From: Radu Grigore <radugrigore@gmail.com>
To: caml-list@yquem.inria.fr
Subject: mutable and polymorphism
Date: Wed, 15 Sep 2010 18:10:26 +0100 [thread overview]
Message-ID: <AANLkTimOrmnhFmzgDBVO5ZgPKF89ePHBnHqf=w+2Fynu@mail.gmail.com> (raw)
Compile the following three files one-by-one.
(*a.ml*) let _ = ref () in let f = fun _ -> () in f 1; f 'a'
(*b.ml*) let f = let _ = () in fun _ -> () in f 1; f 'a'
(*c.ml*) let f = let _ = ref () in fun _ -> () in f 1; f 'a'
The files a.ml and b.ml compile; the file c.ml fails with
Error: This expression has type char
but an expression was expected of type int
Could someone explain why having a mutable field ("contents" in this
case) restricts the polymorphism of f?
PS: A few hours ago I tried to post from Google Groups, but the
message didn't seem to go thru. Apologies if this is a duplicate
next reply other threads:[~2010-09-15 17:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-15 17:10 Radu Grigore [this message]
2010-09-15 17:40 ` [Caml-list] " Andreas Rossberg
2010-09-15 17:59 ` Radu Grigore
2010-09-15 19:10 ` Goswin von Brederlow
2010-09-15 19:38 ` Radu Grigore
2010-09-15 20:44 ` Kaustuv Chaudhuri
2010-09-17 7:31 ` Goswin von Brederlow
2010-09-17 14:04 ` Radu Grigore
2010-09-17 14:08 ` Radu Grigore
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