View source for Module:Roman/doc

__NOTOC__
{{lua|Module:Arguments}}

== Summary ==
This module contains functions for working with Roman numerals. Currently used by:
* {{tl|Roman}}
* {{tl|Roman-to-Arabic}}
* [[Module:Recto-verso]]

Imported from [[commons:Module:Roman]].

== Using this module from templates ==

=== Numeral ===

This function converts an Arabic numeral into a Roman numeral. It works for values between 0 (N) and 4999999999 (M̿M̿M̿M̿C̿M̿X̿C̿I̿X̿C̅M̅X̅C̅I̅X̅CMXCIX): this includes the whole range of unsigned 32-bit integers. The output string no longer contain HTML tags. If needed you can add external CSS formatting using a serif font family, or a small-caps font variant. Arabic numeral zero is output as 'N' (for Classical Latin adverbs "Nec" or "non"), like in standard CLDR Data.

If the input does not look like it contains a number or the number is outside of the supported range, an error message is returned. If an error message is returned, the error message will contain code to categorize pages into [[:Category:Errors reported by Module Roman]].

Usage:
<syntaxhighlight lang="wikitext">{{#invoke:Roman|Numeral|''value''}}</syntaxhighlight>

Example:
<syntaxhighlight lang="wikitext" inline="yes">{{#invoke:Roman|Numeral|8}}</syntaxhighlight> produces {{#invoke:Roman|Numeral|8}}.

<section begin="toarabic" />
=== Arabic ===

This function converts a Roman numeral into an Arabic numeral. It works for values between 0 (N) and 4999999999 (M̿M̿M̿M̿C̿M̿X̿C̿I̿X̿C̅M̅X̅C̅I̅X̅CMXCIX): this includes the whole range of unsigned 32-bit integers.

If the input does not look like it contains a number or the number is outside of the supported range, an error message is returned. If an error message is returned, the error message will contain code to categorize pages into [[:Category:Errors reported by Module Roman]].

Usage:
<syntaxhighlight lang="wikitext">{{#invoke:Roman|Arabic|''value''}}</syntaxhighlight>

Example:
<syntaxhighlight lang="wikitext" inline="yes">{{#invoke:Roman|Arabic|viii}}</syntaxhighlight> produces {{#invoke:Roman|Arabic|viii}}.

== Using this module from Lua code ==

In order to use the functions in this module from another Lua module you first have to import this module.

Example:
<syntaxhighlight lang="lua">local roman = require('Module:Roman')</syntaxhighlight>

=== _Numeral ===

This function converts an Arabic numeral into a Roman numeral. It works for values between 0 and 4999999. The output string may contain HTML tags. Arabic numeral zero is output as an empty string. If the input does not look like it contains a number or the number is outside of the supported range an error message is returned. If an error message is returned, the error message will contain code to categorize pages into [[:Category:Errors reported by Module Roman]].

Usage:
<syntaxhighlight lang="lua">roman_value = roman._Numeral(value)</syntaxhighlight>
<section end="toarabic" />
=== isRoman ===

Tests if the input is a valid Roman numeral. Returns true if so, false if not. For the purposes of this function, the empty string is not a valid Roman numeral.

Usage:
<syntaxhighlight lang="lua">if roman.isRoman(roman_value) then</syntaxhighlight>


=== toArabic ===

This function converts a Roman numeral into an Arabic numeral. It works for values between 0 and 4999999999. The string 'N' is converted to zero. If the input is not a valid Roman numeral this function attempts to parse it as an Arabic number and returns nil if it also fails.

Usage:
<syntaxhighlight lang="lua">arabic_value = roman.toArabic(value)</syntaxhighlight>