[plt-scheme] Re: HTDP: So you thought us empty? and empty

Sorry for bothering, but where do you find tail-recursion in
the example mentioned?

Regards,

Zbyszek Jurkiewicz

On Sat, 6 Dec 2003, Matthias Felleisen wrote:

>   For list-related administrative tasks:
>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> 
> Good for you. Good programmers stand up for their rights, and one of 
> them is tail-recursion. It's the only way to match your program's 
> structure to the structure of the data. Everything else is buggy over 
> the long run. -- Matthias
> 
> 
> On Saturday, December 6, 2003, at 08:02 PM, Guenther Schmidt wrote:
> 
> >  For list-related administrative tasks:
> >  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> >
> > Dear Matthias,
> >
> > apologies for *firing* this off.
> >
> > I'm switching back and forth between PLT Scheme and Lispworks (CL) and 
> > just to make it up to you I'll show you what I just *fired* at Xanalys 
> > five minutes before:
> >
> >
> > Hi,
> >
> > I heard that one of the differences between Scheme and CL is that 
> > Scheme is "proper tail recursive" and CL isn't. Until today I'm not 
> > 100% what that could mean but I think I'm seeing an effect of it here.
> >
> > (defun my-make-list (n)
> > (cond
> >  ((< n 1) nil)
> >  (t (cons nil (my-make-list (- n 1))))))
> >
> > If I run this on Lispworks with let's say merely n=200 I get a stack 
> > overflow, if I run it in Scheme with +100000 I just have to wait a 
> > little, but no stack overflow.
> >
> > What I really do like about CL and Scheme is the excessive use of 
> > recursion, and the parenthesis too.
> > Does this mean I need to switch back to iteration when dealing with 
> > lists of over 200 elements in CL?
> > Setting the *stack-size* to a higher level?
> >
> > If so ............. STUFF THAT!!!
> >
> > Guenther
> >
> >
> >
> > Matthias Felleisen wrote:
> >
> >>  For list-related administrative tasks:
> >>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> >> Use Pretty Big for now. -- Matthias
> >> On Saturday, December 6, 2003, at 07:20 PM, Guenther Schmidt wrote:
> >>>  For list-related administrative tasks:
> >>>  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> >>>
> >>> ..... in HTDP.
> >>>
> >>> But as soon as one switches to MrED it turns out that's not even 
> >>> part of the standard.
> >>>
> >>> What exactly was the point of teaching us empty? and empty ?
> >>>
> >>> I mean I'm sure that I will find a function that is the equivalent 
> >>> of the above because there just has to be, but what was the point?
> >>>
> >>> Best regards
> >>>
> >>> Guenther
> >>>
> >>> BTW I figure it is "null"
> >>>
> >
> 
>