giscanner: Use rich comparison methods for Python 3 compatibility

Add lt, le, gt, ge, eq, ne, and hash dunder methods to all classes that
implement custom comparisons with __cmp__. This is needed to support Python 3
compatible sorting of instances of these classes.
Avoid using @functools.total_ordering which does not work for some of these
classes and also is not available in Python 2.6.

https://bugzilla.gnome.org/show_bug.cgi?id=679438

1 files changed, 27 insertions, 4 deletions

diff --git a/giscanner/message.py b/giscanner/message.py
index d474ae9d..f36bcbc1 100644
--- a/giscanner/message.py
+++ b/giscanner/message.py
@@ -27,6 +27,7 @@ from __future__ import unicode_literals
 
 import os
 import sys
+import operator
 
 from . import utils
 
@@ -48,12 +49,34 @@ class Position(object):
         self.line = line
         self.column = column
 
-    def __cmp__(self, other):
-        return cmp((self.filename, self.line, self.column),
-                   (other.filename, other.line, other.column))
+    def _compare(self, other, op):
+        return op((self.filename, self.line, self.column),
+                  (other.filename, other.line, other.column))
+
+    def __lt__(self, other):
+        return self._compare(other, operator.lt)
+
+    def __gt__(self, other):
+        return self._compare(other, operator.gt)
+
+    def __ge__(self, other):
+        return self._compare(other, operator.ge)
+
+    def __le__(self, other):
+        return self._compare(other, operator.le)
+
+    def __eq__(self, other):
+        return self._compare(other, operator.eq)
+
+    def __ne__(self, other):
+        return self._compare(other, operator.ne)
+
+    def __hash__(self):
+        return hash((self.filename, self.line, self.column))
 
     def __repr__(self):
-        return '<Position %s:%d:%d>' % (os.path.basename(self.filename), self.line or -1,
+        return '<Position %s:%d:%d>' % (os.path.basename(self.filename),
+                                        self.line or -1,
                                         self.column or -1)
 
     def format(self, cwd):