Re: What's wrong with Common Lisp's lambda ?

Thank for reply, I was scared a bit :)

Pascal Bourguignon wrote:
"Karol Skocik" <Karol.Skocik@xxxxxxxxx> writes:

Hi,
I have just read this article:

http://www.ddj.com/184404384;jsessionid=KLMB3AY1Q0DHQQSNDLPCKH0CJUNN2JVN?_requestid=71496

and in the section "Impact of Logic", I saw this :

Scheme, a dialect of Lisp which got lambda right (Guy Steele and Gerald
Sussman, 1975; http://www.schemers .org/).

I am a happy CL lambda user, and can't find something wrong in CL's
lambda...

Could some functional guru explain me what they meant?

COMMON-LISP:LAMBDA is ok.
Common Lisp is a dialect of Lisp which got lambda right too.


The lambda in LISP 1.5 and before had some problems. Namely, it
didn't create a lexical scope, like in Scheme and Common Lisp,
nor a closure.

See: http://www-formal.stanford.edu/jmc/history/lisp/node4.html

d. Free variables. In all innocence, James R. Slagle programmed
the following LISP function definition and complained when it
didn't work right:

The object of the function is to find a subexpression of x
satisfying p[x] and return f[x]. If the search is
unsuccessful, then the continuation function u[] of no
arguments is to be computed and its value returned. The
difficulty was that when an inner recursion occurred, the
value of car[x] wanted was the outer value, but the inner
value was actually used. In modern terminology, lexical
scoping was wanted, and dynamic scoping was obtained.


The lambda of emacs lisp is still 'broken'.

--
__Pascal Bourguignon__ http://www.informatimago.com/

"Logiciels libres : nourris au code source sans farine animale."

.

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