Type::Tiny::Manual::NoUser3Contributed Perl DocuType::Tiny::Manual::NonOO(3pm)
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, 2017-2023 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 v5.36.0 2023-02-01 Type::Tiny::Manual::NonOO(3pm)
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