From: Toby Kelsey <toby.kelsey@gmail.com>
To: caml-list@inria.fr
Subject: Re: [Caml-list] Are record types generative?
Date: Fri, 2 Feb 2018 23:07:05 +0000 [thread overview]
Message-ID: <2e9462f5-4042-230f-104b-943f1e2ebe76@gmail.com> (raw)
In-Reply-To: <4C24893D-6053-4F0D-BFDD-DF76172E64F9@math.nagoya-u.ac.jp>
On 24/01/18 08:43, Jacques Garrigue wrote:
> I.e., types can be used to optimize a program, but they do not change its semantics.
> It’s true of so-called “overloaded” record labels, it’s true of a labeled and default arguments
> (which use type information for compilation, but not semantics), it’s true of objects,
> it’s true of GADT pattern-matching (again optimized), etc…
type foo = { x : int }
type bar = { x : string }
let f r = r.x (* OK: uses bar *)
let f r = (r:foo).x (* OK: uses foo *)
let f r = (r.x : int) (* type error - wrong type inferred *)
Aren't the semantics different? 'f' has different types in the first two definitions, And why does type inference fail
for the last example?
Toby
next prev parent reply other threads:[~2018-02-02 23:07 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-23 14:54 Oleg
2018-01-23 16:05 ` Jeremy Yallop
2018-01-23 17:39 ` Chet Murthy
2018-01-23 20:35 ` Jeremy Yallop
2018-01-23 21:36 ` Chet Murthy
2018-01-23 22:06 ` Jeremy Yallop
2018-01-23 23:14 ` Hendrik Boom
2018-01-24 1:06 ` Chet Murthy
2018-01-24 1:35 ` Francois BERENGER
2018-02-07 2:00 ` [Caml-list] [ANN] first release of bst: a bisector tree implementation Francois BERENGER
2018-02-07 12:40 ` Ivan Gotovchits
2018-02-08 0:46 ` Francois BERENGER
2018-01-24 1:56 ` [Caml-list] Are record types generative? Yawar Amin
2018-01-25 10:49 ` Matej Košík
2018-01-25 13:39 ` Simon Cruanes
2018-01-25 16:24 ` Yawar Amin
2018-01-24 1:05 ` Chet Murthy
2018-01-24 8:43 ` Jacques Garrigue
2018-02-02 23:07 ` Toby Kelsey [this message]
2018-02-02 23:23 ` Evgeny Roubinchtein
2018-02-04 1:27 ` Jacques Garrigue
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