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Date: Sat, 21 Oct 2006 16:00:11 +0200
From: Christophe Raffalli <raffalli@univ-savoie.fr>
Subject: try and tail call
To: caml-list@inria.fr
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X-Spam: no; 0.00; christophe:01 raffalli:01 raffalli:01 univ-savoie:01 syntax:01 usefull:01 bug:01 avoided:01 christophe:01 encode:01 exception:01 tail:01 tail:01 handles:03 let:03 


consider this piece of code:

  (try
    let b = f a in
    (fun () -> g b)
  with
    (fun () -> h a)) ()


Is the call to "g" a tail call and is it omptimized as such ?

If not, how to encode a feature like this one:

  try
    ...
  end
    ... (* the exception raised here are not handles by with but 
propagated *)
  with
    ...

By the way I think this "try ... [end ...] with ..." syntax is usefull 
anyway because you have often a bug when
you write

try
  let b = f a in (* you know this may raise Not_found *)
  g b (* you assume wrongly that this can not raise Not_found *)
with
  Not_found -> h a

The unwanted capture of Not_found could be avoided with try ... end ... 
with ...

Christophe Raffalli