Lua class library

Introduction

The Lua Class library provides support for object-oriented programming in Lua. With it, you can create classes and objects easily and intuitively, using concepts such as inheritance, polymorphism, interfaces and method overloading. [ Still in improvement ]

Installation

Just download file class-oop.lua and put it in your project directory. it will work in any project that uses Lua.

• Note: This library he was created and tested on Lua 5.1

Creating classes

To create a class, simply call the class function and pass the class name and a table containing the method constructor and attributes. For example:

class 'Animal' {
    constructor = function(self, name, type)
        self.name = name
        self.type = type
    end
}

Instantiating

To instantiate an object, simply call the new function and pass the class name and the arguments of the constructor. For example:

local dog = new 'Animal'('Dog', 'Mammal')

Inheritance

The Lua Class library supports simple and multiple class inheritance. To create a child class that inherits from another parent class, simply call the extends function and pass the child class name, the parent class name and a table containing the method constructor and attributes. For example:

class 'Animal' {
    constructor = function(self, name, type)
        self.name = name
        self.type = type
    end,

    eat = function(self)
        print('Eating...')
    end
}

class 'Dog' : extends 'Animal' {
    constructor = function(self, name)
        self.name = name
    end
}

local dog = new 'Dog'('Bob')
dog:eat() -- Eating...

Polymorphism

The Lua Class library supports polymorphism naturally. This means it is possible to overload methods from the parent class in a child class, so that the implementation of the method in the child class is called intead of the implementation in the parent class. For example:

class 'Animal' {
    constructor = function(self, name, type)
        self.name = name
        self.type = type
    end,

    speak = function(self)
        print('Hello, my name is ' .. self.name .. ' and I am a ' .. self.type .. '.')
    end
}

class 'Dog' : extends 'Animal' {
    constructor = function(self, name)
        self.name = name
    end,

    speak = function(self)
        print('Woof! My name is ' .. self.name .. '.')
    end
}

Interfaces

The Lua Class library als supports interface concepts. An interface is a blueprint of a class that defines the methods and attributes that a class must implement. A class can implement multiple interfaces and must implement all the methods and attributes defined in the interfaces it implements.

To create an interface, simply call the interface function and pass the interface name and table containing the methods attributes of the interface as arguments. For example:

interface 'telePhone' {
    'call',
    'sendSMS',
    'receiveSMS'
}

To make a class implement an interface, simply pass the interface name as an argument to the implements function. For example:

class 'SmartPhone' : implements 'telePhone' {
    constructor = function(self, number)
        self.number = number
    end,

    call = function(self, number)
        print('Calling ' .. number .. ' from ' .. self.number .. '...')
    end,

    sendSMS = function(self, number, message)
        print('Sending SMS to ' .. number .. ' from ' .. self.number .. '...')
    end,

    receiveSMS = function(self, number, message)
        print('Received SMS from ' .. number .. ' to ' .. self.number .. '...')
    end
}

Multiple interfaces

The Lua Class library also supports multiple interfaces. This means that a class can implement multiple interfaces. To make a class implement multiple interfaces, simply pass the interface names as arguments to the implements function. For example:

interface 'telePhone' {
    'call',
    'sendSMS',
    'receiveSMS'
}

interface 'smartPhone' {
    'touchScreen',
    'internet'
}

class 'SmartPhone' : implements ('telePhone', 'smartPhone') {
    constructor = function(self, number)
        self.number = number
    end,

    call = function(self, number)
        print('Calling ' .. number .. ' from ' .. self.number .. '...')
    end,

    sendSMS = function(self, number, message)
        print('Sending SMS to ' .. number .. ' from ' .. self.number .. '...')
    end,

    receiveSMS = function(self, number, message)
        print('Received SMS from ' .. number .. ' to ' .. self.number .. '...')
    end,

    touchScreen = function(self)
        print('Touching screen...')
    end,

    internet = function(self)
        print('Accessing internet...')
    end
}

Inheritance of interfaces

The Lua Class library also supports inheritance of interfaces. This means that a class can implement an interface that inherits from another interface. To make a class implement an interface that inherits from another interface, simply pass the interface name as an argument to the extends function. For example:

interface 'telePhone' {
    'call',
    'sendSMS',
    'receiveSMS'
}

interface 'smartPhone' : extends 'telePhone' {
    'touchScreen',
    'internet'
}

instanceof

The Lua Class library also supports the instanceof operator. This operator is used to check if an object is an instance of a class. For example:

local dog = new 'Animal'('Dog', 'Mammal')
print(instanceOf(dog, 'Animal')) -- true

License

This project is licensed under the MIT License - see the LICENSE file for details