NAME
     Class::Params - Parameter utils for constructor.

SYNOPSIS
     use Class::Params qw(params);
     params($self, $def_hr, $params_ar);

DEFINITION FORMAT
     There is hash with parameters.
     internal_name => [real_name, class, possible_types, requirement]

     Example:
     'par1' => ['_par1', undef, 'SCALAR', 1],
     'par2' => ['_par2', undef, ['SCALAR', 'HASH'], 0],
     'par3' => ['_par3', 'Class', ['SCALAR', 'Class'], 0],

SUBROUTINES
    "params($self, $def_hr, $params_ar)"
             Check for structure over definition and save input data to $self.
             Parameters:
             $self - Structure, for data save.
             $def_hr - Definition hash ref.
             $params_ar - Reference to array of key-value pairs.
             Returns undef.

ERRORS
     params():
             Bad parameter '%s' type.
             Parameter '%s' is required.
             Unknown parameter '%s'.

EXAMPLE1
     # Pragmas.
     use strict;
     use warnings;

     # Modules.
     use Class::Params qw(params);

     # Definition.
     my $self = {};
     my $def_hr = {
             'par' => ['_par', undef, 'SCALAR', 1],
     };

     # Check.
     # output_structure, definition, array of pairs (key, value).
     params($self, $def_hr, ['bad_par', 1]);

     # Output:
     # Unknown parameter 'bad_par'.

EXAMPLE2
     # Pragmas.
     use strict;
     use warnings;

     # Modules.
     use Class::Params qw(params);
     use Data::Printer;

     # Definition.
     my $self = {};
     my $def_hr = {
             'par' => ['_par', undef, 'SCALAR', 1],
     };

     # Check.
     # output_structure, definition, array of pairs (key, value).
     params($self, $def_hr, ['par', 1]);

     # Dump $self.
     p $self;

     # Output:
     # \ {
     #     _par   1
     # }

EXAMPLE3
     # Pragmas.
     use strict;
     use warnings;

     # Modules.
     use Class::Params qw(params);

     # Definition.
     my $self = {};
     my $def_hr = {
             'par' => ['_par', 'Moo', ['ARRAY', 'Moo'], 0],
     };

     # Fake class.
     my $moo = bless {}, 'Moo';

     # Check bad 'par' parameter which has bad 'bar' scalar.
     params($self, $def_hr, ['par', [$moo, 'bar']]);

     # Output like:
     # Bad parameter 'par' class.

EXAMPLE4
     # Pragmas.
     use strict;
     use warnings;

     # Modules.
     use Class::Params qw(params);
     use Data::Printer;

     # Definition.
     my $self = {};
     my $def_hr = {
             'par' => ['_par', 'Moo', ['ARRAY', 'Moo'], 0],
     };

     # Fake class.
     my $moo = bless {}, 'Moo';

     # Check right 'par' parameter which has array of 'Moo' objects.
     params($self, $def_hr, ['par', [$moo, $moo]]);

     # Dump $self.
     p $self;

     # Output like:
     # \ {
     #     _par   [
     #         [0] Moo  {
     #             public methods (0)
     #             private methods (0)
     #             internals: {}
     #         },
     #         [1] var{_par}[0]
     #     ]
     # }

DEPENDENCIES
    Error::Pure, Exporter, Readonly, Scalar::Util.

REPOSITORY
    <https://github.com/tupinek/Class-Params>

AUTHOR
    Michal Josef Špaček skim@cpan.org

LICENSE AND COPYRIGHT
     © Michal Josef Špaček 2011-2018
     BSD 2-Clause License

VERSION
    0.05