Support DOMStringMap in generators.

lib/dom/scripts/generator.py

 #!/usr/bin/python
 # 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.
 
 """This module provides shared functionality for systems to generate
 Dart APIs from the IDL database."""
 
 import re
 
 # IDL->Dart primitive types conversion.
 _idl_to_dart_type_conversions = {
     'any': 'Object',
     'any[]': 'List',
     'custom': 'Dynamic',
     'boolean': 'bool',
     'DOMObject': 'Object',
     'DOMString': 'String',
     'DOMStringList': 'List<String>',
+    'DOMStringMap': 'Map<String, String>',

[sra1, 2012/04/06 18:23:39]

We can't do this.

There is a DOMStringMap type.
In the JavaScript world, element.dataset returns an object that satisfies  (x
instanceof DOMStringMap).
DOMStringMap should *implement* Map<String, String>.

An interface method / getter may returning DOMStringMap may widen to
Map<String,String> but the implementation class (in the frog code) absolutely
must have the correct implementation type.

DOMStringMap is magical - 
element.dataset['foo'] = bar
modifies the element to add a data-foo attribute.

DOMStringList also needs to be handled correctly.
When we access IDBDatabase.objectStoreNames we get a DOMStringList which needs
to implement List<String>
There are two differences:
1. DOMStringList is immutable so no magical behaviour
2. DOMStringList is also an input (e.g. to IDBDatabase.transaction), so this
needs to work:

    mydatabase.transaction(mydatabase.objectStoreNames, ...)

[Anton Muhin, 2012/04/09 09:50:51]

No, we can :)
No, as of now there are none.  As there was no dataset attribute on Element
interface---this line is necessary to make us generate dataset attribute if we
remove DOMStringMap interface as we do now.
No doubt about that.
That's NodeList's level of magic.
No doubt about that as well.
Absolutely, I even already have a todo for that in Dartium code.

     'DOMTimeStamp': 'int',
     'Date': 'Date',
     # Map to num to enable callers to pass in Dart int, rational
     # types.  Our implementations will need to convert these to
     # doubles or floats as needed.
     'double': 'num',
     'float': 'num',
     'int': 'int',
     # Map to extra precision - int is a bignum in Dart.
     'long': 'int',
@@ skipping 492 matching lines @@
     if self._idl_type.startswith('SVGPathSeg'):
       include = self._idl_type.replace('Abs', '').replace('Rel', '')
     else:
       include = self._idl_type
     return ['"%s.h"' % include] + _svg_supplemental_includes
 
   def receiver(self):
     return 'receiver->'
 
   def conversion_includes(self):
-    def NeededDartType(type_name):
+    def NeededDartTypes(type_name):
       match = re.match(r'List<(\w*)>$', type_name)
       if match:
-        return NeededDartType(match.group(1))
-      return type_name
+        return NeededDartTypes(match.group(1))
+      match = re.match(r'Map<(\w*), (\w*)>$', type_name)
+      if match:
+        return NeededDartTypes(match.group(1)) + NeededDartTypes(match.group(2))
+      if IsPrimitiveType(type_name):
+        return []
+      return [type_name]
 
-    return ['"Dart%s.h"' % include for include in [NeededDartType(self.dart_type())] + self._conversion_includes]
+    return ['"Dart%s.h"' % include for include in NeededDartTypes(self.dart_type()) + self._conversion_includes]
 
   def conversion_cast(self, expression):
     if self._conversion_template:
       return self._conversion_template % expression
     return expression
 
   def custom_to_dart(self):
     return self._custom_to_dart
 
 class PrimitiveIDLTypeInfo(IDLTypeInfo):
@@ skipping 122 matching lines @@
     '"SVGAnimatedPropertyTearOff.h"',
     '"SVGAnimatedListPropertyTearOff.h"',
     '"SVGStaticListPropertyTearOff.h"',
     '"SVGAnimatedListPropertyTearOff.h"',
     '"SVGTransformListPropertyTearOff.h"',
     '"SVGPathSegListPropertyTearOff.h"',
 ]
 
 def GetIDLTypeInfo(idl_type_name):
   return _idl_type_registry.get(idl_type_name, IDLTypeInfo(idl_type_name))