toolua

The Object-Oriented Lua, just a OO library for Lua.

Example

To see a whole example for toolua, check out testToolua.lua inside the repo.

Tutorial

What are we gonna do?

We're gonna write a simple program that can output the area of a specific rectangle or circle, just like what we read on basic OOP books.

Set Up toolua

The first thing we need to do is set up toolua. All you need to do is copy the toolua.lua file into your folder, and create a file beside it, and add a line at the top of your file:

dofile( "toolua.lua" )

That's all.

Declare the "Shape" class

If you come from a mainstream OOP language, say C#, you will familiar with this:

public class Shape
{
}

Using toolua, you can do the same:

toolua.class( "Shape" )

Implement the constructor of the Shape class

In C#, writing constructor is like this:

public Shape( string name )
{
    _name = name;
}

Using toolua, you do it like this:

function Shape:__init( name )
    self.name = name
end

Create a subclass called "Circle"

To create a subclass, we need to implement the constructor, so that it calls the constructor of the base class.

In C#:

public class Circle : Shape
{
    public Circle( string name )
        : base( name )
    {
        _radius = 0.0f;
    }

    private float _radius;
}

Using toolua:

toolua.class( "Circle", Shape )

function Circle:__init( name )
    Shape.__init( self, name )
    self.radius = 0
end

Note that using toolua, calling base class constructor should pass "self" in as the first parameter, and you also need to specify the name of the base class "Shape".

Implement a static function for Circle

In C#, a static function is specified by adding the "static" keyword where in toolua, all you have to do is to change the colon (:) to a dot (.).

C#:

public static float GetPi()
{
    return 3.14f;
}

toolua:

function Circle.getPi()
    return 3.14
end

Implement the getArea() function for Circle

C#:

public float GetArea()
{
    return GetPi() * this._radius * this._radius;
}

toolua:

function Circle:getArea()
    return Circle.getPi() * self.radius * self.radius
end

Create the circle object

C#:

var circle = new Circle( "C#Circle" );
circle.Radius = 1;
Console.WriteLine( circle.GetArea() );

toolua:

local circle = Circle.new( "LuaCircle" )
circle.radius = 1
print( circle:getArea() )