=head1 TITLE
Multiway comparisons
=head1 VERSION
Maintainer: Damian Conway <[EMAIL PROTECTED]>
Date: 4 August 2000
Version: 1.00
Mailing List: [EMAIL PROTECTED]
Number: 25
=head1 ABSTRACT
This RFC proposes that multiway comparisons such as:
if ( 0 <= $x < 10 ) {
print "digit"
}
should do what the user means.
=head1 DESCRIPTION
It is proposed that expressions involving multiple chained comparisons
should be automagically expanded to the equivalent binary conjunction. That is:
0 <= $x < 10
is DWIMmed to:
0 <= $x && $x < 10
Furthermore, it is proposed that any operations, function calls, or subroutine
invocations should only be performed once in such expansions and that such
expansions should short-circuit on failure. That is:
$min < nextval() < $x+$y < length $string
should become:
do {
my $tmp1, $tmp2;
$min < do{$tmp1=nextval} &&
$tmp1 < do{$tmp2=$x+$y} &&
$tmp2 < length $string;
}
=head1 IMPLEMENTATION
As described above
