Make hash of equivalent terms the same

Author: jml

terml/nodes.py

@@ -24,6 +24,10 @@ def __eq__(self, other):
             return False
 
 
+    def __hash__(self):
+        return hash((Term, self.tag, self.data, self.args))
+
+
     def __repr__(self):
         return "term('%s')" % (self._unparse(4).replace("'", "\\'"))
 
@@ -105,6 +109,9 @@ def __ne__(self, other):
     def __repr__(self):
         return "Tag(%r)" % (self.name,)
 
+    def __hash__(self):
+        return hash((Tag, self.name))
+
     def _unparse(self, indentLevel=0):
         return self.name
 

terml/test/test_terml.py

@@ -1,6 +1,6 @@
 from twisted.trial import unittest
 from ometa.runtime import ParseError
-from terml.nodes import Tag, Term, coerceToTerm, TermMaker
+from terml.nodes import Tag, Term, coerceToTerm, TermMaker, termMaker
 from terml.parser import TermLParser, character, parseTerm
 
 
@@ -156,3 +156,9 @@ def test_coerce(self):
             coerceToTerm({3: 4, "a": character('x'), (2, 3): [4, 5]}),
             parseTerm('{"a": \'x\', 3: 4, [2, 3]: [4, 5]}'))
 
+
+    def test_hash(self):
+        t = TermMaker()
+        a = t.Arbitrary('foo')
+        b = t.Arbitrary('foo')
+        self.assertEqual(hash(a), hash(b))