Re: [Haskell-cafe] Laziness enhances composability: an example

On Thursday 09 July 2009, you wrote:

2009/7/9 Marcin Kosiba :

...

I thought I'll go the "smart" way and rely on the Python yield construct to do a CPS transformation of my code.        While this worked to a certain extent, composability was a problem, because any sub-procedure which used yield (and thus was an iterator) required being called in a rather inelegant way.

i confess to not understanding the inelegance. can you provide an example where an iterator inside CPS requires special support?

Hi, To illustrate what I meant I'm attaching two examples. In example_1.py I've written code the way I think would be elegant (but it doesn't work). In example_2.py I've written code so that it works, but it isn't elegant. I know I'm abusing Python iterators here. Also, I'm not sure the way to compose iterators shown in example_2.py is the only option. Actually I'd love to see a better solution, because it would remove a lot of bloat from my code ;) Thanks! Marcin Kosiba