LOOa library - Classes with properties and member hiding in pure Lua

--declare class:
a = class {
  i = 2; --public fields begin with letter
  _x = 4; --private fields begin with underscore
  show = function(this) --functions can be private and public, too
	print(this.i)
	print(this.o)
	print(this._x) -- here you can access private vars because it's inside the class
  end;
}
--you can actually use the class itself, because the class is an instance itself
a.o = 4 -- you can add extra fields later, but only public
a._x = 5 --this will actually not change anything, my small library will ignore it
a.show() -- will print 2 2 4
-- create a clone (instance)
b = a()
b.show() -- will show 2 2 4
b.i = 7 -- will set b's i to 7, but not a's because b is (almost) independent now
print(b.i) -- output is 7
b.show() -- output is 7 2 4
a.show() -- output is 2 2 4

a = class {
  _privatefunc = function(this)
	print("hi there from privatefunc from a")
  end;
  show = function(this)
	this._privatefunc()
	print("hi from show from a")
  end;
}
b = a { --extend a
  show = function(this)
	print("hi there from show from b")
  end;
}
b.show() --output: hi there from show from b
c = class( --different way of extending
{
  _privatefunc = function(this)
	print("hi there from privatefunc from c")
  end;
}, a)
c.show() --output: hi there from privatefunc from c hi from show from a
--as you can see everything is virtual by default, like in Java
--reminder:
c._privatefunc() -- of course this is attempt to call nil outside the class declaration

a = class {
  _i = 2;
  show = function(this)
	print(this.i)
  end;
  _get_i = function(this)
	print("i was requested")
	return this._i
  end;
  _set_i = function(this,value)
	print("i will be "..tostring(value))
	this._i = value
  end;
}
a.i = 3 --output: i will be 3
a.show() --output i was requested 3

f = fastclass {
  private = {
	l = function(this)
	  return this.public.i()
	end;
	i = 7;
  };
  public = {
	l = function(this)
	  print(this.private.l())
	end;
	i = function(this)
	  return this.private.i + this.public.a
	end;
	a = 5;
  };
}
f.l() -- output 12