trigraphs in X3J11

[Chuck Harris]

In article <5215 at ico.ISC.COM> rcd at ico.ISC.COM (Dick Dunn) writes:
>
>2.  Replacement in program text:  My philosophical objections to
>    replacement of trigraphs within a program are much less...but I wonder
>    who might ever use them.  Is there any precedent for these sequences?

Yes, back in the olden days, some implementations of APL had a "digraph"
character set that was composed of combinations of "$" and another char.
I <<had>> to use this set while I was at UoM, using Model 33's.  It was pretty
disgusting, but worked.
Our particular implimentation was controlled by an option flag, so it didn't
harm native mode APL work.  A clear deficiency in the ANSI proposal.

>    Is there any reason to think they'll be used?  Let's take another

Not in my opinion.  the "digraph" set was simple enough, and APL's needs
easy enough to accomodate, that it didn't cause any real confusion.
(you ended up with something that looked a little like DEC's FOCAL)

APL needed an <- ($P), matrix divide ($#), "lamp" ($.), delta ($F) (or was
it $D), index ($I), ...  It's been so long, I forget most of it.

"C" uses a very rich set of characters, even when compared with APL.
Many of its most used characters are not representable in ISO (eg. {|\}[])

I LOVE IT!! 8-)

>
>	if (line??(0??)=='??=' ??!??! line??(0??)=='%') ??<
>		prepro(&line??(1??));
>		linect++;
>	??>
>
>    I submit that this will produce code which is so near to unreadable
>    that there is virtually no prospect of the mechanism ever seeing
>    significant use.  If you believe that, you have to wonder why every
>-- 

The last time I railed about Trigraphs, I caused quite a stir.  I gave
a few examples of the garbage that would result, likened the use of 
trigraphs to the techniques used to "enhance" the deficiencies of the
old Model 33 TTY, called the offending ISO terminals "Braindamaged",
ranted and raved about how simple it was for anybod who was stuck
with the ISO terminals to implement their own "trigraph" preprocessor
and leave the language intact.

For my efforts, I got called a "Chauvanistic American" , a fool, and a few
other things that might have harmed my EGO.

So, outside of it being too late to change things, there is NO way that
I will risk post anything on this subject. :-)

		Chuck Harris
		C.F. Harris - Consulting