Syntax::Keyword::Junction3pm

Usage

  use Syntax::Keyword::Junction qw/ all any none one /;
  if (any(@grant) eq 'su') {
    ...
  }
  if (all($foo, $bar) >= 10) {
    ...
  }
  if (qr/^\d+$/ == all(@answers)) {
    ...
  }
  if (all(@input) <= scalar @limits) {
    ...
  }
  if (none(@pass) eq 'password') {
    ...
  }
  if (one(@answer) == 42) {
    ...
  }

  use Syntax::Keyword::Junction any => { -as => 'robot_any' };
  if (robot_any(@grant) eq 'su') {
    ...
  }

Overview

This is a lightweight module which provides 'Junction' operators, the most commonly used being "any" and "all".

Inspired by the Perl 6 design docs, <https://web.archive.org/web/20230922160729/https://raku.org/archive/doc/design/exe/E06.html#The%20Wonderful%20World%20of%20Junctions>.

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

  '<',  '<=', '>',  '>=', '==', '!=',
  'lt', 'le', 'gt', 'ge', 'eq', 'ne',
  '~~'

  '<',  '<=', '>',  '>=', '==', '!=',
  'lt', 'le', 'gt', 'ge', 'eq', 'ne',
  '~~'

  '<',  '<=', '>',  '>=', '==', '!=',
  'lt', 'le', 'gt', 'ge', 'eq', 'ne',
  '~~'

  '<',  '<=', '>',  '>=', '==', '!=',
  'lt', 'le', 'gt', 'ge', 'eq', 'ne',
  '~~'

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

You can also use the "map" method:

  my $numbers = any(qw/1 2 3 4 5/);
  my $prime   = $numbers->map( \&is_prime );
  say for $prime->values; # prints 0, 1, 1, 0, 1

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 Syntax::Keyword::Junction;
  if (Syntax::Keyword::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 overridden.

To do

Add overloading for arithmetic operators, such that this works:

  $result = any(2,3,4) * 2;
  if ($result == 8) {...}

Contributors

Copyright and license

This software is copyright (c) 2024 by Arthur Axel "fREW" Schmidt.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.