[Mesa-dev] [PATCH 21/26] python: Use key-functions when sorting containers

[Mathieu Bridon]

In Python 2, the traditional way to sort containers was to use a
comparison function (which returned either -1, 0 or 1 when passed two
objects) and pass that as the "cmp" argument to the container's sort()
method.

Python 2.4 introduced key-functions, which instead only operate on a
given item, and return a sorting key for this item.

In general, this runs faster, because the cmp-function has to get run
multiple times for each item of the container.

Python 3 removed the cmp-function, enforcing usage of key-functions
instead.

This change makes the script compatible with Python 2 and Python 3.

Signed-off-by: Mathieu Bridon <bochecha at daitauha.fr>
---
 src/mapi/mapi_abi.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/mapi/mapi_abi.py b/src/mapi/mapi_abi.py
index 67fdb10650..19fdc4572a 100644
--- a/src/mapi/mapi_abi.py
+++ b/src/mapi/mapi_abi.py
@@ -32,6 +32,7 @@ import os
 GLAPI = os.path.join(".", os.path.dirname(sys.argv[0]), "glapi/gen")
 sys.path.append(GLAPI)
 
+from operator import attrgetter
 import re
 from optparse import OptionParser
 import gl_XML
@@ -305,7 +306,7 @@ class ABIPrinter(object):
 
         # sort entries by their names
         self.entries_sorted_by_names = self.entries[:]
-        self.entries_sorted_by_names.sort(lambda x, y: cmp(x.name, y.name))
+        self.entries_sorted_by_names.sort(key=attrgetter('name'))
 
         self.indent = ' ' * 3
         self.noop_warn = 'noop_warn'
@@ -455,7 +456,7 @@ class ABIPrinter(object):
         """Return the string pool for use by stubs."""
         # sort entries by their names
         sorted_entries = self.entries[:]
-        sorted_entries.sort(lambda x, y: cmp(x.name, y.name))
+        sorted_entries.sort(key=attrgetter('name'))
 
         pool = []
         offsets = {}
-- 
2.17.1