From: Chet Murthy <murthy.chet@gmail.com>
To: Jeremy Yallop <yallop@gmail.com>
Cc: Oleg <oleg@okmij.org>, Caml List <caml-list@inria.fr>
Subject: Re: [Caml-list] Are record types generative?
Date: Tue, 23 Jan 2018 09:39:16 -0800 [thread overview]
Message-ID: <CA++P_ge5yhCTmofjpPXpDm10uM1LCvJg6fejvcpiPRUPYu4vfA@mail.gmail.com> (raw)
In-Reply-To: <CAAxsn=GU_NBNAs=DJi0EZqibtZOgr2cOugXqkYdDU+Su7-qUzw@mail.gmail.com>
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The generativity of record types is, I believe, one of the key prereqs for
achieving a decidable type inference algorithm in the absence of any type
annotations, in caml. That is, when you write a caml program and it fails
to type-check, you can't make it type-check by adding "enough"
type-annotations. For a programmer, this is critical -- when the compiler
tells you that your program doesn't type-check, it means that your code is
actually broken. Whereas in SML/NJ, you might need to add some more
type-annotations.
It was one of the things that convinced me to switch to caml, lo these many
decades.
On Tue, Jan 23, 2018 at 8:05 AM, Jeremy Yallop <yallop@gmail.com> wrote:
>
> Yes: record definitions are indeed generative in OCaml, unlike in Standard
> ML.
>
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next prev parent reply other threads:[~2018-01-23 17:39 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 [this message]
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
2018-02-02 23:23 ` Evgeny Roubinchtein
2018-02-04 1:27 ` Jacques Garrigue
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