I agree that this is a bug. But what is a better fix? I see two different potential fixes, with one common objective to make the interpretation of "print $a--" and "print $a++" consistant.

  1. make both to follow what is happening to post -- now, that is to treat $a as uninitialized, and issue a warining. This might be the only fix for some other languages in a similar case, but not Perl, and I personaly don't like this fix.
  2. Perl is special, and it is not uncommon for Perl to automatically initialize variables for you. Whatever it is post --, or post ++, Perl can predict $a as number, so Perl can just go ahead, and initialize $a to 0. This fix sounds more perlish to me, and I feel that it has a much greater consistancy with the rest part of Perl.

Try this code: 
$a --; # also try to coment this, and uncomment the next staement
#$a ++;
print $a; #either -1 or 1, depends on what you uncomment

[download]
In the above demo, whatever it is post --, or post ++, perl would initialied $a to 0, and this is what should happen to print $a-- and print $a++.

In reply to Re: Re: dumb question by pg
in thread post-increment and post-decrement behavior (was: dumb question) by Anonymous Monk

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