Subject: Re: Small read macro issue
From: Erik Naggum <>
Date: 08 Oct 2002 01:16:20 +0000
Newsgroups: comp.lang.lisp
Message-ID: <>

* Adam Warner
| It's CLISP 2.30. I take it you consider this implementation is conforming
| in this respect?

  That was a reasonably mild restatement of what I mean.  To signal an
  error is just plain wrong and /will/ break conforming code.

| I can see the long term benefit in refusing to allow a macro character to
| return more than one value when it is not supported: This strict
| implementation would make it easier to extend the functionality of the
| ANSI Common Lisp reader to support splicing macros without breaking
| existing code.

  Because reader macro functions are allowed to return more than one value
  today, you would need a different mechanism to do something other than to
  ignore them.  CLISP has, however, a disturbing tradition of thinking it
  is better than the ANSI Standard, although this is being improved (i.e.,
  removed) as each of the cases receive public condemnation.

| I have not lost track of the problem. I only had to reply to fix your
| misapprehension that I could ignore multiple return values from the
| reader macro.

  One of the annoying things with languages that have very good
  specifications is that people tend to relate to the specification and
  file bug reports with implementations that deviate from them.  Newcomers
  to a language that come from a language where there is no standard or a
  bad standard such that they have to test things out in implementations,
  tend to get into trouble.  There is such a thing in Common Lisp as non-
  conforming implementations.  That concept does not exist for Python,
  Perl, PHP, etc.

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.