From: Robert Klemme <bob.news@...>
Date: 2005-03-27T03:09:48+09:00
Subject: [OT] on Lisp (was: Re: Getting the word to conventional programmers)


"Christian Neukirchen" <chneukirchen@gmail.com> schrieb im Newsbeitrag 
news:m2br96vgn3.fsf@lilith.local...
> Csaba Henk <csaba@phony_for_avoiding_spam.org> writes:

(snip)

> Common Lisp:
>
> (dolist (a (list dog cat cow))
>  (squeak a))
>
> ;; alternatively:
> (mapc #'squeak (list dog cat cow))
>
> ;; AFAICS, there is no each_with_index, therefore we use LOOP.
> ;; Paul Graham would define a new macro :-)
> (loop for a in (list dog cat cow)
>      counting a into i
>      do (say a (format nil "I'm the ~:R animal~%" i)))  ; feat. english 
> numbers
>
>> Note that in "foreach(i,a,a squeak)" there is no syntactic difference
>> between the index/value pair which are to be used as immediate values
>> and the "block argument", to say it in ruby lingo, which is to be
>> run in each iteration. This phenomenon becomes much more interesting
>> when you discover you can as well write methods like this.
>
> This behavior can be done trivially with macros in Lisp.
>
>> So the point is that you can get "lisp powa" in a modern scripting
>> language as well without burying yourself under tons of parens and
>> whew-how-the-heck-should-I-name-this-one like function names.
>
> I don't think there were *too* many parentheses in above code, were
> there?

No.

>  Also, the method names were totally readable.  (From MAPC, you
> can at least guess that it maps a sequence.  MAPC has the advantage of
> not collecting the results.  If you dont like the name of MAPC, you
> are free to rename it as you like.  Don't expect anyone to understand
> that. :-))

Well, yes, but it's not only method names.  It's the way you have to group 
things together plus the multitude of methods / ways to do certain things. 
And probably it's also the power of macros that make Lisp code difficult to 
comprehend for starters: a function call and a macro call look totally alike 
on the syntactical level yet they are so totally different (the most 
significant difference being the point in time when something is evaluated 
if my Lisp knowledge doesn't betray me).  And then you have these different 
ways of quoting inside a macro...

I readily believe that Lisp is extraordinary productive - and I admire Lisp 
solutions once in a while.  But I've never been exposed to it long enough to 
really embrace it.  Maybe I've done too much procedural and object oriented 
development - or it's just that my brain is more suited to OO thinking, 
dunno... :-)

If someone out there knows a Common-Lisp-in-30-days-guaranteed-comprehension 
tutorial, let me know and I'll might give Lisp another try.

Thanks for listening and sorry for the noise

    robert