Fix type conversion in TensorType and expand it to other similar types.

theano/gof/type.py

@@ -277,6 +277,11 @@ class PureType(object):
             # a Constant of the appropriate Type.
             other = self.Constant(type=self, data=other)
 
+        if other.type != self:
+            other2 = self.convert_variable(other)
+            if other2 is not None:
+                return other2
+
         if other.type != self:
             raise TypeError(
                 'Cannot convert Type %(othertype)s '

theano/sandbox/cuda/type.py

@@ -146,10 +146,14 @@ class CudaNdarrayType(Type):
             raise TypeError('Incompatible number of dimensions.'
                             ' Expected %d, got %d.' % (self.ndim, other.ndim))
         if other.type.broadcastable != self.broadcastable:
-            raise TypeError('Incompatible broadcastable dimensions.'
-                            ' Expected %s, got %s.' %
-                            (str(other.type.broadcastable),
-                             str(self.broadcastable)))
+            type2 = other.type.clone(broadcastable=self.broadcastable)
+            other2 = type2.convert_variable(other)
+            if other2 is None:
+                raise TypeError('Incompatible broadcastable dimensions.'
+                                ' Expected %s, got %s.' %
+                                (str(other.type.broadcastable),
+                                 str(self.broadcastable)))
+            other = other2
 
         return theano.sandbox.cuda.basic_ops.GpuFromHost()(other)
 

theano/sandbox/gpuarray/type.py

@@ -108,10 +108,14 @@ class GpuArrayType(Type):
             raise TypeError('Incompatible number of dimensions.'
                             ' Expected %d, got %d.' % (self.ndim, other.ndim))
         if other.type.broadcastable != self.broadcastable:
-            raise TypeError('Incompatible broadcastable dimensions.'
-                            ' Expected %s, got %s.' %
-                            (str(other.type.broadcastable),
-                             str(self.broadcastable)))
+            type2 = other.type.clone(broadcastable=self.broadcastable)
+            other2 = type2.convert_variable(other)
+            if other2 is None:
+                raise TypeError('Incompatible broadcastable dimensions.'
+                                ' Expected %s, got %s.' %
+                                (str(other.type.broadcastable),
+                                 str(self.broadcastable)))
+            other = other2
 
         return theano.sandbox.gpuarray.basic_ops.gpu_from_host(other)
 

theano/tensor/type.py

@@ -209,9 +209,9 @@ class TensorType(Type):
             return other
 
         # Attempt safe broadcast conversion.
-        other = self.convert_variable(other)
-        if other.type == self:
-            return other
+        other2 = self.convert_variable(other)
+        if other2 is not None and other2.type == self:
+            return other2
 
         raise TypeError(
             'Cannot convert Type %(othertype)s '