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From: Hendrik Boom <hendrik@topoi.pooq.com>
To: dario.teixeira@yahoo.com
Cc: "caml-list@inria.fr" <caml-list@inria.fr>
Subject: [Caml-list] octothorpes and backticks?
Date: Fri, 10 Jun 2016 15:05:03 -0400	[thread overview]
Message-ID: <20160610190503.GA29121@topoi.pooq.com> (raw)
In-Reply-To: <1954387336.802086.1465583157701.JavaMail.yahoo@mail.yahoo.com>

On Fri, Jun 10, 2016 at 06:25:57PM +0000, dario.teixeira@yahoo.com wrote:
> Hi,
> 
> > (b) Is there any way to do a run-time type-test on a value of a
> > specific statically known supertype to test whether it is actually a
> > value of a known specified subtype, and if so to proceed to use it as
> > that subtype?
> 
> I reckon the "#" syntax may be what you are looking for.
> It works with polymorphic variants and objects (types
> where row-polymorphism applies).  Small example:
> 
> type foo = [ `A | `B | `C ]
> type bar = [ `D | `E | `F ]
> type foobar = [ foo | bar ]
> 
> let f = function
>   | #foo -> "Foo"
>   | #bar -> "Bar"

Haven't encountered the 3 syntax or the ` syntax.  Where is it 
docuumented, so I can start to understand?

-- hendrik

> 
> Hope this helps!
> Best regards,
> 
> Dario Teixeira

  reply	other threads:[~2016-06-10 19:05 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-10 18:12 [Caml-list] reverse coercions Hendrik Boom
2016-06-10 18:25 ` dario.teixeira
2016-06-10 19:05   ` Hendrik Boom [this message]
2016-06-10 20:04     ` [Caml-list] octothorpes and backticks? Anthony Tavener
2016-06-10 18:34 ` [Caml-list] reverse coercions Gerd Stolpmann
     [not found] ` <CAPFanBFa+MJzvt_KYmReuHSzRpD=fT=nEaXB4c7dMwWSL3w7Vg@mail.gmail.com>
2016-06-10 18:59   ` Hendrik Boom

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