IVXL

convert integers to roman numerals and vice versa

Usage

Integers from 1 to 4999 and their Roman Numeral ASCII string representation are supported.

import { roman } from "ivxl"

roman("IX") // -> 9
roman(420) // -> "CDXX"
roman("CDXX") // -> 420
roman(4999) // -> "MMMMCMXCIX"
roman("MMMMCMXCIX") // -> 4999

roman("4Twenty") // -> ""
roman(42.2) // -> ""
roman(0) // -> ""
roman(5000) // -> ""
roman("IVXL") // -> ""

Install

pnpm add ivxl

# or with bun
bun add ivxl

API

roman

roman :: (number | string) -> (number | string)

Given a valid ASCII Roman Numeral string, returns an integer between 1 and 4999. Given a valid integer between 1 and 4999, returns an ASCII Roman Numeral string. Given an invalid input returns an empty string.

import { roman } from "ivxl"

roman("XIV") // -> 14
roman(14) // -> "XIV"
roman(14).toLowerCase() // -> "xiv"
roman("42") // -> "XLII"
roman("666") // -> "DCLXVI"
roman(-99) // -> ""

numberToRoman

numberToRoman :: number -> string

Given an integer between 1 and 4999, returns an ASCII Roman Numeral string. Everything else returns an empty string. The input type is more strict than the roman funtion's types.

import { numberToRoman } from "ivxl"

numberToRoman(42) // -> "XLII"
numberToRoman(-42) // -> ""
numberToRoman("42") // -> ""
numberToRoman(42.2) // -> ""

romanToNumber

romanToNumber :: string -> number

Given a valid ASCII Roman Numeral string, returns an integer between 1 and 4999. Everything else returns 0.

import { romanToNumber } from "ivxl"

romanToNumber("XXVI") // -> 26
romanToNumber("xxvi") // -> 26
romanToNumber("IVXL") // -> 0

romanToUnicode

romanToUnicode :: string -> string

Given an ASCII string, returns a string with the Roman Numeral characters replaced by their Unicode counterparts. No validity checks are performed.

I -> Ⅰ
V -> Ⅴ
X -> Ⅹ
L -> Ⅼ
C -> Ⅽ
D -> Ⅾ
M -> Ⅿ

import { romanToUnicode } from "ivxl"

romanToUnicode("XXVI") // -> "ⅩⅩⅤⅠ"
romanToUnicode("xxvi") // -> "ⅩⅩⅤⅠ"
romanToUnicode("IVXL") // -> "ⅠⅤⅩⅬ"
romanToUnicode("0U812 IVXL") // -> "0U812 ⅠⅤⅩⅬ"