Thun

A Dialect of Joy.

Version 0.5.0

Simple pleasures are the best.

Joy is a programming language created by Manfred von Thun that is easy to use and understand and has many other nice properties. Thun is a dialect of Joy that attempts to stay very close to the spirit of Joy but does not precisely match the behaviour of the original version written in C. It started as a Python project called "Joypy", but after someone claimed that name on PyPI before me I renamed it to Thun in honor of Manfred Von Thun. Now there are interpreters implemented in several additional languages (C, Elm, Nim, OCaml, Prolog, and Scheme).

Joy is:

• Purely Functional
• Stack-based
• Concatinative (See also concatenative.org)
• Categorical

The best source for learning about Joy is the information made available at the website of La Trobe University | (mirror) which contains source code for the original C interpreter, Joy language source code for various functions, and a great deal of fascinating material mostly written by Von Thun on Joy and its deeper facets as well as how to program in it and several interesting aspects. It's quite a treasure trove.

• Wikipedia entry for Joy
• Homepage at La Trobe University (Kevin Albrecht's mirror)
• The original Thun/Joypy site

Example Code

Here is an example of Joy code. This function square_spiral accepts two integers and increments or decrements one of them such that the new pair of numbers is the next coordinate pair in a square spiral (like the kind used to construct an Ulam Spiral). For more information see Square Spiral Example Joy Code.

square_spiral [_p] [_then] [_else] ifte

_p  [_p0] [_p1] and
_p0 [abs] ii <=
_p1 [<>] [pop !-] or

_then [    !-] [[++]] [[--]] ifte dip
_else [pop !-]  [--]   [++]  ifte

It might seem unreadable but with familiarity it becomes as legible as any other notation.

Project Hosted on SourceHut

• Source Repository (mirror)
• Bug tracker (old tracker)
• Forums
• Mailing list

Documentation

The Thun.md document describes the Thun dialect. Most of the rest of documentation is in the form of Jupyter Notebooks that go into more detail.

Jupyter Notebooks

I had a Joy kernel for the Jupyter Notebook system, but I can no longer figure out how to use it, so I'm rewriting the notebooks by hand.

There's also a Function Reference that lists each function and combinator by name and gives a brief description. (It's usually out of date, I'm working on it.)

Function Reference

There is more in the docs directory but it's kind of a mess right now (Aug 2023).

Directory structure

Thun
|-- LICENSE - GPLv3
|-- README.md - this file
|
|-- archive
|   |-- Joy-Programming.zip
|   `-- README
|
|-- docs
|   |-- dep-graphs - Generated dependency graphs.
|   |-- html - Generated HTML docs.
|   |-- notebooks - Jupyter Notebooks and supporting modules
|   `-- reference - Docs for each function.
|
|-- implementations
|   |-- defs.txt - common Joy definitions for all interpreters
|   |-- C - interpreter
|   |-- GNU Prolog - type inference
|   |-- Elm - interpreter
|   |-- Nim - interpreter
|   |-- Ocaml - work-in-progress interpreter
|   |-- Python - interpreter
|   |-- Scheme - interpreter
|   `-- SWI Prolog - interpreter
|                    type inference
|                    work-in-progress compiler
|
`-- joy_code - Source code written in Joy.
    `-- bigints
        `-- bigints.joy

Installation

Clone the repo:

git clone https://git.sr.ht/~sforman/Thun

Then follow the instructions in the individual implementations directories. In most cases you can just run make and that will build a binary called joy (in Python it's a script.)

There isn't really any installation as such. You can put the binaries in your PATH.

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Copyright © 2014 - 2023 Simon Forman

This file is part of Thun