LunarML

The Standard ML compiler that produces Lua/JavaScript.

The documentation is available at https://lunarml.readthedocs.io/en/latest/.

Trying pre-built binaries

Docker image is available.

$ docker pull ghcr.io/minoki/lunarml:latest
$ docker run --rm --platform linux/amd64 -v "$(pwd)":/work -w /work ghcr.io/minoki/lunarml:latest lunarml compile example/hello.sml
$ lua example/hello.lua
Hello world!

In case you do not want to use Docker, there are precompiled scripts available in the tarball. You can use install-precompiled-lua target to install lunarml.lua which can be run with Lua 5.3/5.4 and LuaFileSystem.

$ make install-precompiled-lua PREFIX=/opt/lunarml
$ export PATH=/opt/lunarml/bin:$PATH
$ lunarml compile example/hello.sml

You can use install-precompiled-node target to install lunarml.mjs to be run with Node.js.

$ make install-precompiled-node PREFIX=/opt/lunarml
$ export PATH=/opt/lunarml/bin:$PATH
$ lunarml compile example/hello.sml

Warning: Script-compiled LunarML is slow. Use native binary for serious use.

Building and Installing

You need a recent version of MLton to build the executable, and Lua 5.3+ or recent Node.js to run the compiled script.

$ make
$ make test-lua
$ make test-lua-continuations
$ make test-luajit
$ make test-nodejs
$ make test-nodejs-cps
$ bin/lunarml compile example/hello.sml
$ lua example/hello.lua
Hello world!

You can install the built binary with make install:

$ make install PREFIX=/opt/lunarml
$ export PATH="/opt/lunarml/bin:$PATH"
$ lunarml compile example/hello.sml

Alternatively, you can use Docker to build and run LunarML.

$ docker build --platform linux/amd64 -f package/docker/Dockerfile -t lunarml:0.2.1 .
$ docker run --rm -v "$(pwd)":/work -w /work --platform linux/amd64 lunarml:0.2.1 lunarml compile example/hello.sml
$ lua example/hello.lua
Hello world!

Usage

lunarml compile [options] input.(sml|mlb)

Subcommands:

• compile: Compile a program.
• help: Show help.
• version: Show version information.

Targets:

• Lua
  • --lua (default): Targets Lua 5.3+.
  • --lua-continuations: Targets Lua 5.3+. Supports one-shot delimited continuations. Also, supports deeply nested handle.
  • --luajit: Targets LuaJIT.
• JavaScript (ES2020+)
  • --nodejs: Produces a JavaScript program for Node.js. The default extension is .mjs.
  • --nodejs-cps: Produces a JavaScript program for Node.js (CPS mode; supports delimited continuations). The default extension is .mjs.

Output type:

• --exe (default): Produces Lua/JavaScript program.
• --lib: Produces a Lua/JavaScript module.

Features

• Full SML '97 language, including signatures and functors
  • Note that some features conform to Successor ML rather than SML '97.
• Successor ML features
• Other language extensions
• A subset of SML Basis Library
• ML Basis system for multi-file project
• Interface to Lua
• Interface to JavaScript
• Delimited continuations
• Other libraries