Re: [Chicken-users] Question about set-car! and set-cdr!

[Jörg F. Wittenberger]

Am 06.03.2014 09:05, schrieb Daniel Carrera:
> Hello,
>
> I have recently learned about set-car! and set-cdr! which eventually 
> led me to learn about how Racket removed them years ago for the 
> reasons given in this post:
>
> http://blog.racket-lang.org/2007/11/getting-rid-of-set-car-and-set-cdr.html
>
>
> On the other hand, Chicken certainly has set-car! and set-cdr! and I 
> also see these functions in R7RS. I was wondering if there is a 
> balancing opinion (maybe a post somewhere) on this matter.

Frankly I find the above posting pretty balanced.  Most people agree 
that pure functional code is easier to judge and get right than code 
having mutation.

> Presumably these functions exist because someone thought they were a 
> good idea.

Still there is the history.  Hence Scheme has mutation.

Maybe this could be addressed by splitting the "scheme" module of 
chicken into a "scheme-pure" for the sake of safety, "scheme-mutations" 
having the rest and make "scheme" importing and reexporting both sets of 
bindings.