This and other RFCs are available on the web at http://dev.perl.org/rfc/ =head1 TITLE Operators: Multiway comparisons =head1 VERSION Maintainer: Damian Conway <[EMAIL PROTECTED]> Date: 4 Aug 2000 Last Modified: 18 Sep 2000 Mailing List: [EMAIL PROTECTED] Number: 25 Version: 2 Status: Frozen =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 =head1 REFERENCES None.
