Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!cme!cam!ARTEMIS
From: miller@GEM.cam.nist.gov (Bruce R. Miller)
Newsgroups: comp.lang.lisp
Subject: Re: Case sensitivity (Ugh, Again!)
Message-ID: <2872434369@ARTEMIS.cam.nist.gov>
Date: 9 Jan 91 18:26:09 GMT
References: <10080@pasteur.Berkeley.EDU>
Sender: news@cam.nist.gov
Followup-To: comp.lang.lisp
Organization: NIST - Center for Computing and Applied Mathematics
Lines: 63




In article <10080@pasteur.Berkeley.EDU>, Vance Maverick writes: 
> In article <2872363025@ARTEMIS.cam.nist.gov>, miller@GEMcam.nist.gov
> (Bruce R. Miller) writes:
> > 
> > I'm given to understand that Allegro common lisp has a form
> > 
> >     (set-case-mode :case-sensitive-lower)  
> > 
> > such that, afterwards, Lisp code is case sensitive and to access the
> > `standard' lisp, one must type in lowercase.

[First a note: Thanks to Tim Moore for the excerpt from CLtL2 (I dont
have one yet .. waiting for CLtLreally :> )  But I'm NOT talking solely
about readtables; what I'm talking about is (apparently) a combination
of readtables & intern & printer slashification & ? ... Well, that's
really part of the question, isn't it! :> ] 

> No, this means that 'foo and 'FOO are the same symbol, print name "foo".
>  :case-sensitive-upper would mean the print name would be "FOO", but the
> same code would work, except where it counted on the case of print
> names.  

Are you sure? This has me confused. [no offense]
You seem to describe a :case-insensitive-lower (hypothetical?).
'foo & 'FOO being the same seems to mean that there is case
INsensitivity. One might still want to specify whether print
names are upcased, downcased or casepreserved.

The lisp code of the program that triggered this query has
ALL symbols from the common-lisp package written in lower case.
Some of the new symbols in the applications' own package are written in
with mixed case. 

APPARENTLY the idea is that these new symbols have PRINT NAMES with
mixed case (ie. preserved) and they must be typed in the same way (to
access the same symbol, anyway), and further, they are typed in &
printed out without using |..|'s. 

Or have I totally misunderstood the application? ...

>      It can take a while for CL to scan all the packages and convert
> all the print names.

This I can believe!

> >   3) Who uses it, why, and in what way?
> 
> I use it because I occasionally get code (CLX examples come to mind)
> which assumes case insensitivity.  
                     ^^
I assume you meant case sensitivity?  All `traditional' lisp assumes
case insensitivity. 

But you punt! Why did the writers of that code (eg. CLX) use
case-sensitivity?  Good reasons?  Has it made it harder/easier for you
to use it?  Has it affected your ability to work with different
applications within the same lisp image? 

>				Everything I write is lower-case
> anyway, so it doesn't matter.