[Cython] Utility Codes and templates

[Stefan Behnel]

Vitja Makarov, 25.07.2011 08:41:
> 2011/7/23 Robert Bradshaw<robertwb at math.washington.edu>:
>> On Fri, Jul 22, 2011 at 3:12 AM, mark florisson
>> <markflorisson88 at gmail.com>  wrote:
>>> For my work on the _memview branch (and also on fused types) I noticed
>>> that UtilityCodes started weighing heavily on me in their current
>>> form, so I wrote a little loader in the _memview branch:
>>>
>>> https://github.com/markflorisson88/cython/commit/e13debed2db78680ec0bd8c343433a2b73bd5e64#L2R110
>>>
>>> The idea is simple: you put your utility codes in Cython/Utility in
>>> .pyx, .c, .h files etc, and then load them. It works for both
>>> prototypes and implementations, for UtilityCode and CythonUtilityCode:
>>
>> This sounds like it could be a nice way to organize our UtilityCode
>> snippets. So far we haven't really needed any more templating than
>> simple substitution, but for what you're doing I can see this being
>> quite handy. This may also provide a more flexible way forward for
>> supporting multiple backends.
>>
>>> myutility.c
>>>
>>> // UtilityProto: MyUtility
>>> header code here
>>>
>>> // UtilityCode: MyUtility
>>> implementation code here
>>>
>>> You can add as many other utilities as you like to the same file. You
>>> can then load it using
>>>
>>>     UtilityCode.load_utility_from_file("myutility.c", "MyUtility")
>>
>> I agree with you that having multiple related, named snippets in same
>> file is worthwhile. What about
>>
>> ////////////////////// MyUtility.proto ///////////////////////////
>>
>> and
>>
>> ############ MyCyUtility ##############
>>
>> so the chunks are easy to see.
>>
>
> C++ comments looks ugly. May be it's better to have something like this:
>
> /* UtilityCode:  MyUtility.proto */
> and
>
> # UtilityCode: MyCyUtility
>
> That's also pretty easy to parse

For the parser, it makes no difference. For a human, it does. A big fat 
marker like "/////////////////////" is hard to miss, whereas a tiny one 
like "/* ... */" is easily overlooked within a longer piece of code.

Stefan