IDL: Support iterable<>, maplike<> and setlike<> syntax

Source/bindings/scripts/v8_interface.py

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@@ skipping 106 matching lines @@
     is_active_dom_object = 'ActiveDOMObject' in extended_attributes
 
     # [CheckSecurity]
     is_check_security = 'CheckSecurity' in extended_attributes
     if is_check_security:
         includes.add('bindings/core/v8/BindingSecurity.h')
 
     # [DependentLifetime]
     is_dependent_lifetime = 'DependentLifetime' in extended_attributes
 
-    # [Iterable]
+    # [Iterable], iterable<>, maplike<> and setlike<>
     iterator_method = None
     # FIXME: support Iterable in partial interfaces. However, we don't
     # need to support iterator overloads between interface and
     # partial interface definitions.
     # http://heycam.github.io/webidl/#idl-overloading
-    if 'Iterable' in extended_attributes and not interface.is_partial:
+    if (not interface.is_partial
+        and (interface.iterable or interface.maplike or interface.setlike
+             or 'Iterable' in extended_attributes)):
         iterator_operation = IdlOperation(interface.idl_name)
         iterator_operation.name = 'iterator'
         iterator_operation.idl_type = IdlType('Iterator')
         iterator_operation.extended_attributes['RaisesException'] = None

[jsbell, 2015/01/08 17:02:40]

Will it be possible (not in this CL, but w/o significant rework) to support
blink-specific extended attributes on iterable<> (etc) annotations, e.g.
[RuntimeEnabled=...], that get applied to the
iterator_operation.extended_attributes as well?

[Jens Widell, 2015/01/08 17:12:04]

Supporting extended attributes, and simply transferring them to the iterator
operation and the other implied operations (keys(), values(), et al, once we
support them) wouldn't be hard.

A potentially trickier problem to solve would be to support applying extended
attributes to only one of the implied operations. For instance supporting
[ImplementedAs=...] to override the individual C++ method names.

(I guess I shouldn't really say "full support" in the description, since I
actually don't support extended attributes on these definitions. Or,
alternatively, I should add support for extended attributes on these defitions.)

[jsbell, 2015/01/08 18:24:49]

Noted. 

FWIW, applying the same attribs to all of the implied operations is fine for the
scenario I'm thinking about - experimentally adding iterable<> to existing
interfaces like FormData.

[Jens Widell, 2015/01/13 10:26:26]

Having thought some more about this, one IMO rather agreeable way to support
extended attributes (and perhaps other modifications) on individual implied
methods would be to allow the IDL file to explicitly define some or all of the
implied methods (checking only that they are correct in terms of arguments and
return type) and if so let the explicitly defined methods win.

WebIDL doesn't allow that, but that's not really something we need to follow in
our internal IDL files if we don't want to, as long as the observable behavior
is the intended.

IOW, you could for instance have

  interface FormData {
    [RuntimeEnabled=...] Iterator values(); // not web compatible
    iterable<...>;
  };

We wouldn't need to implement this unless an actual use-case emerges, of course.

         iterator_operation.extended_attributes['CallWith'] = 'ScriptState'
         iterator_method = v8_methods.method_context(interface,
                                                     iterator_operation)
+        # FIXME: iterable<>, maplike<> and setlike<> should also imply the
+        # presence of a subset of keys(), values(), entries(), forEach(), has(),
+        # get(), add(), set(), delete() and clear(), and a 'size' attribute.
 
     # [MeasureAs]
     is_measure_as = 'MeasureAs' in extended_attributes
     if is_measure_as:
         includes.add('core/frame/UseCounter.h')
 
     # [SetWrapperReferenceFrom]
     reachable_node_function = extended_attributes.get('SetWrapperReferenceFrom')
     if reachable_node_function:
         includes.update(['bindings/core/v8/V8GCController.h',
@@ skipping 1112 matching lines @@
         deleter = next(
             method
             for method in interface.operations
             if ('deleter' in method.specials and
                 len(method.arguments) == 1 and
                 str(method.arguments[0].idl_type) == 'DOMString'))
     except StopIteration:
         return None
 
     return property_deleter(deleter)