Brainfuck

This is an implementation of a basic brainfuck interpreter written in Elm.

Commands

The brainfuck language consists of the following eight commands:

• > increments the data pointer
• < decrements the data pointer
• + increments the byte at the data pointer
• - decrements the byte at the data pointer
• . outputs the byte at the data pointer
• , prompts the user for a one byte input
• [ jumps to the next ] if the byte at the data pointer is zero
• ] jumps to the previous [ if the byte at the data pointer is nonzero

Installation

An online demo can be found here: https://www.dragonwasrobot.com/brainfuck/

Ensure you have Elm 0.19.1 installed. I personally recommend using asdf, https://github.com/asdf-vm/asdf, to handle version management of compilers.

With Elm installed, perform the following steps:

• Run the command ./build.sh to compile the source, then
• open docs/index.html in your favorite browser.

Development loop

$ npm run css-watch
$ npm run compile-watch
$ npm run test-watch
# npm run local-server

• css-watch: tailwindcli tool for spotting changes to CSS classes.
• compile-watch: elm-watch recompiling on code change.
• test-watch: elm-test re-running test suite on code change.
• local-server: python3 HTTP server to support serving BF source files.

Inspiration

• The look and feel of the UI is adapted from the 70's technical documentation inspired mock-ups at https://usgraphics.com/products/berkeley-mono
• Most of the example brainfuck programs are from https://brainfuck.org/ and authored by Daniel B Cristofani.