April 1, 2012

[updated] Functional programming language for C programmers and friends

Just for you:

module main {
    import std (range);
    import std.io (printf, IO);
    /* print the Fahrenheit-Celcius table
        for fahr = 0, 20, ..., 300 */
    function main(mutable IO io) {
        Int lower = 0;   // lower bound
        Int upper = 300; // upper bound
        Int step = 20;   // step
        for (Int fahr in range(lower, upper, step)) {
            Double celcius = 5 * (fahr - 32) / 9;
            std.io.printf(io, "%3d\t%6.1f\n", fahr, celcius);

It does not really look like it, but this language is purely functional. It represents side effects using unique types. If you declare a mutable parameter, you basically declare a unique input parameter and a unique output parameter.

I’m also giving you a list implementation

module std.container.list {

    /** The standard singly-linked list type */
    type List[E] {
        Nil;                    /** empty list */
        Node {
            E value;            /** current value */
            List[E] next;       /** remaining list */

Thus are only excerpts from a document with tens of pages and the reference implementation of the standard library. The incomplete working draft for the language is attached: JAK Programming Language Early Working Draft (28 pages).

Update: Fixed the link.

Reactions from Mastodon

Copyright © 2018-2020 Julian Andres Klode, articles licensed under CC BY-SA 4.0.
Comments are provided by Mastodon and copyright of their authors.

This website does not store any personally identifiable information. As part of standard web server access_log logging, it stores requests and the user agents and shortened IP addresses used to make them. It does, however, load some avatars from mastodon.

Powered by Hugo, and the Ernest theme.