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From: ags@pucc-h (Dave Seaman)
Newsgroups: net.lang.lisp
Subject: Re: Changing syntax of characters in Franz
Message-ID: <2871@pucc-h>
Date: Mon, 2-Jun-86 14:55:16 EDT
Article-I.D.: pucc-h.2871
Posted: Mon Jun  2 14:55:16 1986
Date-Received: Wed, 4-Jun-86 19:29:18 EDT
References: <555@bcsaic.UUCP>
Reply-To: ags@pucc-h.UUCP (Dave Seaman)
Organization: Purdue University Computing Center
Lines: 39

In article <555@bcsaic.UUCP> michaelm@bcsaic.UUCP (michael maxwell) writes:
>This is on Franz Lisp (v38.91) under BSD 4.2 on a Sun II...
>
>(1) I would like to set a control character to do a (return) from a break 
>level, using 'setsyntax.'  It doesn't work; Lisp says
>	No prog to return from

This is not a 'setsyntax' problem.  It's just that the (return) must appear
(lexically) within a prog.  I don't know any way around this.

>(2) Some characters seem to be impossible to reset as vmacros using 
>'setsyntax.'  I can understand why you can't reset ^Y, etc., but why not ^R?  
>According to 'getsyntax', the syntax of ^R has been reset, but the reader
>seems to ignore it.

I believe any character can be reset.  For ^Y you might have to use (ascii 25),
but it should work.  On the other hand, any keyboard character that is 
intercepted before it is seen by Franz will continue to have its special 
meaning in the shell.

>(3) Assuming a character's syntax has been reset as a "vmacro," how can you 
>find out exactly what function the character has been set to (short of typing 
>it and observing what Lisp does)?  Is there a way for a program to find out?

I don't know of a built-in way to find this, but it wouldn't be hard to
use property lists to keep track of the information if it is actually needed.

>(4) Finally, has anyone had any luck in changing the readtable in compiled
>code?  (I think  I've asked this before, w/o luck.)

Yes, I have done this.  There is no problem if readtable is declared special.
-- 
Dave Seaman	  					pur-ee!pucc-h!ags

	"You would think the President would spend his time worrying
	about Russia or China.  He hasn't slept in eight nights,
	worrying about Libya!"

		    - James Coburn in "The President's Analyst" (1967)