1Text::Roman(3) User Contributed Perl Documentation Text::Roman(3)
2
6 Text::Roman - Allows conversion between Roman and Arabic algarisms.
7
9 version 3.5
10
12 #!/usr/bin/env perl
13 use strict;
14 use warnings;
15 use Text::Roman qw(:all);
16 print int2roman(123), "\n";
18 my $roman = "XXXV";
20 print roman2int($roman), "\n" if isroman($roman);
21 my $milhar = 'L_X_XXIII'; # = 60,023
23 print milhar2int($milhar), "\n" if ismilhar($milhar);
24
26 This package supports both conventional Roman algarisms (which range
27 from 1 to 3999) and Milhar Romans, a variation which uses a bar across
28 the algarism to indicate multiplication by 1_000. For the purposes of
29 this module, acceptable syntax consists of an underscore suffixed to
30 the algarism e.g. IV_V = 4_005. The term Milhar apparently derives
31 from the Portuguese word for "thousands" and the range of this notation
32 extends the range of Roman numbers to 3999 * 1000 + 3999 = 4_002_999.
33 Note: the functions in this package treat Roman algarisms in a case-
35 insensitive manner such that "VI" == "vI" == "Vi" == "vi".
36 The following functions may be imported into the caller package by
38 name:
39
41 isroman
42 Tests a string to be a valid Roman algarism. Returns a boolean value.
43 int2roman
45 Converts an integer expressed in Arabic numerals, to its corresponding
46 Roman algarism. If the integer provided is out of the range
47 expressible in Roman notation, an undef is returned.
48 roman2int
50 Does the converse of "int2roman", converting a Roman algarism to its
51 integer value.
52 ismilhar
54 Determines whether a string qualifies as a Milhar Roman algarism.
55 milhar2int
57 Converts a Milhar Roman algarism to an integer.
58 ismroman/mroman2int/roman
60 These functions belong to the module's old interface and are considered
61 deprecated. Do not use them in new code and they will eventually be
62 discontinued; they map as follows:
63 • ismroman => ismilhar
65 • mroman2int => milhar2int
67 • roman => int2roman
69
71 Some changes worth noting from this module's previous incarnation:
72 namespace imports
74 The call to use must now explicitly request function names imported
75 into it's namespace.
76 argument defaults/void context
78 All functions now will operate on $_ when no arguments are passed,
79 and will set $_ when called in a void context. This allows for
80 writing code like:
81 @x = qw/V III XI IV/;
83 roman2int() for @x;
84 print join("-", @x);
85 instead of the uglier:
87 @x = qw/V III XI IV/;
89 $_ = roman2int($_) for @x;
90 print join("-", @x);
91
93 Roman algarisms may be described using the following BNF-like formula:
94 a = I{1,3}
96 b = V\a?|IV|\a
97 e = X{1,3}\b?|X{0,3}IX|\b
98 ee = IX|\b
99 f = L\e?|XL\ee?|\e
100 g = C{1,3}\f?|C{0,3}XC\ee?|\f
101 gg = XC\ee?|\f
102 h = D\g?|CD\gg?|\g
103 j = M{1,3}\h?|M{0,3}CM\gg?|\h
104
106 For a description of the Roman numeral system see:
107 <http://www.novaroma.org/via_romana/numbers.html>. A reference to
108 Milhar Roman alagarisms (in Portuguese) may be found at:
109 <http://web.archive.org/web/20020819094718/http://www.estado.com.br/redac/norn-nro.html>.
110
112 This module was originally written by Peter de Padua Krauss and
113 submitted to CPAN by Stanislaw Pusep <https://metacpan.org/author/SYP>
114 who has relinquished control to Erick Calder
115 <https://metacpan.org/author/ECALDER> since the original author has
116 never maintained it and can no longer be reached.
117 Erick have completely rewritten the module, implementing simpler
119 algorithms to perform the same functionality, adding a test suite, a
120 Changes file, etc. and providing more comprehensive documentation.
121 Ten years later, Stanislaw returned as a maintainer.
123
125 Stanislaw Pusep <stas@sysd.org>
126
128 This software is copyright (c) 2003 by Erick Calder <ecalder@cpan.org>.
129 This is free software; you can redistribute it and/or modify it under
131 the same terms as the Perl 5 programming language system itself.
132perl v5.38.0 2023-07-21 Text::Roman(3)