Rembulan

(Rembulan is Javanese/Indonesian for Moon.)

An implementation of Lua 5.3 for the Java Virtual Machine (JVM). Implements coroutines using continuations rather than mapping them onto Java threads.

The goal of the Rembulan project is to develop a scalable, correct, complete and performant implementation for untrusted Lua code on the JVM.

Feature list

• Full Lua 5.3 semantics -- Rembulan implements Lua 5.3 as specified by the Lua Reference Manual, explicitly attempting to mimic the behaviour of PUC-Lua whenever possible. This includes language-level features (such as metamethods and coroutines) and the standard library.

• Compiled, not interpreted -- Rembulan is a compiler and a runtime for Lua. Lua functions are compiled into Java classes and loaded by the JVM.

• Basic static type checking -- The Rembulan compiler performs a type analysis of the Lua programs in order to generate a more tightly-typed code whenever feasible. More type information means fewer run-time checks, leading to faster execution.

• Scalable coroutines -- Coroutines are decoupled from (Java) threads. On coroutine switches and interrupts, Rembulan stores the call stack, and recreates it on resume.

Project structure

This is a multi-module Maven project, containing the following modules:

• rembulan-lua-common ... common Lua utilities and constants
• rembulan-core ... the runtime and the standard library
• rembulan-parser ... parser for Lua 5.3, producing a (de-sugared) AST
• rembulan-compiler ... Lua-to-Java bytecode compiler
• rembulan-lbc ... PUC-Lua bytecode utilities
• rembulan-lbc-recompiler ... recompiler from PUC-Lua bytecode to Java bytecode (obsolete)
• rembulan-tests ... the project test suite, including benchmarks from the Benchmarks Game
• rembulan-benchmarks ... micro-benchmarks used for selecting the implementation strategy (obsolete)