Re: [PATCH] %nil-handling optimization and fixes v1

[Mark H Weaver <mhw@netris.org>]

I wrote:
> > I added the following macros, whose names explicitly state how %nil
> > should be handled.  See the comments in the patch for more information
> > about these.
> >
> >   scm_is_false_assume_not_lisp_nil  scm_is_true_assume_not_lisp_nil
> >   scm_is_false_and_not_lisp_nil     scm_is_true_or_lisp_nil
> >   scm_is_false_or_lisp_nil          scm_is_true_and_not_lisp_nil
> >
> >   scm_is_lisp_false                 scm_is_lisp_true
> >
> >   scm_is_null_assume_not_lisp_nil
> >   scm_is_null_and_not_lisp_nil
> >   scm_is_null_or_lisp_nil
> >
> >   scm_is_bool_and_not_lisp_nil
> >   scm_is_bool_or_lisp_nil

Andy wrote:
> These are terrible names. But they seem to be the best names for the
> concepts we're trying to express. I don't understand all of them yet,
> will wait for a review -- unless Neil takes care of that before I do ;-)

I agree that the names are uncomfortably long.  We could shorten them
without much loss of clarity by replacing "lisp_nil" with "nil" and
"and_not" with "not", yielding:

  scm_is_false_assume_not_nil  scm_is_true_assume_not_nil
  scm_is_false_not_nil         scm_is_true_or_nil
  scm_is_false_or_nil          scm_is_true_not_nil

  scm_is_lisp_false            scm_is_lisp_true

  scm_is_null_assume_not_nil
  scm_is_null_not_nil
  scm_is_null_or_nil

  scm_is_bool_not_nil
  scm_is_bool_or_nil

I can still do this if y'all would prefer the shorter names.  However,
if we've all agreed that scm_is_null/false/true will treat %nil as
both false and null (have we?), the longer names will rarely be
needed.

Are there any remaining objections to mapping scm_is_false/true/null
as follows?

  scm_is_null   -->  scm_is_null_or_lisp_nil
  scm_is_false  -->  scm_is_false_or_lisp_nil
  scm_is_true   -->  scm_is_true_and_not_lisp_nil

      Mark