Re: [Chicken-users] Re: Style Guide

[Sunnan]

Kon Lovett wrote:
> > (define (fib)
> >  (let loop ((a 1) (b 1))
> >    (set! fib (lambda () (loop b (+ a b))))
> >    a))
> >
> >
> > ;; maybe non-portable outside of current chicken semantics?
>
> Except for the caveat about some compilers, no. However the above 
> doesn't "make" a generator, in the sense that it can be reused. To 
> restart the sequence 'fib' must be rebound. Certainly not 
> "disgusting", just of limited use.
I've used the idiom for more complex generators with multiple yield 
points but it quickly becomes tangled. I don't like the programming 
style that too many generators afford, so I don't do this so much. I 
usually use generator for generating ids where 
http://okmij.org/ftp/Scheme/monad-in-Scheme.html would use either a 
global variable or a state monad.


Sunnan