Re: Reading X lines at a time

[Georg Moritz]

From the keyboard of Rick Delaney [03.05.04,09:42]:

> On Mon, May 03, 2004 at 03:27:01PM +0200, Georg Moritz wrote:
> > From the keyboard of Rick Delaney [03.05.04,09:23]:
> >
> > >     while (my @a = map { eof() ? () : scalar <> } 1 .. $n) {
> > >         print @a;
> > >         print "SEPARATOR\n";
> > >     }
> >
> > but this will loop forever, since the array @a is always defined, even
> > on eof(). map() will return a bunch of undefs.
>
> What makes you say that?

well, I assumed it by

perl -le 'print scalar map{undef} 1..4'
4

but then..
perl -le 'print scalar map{()} 1..4;'
0

how subtle. once again, nothing and nothing aren't the same...
an empty list doesn't increase the array count on the lhs.
undef does.

obviously undef returns a scalar value (which is undef).

thanks,
georg

-- 
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                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s,/,($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e,e && print}