Re: [Caml-list] reverse coercions

[<dario.teixeira@yahoo.com>]

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"

Hope this helps!
Best regards,

Dario Teixeira