I noticed some people advocating the idea that functions should be
lists (as in the olden times). What are the advantages of
treating functions as lists? Serialization of functions and
closures? Anything else?
From: Christopher C. Stacy
Subject: Re: functions as lists
Date:
Message-ID: <ud6ebokrk.fsf@dtpq.com>
>>>>> On Sun, 7 Sep 2003 21:41:16 -0700 (PDT), mike420 ("mike420") writes:
mike420> I noticed some people advocating the idea that functions
mike420> should be lists (as in the olden times)
Common Lisp is not an accident, regardless of what some new computer
students who just learned Scheme might imagine. Maybe there were
good reasons that those particular things were changed (by the "old
people" who knew all about it and were trying to create the "modern times").
·······@ziplip.com wrote in message news:<········································@ziplip.com>...
> I noticed some people advocating the idea that functions should be
> lists (as in the olden times).
What olden times would that be? Before the first Lisp compiler was
developed?
> What are the advantages of treating functions as lists?
The advantages can be realized by retaining the original list-based
source code, in addition to the internal representation that is
actually executed. Code can have more than one representation at the
same time, so advocating one representation over another is too
simple-minded.
·······@ziplip.com wrote:
> I noticed some people advocating the idea that functions should be
> lists (as in the olden times). What are the advantages of
> treating functions as lists? Serialization of functions and
> closures? Anything else?
Read ftp://publications.ai.mit.edu/ai-publications/pdf/AIM-453.pdf
Pascal
--
Pascal Costanza University of Bonn
···············@web.de Institute of Computer Science III
http://www.pascalcostanza.de R�merstr. 164, D-53117 Bonn (Germany)
·······@ziplip.com writes:
> I noticed some people advocating the idea that functions should be
> lists (as in the olden times). What are the advantages of
> treating functions as lists? Serialization of functions and
> closures? Anything else?
This query does not distinguish between "functions" and "function
specifications". Functions are not lists, and have not been for
a long time. The result of
(QUOTE (LAMBDA (X) X))
is not a function. It is
(LAMBDA (X) X)
which is a list. The result of
(FUNCTION (LAMBDA (X) X))
is a function and usually prints as
#<FUNCTION ...>
The most obvious problem with representing a function as a list is that
it doesn't accomodate closure. That is,
(DEFUN FOO (X)
(LAMBDA (Y) (+ X Y)))
can't return
(LAMBDA (Y) (+ X Y))
because there's no place to remember the value that X had at the
time of creation of executing the form that should have created a closure.
So I'm not sure really what you're asking.