Extract new operator and class creation boilerplate to a lualib

[ark120202]

Was discussed in Discord a while back.

Input:

class A {}
new A(args);

Current result:

A = ...
function A.new(...)
    local self = setmetatable({}, A.prototype)
    self:____constructor(...)
    return self
end
A.new(args)

Proposed Result:

function __TS_New(class, ...)
    local self = setmetatable({}, class.prototype)
    return self:____constructor(...) or self
end

A = ...
__TS_New(A, args)

---

Input:

class A {}
class B extends A {}

Current Result:

A = {}
A.name = "A"
A.__index = A
A.prototype = {}
A.prototype.__index = A.prototype
A.prototype.constructor = A
B = {}
B.name = "B"
B.__index = B
B.prototype = {}
B.prototype.__index = B.prototype
B.prototype.constructor = B
B.____super = A
setmetatable(B, B.____super)
setmetatable(B.prototype, B.____super.prototype)

Proposed Result:

function __TS_CreateClass()
    local class = {}
    class.__index = class
    class.name = name
    class.prototype = {}
    class.prototype.__index = class.prototype
    class.prototype.constructor = class
    return class
end

function __TS_ClassExtends(class, base)
	class.____super = base
    setmetatable(class, class.____super)
    setmetatable(class.prototype, class.____super.prototype)
end

A = __TS_CreateClass()
A.name = "A"
B = __TS_CreateClass()
B.name = "B"
__TS_ClassExtends(B, A)

[tomblind]

I'm definitely a fan of doing it this way, but one issue that will need to be handled is the multitude of combinations of get/set accessors in base & derived classes.