1 files changed, 89 insertions, 0 deletions
diff --git a/sleekxmpp/thirdparty/orderedset.py b/sleekxmpp/thirdparty/orderedset.py
new file mode 100644
index 00000000..f6642db3
--- /dev/null
+++ b/sleekxmpp/thirdparty/orderedset.py
@@ -0,0 +1,89 @@
+# Copyright (c) 2009 Raymond Hettinger
+#
+# Permission is hereby granted, free of charge, to any person
+# obtaining a copy of this software and associated documentation files
+# (the "Software"), to deal in the Software without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Software,
+# and to permit persons to whom the Software is furnished to do so,
+# subject to the following conditions:
+#
+#     The above copyright notice and this permission notice shall be
+#     included in all copies or substantial portions of the Software.
+#
+#     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+#     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+#     OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+#     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+#     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+#     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+#     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+#     OTHER DEALINGS IN THE SOFTWARE.
+
+import collections
+
+class OrderedSet(collections.MutableSet):
+
+    def __init__(self, iterable=None):
+        self.end = end = []
+        end += [None, end, end]         # sentinel node for doubly linked list
+        self.map = {}                   # key --> [key, prev, next]
+        if iterable is not None:
+            self |= iterable
+
+    def __len__(self):
+        return len(self.map)
+
+    def __contains__(self, key):
+        return key in self.map
+
+    def add(self, key):
+        if key not in self.map:
+            end = self.end
+            curr = end[1]
+            curr[2] = end[1] = self.map[key] = [key, curr, end]
+
+    def discard(self, key):
+        if key in self.map:
+            key, prev, next = self.map.pop(key)
+            prev[2] = next
+            next[1] = prev
+
+    def __iter__(self):
+        end = self.end
+        curr = end[2]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[2]
+
+    def __reversed__(self):
+        end = self.end
+        curr = end[1]
+        while curr is not end:
+            yield curr[0]
+            curr = curr[1]
+
+    def pop(self, last=True):
+        if not self:
+            raise KeyError('set is empty')
+        key = self.end[1][0] if last else self.end[2][0]
+        self.discard(key)
+        return key
+
+    def __repr__(self):
+        if not self:
+            return '%s()' % (self.__class__.__name__,)
+        return '%s(%r)' % (self.__class__.__name__, list(self))
+
+    def __eq__(self, other):
+        if isinstance(other, OrderedSet):
+            return len(self) == len(other) and list(self) == list(other)
+        return set(self) == set(other)
+
+
+if __name__ == '__main__':
+    s = OrderedSet('abracadaba')
+    t = OrderedSet('simsalabim')
+    print(s | t)
+    print(s & t)
+    print(s - t)
+\ No newline at end of file