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Postings from April 2003
On Fri, Apr 25, 2003 at 12:08:33AM -0400, Rick Delaney wrote:
> On Thu, Apr 24, 2003 at 10:48:36PM -0400, Mark Jason Dominus wrote:
> > Rick Delaney <rick.delaney@rogers.com>:
> > >
> > > Should these be different?
> > >
> > > my $rv2 = ('a', 'b', 'c', f());
> > > my $rv2 = ('a', 'b', 'c', );
> > > sub f { () }
> >
> > Yes.
> >
> > This
> >
> > my $rv2 = ('a', 'b', 'c', f());
> > sub f { () }
> >
> > is identical to this:
> >
> > my $rv2 = ('a', 'b', 'c', f());
> > sub f { }
> >
> > because the empty parentheses don't matter.
>
> They're not identical at the opcode level because the parentheses do
> matter, since they create a stub expression that returns undef in scalar
> context.
Right. A list in a scalar context evaluates each element in a scalar context
before any flatening is done.
sub f { warn wantarray ? 1 : 0; return }
@a = ('a', f(),'');
$a = ('a', f(),'');
__END__
1 at - line 1.
0 at - line 1.
() in a scalar context yeilds undef.
Graham.
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