The compiler of the programming language Shem
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Shem is a new compiled-to-JS, statically typed, pure-by-default functional programming language. The semantics are based on Haskell but the language evaluates strictly in a similar way to PureScript. The syntax is S-expressions-based, allowing for a full-blown LISP-like macro system. Shem's prelude includes a full-featured, highly-polymorphic collections library backed by ImmutableJS.

The language has been designed for the use within its custom built IDE, Golem available at, inspired by Bret Victor.

A screenshot of the Golem IDE showing the source and debugging of a binary search function

A screenshot of the Golem IDE with a running animation

Here Be Lions

Use without Golem

Clone this repo, go to the folder, then

npm install
npm run build

To run a single file

echo '_ (.log (global "console") "Hello world!")' > test.shem
bin/shem test.shem

To compile a single file to JavaScript

bin/shem -c test.shem

To run a module

mkdir test-modules
echo 'message "Hello, hello, world!"' > test-modules/Hello.shem
echo '[message] (req ./Hello) _ (.log (global "console") message)' > test-modules/index.shem
bin/shem test-modules

To compile a module

bin/shem -o test-modules-out-dir -c test-modules

Demo (for now)

I am providing code in this repository to you under an open source license. Because this is my personal repository, the license you receive to my code is from me and not from my employer (Facebook).