Type::Tiny::Bitfield(3)                    User Contributed Perl Documentation


NAME
       Type::Tiny::Bitfield - bitfield/bitflag type constraints

SYNOPSIS
       Using Type::Tiny::Bitfield's export feature:

         package LightSource {
           use Moo;

           use Type::Tiny::Bitfield LedSet => {
             RED   => 1,
             GREEN => 2,
             BLUE  => 4,
           };

           has leds => ( is => 'ro', isa => LedSet, default => 0, coerce => 1 );

           sub new_red {
             my $class = shift;
             return $class->new( leds => LEDSET_RED );
           }

           sub new_green {
             my $class = shift;
             return $class->new( leds => LEDSET_GREEN );
           }

           sub new_yellow {
             my $class = shift;
             return $class->new( leds => LEDSET_RED | LEDSET_GREEN );
           }
         }

       Using Type::Tiny::Bitfield's object-oriented interface:

         package LightSource {
           use Moo;
           use Type::Tiny::Bitfield;

           my $LedSet = Type::Tiny::Bitfield->new(
             name   => 'LedSet',
             values => {
               RED   => 1,
               GREEN => 2,
               BLUE  => 4,
             },
             coercion => 1,
           );

           has leds => ( is => 'ro', isa => $LedSet, default => 0, coerce => 1 );

           sub new_red {
             my $class = shift;
             return $class->new( leds => $LedSet->RED );
           }

           sub new_green {
             my $class = shift;
             return $class->new( leds => $LedSet->GREEN );
           }

           sub new_yellow {
             my $class = shift;
             return $class->new( leds => $LedSet->coerce('red|green') );
           }
         }

STATUS
       This module is covered by the Type-Tiny stability policy.

DESCRIPTION
       Bitfield type constraints.

       This package inherits from Type::Tiny; see that for most documentation.
       Major differences are listed below:

   Attributes
       "values"
           Hashref of bits allowed in the bitfield. Keys must be
           UPPER_SNAKE_CASE strings.  Values must be positive integers which
           are powers of two. The same number cannot be used multiple times.

       "constraint"
           Unlike Type::Tiny, you cannot pass a constraint coderef to the
           constructor.  Instead rely on the default.

       "inlined"
           Unlike Type::Tiny, you cannot pass an inlining coderef to the
           constructor.  Instead rely on the default.

       "parent"
           Parent is always Types::Common::Numeric::PositiveOrZeroInt, and
           cannot be passed to the constructor.

       "coercion"
           If "coercion => 1" is passed to the constructor, the type will have
           an automatic coercion from Str. Types built by the "import" method
           will always have "coercion => 1".

           In the SYNOPSIS example, the coercion from Str will accept strings
           like:

             "RED"
             "red"
             "Red Green"
             "Red+Blue"
             "blue | GREEN"
             "LEDSET_RED + LeDsEt_green"

   Methods
       This class uses "AUTOLOAD" to allow the names of each bit in the
       bitfield to be used as methods. These method names will always be
       UPPER_SNAKE_CASE.

       For example, in the synopsis, "LedSet->GREEN" would return 2.

       Other methods it provides:

       from_string( $str )
           Provides the standard coercion from a string, even if this type
           constraint doesn't have a coercion.

       to_string( $int )
           Does the reverse coercion.

       constant_names()
           This is a convenience to allow for:

             use base 'Exporter::Tiny';
             push our @EXPORT_OK, LineStyle->constant_names;

   Exports
       Type::Tiny::Bitfield can be used as an exporter.

         use Type::Tiny::Bitfield LedSet => {
           RED    => 1,
           GREEN  => 2,
           BLUE   => 4,
         };

       This will export the following functions into your namespace:

       "LedSet"
       is_LedSet( $value )
       assert_LedSet( $value )
       to_LedSet( $string )
       LedSet_to_Str( $value )
       "LEDSET_RED"
       "LEDSET_GREEN"
       "LEDSET_BLUE"

       Multiple bitfield types can be exported at once:

         use Type::Tiny::Enum (
           LedSet     => { RED => 1, GREEN => 2, BLUE => 4 },
           LedPattern => { FLASHING => 1 },
         );

   Overloading
       It is possible to combine two Bitfield types using the "+" operator.

         use Type::Tiny::Enum (
           LedSet     => { RED => 1, GREEN => 2, BLUE => 4 },
           LedPattern => { FLASHING => 8 },
         );

         has leds => (
           is      => 'ro',
           isa     => LedSet + LedPattern,
           default => 0,
           coerce  => 1
         );

       This will allow values like "11"
       (LEDSET_RED|LEDSET_GREEN|LEDPATTERN_FLASHING).

       An exception will be thrown if any of the names in the two types being
       combined conflict.

BUGS
       Please report any bugs to
       <https://github.com/tobyink/p5-type-tiny/issues>.

SEE ALSO
       Type::Tiny::Manual.

       Type::Tiny.

AUTHOR
       Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE
       This software is copyright (c) 2023 by Toby Inkster.

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

DISCLAIMER OF WARRANTIES
       THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
       WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
       MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

perl v5.38.2                      2024-03-13           Type::Tiny::Bitfield(3)