NAME

Sub::Meta::Parameters - meta information about parameters

SYNOPSIS

    use Sub::Meta::Parameters;

    my $p1 = Sub::Meta::Parameters->new(
        args => ['Str']
    );
    $p1->invocant;            # => undef;
    $p1->invocants;           # => [];
    $p1->positional;          # => [Sub::Meta::Param->new('Str')]
    $p1->positional_required; # => [Sub::Meta::Param->new('Str')]
    $p1->positional_optional; # => []
    $p1->named;               # => []
    $p1->named_required;      # => []
    $p1->named_optional;      # => []
    $p1->nshift;              # => 0
    $p1->slurpy;              # => 0
    $p1->args_min;            # => 1
    $p1->args_max;            # => 1


    my $x = Sub::Meta::Param->new({ type => 'Int', name => '$x', named => 1 });
    my $y = Sub::Meta::Param->new({ type => 'Int', name => '$y', named => 1 });

    my $p2 = Sub::Meta::Parameters->new(
        nshift => 1,
        args => [
            'ClassName', $x, $y
        ]
    );

    $p2->invocant;            # => Sub::Meta::Param->new('ClassName');
    $p2->invocants;           # => [Sub::Meta::Param->new('ClassName')];
    $p2->positional;          # => []
    $p2->positional_required; # => []
    $p2->positional_optional; # => []
    $p2->named;               # => [$x, $y]
    $p2->named_required;      # => [$x, $y]
    $p2->named_optional;      # => []
    $p2->nshift;              # => 1
    $p2->slurpy;              # => 0
    $p2->args_min;            # => 5
    $p2->args_max;            # => 0+'Inf'

METHODS

new

Constructor of Sub::Meta::Parameters.

    my $p = Sub::Meta::Parameters->new(
        args   => ['Str'], # required. arguments
        nshift => 0,       # optional. number of shift arguments
        slurpy => 0,       # optional. whether get all rest arguments
    );

args

Subroutine arguments arrayref.

set_args(LIST), set_args(ArrayRef)

Setter for subroutine arguments. An element can be an argument of Sub::Meta::Param or any object which has positional,named,required and optional methods.

nshift

Number of shift arguments.

set_nshift($nshift)

Setter for nshift. For example, it is assumed that 1 is specified in the case of methods, and 0 is specified in the case of normal functions.

slurpy

A boolean whether get all rest arguments.

set_slurpy($bool)

Setter for slurpy.

positional

Returns an arrayref of parameter objects for the positional arguments.

positional_required

Returns an arrayref of parameter objects for the required positional arguments.

positional_optional

Returns an arrayref of parameter objects for the optional positional arguments.

named

Returns an arrayref of parameter objects for the named arguments.

named_required

Returns an arrayref of parameter objects for the required named arguments.

named_optional

Returns an arrayref of parameter objects for the optional named arguments.

invocant

First element of invocants.

invocants

Returns an arrayref of parameter objects for the variables into which initial arguments are shifted automatically. This will usually return () for normal functions and ('$self') for methods.

args_min

Returns the minimum number of required arguments.

This is computed as follows: Invocants and required positional parameters count 1 each. Optional parameters don't count. Required named parameters count 2 each (key + value). Slurpy parameters don't count either because they accept empty lists.

args_max

Returns the maximum number of arguments.

This is computed as follows: If there are any named or slurpy parameters, the result is Inf. Otherwise the result is the number of all invocants and positional parameters.

is_same_interface($other_meta)

A boolean value indicating whether Sub::Meta::Parameters object is same or not. Specifically, check whether args, nshift and slurpy are equal.

SEE ALSO

Function::Parameters::Info.

The methods in this module are almost copied from the Function::Parameters::Info methods.

LICENSE

Copyright (C) kfly8.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

kfly8 <kfly@cpan.org>

cpanm Sub::Meta

perl -MCPAN -e shell
install Sub::Meta