Constructors in Turing

[uncompetence]

I'm toying with Object-Oriented in Turing and looked through the reference under 'class' and found no means of writing a constructor for an object. All calls to new perform the initialization of the object, but there seems to be no way of passing in variables. Is there no other way than to write and call a method of my own?

[wtd]

As far as I know, there is no way to have a constructor in the sense that other object-oriented programming languages have.

[[Gandalf]]

Indeed, you are stuck with creating your own initialize() function and always calling that.

[DemonWasp]

Similarly, there's no way to have a proper destructor.

[Tyr_God_Of_War]

I do not think that you can have any class methods (also know as static methods) at all. That's why I think it's better to use a type and a module. You can treat it like python, where you have to list 'self' as a parameter for your methods.

Turing:

module Boxes     export unqualified opaque/* if you want the boxes to be only moddified inside the class*/ Box, draw, create     type Box :         record             left, bottom, right, top : int         end record     fcn create (l, b, r, t : int) : Box         var temp : Box         temp.left := l         temp.bottom := b         temp.right := r         temp.top := t         result temp     end create     proc draw (b : Box, col : int)         Draw.Box (b.left, b.bottom, b.right, b.top, col)     end draw     %....................... end Boxes var myBox : Box := Boxes.create (20, 40, 30, 50) Boxes.draw (myBox, black)

Compare this to a class version.

Turing:

class Box     export left, bottom, right, top,         create, draw % and so on     var left, bottom, right, top : int     proc create (l, b, r, t : int)         left := l         bottom:=b         right:=r         top:=t            end create     proc draw (col : int)         Draw.Box (left, bottom, right, top, col)     end draw     % ect... end Box var myBox : ^Box new Box, myBox Box (myBox).create (20, 40, 30, 50) Box (myBox).draw (black) free myBox

Or if you really want dynamically allocated stuff:

Turing:

module Boxes     export ~.Box, draw,  create, delete     type Box :         record             left, bottom, right, top : int         end record     fcn create (l, b, r, t : int) : ^Box         var temp : ^Box         new temp         ^temp.left := l         ^temp.bottom := b         ^temp.right := r         ^temp.top := t         result temp     end create     proc draw (b : ^Box, col : int)         Draw.Box ( ^b.left, ^b.bottom, ^b.right, ^b.top, col)     end draw         proc delete(var b:^Box)         free b     end delete end Boxes var boxPtr:^Box:=Boxes.create(20,40,30,50) put "Left =  ",^boxPtr.left Boxes.draw(boxPtr, blue) Boxes.delete(boxPtr)

As you can see, using a module and a type is much like using a class.
Modules can have static methods, while classes get inheritence and polymorphism.