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To: caml-list@inria.fr
Subject: Re: one-time initialization
References: <199901280508.AAA21644@codex.cis.upenn.edu>
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From: John Prevost <prevost@maya.com>
Date: 28 Jan 1999 04:54:07 -0500
In-Reply-To: Michael Hicks's message of "Thu, 28 Jan 1999 00:08:23 -0500 (EST)"
Message-ID: <ya2d83z67uo.fsf@zarya.maya.com>
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Michael Hicks <mwh@dsl.cis.upenn.edu> writes:

> I wonder if anyone knows how to optimize the following (simplified for the
> sake of dicussion) situation:

The only alternative I can think of that might provide a significant
performance boost is to make the reference a "default" value when the
initialization hasn't yet been done.  Another alternative that may win
some speed (but I sort of doubt it) is to make the reference be to a
function that raises an exception, like so:

val global = (ref (fun () -> failwith "not initialized") :
	(mytype -> unit) ref)

let init i = global := fun () -> i

let f () = ... (!global ())
let g () = (!global ()) ...

this at least has the advantage that you don't have to have a big
hairy pattern match in every function.

jmp