Tue, 3 Sep 2002 19:55:22 +0200
Sorry for my late reply,
But is it possible to be more specific (little examples)
In Haskell one can use existential lists but I doubt about the efficiency.
It is not my aim to make of everything an object like in Jave e.g. . The
objects I have in mind are showable ojects: windows, scrollbars,
messageboxes, etc. . Of such objects I demand fast response with respect to
key input or mouse clicks. I am sure Ocamel can do that.
----- Original Message -----
From: "Manuel M T Chakravarty" <firstname.lastname@example.org>
Sent: Tuesday, September 03, 2002 10:37 AM
Subject: Re: mutable records
> "Scott J." <email@example.com> wrote,
> > Is it possible to define oject types in Haskell and what does one
propose to do it?
> Depends on what you mean by object types. You can surely
> define a record with funcions dubbing as methods and
> non-functional values dubbing as object data.
> > Is it possible to define parts of a record with the help of the ST s
monad mutable during the whole program? (As is possible in Ocamel)?
> Just make the fields that you want to update be values of
> `STRef s a'. (You can also do the same with the IO monad
> and `IORef's.)
> Having said this, there are not that many situations where
> you need to do this (and in consequence ST-monadify your
> program). Purely functional updates (using the record
> syntax) where the system effectively copies the whole record
> (not all data in it, just the references to that data) is
> perfectly suitable in most cases. If you are concerned
> about efficiency first profile the code to see whether the
> performance bottleneck is really where you think it is.