Params::ValidationCompiler(3)

NAME
Params::ValidationCompiler - Build an optimized subroutine parameter validator once, use it forever

VERSION
version 0.13

SYNOPSIS
    use Types::Standard qw( Int Str );
    use Params::ValidationCompiler qw( validation_for );

    {
        my $validator = validation_for(
            params => {
                foo => { type => Int },
                bar => {
                    type     => Str,
                    optional => 1,
                },
                baz => {
                    type    => Int,
                    default => 42,
                },
            },
        );

        sub do_something {
            my %args = $validator->(@_);
        }
    }

DESCRIPTION
This is very alpha. The module name could change. Everything could change. You have been warned.

Create a customized, optimized, non-lobotomized, uncompromised, and thoroughly specialized parameter checking subroutine.

EXPORTS
This module has two options exports, "validation_for" and "source_for". Both of these subs accept the same options:

•   params

    An arrayref or hashref containing a parameter specification.

    If you pass an arrayref, the check will expect positional params. Each member of the arrayref represents a single parameter to validate.

    If you pass a hashref then it will expect named params. For hashrefs, the parameters names are the keys and the specs are the values.

    The spec can contain either a boolean or hashref. If the spec is a boolean, this indicates required (true) or optional (false).

    The hashref accepts the following keys:

    •   type

        A type object. This can be a Moose type (from Moose or MooseX::Types), a Type::Tiny type, or a Specio type.

        If the type has coercions, those will always be used.

    •   default

        This can either be a simple (non-reference) scalar or a subroutine reference. The sub ref will be called without any arguments (for now).

    •   optional

        A boolean indicating whether or not the parameter is optional. By default, parameters are required unless you provide a default.

•   slurpy

    If this is a simple true value, then the generated subroutine accepts additional arguments not specified in "params". By default, extra arguments cause an exception.

    You can also pass a type constraint here, in which case all extra arguments must be values of the specified type.

  validation_for(...)
This returns a subroutine that implements the specific parameter checking. Pass this the arguments in @_ and it will return a hash of parameters or throw an exception. The generated subroutine accepts either a hash or a single hashref.

For now, you must shift off the invocant yourself.

This subroutine accepts an additional parameter:

•   name

    If this is given, then the generated subroutine will be named using Sub::Util. This is strongly recommended as it makes it possible to distinguish different check subroutines when profiling or in stack traces.

    Note that you must install Sub::Util yourself separately, as it is not required by this distribution, in order to avoid requiring a compiler.

•   name_is_optional

    If this is true, then the name is ignored when "Sub::Util" is not installed. If this is false, then passing a name when Sub::Util cannot be loaded causes an exception.

    This is useful for CPAN modules where you want to set a name if you can, but you do not want to add a prerequisite on Sub::Util.

  source_for(...)
This returns a two element list. The first is a string containing the source code for the generated sub. The second is a hashref of "environment" variables to be used when generating the subroutine. These are the arguments that are passed to Eval::Closure.

SUPPORT
Bugs may be submitted through the RT bug tracker <http://rt.cpan.org/Public/Dist/Display.html?Name=Params-ValidationCompiler> (or bug-params-validationcompiler@rt.cpan.org <mailto:bug-params-validationcompiler@rt.cpan.org>).

I am also usually active on IRC as 'drolsky' on "irc://irc.perl.org".

DONATIONS
If you'd like to thank me for the work I've done on this module, please consider making a "donation" to me via PayPal. I spend a lot of free time creating free software, and would appreciate any support you'd care to offer.

Please note that I am not suggesting that you must do this in order for me to continue working on this particular software. I will continue to do so, inasmuch as I have in the past, for as long as it interests me.

Similarly, a donation made in this way will probably not make me work on this software much more, unless I get so many donations that I can consider working on free software full time (let's all have a chuckle at that together).

To donate, log into PayPal and send money to autarch@urth.org, or use the button at <http://www.urth.org/~autarch/fs-donation.html>.

AUTHOR
Dave Rolsky <autarch@urth.org>

COPYRIGHT AND LICENSE
This software is Copyright (c) 2016 by Dave Rolsky.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)