----------------------------------------------------------------------------- | Want v0.03 - Robin Houston, 2001-07-25 ----------------------------------------------------------------------------- Changes since v0.02: - Fix documentation snafus - add want('COUNT') as a synonym for C and want('REF') for C - BOOLEAN context - now compiles & passes tests under ithreads - SCALARREF and OBJECT reference contexts (want('REF') eq 'SCALAR' || want('REF') eq 'OBJECT') - Reorganised test suite Changes since v0.01: - Give correct expectation count for constructs like my ($x, $y, $z) = (23, foo()); # foo's expectation count is 2 - want(2) should be true in C<@x = foo()> etc; i.e. infinity > N for any finite N :-) - Support '!' negative requests - correct expectation count for slices For full documentation, see the POD included with the module. Below is a brief extract of the documentation, to give you an idea of what this module does. It requires Perl version 5.6 or later. NAME Want - Implement the `want' command SYNOPSIS use Want ('want'); sub foo :lvalue { if (want('lvalue')) { return $x; } elsif (want('LIST')) { return (1, 2, 3); } DESCRIPTION This module generalises the mechanism of the wantarray function, allowing a function to determine in some detail how its return value is going to be immediately used. ... EXAMPLES use Carp 'croak'; use Want 'howmany'; sub numbers { my $count = howmany(); croak("Can't make an infinite list") if !defined($count); return (1..$count); } my ($one, $two, $three) = numbers(); use Want 'want'; sub pi () { if (want('ARRAY')) { return [3, 1, 4, 1, 5, 9]; } elsif (want('LIST')) { return (3, 1, 4, 1, 5, 9); } else { return 3; } } print pi->[2]; # prints 4 print ((pi)[3]); # prints 1 AUTHOR Robin Houston, SEE ALSO o the wantarray entry in the perlfunc manpage o Perl6 RFC 21, by Damian Conway. http://dev.perl.org/rfc/21.html COPYRIGHT Copyright (c) 2001, Robin Houston. All Rights Reserved. This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.