Type::Tiny::Manual::NonOO(3)

NAME
Type::Tiny::Manual::NonOO - Type::Tiny in non-object-oriented code

MANUAL
Although Type::Tiny was designed with object-oriented programming in mind, especially Moose-style classes and roles, it can be used in procedural and imperative programming.

If you have read Type::Tiny::Manual::UsingWithMoo, you should understand how Type::Params can be used to validate method parameters. This same technique can be applied to regular subs too. More information about checking parameters can be found in Type::Tiny::Manual::Params.

The "is_*" and "assert_*" functions exported by type libraries may be useful in non-OO code too. See Type::Tiny::Manual::UsingWithMoo3.

  Type::Tiny and Smart Match
Perl 5.10 introduced the smart match operator "~~", which has since been deprecated because though the general idea is fairly sound, the details were a bit messy.

Nevertheless, Type::Tiny has support for smart match and I'm documenting it here because there's nowhere better to put it.

The following can be used as to check if a value passes a type constraint:

  $value ~~ SomeType

Where it gets weird is if $value is an object and overloads "~~". Which overload of "~~" wins? I don't know.

Better to use:

  SomeType->check( $value )   # more reliable, probably faster
  is_SomeType($value)         # more reliable, definitely faster

It's also possible to do:

  $value ~~ SomeType->coercion

This checks to see if $value matches any type that can be coerced to SomeType.

But better to use:

  SomeType->coercion->has_coercion_for_value( $value )

  "given" and "when"
Related to the smart match operator is the "given"/"when" syntax.

This will not do what you want it to do:

  use Types::Standard qw( Str Int );

  given ( $value ) {
    when ( Int ) { ... }
    when ( Str ) { ... }
  }

This will do what you wanted:

  use Types::Standard qw( is_Str is_Int );

  given ( $value ) {
    when ( \&is_Int ) { ... }
    when ( \&is_Str ) { ... }
  }

Sorry, that's just how Perl be.

Better though:

  use Types::Standard qw( Str Int );
  use Type::Utils qw( match_on_type );

  match_on_type $value => (
    Str, sub { ... },
    Int, sub { ... },
  );

If this is part of a loop or other frequently called bit of code, you can compile the checks once and use them many times:

  use Types::Standard qw( Str Int );
  use Type::Utils qw( compile_match_on_type );

  my $dispatch_table = compile_match_on_type(
    Str, sub { ... },
    Int, sub { ... },
  );

  $dispatch_table->($_) for @lots_of_values;

As with most things in Type::Tiny, those coderefs can be replaced by strings of Perl code.

NEXT STEPS
Here's your next step:

•   Type::Tiny::Manual::Optimization

    Squeeze the most out of your CPU.

AUTHOR
Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE
This software is copyright (c) 2013-2014, 2017-2025 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.