= 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