Dag Sverre Seljebotn wrote:
> Stefan Behnel wrote:
>> That makes me wonder if it's not worth using such an implementation for
>>
>>     cdef dict d
>>     ...
>>     for (key|value|key,value) in d.iter(keys|values|items)():
>>         ...
>>
>> internally - but *only* for the ".iter*()" variants to avoid introducing
>> problems with dict modification during iteration. That would be a pretty
>> cool optimisation. The generic loop code we currently generate is huge
>> compared to a straight call to PyDict_Next().
>>
>> Maybe a tree transformation could replace the for-loops above with a new
>> DictLoopNode that would generate the respective code.
> 
> +1, good idea -- though I'd definitely not have a DictLoopNode; instead 
> one should use a regular WhileStatNode containing a SimpleCallNode 
> calling PyDict_Next. The direction things should be taking is less loop
> node types, not more (e.g. transform ForInStatNode into WhileStatNode if 
> an iterator is used). (See also: The copy&paste-style code duplication 
> going on in the generate_..._code-implementations of the current looping 
> nodes.)

Very true. I just noticed that when I looked through the current
implementations. There's also the range() optimisation which could be done
with a tree transform now that we have them in place.

Stefan

_______________________________________________
Cython-dev mailing list
[email protected]
http://codespeak.net/mailman/listinfo/cython-dev

Reply via email to