NAME

Types::Equal - type constraints for single value equality

SYNOPSIS

    use Types::Equal qw( Eq Equ );
    use Types::Standard -types;
    use Type::Utils qw( match_on_type );

    # Check single string equality
    my $Foo = Eq['foo'];
    $Foo->check('foo'); # true
    $Foo->check('bar'); # false

    eval { Eq[undef]; };
    ok $@; # dies


    # Check single string equality with undefined
    my $Bar = Equ['bar'];
    $Bar->check('bar'); # true

    my $Undef = Equ[undef];
    $Undef->check(undef);


    # Can combine with other types
    my $Baz = Eq['baz'];
    my $ListBaz = ArrayRef[$Baz];
    my $Type = $ListBaz | $Baz;

    $Type->check(['baz']); # true
    $Type->check('baz'); # true

    # Easily use pattern matching
    my $Publish = Eq['publish'];
    my $Draft = Eq['draft'];

    my $post = {
        status => 'publish',
        title => 'Hello World',
    };

    match_on_type($post->{status},
        $Publish => sub { "Publish!" },
        $Draft => sub { "Draft..." },
    ) # => Publish!;


    # Create simple Algebraic Data Types(ADT)
    my $LoginUser = Dict[
        _type => Eq['LoginUser'],
        id => Int,
        name => Str,
    ];

    my $Guest = Dict[
        _type => Eq['Guest'],
        name => Str,
    ];

    my $User = $LoginUser | $Guest;

    my $user = { _type => 'Guest', name => 'ken' };
    $User->assert_valid($user);

    match_on_type($user,
        $LoginUser => sub { "You are LoginUser!" },
        $Guest => sub { "You are Guest!" },
    ) # => 'You are Guest!';

DESCRIPTION

Types::Equal provides type constraints for single string equality like TypeScript's string literal types.

Eq

Eq is function of a type constraint Type::Tiny::Eq which is for single string equality.

Equ

Equ is function of a type constraint Type::Tiny::Equ which is for single string equality with undefined.

NumEq

NumEq is function of a type constraint Type::Tiny::NumEq which is for single number equality.

NumEqu

NumEqu is function of a type constraint Type::Tiny::NumEqu which is for single number equality with undefined.

LICENSE

Copyright (C) kobaken.

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

AUTHOR

kobaken <kfly@cpan.org>