[Tutor] Text processing and functional programming?

[Clay Shirky]

> And further on think about closures.  They allow nice constructs (people
> who know Common Lisp or Scheme use them all the time).
> 
> In [2]: def make_counter(start=0, step=1):
>  ....:     def cfun(step=step, counter=[start]):
>  ....:         counter[0] += step
>  ....:         return counter[0]
>  ....:     return cfun

Isn't this what yield does? Are there kinds of closures that can't be
implemented with iterators? Or are iterators another way of creating
closures?

-clay