NAME

Class::Type::Enum - Build Enum-like classes

VERSION

version 0.011

SYNOPSIS

  package Toast::Status {
    use Class::Type::Enum values => ['bread', 'toasting', 'toast', 'burnt'];
  }

  package Toast {
    use Moo;

    has status => (
      is      => 'rw',
      isa     => Toast::Status->type_constraint,
      coerce  => 1,
      handles => [ Toast::Status->list_is_methods ],
    );
  }

  my @toast = map { Toast->new(status => $_) } qw( toast burnt bread bread toasting toast );

  my @trashcan = grep { $_->is_burnt } @toast;
  my @plate    = grep { $_->is_toast } @toast;

  my $ready_status   = Toast::Status->new('toast');
  my @eventual_toast = grep { $_->status < $ready_status } @toast;

  # or:

  @eventual_toast = grep { $_->status lt 'toast' } @toast;

  # or:

  @eventual_toast = grep { $_->status->none('toast', 'burnt') } @toast;

DESCRIPTION

Class::Type::Enum is a class builder for type-like classes to represent your enumerated values. In particular, it was built to scratch an itch with DBIx::Class value inflation.

I wouldn't consider the interface stable yet; I'd love feedback on this dist.

When useing Class::Type::Enum:

  • Required:

    values => [@symbols]

    The list of symbolic values in your enum, in ascending order if relevant.

    values => {symbol => ordinal, ...}

    The list of symbols and ordinal values in your enum. There is no check that a given ordinal isn't reused.

Custom Ordinal Values

If you'd like to build an enum that works like a bitfield or some other custom setup, you need only pass a more explicit hashref to Class::Type::Enum.

  package BitField {
    use Class::Type::Enum values => {
      READ    => 1,
      WRITE   => 2,
      EXECUTE => 4,
    };
  }

METHODS

$class->import(values => ...)

Sets up the consuming class as a subclass of Class::Type::Enum and installs functions that are unique to the class.

$class->new($value)

Your basic constructor, expects only a value corresponding to a symbol in the enum type. Also works as an instance method for enums of the same class.

$class->inflate_symbol($symbol)

Does the actual work of $class->new($value), also used when inflating values for DBIx::Class::InflateColumn::ClassTypeEnum.

$class->inflate_ordinal($ord)

Used when inflating ordinal values for DBIx::Class::InflateColumn::ClassTypeEnum or if you need to work with ordinals directly.

$class->sym_to_ord

Returns a hashref keyed by symbol, with ordinals as values.

$class->ord_to_sym

Returns a hashref keyed by ordinal, with symbols as values.

$class->values

Returns an arrayref of valid symbolic values, in order.

$class->list_is_methods

Returns a list of is_ methods defined for each symbolic value for the class.

$class->type_constraint

This method requires the optional dependency Type::Tiny.

Returns a type constraint suitable for use with Moo and friends.

$class->test_symbol($value)

Test whether or not the given value is a valid symbol in this enum class.

$class->test_ordinal($value)

Test whether or not the given value is a valid ordinal in this enum class.

$class->coerce_symbol($value)

If the given value is already a $class, return it, otherwise try to inflate it as a symbol. Dies on invalid value.

$class->coerce_ordinal($value)

If the given value is already a $class, return it, otherwise try to inflate it as an ordinal. Dies on invalid value.

$class->coerce_any($value)

If the given value is already a $class, return it, otherwise try to inflate it first as an ordinal, then as a symbol. Dies on invalid value.

$o->is($value)

Given a test symbol, test that the enum instance's value is equivalent.

An exception is thrown if an invalid symbol is provided

$o->is_$value

Shortcut for $o->is($value)

$o->stringify

Returns the symbolic value.

$o->numify

Returns the ordinal value.

$o->cmp($other, $reversed = undef)

The string-compare implementation used by overloading. Returns the same values as cmp. The optional third argument is an artifact of overload, set to true if the order of $o and $other have been reversed in order to make the overloaded method call work.

$o->any(@cases)

True if $o->is(..) for any of the given cases.

$o->none(@cases)

True if $o->is(..) for none of the given cases.

SEE ALSO

AUTHOR

Meredith Howard <mhoward@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Meredith Howard.

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