NAME¶
Perl6::Junction - Perl6 style Junction operators in Perl5.
SYNOPSIS¶
use Perl6::Junction qw/ all any none one /;
if (any(@grant) eq 'su') {
...
}
if (all($foo, $bar) >= 10) {
...
}
if (qr/^\d+$/ == all(@answers)) {
...
}
if (all(@input) <= @limits) {
...
}
if (none(@pass) eq 'password') {
...
}
if (one(@answer) == 42) {
...
}
DESCRIPTION¶
This is a lightweight module which provides 'Junction' operators, the most
commonly used being "any" and "all".
Inspired by the Perl6 design docs,
<
http://dev.perl.org/perl6/doc/design/exe/E06.html>.
Provides a limited subset of the functionality of Quantum::Superpositions, see
"SEE ALSO" for comment.
Notice in the "SYNOPSIS" above, that if you want to match against a
regular expression, you must use "==" or "!=".
Not
"=~" or "!~". You must also use a regex object, such as
"qr/\d/", not a plain regex such as "/\d/".
SUBROUTINES¶
all()
Returns an object which overloads the following operators:
'<', '<=', '>', '>=', '==', '!=',
'lt', 'le', 'gt', 'ge', 'eq', 'ne',
Returns true only if
all arguments test true according to the operator
used.
any()
Returns an object which overloads the following operators:
'<', '<=', '>', '>=', '==', '!=',
'lt', 'le', 'gt', 'ge', 'eq', 'ne',
Returns true if
any argument tests true according to the operator used.
none()
Returns an object which overloads the following operators:
'<', '<=', '>', '>=', '==', '!=',
'lt', 'le', 'gt', 'ge', 'eq', 'ne',
Returns true only if
no argument tests true according to the operator
used.
one()
Returns an object which overloads the following operators:
'<', '<=', '>', '>=', '==', '!=',
'lt', 'le', 'gt', 'ge', 'eq', 'ne',
Returns true only if
one and only one argument tests true according to
the operator used.
ALTERING JUNCTIONS¶
You cannot alter junctions. Instead, you can create new junctions out of old
junctions. You can do this by calling the "values" method on a
junction.
my $numbers = any(qw/1 2 3 4 5/);
print $numbers == 3 ? 'Yes' : 'No'; # Yes
$numbers = any( grep { $_ != 3 } $numbers->values );
print $numbers == 3 ? 'Yes' : 'No'; # No
EXPORT¶
'all', 'any', 'none', 'one', as requested.
All subroutines can be called by its fully qualified name, if you don't want to
export them.
use Perl6::Junction;
if (Perl6::Junction::any( @questions )) {
...
}
WARNING¶
When comparing against a regular expression, you must remember to use a regular
expression object: "qr/\d/"
Not "/d/". You must
also use either "==" or "!=". This is because
"=~" and "!~" cannot be overriden.
TO DO¶
Add overloading for arithmetic operators, such that this works:
$result = any(2,3,4) * 2;
if ($result == 8) {...}
SUPPORT / BUGS¶
Submit to the CPAN bugtracker <
http://rt.cpan.org>
SEE ALSO¶
Quantum::Superpositions provides the same functionality as this, and more.
However, this module provides this limited functionality at a much greater
runtime speed, with my benchmarks showing between 500% and 6000% improvment.
<
http://dev.perl.org/perl6/doc/design/exe/E06.html> - "The Wonderful
World of Junctions".
AUTHOR¶
Carl Franks
ACKNOWLEDGEMENTS¶
Thanks to "Curtis "Ovid" Poe" for the "ALTERING
JUNCTIONS" changes in release 0.40000.
COPYRIGHT AND LICENSE¶
Copyright 2005, Carl Franks. All rights reserved.
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself (perlgpl, perlartistic).