NAME¶

Text::Roman - Allows conversion between Roman and Arabic algarisms.

VERSION¶

version 3.5

SYNOPSIS¶

    #!/usr/bin/env perl
    use strict;
    use warnings;
    use Text::Roman qw(:all);
    print int2roman(123), "\n";
    my $roman = "XXXV";
    print roman2int($roman), "\n" if isroman($roman);
    my $milhar = 'L_X_XXIII'; # = 60,023
    print milhar2int($milhar), "\n" if ismilhar($milhar);

DESCRIPTION¶

This package supports both conventional Roman algarisms (which range from 1 to 3999) and Milhar Romans, a variation which uses a bar across the algarism to indicate multiplication by 1_000. For the purposes of this module, acceptable syntax consists of an underscore suffixed to the algarism e.g. IV_V = 4_005. The term Milhar apparently derives from the Portuguese word for "thousands" and the range of this notation extends the range of Roman numbers to 3999 * 1000 + 3999 = 4_002_999.

Note: the functions in this package treat Roman algarisms in a case-insensitive manner such that "VI" == "vI" == "Vi" == "vi".

The following functions may be imported into the caller package by name:

FUNCTIONS¶

CHANGES¶

Some changes worth noting from this module's previous incarnation:

namespace imports

The call to use must now explicitly request function names imported into it's namespace.

argument defaults/void context

All functions now will operate on $_ when no arguments are passed, and will set $_ when called in a void context. This allows for writing code like:

    @x = qw/V III XI IV/;
    roman2int() for @x;
    print join("-", @x);
    

instead of the uglier:

    @x = qw/V III XI IV/;
    $_ = roman2int($_) for @x;
    print join("-", @x);
    

SPECIFICATION¶

Roman algarisms may be described using the following BNF-like formula:

    a   = I{1,3}
    b   = V\a?|IV|\a
    e   = X{1,3}\b?|X{0,3}IX|\b
    ee  = IX|\b
    f   = L\e?|XL\ee?|\e
    g   = C{1,3}\f?|C{0,3}XC\ee?|\f
    gg  = XC\ee?|\f
    h   = D\g?|CD\gg?|\g
    j   = M{1,3}\h?|M{0,3}CM\gg?|\h

REFERENCES¶

For a description of the Roman numeral system see: <http://www.novaroma.org/via_romana/numbers.html>. A reference to Milhar Roman alagarisms (in Portuguese) may be found at: <http://web.archive.org/web/20020819094718/http://www.estado.com.br/redac/norn-nro.html>.

ACKNOWLEDGEMENTS¶

This module was originally written by Peter de Padua Krauss and submitted to CPAN by Stanislaw Pusep <https://metacpan.org/author/SYP> who has relinquished control to Erick Calder <https://metacpan.org/author/ECALDER> since the original author has never maintained it and can no longer be reached.

Erick have completely rewritten the module, implementing simpler algorithms to perform the same functionality, adding a test suite, a Changes file, etc. and providing more comprehensive documentation.

Ten years later, Stanislaw returned as a maintainer.

AUTHOR¶

Stanislaw Pusep <stas@sysd.org>

COPYRIGHT AND LICENSE¶

This software is copyright (c) 2003 by Erick Calder <ecalder@cpan.org>.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.