Fix comparison of Token from different docs. Closes #1257

spacy/tests/regression/test_issue1257.py

@@ -0,0 +1,12 @@
+'''Test tokens compare correctly'''
+from __future__ import unicode_literals
+
+from ..util import get_doc
+from ...vocab import Vocab
+
+
+def test_issue1257():
+    doc1 = get_doc(Vocab(), ['a', 'b', 'c'])
+    doc2 = get_doc(Vocab(), ['a', 'c', 'e'])
+    assert doc1[0] != doc2[0]
+    assert not doc1[0] == doc2[0]

spacy/tokens/token.pyx

@@ -62,18 +62,26 @@ cdef class Token:
 
     def __richcmp__(self, Token other, int op):
         # http://cython.readthedocs.io/en/latest/src/userguide/special_methods.html
+        cdef Doc my_doc = self.doc
+        cdef Doc other_doc = other.doc
         my = self.idx
         their = other.idx if other is not None else None
         if op == 0:
             return my < their
         elif op == 2:
-            return my == their
+            if my_doc is other_doc:
+                return my == their
+            else:
+                return False
         elif op == 4:
             return my > their
         elif op == 1:
             return my <= their
         elif op == 3:
-            return my != their
+            if my_doc is other_doc:
+                return my != their
+            else:
+                return True
         elif op == 5:
             return my >= their
         else: