Re: eval order of args to a sub

I think the general rule of thumb is, "don't." As in, don't modify parameters to a function in the line that calls the function in such a way that could be confusing.

  foo($i++); # ok
  foo(++$i); # ok
  foo($i,$i++); # not ok
  foo($i++,$i); # not ok
  foo($i++,++$i); # WTF?
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If perl defined this, it would be one of very few languages that did so. And thus would still be confusing, IMO. It's not really that much extra work to avoid it. Use do if you have to:

  my $flubber = do {
    my @args;
    push @args, $i++;
    push @args, ++$i;
    foo(@args)
  }; # well defined: $_[1] == $_[0]+2
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Re^2: eval order of args to a sub by shmem (Chancellor) on Jun 03, 2007 at 10:17 UTC
Tanktalus++, best post in this thread: just "don't." And: avoid confusion. In that context I'd like to point at Quantum Weirdness and the Increment Operator, again, for a lengthy discussion of why modifying a variable more than one time via auto-{inc,dec}rement in the same statement is a very bad idea. --shmem _($_=" "x(1<<5)."?\n".q·/)Oo. G°\ / /\_¯/(q / ---------------------------- \__(m.====·.(_("always off the crowd"))."· ");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}	[reply]

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Re^2: eval order of args to a sub
by shmem (Chancellor) on Jun 03, 2007 at 10:17 UTC

Tanktalus

In that context I'd like to point at Quantum Weirdness and the Increment Operator, again, for a lengthy discussion of why modifying a variable more than one time via auto-{inc,dec}rement in the same statement is a very bad idea.

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}

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