LunarML

A Standard ML compiler that produces Lua.

Building

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

$ make
$ make test
$ ./lunarml example/hello.sml
$ lua example/hello.lua
Hello world!

Features

• Most of SML '97 language, including signatures and functors
• A subset of SML Basis Library
• Interface to Lua
• ML Basis system like MLton

Successor ML features:

• Monomorphic non-exhaustive bindings
• Simplified recursive value bindings
  • SML '97-compatible ordering for type variables is also supported: val <tyvarseq> rec <valbind>
• Abstype as derived form
• Fixed manifest type specifications
• Abolish sequenced type realizations
• Line comments
• Extended literal syntax
• Record punning
• Record extension
  • in patterns
  • in expressions
  • in types
• Record update
• Conjunctive patterns
• Nested matches
• Pattern guards
• Optional bars and semicolons
• Optional else branch
• Do declarations
• Withtype in signatures

Other extensions planned:

• Vector expressions and patterns
• Packaged modules (like in Alice ML or HaMLet S)
• Hexadecimal floating-point literals
• Variably-encoded Unicode escape sequence in string literals