Fix some small comments from review.

doc/extending/extending_theano_gpu.txt

@@ -72,7 +72,10 @@ The last place where you might need the context is in the C
 initialization code.  For that you will have to use the :ref:`params
 <extending_op_params>`.  The params type should be
 :class:`theano.gpuarray.type.gpu_context_type` and the params object
-should be a context object from one of your input variables.
+should be a context object from one of your input variables::
+
+    def get_params(self, node):
+        return node.inputs[0].type.context
 
 If you don't have any input variables on the GPU you can follow the
 the example of :class:`theano.gpuarray.basic_ops.GpuFromHost` or

theano/gpuarray/basic_ops.py

@@ -162,10 +162,13 @@ class Kernel(object):
         dictionary of flags
     codevar: str
         the name of the variable for the code object.
+        (defaults to 'kcode_' + name)
     binvar: str
         the name of the variable for the binary object.
+        (defaults to 'kbin_' + name)
     objvar: str
         the name of the variable for the kernel object.
+        (defaults to 'k_' + name)
 
     """
 
@@ -362,7 +365,7 @@ class GpuKernelBase(object):
         return (4, self.get_params(node).bin_id)
 
 
-def fwds(name):
+def forward_string_meth(name):
     def f(*args):
         res = getattr(GpuKernelBase, name)(*args)
         try:
@@ -386,11 +389,11 @@ class CGpuKernelBase(COp, GpuKernelBase):
 
     kernel_re = re.compile(r'^#kernel ([a-zA-Z_].*?)$', re.MULTILINE)
 
-    c_support_code = fwds('c_support_code')
-    c_support_code_apply = fwds('c_support_code_apply')
-    c_support_code_struct = fwds('c_support_code_struct')
-    c_init_code_struct = fwds('c_init_code_struct')
-    c_cleanup_code_struct = fwds('c_cleanup_code_struct')
+    c_support_code = forward_string_meth('c_support_code')
+    c_support_code_apply = forward_string_meth('c_support_code_apply')
+    c_support_code_struct = forward_string_meth('c_support_code_struct')
+    c_init_code_struct = forward_string_meth('c_init_code_struct')
+    c_cleanup_code_struct = forward_string_meth('c_cleanup_code_struct')
 
     def _type_macros(self, node):
         define_template = "#define %s %s"
@@ -428,7 +431,7 @@ class CGpuKernelBase(COp, GpuKernelBase):
             res = []
             while n < len(split):
                 kspec = split[n]
-                kcode = split[n+1]
+                kcode = split[n + 1]
                 splt2 = kspec.split(':')
                 if len(splt2) != 3:
                     raise ValueError("Bad kernel spec: %s" % (kspec,))