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From: worley@compass.com (Dale Worley)
Newsgroups: comp.lang.perl
Subject: Crock involving $^
Message-ID: <1991Feb12.180057.20540@uvaarpa.Virginia.EDU>
Date: 12 Feb 91 18:00:57 GMT
Sender: mmdf@uvaarpa.Virginia.EDU (Uvaarpa Mail System)
Reply-To: worley@compass.com
Organization: The Internet
Lines: 40

Here's a patch to make $^ behave somewhat more civilly.  When it is
installed, $^ only absorbs the next character if it is a letter or one
of @[\]^_.  That should fix most of the strange behavior.  This still
leaves the ambiguity in $^^ (it is interpreted as "variable
control-^), but that can be lived with.

*** toke.c.orig	Tue Feb 12 11:43:22 1991
--- toke.c	Tue Feb 12 11:46:09 1991
***************
*** 1466,1472 ****
  	else
  	    d[1] = '\0';
      }
!     if (*d == '^' && !isspace(*s))
  	*d = *s++ & 31;
      return s;
  }
--- 1466,1473 ----
  	else
  	    d[1] = '\0';
      }
!     if (*d == '^' &&
! 	(('@' <= *s && *s <= '_') || ('a' <= *s && *s <= 'z')))
  	*d = *s++ & 31;
      return s;
  }

Root Boy Jim writes:
   On a PDP-11, I would guess that $^f would be the switch register.

TECO fiend!  But since Perl claims Basic-Plus as one of its
(illegitimate) parents, it sounds reasonable.  I remember that the
only peek that didn't require privileges was PEEK(-56), which returned
the switch register...

Dale Worley		Compass, Inc.			worley@compass.com
--
The United States has entered an anti-intellectual phase in its
history, perhaps most clearly seen in our virtually thought-free
political life. -- David Baltimore