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

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