Browse thread
[Caml-list] Delegation based OO
[
Home
]
[ Index:
by date
|
by threads
]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
| Date: | -- (:) |
| From: | Kenneth Knowles <kknowles@b...> |
| Subject: | Re: [Caml-list] Delegation based OO |
> class *type* does_something = object ... end > > class does_more (an_object:#does_something) = object > delegates an_object > ... > end > > "an_object" may have a method, say, "an_object#foo : int". > "does_more" could overwrite the method, and define "does_more#foo : > float". Now, what type should "self#pooh" have in the definition of > an_object? This is a type error, just as if you override a class method with one of a different type: # class x = object method y = 3 end;; class x : object method y : int end # class y = object inherit x method y = 4 end;; class y : object method y : int end # class z = object inherit x method y = "hello" end;; This expression has type string but is here used with type int The same strictness could be applied to delegation. Kenn ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners