[Tutor] Text processing and functional programming?

[Abel Daniel]

> > 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?

In the above, cfun can get extra parameters, so you can do:
>>> c=make_counter()
>>> c()
1
>>> c()
2
>>> c(2)
4

I don't think this is possible with iterators.

Abel Daniel