' || str === '|=') str = 'or';
     return new SourceString('$receiver\$$str');
   }
 }