mojo: Generate top level enums for python bindings.

mojo/public/python/mojo/bindings/reflection.py

Index: mojo/public/python/mojo/bindings/reflection.py
diff --git a/mojo/public/python/mojo/bindings/reflection.py b/mojo/public/python/mojo/bindings/reflection.py
new file mode 100644
index 0000000000000000000000000000000000000000..d7ba5241122a51dc79a48577ae68c215eac12bf7
--- /dev/null
+++ b/mojo/public/python/mojo/bindings/reflection.py
@@ -0,0 +1,39 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""The meta classes used by the mojo python bindings."""
+
+class MojoEnumType(type):
+  """Meta class for enumerations.
+
+  Usage:
+    class MyEnum(object):
+      __metaclass__ = MojoEnumType
+      VALUES = [
+        ('A', 0),
+        'B',
+        ('C', 5),
+      ]
+
+      This will define a enum with 3 values, A = 0, B = 1 and C = 5.
+  """
+  def __new__(mcs, name, bases, dictionary):
+    class_members = {
+      '__new__': None,

[sdefresne, 2014/09/09 08:46:10]

nit: you probably want to keep __module__ defined here to what is in dictionary.

+    }
+    for value in dictionary.pop('VALUES', []):
+      if not isinstance(value, tuple):
+        raise ValueError('incorrect value: %r' % value)
+      key, enum_value = value
+      if isinstance(key, str) and isinstance(enum_value, int):
+        class_members[key] = enum_value
+      else:
+        raise ValueError('incorrect value: %r' % value)
+    return type.__new__(mcs, name, bases, class_members)
+
+  def __setattr__(mcs, key, value):
+    raise AttributeError, 'can\'t set attribute'
+
+  def __delattr__(mcs, key):
+    raise AttributeError, 'can\'t delete attribute'