https://github.com/brendanator/jsforth

Forth implemented in js
https://github.com/brendanator/jsforth

forth

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Forth implemented in js

• Host: GitHub
• URL: https://github.com/brendanator/jsforth
• Owner: brendanator
• Created: 2016-02-11T15:45:53.000Z (almost 9 years ago)
• Default Branch: gh-pages
• Last Pushed: 2018-01-17T14:30:41.000Z (almost 7 years ago)
• Last Synced: 2024-11-01T02:21:38.103Z (13 days ago)
• Topics: forth
• Language: JavaScript
• Homepage: http://brendanator.github.io/jsForth/
• Size: 817 KB
• Stars: 84
• Watchers: 8
• Forks: 19
• Open Issues: 2
• Metadata Files:
  • Readme: readme.md

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README

        
## jsForth

An implementation of [Forth](https://en.wikipedia.org/wiki/Forth_(programming_language)) in JavaScript

Try it out [here](https://brendanator.github.io/jsForth/) 

### ANS Forth

jsForth implements the full core ANS standard

The following word sets are implemented:

- Core words - fully implemented

    - All tests pass except some integer multiplication/division edge cases where the ANS spec differs from the results given by the [long](https://github.com/dcodeIO/long.js) package

- Core plus words - fully implemented and all tests pass

- Core extension words - fully implemented and all tests pass

The ANS Forth tests can be run using `npm run test` or in the intepreter with the following Forth code

```

include test/verbose-tester.fth

include https://raw.githubusercontent.com/gerryjackson/forth2012-test-suite/master/src/core.fr

```

The complete test suite is available [here](https://github.com/gerryjackson/forth2012-test-suite/)

### JavaScript interoperability

- global variable access   `js /document`

- array access             `js .0.2`

- property access          `js .name`

- property setting         `js .name!`

- function calling         `js .sin{1}`

- method calling           `js /document.getElementById{1}`

- new with params          `js .new{1}`

### Threading model - trampolined threading

All of the standard [threading models](https://en.wikipedia.org/wiki/Threaded_code#Threading_models) require `call` or `jump` to execute the next instruction. In JavaScript these both translate into functions calls in tail position. Without tail call optimisation this will lead to a stack overflow. Therefore jsForth uses a trampoline to execute instructions.

ECMAScript 6 specifies tail call optimisation, but unfortunately most [browsers don't support it yet](https://kangax.github.io/compat-table/es6/).