joy-js

A JavaScript interpreter for the Joy programming language.

Work in progress

Todo

• Lexer
• Parser
• Interpreter (in progress)
  • Operand words defined (Skipped: conts, undefs, clock, stdin, stdout, stderr)
  • Operator words defined (Skipped: frexp, strftime, srand, fclose, feof, ferror, fflush, fgetch, fgets, fopen, fread, fwrite, fremove, frename, fput, fputch, fputchars, fputstring, fseek, ftell, opcase, case, name; partial functionality: format, formatf)
  • Predicate words defined (Skipped: user, file)
  • Combinator words defined
  • "Miscellaneous" words defined
• Demo site (simple site available, must run locally)
  • Basic site
  • Make responsive
  • Publish to GitHub pages
  • Syntax-highlighted editor
  • Add output options
  • Joy tutorial or similar?
• REPL

How to run

The interpreter may be run locally via the Node repl, or via a local express server.

Node.js repl:

$ node
> Joy = require('./src/joy/joy')
> Joy.run('19 23 + .')
'42'
>

Dev server:

$ npm install
$ npm start

Motivation

This project started after the following tweet by @lorentzframe popped into my Twitter timeline:

"SICP" by Abelson & Sussman should be read continuously, ~2 pages a day, returning to page 1 every year. Ditto "Thinking Forth" by Leo Brodie, tho' only ~1 page a day. The former teaches how to think, the latter how to engineer. Both are in unpopular languages, on purpose.'"

I own SICP, and while the suggestion of re-reading it yearly strikes me as a tad extreme, I do think the content is great. "Thinking Forth" on the other hand was completely new to me. Within a few days time I had found myself combing through content on Forth on the web, as well as related, concatenative / stack-based languages, including Joy. In that search, I stumbled on this online Forth interpreter written in JavaScript, and immediately fell in love with the idea. I wanted to do something similar. Joy looked like a good target, as there is little in the way of actual working implementations, and the syntax and surface area are relatively small. Thus, joy-js was born.

License

MIT