change type-check, added comments

theano/tensor/extra_ops.py

@@ -647,8 +647,7 @@ def repeat(x, repeats, axis=None):
 
     .. versionadded:: 0.6
     """
-    if isinstance(repeats, (int, long, numpy.integer, list)):
-        repeats = numpy.asarray(repeats)
+    repeats = tensor.as_tensor_variable(repeats)
 
     if repeats.ndim > 1:
         raise ValueError('The dimension of repeats should not exceed 1.')
@@ -666,14 +665,20 @@ def repeat(x, repeats, axis=None):
                 axis = x.ndim+axis
 
         shape = [x.shape[i] for i in xrange(x.ndim)]
+        
+        # shape_ is the shape of the intermediate tensor which has
+        # an additional dimension comparing to x. We use alloc to
+        # launch space for this intermediate tensor to replicate x
+        # along that additional dimension.
         shape_ = shape[:]
         shape_.insert(axis+1, repeats)
         shape[axis] = shape[axis]*repeats
 
-        dims = list(numpy.arange(x.ndim))
-        dims.insert(axis+1, 'x')
+        # dims_ is the dimension of that intermediate tensor. 
+        dims_ = list(numpy.arange(x.ndim))
+        dims_.insert(axis+1, 'x')
 
-        z = tensor.alloc(x.dimshuffle(*dims), *shape_).reshape(shape) 
+        z = tensor.alloc(x.dimshuffle(*dims_), *shape_).reshape(shape) 
         return z