# NAME
Params::ValidationCompiler - Build an optimized subroutine parameter validator once, use it forever
# VERSION
version 0.09
# SYNOPSIS
use Types::Standard qw( Int Str );
use Params::ValidationCompiler qw( validation_for );
{
my $check = validation_for(
params => {
foo => { type => Int },
bar => {
type => Str,
optional => 1,
},
baz => {
type => Int,
default => 42,
},
},
);
sub do_something {
my %args = $check->(@_);
}
}
# 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](https://metacpan.org/pod/Moose) type (from [Moose](https://metacpan.org/pod/Moose) or
[MooseX::Types](https://metacpan.org/pod/MooseX::Types)), a [Type::Tiny](https://metacpan.org/pod/Type::Tiny) type, or a [Specio](https://metacpan.org/pod/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::Name](https://metacpan.org/pod/Sub::Name). 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::Name](https://metacpan.org/pod/Sub::Name) yourself separately, as it is not
required by this distribution, in order to avoid requiring a compiler.
## 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](https://metacpan.org/pod/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](http://www.urth.org/~autarch/fs-donation.html).
# AUTHOR
Dave Rolsky <autarch@urth.org>
# COPYRIGHT AND LICENCE
This software is Copyright (c) 2016 by Dave Rolsky.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)