ansaurus

Question

What languages other than Python have an explicit self?

Answer 1

+4 A:

By explicit, do you mean "explicitely passed as an argument to all the functions"? If so, then Python's the only one I know off-hand. Most OO languages support this or self in some form, but most of them let you define class methods without always defining self as the first argument.

linked 2009-12-08 07:45:29

s/functions/methods

Virgil Dupras 2009-12-08 08:09:14

Answer 2

+3 A:

F# (presumably from its OCAML heritage) requires an explicit name for all self-references; though the name is any arbitrary identifier e.g.

 override x.BeforeAnalysis() = 
    base.BeforeAnalysis()
    DoWithLock x.AddReference

Here we're defining an overriding member function BeforeAnalysis which calls another member function AddReference. The identifier x here is arbitrary, but is required in both the declaration and any reference to members of the "this"/"self" instance.

Steve Gilham 2009-12-08 07:54:01

Answer 3

+3 A:

Depending on your point of view, Lua. To quote the reference: "A call v:name(args) is syntactic sugar for v.name(v,args), except that v is evaluated only once." You can also define methods using either notation. So you could say that Lua has an optional explicit self.

Boojum 2009-12-08 07:57:31

how would you define a method `foo(self, a, b, **kwargs)` in lua?

uswaretech 2009-12-08 08:22:57

I'm not really an expert in Lua. As far as I know, it doesn't have keyword arguments, but you could simulate their behavior by using the syntactic sugar for sending a table to the method. Tables have an array like part and a hashlike part.So define something like "function object:foo(args) a = args[1]; b = args[2]; self.argx = args.argx; end" and then call it with something like "object:foo{1, 2, argx=3}".If you want an explicit self, you can define "object.foo = function(self, args) a = args[1]; b = args[2]; self.argx = args.argx; end" and then call "object.foo(object, {1, 2, argx=3})

Boojum 2009-12-08 09:37:14

Answer 4

+1 A:

any Object-Oriented language has a notion of this or self within member functions.

Scott Evernden 2009-12-08 07:57:49

Answer 5

+1 A:

many object oriented languages if not all of them

for example c++ support "this" instead of "self"

but you dont have to pass it, it is passed passively

hope that helps ;)

Ahmad Dwaik 2009-12-08 08:04:23

Not "passively" but "implicitly". Like Java, the C++ compiler reasons out where `this` belongs. Sometimes it will be unable to reason out if a `this` belongs in front of a variable reference, and you must put it in to resolve the ambiguous name.

S.Lott 2009-12-08 11:35:04

Answer 6

+3 A:

The programming language Oberon 2 has an explicitly named but not explicitly passed 'this' or 'self' argument for member functions of classes (known as type bound procedures in Oberon terminology)

The following example is an Insert method on a type Text, where the identifier 't' is specified to bind to the explicit 'this' or 'self' reference.

PROCEDURE (t: Text) Insert (string: ARRAY OF CHAR; pos: LONGINT);
BEGIN ...
END Insert;

More details on Object Orientation in Oberon are here.

grrussel 2009-12-08 08:27:04

ansaurus

tags:

views:

answers:

What languages other than Python have an explicit self?

related questions