rufus-lua

Lua embedded in Ruby, via Ruby FFI

Lua

www.lua.org/about.html says :

“”“ Lua is a powerful, fast, lightweight, embeddable scripting language.

Lua combines simple procedural syntax with powerful data description constructs based on associative arrays and extensible semantics. Lua is dynamically typed, runs by interpreting bytecode for a register-based virtual machine, and has automatic memory management with incremental garbage collection, making it ideal for configuration, scripting, and rapid prototyping. “”“

www.lua.org/

other Ruby and Lua bridges / connectors

rubyluabridge.rubyforge.org/ raa.ruby-lang.org/project/ruby-lua

using rufus-lua

If you don’t have liblua.dylib on your system, scroll until “compiling liblua.dylib” to learn how to get it.

sudo gem install rufus-lua

then

require 'rubygems'
require 'rufus/lua'

s = Rufus::Lua::State.new

puts s.eval("return table.concat({ 'hello', 'from', 'Lua' }, ' ')")
  #
  # => "Hello from Lua"

s.close

binding Ruby code as Lua functions

require 'rubygems'
require 'rufus/lua'

s = Rufus::Lua::State.new

s.function 'key_up' do |table|
  table.inject({}) do |h, (k, v)|
    h[k.to_s.upcase] = v
  end
end

p s.eval(%{
  local table = { CoW = 2, pigs = 3, DUCKS = 'none' }
  return key_up(table) -- calling Ruby from Lua...
}).to_h
  # => { 'COW' => 2.0, 'DUCKS => 'none', 'PIGS' => 3.0 }

s.close

It’s OK to bind a function inside of a table (library) :

require 'rubygems'
require 'rufus/lua'

s = Rufus::Lua::State.new

s.eval("rubies = {}")
s.function 'add' do |x, y|
  x + y
end

s.eval("rubies.add(1, 2)")
  # => 3.0

s.close

You can omit the table definition (only 1 level allowed here though) :

require 'rubygems'
require 'rufus/lua'

s = Rufus::Lua::State.new

s.function 'rubies.add' do |x, y|
  x + y
end

s.eval("rubies.add(1, 2)")
  # => 3.0

s.close

The specs contain more examples :

github.com/jmettraux/rufus-lua/tree/master/spec/

rufus-lua’s rdoc is at :

rufus.rubyforge.org/rufus-lua/

compiling liblua.dylib

original instructions by Adrian Perez at :

lua-users.org/lists/lua-l/2006-09/msg00894.html

get the source at

www.lua.org/ftp/lua-5.1.4.tar.gz

then

tar xzvf lua-5.1.4.tar.gz
cd lua-5.1.4

modify the file src/Makefile as per lua-users.org/lists/lua-l/2006-09/msg00894.html

make 
make macosx # or make linux ...
make -C src liblua.dylib
sudo cp src/liblua.dylib /usr/local/lib/

sudo make macosx install

build dependencies

The following gems are needed to run the specs

sudo gem install bacon

tested with

ruby 1.8.7p72, ruby 1.9.1p0, jruby 1.2.0 jruby 1.1.6 has an issue with errors raised inside of Ruby functions (callbacks)

ruby-ffi 0.4.0 and 0.5.0

dependencies

the ruby gem ‘ffi’

mailing list

On the rufus-ruby list :

groups.google.com/group/rufus-ruby

issue tracker

github.com/jmettraux/rufus-lua/issues

irc

irc.freenode.net #ruote

source

github.com/jmettraux/rufus-lua

git clone git://github.com/jmettraux/rufus-lua.git

credits

many thanks to the authors of Ruby FFI, and of Lua

wiki.github.com/ffi/ffi lua.org/

authors

John Mettraux, jmettraux@gmail.com, jmettraux.wordpress.com Alain Hoang, blogs.law.harvard.edu/hoanga/ Scott Persinger, github.com/scottpersinger/

the rest of Rufus

rufus.rubyforge.org

license

MIT

Lua itself is licensed under the MIT license as well :

www.lua.org/license.html