Re: DEFAULT-CASE

[David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>]

    Date: Thu, 16 Mar 89 21:38:14 PST
    From: franz!frisky!jkf@ucbarpa.Berkeley.EDU (John Foderaro)

     I'm not trying to start a religious war.  I'm not saying that
    case-sensitive is better or worse than case-insensitive.   I'm just
    saying that there are large numbers of people who favor each position
    and that Common Lisp should support both.    

Agreed.  I'm trying to help you not start a religious war.

      Regarding internal vrs external:  The internal representation shows
    through in a number of places.   For example the functions symbol-name
    and make-symbol let the user deal with the actual internal
    representation of the names of symbols.   The idea of having a
    *print-case* value that inverts the case on output is interesting but 
    that would make things awkward:  To make the symbol FooBar you 
    would have to (make-symbol "fOObAR").   Also examining the characters
    of a print-name with aref would give confusing results.  

The internal representation is accessible to programs, but I don't think
it's particularly important.  You seem to disagree.  It might be that we
have different experience with how often these primitives are used in
portable programs.  I don't think they are used enough that having an
internal representation in the opposite case from the external one would
cause bugs, but I do think they are used often enough that an incompatible
change would cause bugs in the medium term.

    >> I also claim that the choice of case in internal representation
    >> is arbitrary and need not prejudice the external representation
    >> at all.

     For a case-insensitive Lisp I completely agree.  For a case-sensitive
    Lisp, as I've shown above, this just isn't true.   Thus if the needs
    of the case-sensitive Lisp are met, then the needs of both are met.

True, but if the discussion gets side-tracked by flaming controversy over
the relatively unimportant issue of internal representation, I suspect
that the only outcome will be that everyone will give up on reaching a
concensus and we will be stuck with the status quo.  On the other hand,
if you compromise and keep the internal representation compatible, I
predict that you can very easily get what you really want, at the cost
of having a language 0.01% more inelegant than it would otherwise be.