Subject: Re: count symbols in a list
From: Erik Naggum <erik@naggum.no>
Date: 02 Dec 2002 11:00:43 +0000
Newsgroups: comp.lang.lisp
Message-ID: <3247815643556673@naggum.no>

* Christophe Rhodes
| No /feeling/ here, but at least the issue writeup of
| MAPPING-DESTRUCTIVE-INTERACTION:EXPLICITLY-VAGUE disagrees with you;

  I do not see how mapping and list traversal are even remotely connected.

| and the CLHS page on DOLIST does not seem to give a guarantee that
| your view is the right one; in fact, it seems to go out of its way not
| to:
|   dolist evaluates list-form, which should produce a list. It then
|   executes the body once for each element in the list, in the order in
|   which the tags and statements occur, with var bound to the
|   element. Then result-form is evaluated. tags label statements.

  This appears to be an argumentum ad ignorantiam.  It does not say, from
  which you can legitimately conclude nothing.

| I agree that normal practice is to expand into something that walks the
| list once, but I think ANSI was careful not to mandate this; 

  I do not see how you find evidence for this.

| the downside of this absence of mandate is that you have to be slightly
| more careful than you might otherwise want to be.

  Oh, Christ.  So unroll the goddamn list, already.

  Instead of getting the point, that you can traverse a tree without
  resorting to recursion, we have this moronic quibble.  Fuck it.

-- 
Erik Naggum, Oslo, Norway

Act from reason, and failure makes you rethink and study harder.
Act from faith, and failure makes you blame someone and push harder.