Re: [Caml-list] a reckless proposal

[Miles Egan <miles@caddr.com>]

On Wed, Jul 25, 2001 at 10:30:09AM +0100, Dave Berry wrote:
> So perhaps Ocaml should adopt the approach used in Dylan and Moby,
> where field names in class definitions have module scope.  Then
> records and objects would have similar scoping rules, instead of
> the current clash, and the distinction between modules and objects
> would be clearer.

I suppose this is also similar to CLOS generics, right?  I suppose this would be
more consistent but perhaps even more confusing to people who've been writing
ClassA.field and ClassB.field since the first day of their first Java class.

> But if you then replace the field with an accessor method, you
> have to edit all uses of that field.  It's a common recommendation
> that OO languages should only access field by accessor methods (or
> at least use the same syntax as accessor methods).  As you point
> out, Ruby does it this way.  Dylan and Eiffel are other examples.

Ocaml could observe this protocol as well.  This is valid code:

class a =
  object
    val x = 1
    method x = x
  end

let _ = new a in
  a#x

So a "macro" like attr_r could transform:

class a =
  object
   attr_r x = 1
  end

into the above class definition.

Of course, you won't be able to assign to x in the way you'd expect:

let _ = new a in
  a#x = 2

Won't work.

-- 
miles

"We in the past evade X, where X is something which we believe to be a
lion, through the act of running." - swiftrain@geocities.com
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