Subject: Re: LET <==> LAMBDA
From: rpw3@rpw3.org (Rob Warnock)
Date: Fri, 26 Jan 2007 06:32:38 -0600
Newsgroups: comp.lang.lisp
Message-ID: <pb-dnaZ6ooB7aSTYnZ2dnUVZ_s6onZ2d@speakeasy.net>
Harald Hanche-Olsen  <hanche@math.ntnu.no> wrote:
+---------------
| + rpw3@rpw3.org (Rob Warnock):
| | Barry Margolin <barmar@alum.mit.edu> wrote:
| | +---------------
| | | Since establishing restarts manipulates the stack, they need to expand 
| | | into special operators.  There aren't functional equivalents for the 
| | | same reason that there's no functional equivalent to LET.
| | +---------------
| |
| | Actually, isn't LET just syntactic sugar around LAMBDA?
| 
| I'm sure it could be.  But lambda isn't a function either, so what's
| your point?
+---------------

That unlike restarts, which have to play whack-a-stack under the
covers and are thus something a user can't implement with functions,
LET *is* something that a user can implement directly in terms of
function calls [albeit however ugly it might be without macros].
The fact that LAMBDA is also a special form is not an issue here,
since without LAMBDA you don't even *have* functions.

Never mind, it was only a minor nit about the tail of Barry's post...


-Rob

-----
Rob Warnock			<rpw3@rpw3.org>
627 26th Avenue			<URL:http://rpw3.org/>
San Mateo, CA 94403		(650)572-2607