https://github.com/lindig/roman

OCaml module and command line tool to convert a roman numeral to an integer and vice versa
https://github.com/lindig/roman

Last synced: 4 days ago
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OCaml module and command line tool to convert a roman numeral to an integer and vice versa

• Host: GitHub
• URL: https://github.com/lindig/roman
• Owner: lindig
• License: bsd-2-clause
• Created: 2015-05-02T07:13:50.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-05-14T19:14:20.000Z (over 9 years ago)
• Last Synced: 2023-03-25T00:24:19.271Z (over 1 year ago)
• Language: OCaml
• Homepage:
• Size: 180 KB
• Stars: 4
• Watchers: 3
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        

# Roman - convert roman numerals to integer

This repository provides an OCaml module and minimal command line tool to

convert modern roman numerals to integer and vice versa:

    $ roman mmxv

    2015

    $ roman 1234

    mccxxxiv

The command line tool recognizes integer and roman numerals and emits it

after conversion to the opposite format.

The module accepts the syntax for [modern roman

numerals](http://en.wikipedia.org/wiki/Roman_numerals) as defined by

Wikipedia and detects illegal syntax like the following:

    im 

    xcc  

    ic

    imm

    mxm

    viiii

    ivi

This little exercise was prompted by an article [Radikale

Objektorientierung: Teil 2: Verhalten prinzipiengeleitet

verfeinern](http://www.sigs-datacom.de/fachzeitschriften/objektspektrum) in

OBJEKTspektrum issue 2/12015 that used conversion of roman numerals as an

example for OO design. The [code from that article is available on

GitHub](https://github.com/ralfw/TheArchitectsNapkinBlog).

# Build and Test

    $ make

    $ make test

    $ make PREFIX=$(HOME) install 

The implementation is in `roman.mll` and uses ocamllex to build an

automaton for recognising roman numerals. To use as a module, simply copy

`roman.mll` and `roman.mli` into your own project. (I didn't bother yet to

pack it up for Opam.)

# Syntax

For the syntax of roman numerals recognised by the module, take a look at

`roman.mll` where it is encoded as a regular expression:

    (M|MM|MMM)?

    (D?(C|CC|CCC)?|CD|CM)?

    (L?(X|XX|XXX)?|XL|XC)?

    (V?(I|II|III)?|IV|IX)?

# Author

Christian Lindig 

# License

This code is licensed under the BSD 2-clause license.