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Date: Wed, 17 Oct 2007 21:24:05 +0100 (BST)
From: Dario Teixeira <darioteixeira@yahoo.com>
Subject: Re: [Caml-list] Smells like duck-typing
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X-Spam: no; 0.00; ocaml's:01 subtyping:01 cheers:01 duck:98 carbon:98 avoids:01 caml-list:01 int:01 int:01 reuse:01 variant:02 declaration:02 string:02 string:02 module:03 

Hi,

And a big thanks to everyone -- you've really given me a lot of interesting
ideas.  For the time being, I am going for the no-inheritance object solution:
it avoids the option type mess, provides a clean interface to users of the
module, and allows code reuse thanks to OCaml's structural subtyping feature
(the "duck" in this thread's title).  Moreover, while obviously not as concise
as a record, the declaration of each story variant is still quite economical:

class full (id, title, intro, body) =
object
        method id: int = id
        method title: string = title
        method intro: string = intro
        method body: string = body
end

class blurb (id, title, intro) =
object
        method id: int = id
        method title: string = title
        method intro: string = intro
end


Etc, etc.  I can live with this.

Cheers,
Dario





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