The Perl Toolchain Summit needs more sponsors. If your company depends on Perl, please support this very important event.

NAME

Attribute::Boolean - Mark scalars as pure booleans

VERSION

Version v1.0.8

SYNOPSYS

This allows you to flag a variable as a boolean. In numeric context, it will have the value 0 or 1. In string context is will have the value "false" or "true". In JSON, it will correctly return false or true values.

    my $bool : Boolean;
    print $bool;    # "false"
    $bool = (1 + 2 == 3);
    print $bool;    # "true"
    print $bool ? "yes" : "no";  # "yes"
    $bool = false;
    print $bool ? "yes" : "no";  # "no"

EXPORT

This exports constants true and false.

USAGE

An attribute can be declared boolean as follows:

    my $bool : Boolean;

or

    my $bool : Boolean = true;

If any perl true value is assigned, the variable is true; if a perl false value is assigned, the variable is false.

true

This returns 1 in numeric context, "true" in string context.

false

This returns 0 in numeric context, "false" in string context.

TO_JSON

Provided that convert_blessed is set on the JSON (or JSON::XS) object, the variable will correctly convert to JSON true or false.

    my $json = new JSON;
    $json->pretty->convert_blessed;
    my $bool : Boolean;
    my %hash = (
        value => $bool,
        me    => true,
    );
    print $json->encode(\%hash);    # {
                                    #     "value" : false,
                                    #     "me"    : true
                                    # }
                                    

AUTHOR

Cliff Stanford, <cpan@may.be>

BUGS

Please report any bugs or feature requests to bug-attribute-boolean+ at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=attribute-boolean+. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Attribute::Boolean

ACKNOWLEDGEMENTS

Alan Haggai Alavi <alanhaggai@alanhaggai.org> for his Scalar::Boolean module which was the inspiration for this module.

LICENCE AND COPYRIGHT

Copyright 2014 Cliff Stanford.

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