[plt-scheme] Re: (newbie question) About Loop

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Fri Jun 12 07:37:20 EDT 2009

Why would you want to use while in Scheme? You might as well use Java  
then :-)




On Jun 12, 2009, at 7:21 AM, emre berat nebioğlu wrote:

> Can we use while or do while in drscheme.Just i wonder.I mean that
>
> While(list != null)
>      list=list.cdr
>
> On Fri, Jun 12, 2009 at 9:10 AM, Noel Welsh <noelwelsh at gmail.com>  
> wrote:
> On Fri, Jun 12, 2009 at 7:05 AM,  
> Captain___nemo<mmrasheed at gmail.com> wrote:
> > Thanks a lot :)
> >
> > Won't it be inefficient building list for large values (say  
> thousands
> > instead of 10)? Isn't there any direct loop syntax in Scheme?
>
> In PLT there are for comprehensions:
>
> (for ([i (in-range 10)]) ...)
>
> However, it is almost always bad style to use loops like you would in
> Java. Functional programmers think of expressions creating values,
> whereas Java's loops are fundamentally imperative. So rather than a
> for comprehension, I would expect someone to use for/list or another
> value returning comprehension.
>
> N.
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