Carl Franks > Perl6-Junction > Perl6::Junction

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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).

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