Re: Using empty_string as the only "" string

[bojohan+news@dd.chalmers.se (Johan Bockgård)]

Miles Bader <miles@gnu.org> writes:

> I disagree.  I don't think most people expect much one way or the other
> in this case, _especially_ because we're talking about lexical constants
> (for instance, I expect very few people would be surprised if the
> compiler merged various lexical constants).

How about this then?

    (funcall
     (byte-compile
      (lambda ()
        (let ((s1 (concat "ab" "c"))
              (s2 (concat "a" "bc")))
          (eq s1 s2)))))

      => t

There used to be a note about this in FOR-RELEASE, but it was removed:

revision 1.411
date: 2006-11-18 22:07:44 +0100;  author: cyd;  state: Exp;  lines: +0 -3
** Prevent byte compiler from causing spurious string sharing
when it optimizes away calls to functions such as concat.
Fixed.


-- 
Johan Bockgård