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Date: Fri, 16 Sep 2011 22:20:05 +0100
From: "Richard W.M. Jones" <rich@annexia.org>
To: Basile Starynkevitch <basile@starynkevitch.net>
Cc: Walter Cazzola <cazzola@dico.unimi.it>,
        OCaML Mailing List <caml-list@inria.fr>
Message-ID: <20110916212005.GA22906@annexia.org>
References: <alpine.LFD.2.00.1109142210370.2647@surtur.dico.unimi.it>
 <20110914224011.70c49bb251e84a4186a2b44d@starynkevitch.net>
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User-Agent: Mutt/1.5.20 (2009-06-14)
Subject: Re: [Caml-list] pattern matching on strings

On Wed, Sep 14, 2011 at 10:40:11PM +0200, Basile Starynkevitch wrote:
> And there is a reason why you cannot match (in Ocaml) on the content
> of strings (or arrays). It won't be easy to implement efficiently
> (you would need to copy a substring or subarray when matching)

How about just prefix matching?  That on its own would be very useful.

For example in web app that was passed arguments foo_1, foo_2, bar_1,
bar_5 you could parse the arguments like this:

  match arg with
  | "foo_" ^ s -> (* ... *)
  | "bar_" ^ s -> (* ... *)

Rich.

-- 
Richard Jones
Red Hat