GritResourceMap: output sorted by keys

grit/format/resource_map.py

Index: grit/format/resource_map.py
diff --git a/grit/format/resource_map.py b/grit/format/resource_map.py
index 37ac54ad3986d73363c3bc306f8828be02128617..950400496fd478ab30a7724921622b1ccca0e09c 100644
--- a/grit/format/resource_map.py
+++ b/grit/format/resource_map.py
@@ -5,7 +5,8 @@
 
 '''This file contains item formatters for resource_map_header and
 resource_map_source files.  A resource map is a mapping between resource names
-(string) and the internal resource ID.'''
+(string) and the internal resource ID. It is output with an alphabetical order
+of resource names.'''
 
 import os
 from functools import partial
@@ -108,11 +109,15 @@ def _FormatSource(get_key, root, lang, output_dir):
   yield _FormatSourceHeader(root)
   tids = rc_header.GetIds(root)
   seen = set()
+  items = []
   active_descendants = [item for item in root.ActiveDescendants()]
   output_all_resource_defines = root.ShouldOutputAllResourceDefines()
   for item in root:
     if not item.IsResourceMapSource():
       continue
+    items.append(item)

[flackr, 2015/08/27 22:03:15]

nit: Prefer list comprehension over looping to build lists:
e.g.
items = sorted([item for item in root if not item.IsResourceMapSource()],
key=get_key)

+  items = sorted(items, key=get_key)
+  for item in items:
     key = get_key(item)
     tid = item.attrs['name']
     if tid not in tids or key in seen:

[flackr, 2015/08/27 22:03:15]

now that we're sorted by key we should just compare against the last key rather
than build a set of seen keys.

As an aside, skipping duplicate keys where key is defined by the get_key
function (in our cases to be either item name or path) seems dangerous. I'd
prefer that we either output duplicate entries (Which seems to be the case for
some resourecs: https://code.google.com/p/grit-i18n/issues/detail?id=27 ) or
raise an exception to enforce that you can't generate a lossy map file. I filed
https://code.google.com/p/grit-i18n/issues/detail?id=33 for this and it can be
done later.