Provided by: libparams-validationcompiler-perl_0.26-1_all 
NAME
Params::ValidationCompiler - Build an optimized subroutine parameter validator once, use
it forever
VERSION
version 0.26
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 foo {
my %args = $validator->(@_);
}
}
{
my $validator = validation_for(
params => [
{ type => Int },
{
type => Str,
optional => 1,
},
],
);
sub bar {
my ( $int, $str ) = $validator->(@_);
}
}
{
my $validator = validation_for(
params => [
foo => { type => Int },
bar => {
type => Str,
optional => 1,
},
],
named_to_list => 1,
);
sub baz {
my ( $foo, $bar ) = $validator->(@_);
}
}
DESCRIPTION
This module creates a customized, highly efficient parameter checking subroutine. It can
handle named or positional parameters, and can return the parameters as key/value pairs or
a list of values.
In addition to type checks, it also supports parameter defaults, optional parameters, and
extra "slurpy" parameters.
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 a hashref then the generated validator sub will expect named parameters.
The "params" value should be a hashref where the parameter names are keys and the
specs are the values.
If you pass an arrayref and "named_to_list" is false, the validator will expect
positional params. Each element of the "params" arrayref should be a parameter spec.
If you pass an arrayref and "named_to_list" is true, the validator will expect named
params, but will return a list of values. In this case the arrayref should contain a
list of key/value pairs, where parameter names are the keys and the specs are the
values.
Each spec can contain either a boolean or hashref. If the spec is a boolean, this
indicates required (true) or optional (false).
The spec 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.
• named_to_list
If this is true, the generated subroutine will expect a list of key-value pairs or a
hashref and it will return a list containing only values. The "params" you pass must
be a arrayref of key-value pairs. The order of these pairs determines the order in
which values are returned.
You cannot combine "slurpy" with "named_to_list" as there is no way to know how to
order the extra return values.
validation_for(...)
This returns a subroutine that implements the specific parameter checking. This subroutine
expects to be given the parameters to validate in @_. If all the parameters are valid, it
will return the validated parameters (with defaults as appropriate), either as a list of
key-value pairs or as a list of just values. If any of the parameters are invalid it will
throw an exception.
For validators expected named params, the generated subroutine accepts either a list of
key-value pairs or a single hashref. Otherwise the validator expects a list of values.
For now, you must shift off the invocant yourself.
This subroutine accepts the following additional parameters:
• 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.
This name will also be used in some exception messages, even if Sub::Util is not
available.
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 at
<https://github.com/houseabsolute/Params-ValidationCompiler/issues>.
I am also usually active on IRC as 'autarch' on "irc://irc.perl.org".
SOURCE
The source code repository for Params-ValidationCompiler can be found at
<https://github.com/houseabsolute/Params-ValidationCompiler>.
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>
CONTRIBUTORS
• Gregory Oschwald <goschwald@maxmind.com>
• Gregory Oschwald <oschwald@gmail.com>
• Tomasz Konojacki <me@xenu.pl>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2016 - 2017 by Dave Rolsky.
This is free software, licensed under:
The Artistic License 2.0 (GPL Compatible)
The full text of the license can be found in the LICENSE file included with this
distribution.