Paket: erlang-luerl (1:1.0-2)

implementation of Lua in Erlang

An experimental implementation of Lua 5.2 written solely in pure Erlang

When to use Luerl:

Fast Language Switch: Luerl should allow you to switch between Erlang and Lua incredibly fast, introducing a way to use very small bits of logic programmed in Lua, inside an Erlang application, with good performance.

Multicore: Luerl provides a way to transparently utilize multicores. The underlying Erlang VM takes care of the distribution.

Microprocesses: It should give you a Lua environment that allows you to effortlessly run tens of thousands of Lua processes in parallel, leveraging the famed microprocesses implementation of the Erlang VM. The empty Luerl State footprint will be yet smaller than the C Lua State footprint.

Forking Up: Because of the immutable nature of the Luerl VM, it becomes a natural operation to use the same Lua State as a starting point for multiple parallel calculations.

However, Luerl will generally run slower than a reasonable native Lua implementation. This is mainly due the emulation of mutable data on top of an immutable world. There is really no way around this. An alternative would be to implement a special Lua memory outside of the normal Erlang, but this would defeat the purpose of Luerl. It would instead be then more logical to connect to a native Lua.

Some valid use cases for Luerl are:

 * Lua code will be run only occasionally and it wouldn't be worth managing
   an extra language implementation in the application;
 * the Lua code chunks are small so the slower speed is weighed up by Luerl's
   faster interface;
 * the Lua code calculates and reads variables more than changing them;
 * the same Lua State is repeatedly used to 'fork up' as a basis for
   massively many parallel calculations, based on the same state;
 * it is easy to run multiple instances of Luerl which could better utilise
   multicores.