add test for an optimization about scan sequences

theano/scan_module/tests/test_scan.py

@@ -3564,11 +3564,10 @@ def test_scan_merge_nodes(self):
         assert not opt_obj.belongs_to_set(scan_node1, [scan_node2])
         assert not opt_obj.belongs_to_set(scan_node2, [scan_node1])
 
-    def test_remove_constants_and_unused_inputs_scan(self):
-        """
-        Test the opt remove_constants_and_unused_inputs_scan
+    def test_remove_constants_and_unused_inputs_scan_non_seqs(self):
+        """Test the opt remove_constants_and_unused_inputs_scan for
+        non sequences.
 
-        TODO: currently we only test non_seqs, should test 
         """
         W = theano.tensor.matrix(name='W')
         v = theano.tensor.ivector(name='v')
@@ -3594,17 +3593,61 @@ def test_remove_constants_and_unused_inputs_scan(self):
             f(numpy.zeros((3, 3), dtype=theano.config.floatX), [1, 2])
             scan_node = f.maker.fgraph.toposort()[-1]
 
-            # TODO: Why this assert always fail?
-#            assert (len(scan_node.inputs) ==
-#                    len(set(scan_node.inputs)))
+            # The first input is the number of iteration.
+            assert (len(scan_node.inputs[1:]) ==
+                    len(set(scan_node.inputs[1:])))
             inp = scan_node.op.inner_non_seqs(scan_node.op.inputs)
             assert len(inp) == 1
             assert (len(inp) == len(set(inp)))
             inp = scan_node.op.outer_non_seqs(scan_node)
             assert len(inp) == 1
             assert (len(inp) == len(set(inp)))
-            #import pdb;pdb.set_trace()
-            #utt.assert_allclose(f([1, 2]), [[0, 0, 0], [1, 1, 1], [1, 1, 1]])
+
+    def test_remove_constants_and_unused_inputs_scan_seqs(self):
+        """
+        Test the opt remove_constants_and_unused_inputs_scan for sequences.
+
+        """
+        W = theano.tensor.matrix(name='W')
+        v = theano.tensor.ivector(name='v')
+        vv = theano.tensor.matrix(name='vv')
+        y1, _ = theano.scan(lambda i, W: W[i], sequences=v,
+                            outputs_info=None, non_sequences=[W])
+        y2, _ = theano.scan(lambda i, _, W: W[i], sequences=[v, v],
+                            outputs_info=None, non_sequences=W)
+        y3, _ = theano.scan(lambda i, _, W: W[i], sequences=[v, vv[0]],
+                            outputs_info=None, non_sequences=W)
+        y4, _ = theano.scan(lambda _, i, W: W[i], sequences=[vv[0], v],
+                            outputs_info=None, non_sequences=W)
+        y5, _ = theano.scan(lambda _, i, _2, W: W[i], sequences=[vv, v, vv[0]],
+                            outputs_info=None, non_sequences=W)
+        y6, _ = theano.scan(lambda _, _2, i, W: W[i], sequences=[vv[0], vv, v],
+                            outputs_info=None, non_sequences=W)
+        y7, _ = theano.scan(lambda i, _, _2, W: W[i],
+                            sequences=[v, vv[0], vv[0]],
+                            outputs_info=None, non_sequences=W)
+        y8, _ = theano.scan(lambda _, i, W, _2, _3: W[i], sequences=[vv[0], v],
+                            outputs_info=None, non_sequences=[W, W[0], W[0]])
+        for out in [y1, y2, y3, y4, y5, y6, y7, y8]:
+            #This used to raise an exception
+            f = theano.function([W, v, vv], out, on_unused_input='ignore',
+                                mode=mode_with_opt)
+            f(numpy.zeros((3, 3), theano.config.floatX),
+              [1, 2],
+              numpy.zeros((3, 3), theano.config.floatX))
+            scan_node = f.maker.fgraph.toposort()[-1]
+
+            # The first input is the number of iteration.
+            assert (len(scan_node.inputs[1:]) ==
+                    len(set(scan_node.inputs[1:])))
+            inp = scan_node.op.inner_seqs(scan_node.op.inputs)
+            assert len(inp) == 1
+            inp = scan_node.op.outer_seqs(scan_node)
+            assert len(inp) == 1
+            inp = scan_node.op.inner_non_seqs(scan_node.op.inputs)
+            assert len(inp) == 1
+            inp = scan_node.op.outer_non_seqs(scan_node)
+            assert len(inp) == 1
 
 
 def test_speed():