Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!decwrl!mcnc!uvaarpa!mmdf
From: worley@compass.com (Dale Worley)
Newsgroups: comp.lang.perl
Subject: Crock involving $^
Message-ID: <1991Feb8.174228.678@uvaarpa.Virginia.EDU>
Date: 8 Feb 91 17:42:28 GMT
Sender: mmdf@uvaarpa.Virginia.EDU (Uvaarpa Mail System)
Reply-To: worley@compass.com
Organization: The Internet
Lines: 21

Beware when using the $^ variable to always follow it with a
whitespace character!  Otherwise the next character will be eaten and
(probably) the variable misinterpreted.

The culprint is the following two lines from scanreg() in toke.c:

    if (*d == '^' && !isspace(*s))
	*d = *s++ & 31;

It appears that these are to allow constructions like: $^T means "the
variable whose name is control-T".  Since there are no such variables
anymore, these lines should probably be removed.  (It would not be
simple to restrict the third character of the construction to
characters that can be legitimately controlized (letters, @, [, \, ],
_, ^), because '^' is also an operator, leading to $^^ meaning either
"the variable control-^" and "the variable $^ followed by the operator
^".

Dale Worley		Compass, Inc.			worley@compass.com
--
I try to make everyone's day a little more surreal.