= rufus-lua

Lua embedded in Ruby, via Ruby FFI

Tested with
  ruby 1.8.6, ruby 1.9.1p0, jruby 1.2.0
  jruby 1.1.6 has an issue with errors raised inside of Ruby functions (callbacks)


== Lua

http://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. 
"""

http://www.lua.org/


== other Ruby and Lua bridges / connectors


  http://rubyluabridge.rubyforge.org/
  http://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 :

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

rufus-lua's rdoc is at :

http://rufus.rubyforge.org/rufus-lua/


== compiling liblua.dylib

original instructions by Adrian Perez at :

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

get the source at 

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

  make 
  make masocx # or make linux ...
  make -C src src liblua.dylib

  sudo cp src/liblua.dylib /usr/local/lib/


== build dependencies

You need to add the github gems to your gem sources
  gem sources -a http://gems.github.com

The following gems are needed to run the specs
  mislav-hanna
  install bacon


== tested with

ruby 1.8.6, ruby 1.9.1p0, jruby 1.2.0
jruby 1.1.6 has an issue with errors raised inside of Ruby functions (callbacks)


== dependencies

the ruby gem 'ffi'


== mailing list

On the rufus-ruby list :

  http://groups.google.com/group/rufus-ruby


== issue tracker

  http://rubyforge.org/tracker/?atid=18584&group_id=4812&func=browse


== irc

irc.freenode.net #ruote


== source

http://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

http://kenai.com/projects/ruby-ffi/

http://lua.org/


== authors

John Mettraux, jmettraux@gmail.com, http://jmettraux.wordpress.com
Alain Hoang, http://blogs.law.harvard.edu/hoanga/


== the rest of Rufus

http://rufus.rubyforge.org


== license

MIT

Lua itself is licensed under the MIT license as well :

http://www.lua.org/license.html