Type::Tiny::Enum

Status

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

Description

Enum type constraints.

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

Constructors

The new constructor from Type::Tiny still works, of course. But there is also:

new_union( type_constraints => \@enums, %opts ): Creates a new enum type constraint which is the union of existing enum type constraints.
new_intersection( type_constraints => \@enums, %opts ): Creates a new enum type constraint which is the intersection of existing enum type constraints.

Attributes

values: Arrayref of allowable value strings. Non-string values (e.g. objects with overloading) will be stringified in the constructor.
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::Standard::Str, and cannot be passed to the constructor.
unique_values: The list of values but sorted and with duplicates removed. This cannot be passed to the constructor.
coercion: If coercion => 1 is passed to the constructor, the type will have a coercion using the closest_match method.

Methods

as_regexp

Returns the enum as a regexp which strings can be checked against. If you're checking a lot of strings, then using this regexp might be faster than checking each string against

  my $enum  = Type::Tiny::Enum->new(...);
  my $check = $enum->compiled_check;
  my $re    = $enum->as_regexp;
  
  # fast
  my @valid_tokens = grep $enum->check($_), @all_tokens;
  
  # faster
  my @valid_tokens = grep $check->($_), @all_tokens;
  
  # fastest
  my @valid_tokens = grep /$re/, @all_tokens;

You can get a case-insensitive regexp using $enum->as_regexp('i').

closest_match

Returns the closest match in the enum for a string.

  my $enum = Type::Tiny::Enum->new(
    values => [ qw( foo bar baz quux ) ],
  );
  
  say $enum->closest_match("FO");   # ==> foo

It will try to find an exact match first, fall back to a case-insensitive match, if it still can't find one, will try to find a head substring match, and finally, if given an integer, will use that as an index.

  my $enum = Type::Tiny::Enum->new(
    values => [ qw( foo bar baz quux ) ],
  );
  
  say $enum->closest_match(  0 );  # ==> foo
  say $enum->closest_match(  1 );  # ==> bar
  say $enum->closest_match(  2 );  # ==> baz
  say $enum->closest_match( -1 );  # ==> quux

is_word_safe

Returns true if none of the values in the enumeration contain a non-word character. Word characters include letters, numbers, and underscores, but not most punctuation or whitespace.

Exports

Type::Tiny::Enum can be used as an exporter.

  use Type::Tiny::Enum Status => [ 'dead', 'alive' ];

This will export the following functions into your namespace:

Status
is_Status( $value )
assert_Status( $value )
to_Status( $value )
STATUS_DEAD
STATUS_ALIVE

Multiple enumerations can be exported at once:

  use Type::Tiny::Enum (
    Status    => [ 'dead', 'alive' ],
    TaxStatus => [ 'paid', 'pending' ],
  );

Overloading

Arrayrefification calls values.

Bugs

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