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Re: character objects
- To: MOON at MIT-MC (David A. Moon)
- Subject: Re: character objects
- From: Guy.Steele at CMU-10A
- Date: Fri ,15 Aug 80 18:10:00 EDT
- Cc: lisp-forum at MIT-MC
CHARARRAYCALL is silly. One can instead specify that arrays
permit characters as well as fixnums as indices, and implicitly
"coerce" them (in many implementations this will be the identity
coercion). On the other hand, CHARLOGXOR is clearly a loss,
and I would suggest that writing (CODE-CHAR (LOGXOR nnn (CHAR-CODE c)))
at least makes it clear that you're hacking around with the
representation. On the third hand, if you're doing LOGXOR is is probably
for the explicit purpose of changing case or hacking a control bit,
and the proposal CHPROP provides for operations to do these common things.
I think I would rather write (UNMETA (CHAR-UPCASE x)) than
(LOGXOR 1040 x).
Certainly all this stuff only solves part of the transportability problem,
but it is a start. In particular, this problem is a great impediment to
writing a transportable editor, which I would like to see happen.
I I thyink JAR pointed out, having a character standard and having character
objects are distinct notions. The former is very important, the latter
merely nice for some purposes.