question about generators

greg greg at cosc.canterbury.ac.nz
Fri Aug 16 10:32:27 CEST 2002


Andrew Koenig wrote:
> At first I wondered if perhaps calling a generator from
> another generator, and not doing anything with the results, should
> automatically yield them, but decided that was too clever.  Still, I
> wondered if there was an easier way of doing this program
> transformation.  So far, apparently there isn't.

Actually, there is a way, sort of, although it doesn't 
involve using Python generators. You can write it in 
so-called "continuation passing style" like this:

  def f(produce_result):
    for ...:
      if ...:
        produce_result(x)
      else:
        ...
        f(produce_result)
        ...

and you call it with a function (or some other callable
object) that does what you want done with each value.

This is very similar to the way Icon works under the
covers.

Greg Ewing



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