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From: Jean Yang <jeanyang@csail.mit.edu>
To: caml-list@yquem.inria.fr
Subject: OCaml/C variant representation
Date: Wed, 24 Feb 2010 10:26:22 -0500	[thread overview]
Message-ID: <1bd843011002240726u6f0c3b87m7d58ab6415ea21ba@mail.gmail.com> (raw)

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Hello,

  I'm having some trouble with variant representation in the OCaml/C
interface.

  According to the reference I found (
http://caml.inria.fr/pub/docs/manual-ocaml/manual032.html), it seems like if
we have value v = variant VConstr(val), where val is some integer value,
should have Field(val, 0) == hash_variant("VConstr") and Int_val(Field(v, 0)
== val.  I don't seem to be understanding this correctly, since I am getting
Int_val(Field(v, 0)) == val.

  I have the following datatype declaration in my OCaml:
type newty = VConstr of int | ...
In the C implementation of OCaml function foo : newty -> int, I have
something like this;
  CAMLprim value foo (value v) {  ... }
In the body of this function I am looking at the fields of val.  Am I doing
something wrong here?

Thanks,
Jean

-- 
Jean Yang
http://people.csail.mit.edu/jeanyang
Save us!  Think before you print.

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             reply	other threads:[~2010-02-24 15:26 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-24 15:26 Jean Yang [this message]
2010-02-24 16:42 ` Sylvain Le Gall
2010-02-28 15:16   ` [Caml-list] " Jianzhou Zhao
2010-02-28 16:22     ` Sylvain Le Gall
2010-02-24 23:07 ` [Caml-list] " Richard Jones

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