Powerlang

This is Powerlang, a research vehicle to explore implementations of programming languages. While focused on Smalltalk, it aims to be a generic language creation toolkit, something you can use to either evolve Smalltalk, or otherwise build a new language implementation of choice. In this repo we provide tools for bootstrapping a Smalltalk image from specs (files in a pseudo-tonel format). Originally thought as a native-only project, now we also support things like running on top of JavaScript engines. Tools for specific platforms can be found on other related repos.

For example, for running on a native platform you have lmr-cpp which contains a launcher written in C++ and debug scripts. In powerlang/powerlang-js you'll find the things needed to run a Smalltalk image on top of JavaScript.

Bee Smalltalk served as a reference implementation using the framework. We are implementing an evolution of the classic Smalltalk-80. Something adapted to the new kinds of systems that are common these days: from embedded to servers, with or without a gui, supporting local and remote development. Visit Powerlang docs for documentation and our blog for the latest news.

Building

Note: following is tested by CI on Linux, for Windows, please refer to section "Building launcher for Windows" at the end.

After cloning the repo, run make to create a pharo bootstrap image. This image will contain all the tools you need to generate your new image.

git clone [email protected]:powerlang/powerlang.git

Also you will need the sources of your language, that have to be placed in specs/<your lang>. Lets say you want to bootstrap Bee Smalltalk:

git clone [email protected]:powerlang/bee-dmr.git specs/bee-dmr
echo "bee-dmr" >specs/current

Now, just do make:

make

This will genereate bootstrap.image, a Pharo image with the code needed to bootstrap your own Smalltalk image. You can just open it and look for Powerlang-* packages, and run tests. Not that this looks like much at the moment, which bring us to:

Development

...in Pharo

To open Powerlang Pharo development image:

cd bootstrap
./pharo-ui bootstrap.image

All Powerlang code is in packages named Powerlang-*. Have fun!

...in Smalltalk/X

Please refer to README_STX.md for instructions how to load Powerlang into Smalltalk/X jv-branch

How it works

The bootstrapper loads class and method definitions from files into a kind of spec objects. The library used for that is called Ring2. With the class specs, the bootstrapper generates a simulated image which contains all the objects needed to give life to the spec.

After the virtual image is generated, powerlang allows sending messages to the virtual objects. To do that, powerlang includes an evaluator (actually, there are a few) that reads the compiled methods and interprets them. The idea is that you normally tell the virtual image to generate an image file for your desired target platform.

For example, to generate a JavaScript kernel image (which is written in JSON format) you would do:

| bootstrapper module runtime filename |
bootstrapper := PowertalkRingImage fromSpec wordSize: 8; genesis; bootstrap; fillClasses; fillSymbols; generateLMR.
module := bootstrapper loadBootstrapModule.
runtime := bootstrapper result.
filename := runtime newString: 'kernel.json'.
runtime sendLocal: #writeJsonKernelTo: to: module with: {filename}"