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From: Greg Morrisett <jgm@cs.cornell.edu>
To: "'stephanh@win.tue.nl'" <stephanh@win.tue.nl>,
        Pierre Weis
  <Pierre.Weis@inria.fr>, orodeh@cs.huji.ac.il
Cc: caml-list@inria.fr
Subject: RE: Where did the exception occur?
Date: Mon, 30 Oct 2000 10:09:25 -0500
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> I'm not the OP, but this can of course be implemented by having an
> additional (hidden) field in the exception which contains the source
> co-ordinate.

This is really cheap to add.  But it's not very useful in
practice.  The problem is that you call a higher order
function (e.g., find or something like that) and you really
need to know who called that function to narrow down the
context suffiently.  What you really want is a stack backtrace
hence my suggestion.  And Pierre is (rightfully) worried
about the overhead of supporting the full backtrace.

Still, it's so useful that I would highly encourage its
support.  (We've done this with our Popcorn compiler recently
in a rather naive way, and in spite of the overhead, I leave 
it on all the time because it's just so useful.)

-Greg