Get rid of System classes for backend generators.

lib/html/scripts/dartdomgenerator.py

Index: lib/html/scripts/dartdomgenerator.py
diff --git a/lib/html/scripts/dartdomgenerator.py b/lib/html/scripts/dartdomgenerator.py
index b2f462ccca2b38c3040d1e5fd01a1883618759fb..d217cc3293b6baa8e7f965581804283ab3c0a6eb 100755
--- a/lib/html/scripts/dartdomgenerator.py
+++ b/lib/html/scripts/dartdomgenerator.py
@@ -19,9 +19,9 @@ from htmlrenamer import HtmlRenamer
 from systembase import GeneratorOptions
 from systemdart2js import Dart2JSSystem
 from systemhtml import DartLibraryEmitter, HtmlInterfacesSystem,\
-                       HtmlDart2JSSystem
+                       Dart2JSGeneratorBackend
 from systeminterface import InterfacesSystem
-from systemnative import CPPLibraryEmitter, NativeImplementationSystem
+from systemnative import CPPLibraryEmitter, DartiumGeneratorBackend
 from templateloader import TemplateLoader
 
 _logger = logging.getLogger('dartdomgenerator')
@@ -70,14 +70,15 @@ def Generate(database_dir, use_database_cache, dart2js_output_dir=None,
   type_registry = TypeRegistry(webkit_database, renamer)
 
   def RunGenerator(dart_library_template, dart_output_dir, dart_library_path,

[Anton Muhin, 2012/09/26 14:20:36]

overall logic becomes rather complicated, so, sorry, couple of comments in
attempt to make understanding the code below easier

-               backend):
+                   create_generator_backend):

[Anton Muhin, 2012/09/26 14:20:36]

I'd rather name it generator_backend_factory.

[Anton Muhin, 2012/09/26 14:20:36]

generator backend sounds somewhat too much, can it be just generator?  Overall
it looks weird to see class FooGeneratorBackend extending BaseGenerator,
FooBackendGenerator or even FooGenerator looks ways more readable.

[podivilov, 2012/09/26 15:02:04]

Done.

[podivilov, 2012/09/26 15:02:04]

Renamed to FooBackend. Backends should not extend BaseGenerator (subject to a
separate cl).

     template_loader = TemplateLoader(

[Anton Muhin, 2012/09/26 14:20:36]

cannot we lift template_loader creation out of this function?

[podivilov, 2012/09/26 15:02:04]

Done.

         template_dir, ['html/interface', 'html/impl', 'html', ''], {})
     options = GeneratorOptions(

[Anton Muhin, 2012/09/26 14:20:36]

cannot we lift options creation out of this function?

         template_loader, webkit_database, type_registry, renamer)
     dart_library_emitter = DartLibraryEmitter(
         emitters, dart_library_template, dart_output_dir)
-    html_system = HtmlInterfacesSystem(options, dart_library_emitter, backend)
+    html_system = HtmlInterfacesSystem(
+        options, dart_library_emitter, create_generator_backend)
     generator.Generate(
         webkit_database, html_system, common_database, _webkit_renames)
     dart_library_emitter.EmitLibrary(dart_library_path, auxiliary_dir)
@@ -88,14 +89,15 @@ def Generate(database_dir, use_database_cache, dart2js_output_dir=None,
                                      {'DARTIUM': False, 'DART2JS': True})
     backend_options = GeneratorOptions(
         template_loader, webkit_database, type_registry, renamer)
-    backend = HtmlDart2JSSystem(backend_options)
+    def create_generator_backend(interface):

[Anton Muhin, 2012/09/26 14:20:36]

that might be a perfect case for lambda, esp. if you agree to change names

[podivilov, 2012/09/26 15:02:04]

Done.

+      return Dart2JSGeneratorBackend(interface, backend_options)
 
     dart_library_template = template_loader.Load('html_dart2js.darttemplate')
     dart_output_dir = os.path.join(dart2js_output_dir, 'dart')
     dart_library_path = os.path.join(dart2js_output_dir, 'html_dart2js.dart')
 
-    RunGenerator(
-        dart_library_template, dart_output_dir, dart_library_path, backend)
+    RunGenerator(dart_library_template, dart_output_dir, dart_library_path,
+                 create_generator_backend)
 
   if dartium_output_dir:
     template_loader = TemplateLoader(template_dir,
@@ -105,14 +107,16 @@ def Generate(database_dir, use_database_cache, dart2js_output_dir=None,
         template_loader, webkit_database, type_registry, renamer)
     cpp_output_dir = os.path.join(dartium_output_dir, 'cpp')
     cpp_library_emitter = CPPLibraryEmitter(emitters, cpp_output_dir)
-    backend = NativeImplementationSystem(backend_options, cpp_library_emitter)
+    def create_generator_backend(interface):
+      return DartiumGeneratorBackend(
+          interface, cpp_library_emitter, backend_options)
 
     dart_library_template = template_loader.Load('html_dartium.darttemplate')
     dart_output_dir = os.path.join(dartium_output_dir, 'dart')
     dart_library_path = os.path.join(dartium_output_dir, 'html_dartium.dart')
 
-    RunGenerator(
-        dart_library_template, dart_output_dir, dart_library_path, backend)
+    RunGenerator(dart_library_template, dart_output_dir, dart_library_path,
+                 create_generator_backend)
     cpp_library_emitter.EmitDerivedSources(
         template_loader.Load('cpp_derived_sources.template'),
         dartium_output_dir)