mruby-lua

mruby-lua calls Lua script engine from mruby. It provides to use many Lua scripts written for embedded host on mruby environment.

Dependency

• liblua5.2 libraries and headers.

I checked to build on Debian GNU/Linux x86, LMDE2 x64 and MinGW32 on MS-Windows7.

Classes

class Lua

Class Lua provides Lua script engine. It has a pointer to lua_State structure.

Singleton methods

• new -> self
  • Create instance of Lua script engine.

Instance methods

• dostring(script_string) -> nil

  • Run Lua script from string object.

• dofile(script_file_path) -> nil

  • Run Lua script from file.

• [key] -> object, [key] = object

  • Set or Get global variable from Lua.

Examples

Lua#dostring method

lua = Lua.new

script =<<"EOF"
  function twice(x)
    return x * 2
  end
  a = 10
  b = 20
  print(a * twice(b))
EOF

lua.dostring script
  => 400

Lua#dofile method

lua = Lua.new
lua.dofile "test/fib.lua"

Lua#[] method

Get global variable from Lua.

lua = Lua.new

lua.dostring "a = 10; b = 20; c = a * b"

p lua["a"] # => 10
p lua["b"] # => 20
p lua["c"] # => 200

lua.dostring "vec1 = { x = 0.0, y = 1.0, z = 3.0 }"
p lua["vec1"]
# => {"x"=>0, "y"=>1, "z"=>3}

Lua#[]= method

Set global variable to Lua.

lua = Lua.new

lua["a"] = 123
lua["b"] = 23.45
lua["c"] = true
lua["d"] = nil

lua.dostring "print(a)" # => 123
lua.dostring "print(b)" # => 23.45
lua.dostring "print(c)" # => true
lua.dostring "print(d)" # => nil

Supported data convertion

MRuby type	To Lua	From Lua	Lua type
Nil	o	o	NIL
Fixnum	o	o	NUMBER
Float	o	o	NUMBER
String	o	o	STRING
array			TABLE
hash		o	TABLE
C pointer		o	FUNCTION(c)
-			FUNCTION
Exception			-
Bool	o	o	BOOLEAN
-			USERDATA
-			LIGHTUSERDATA
-			THREAD