Gerbil Loader: Use gxc and gsc load Gerbil to JavaScript

The gerbil-loader package makes it easy to load a gerbil file into a JavaScript runtime.

The gerbil-scheme package is based off of Gerbil, a scheme written in itself that compiles to Gambit Scheme.

The gerbil-scheme UMD library allows many different uses of that runtime and will at some point allow loading of gerbil modules.

Installation

Easy! I choose yarn, but npm also works.

yarn add gerbil-loader --dev
yarn add gerbil-scheme

Documentation

For details see the repo, man! https://github.com/drewc/gxjs

Usage

Let’s have a scheme file that uses a few js features.

Here is gambit-scheme-usage.ss.

(import :js)

(js#declaration "console.log('started gerbil scheme!')")

(def (this-is-gerbil!! (val 42))
  (js#statement "console.log('This is GxJS!', (@1@), (@2@))"
                val
                (js#expression "{ foo: 'bar' };")))

(js#statement "console.log('finished gerbil scheme init');
 module.exports = RTS.scm2host(@1@);" this-is-gerbil!!)

To load an .ss file, gerbil-loader is the easy way. The options are the same as gxjs-loader.

Now for a JavaScript file, gerbil-scheme-usage.js. We’ll make this a CommonJS module.

We do not actually need to require('gerbil-scheme') here at all and we export the RTS is exported pretty much so we can see just that. Just wait :)

const RTS = require('gerbil-scheme');

const thisIsGerbil = require('gerbil-loader!./gerbil-scheme-usage.ss');

thisIsGerbil('*');

module.exports = RTS;

That outputs this to the console. As you can see the function automagically converts the string into a Gerbil/Gambit string, but this is the JavaScript output.

started gerbil scheme!
finished gerbil scheme init
This is GxJS! { codes: [ 42 ] } { foo: 'bar' }

By default gerbil-loader automagically requires gerbil-scheme by prepending const RTS = require('gerbil-scheme'); to the top of the “file”.

The RTS.glo is the symbol table.

(import :js)
(js#declaration #<<EOF
console.log('Ok, auto RTS!', Object.keys(RTS.glo).length)

module.exports = RTS;

EOF
)

Now we’ll use that in a js module. This time around es6.

import RTS from './gerbil-scheme-usage.js'
import sameRTS from 'gerbil-loader!./gerbil-scheme-auto.ss';

console.log('Same Runtime?', RTS === sameRTS);

That outputs the following.

started gerbil scheme!
finished gerbil scheme init
This is GxJS! { codes: [ 42 ] } { foo: 'bar' }
Ok, auto RTS! 165
Same Runtime? true

So we just need to use gerbil-loader and have gerbil-scheme as a dependency and there you go.

Support

Go to https://github.com/drewc/gxjs/issues or contact the author.