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Date: Wed, 01 Oct 2014 18:28:16 +0200
From: Xavier Leroy <Xavier.Leroy@inria.fr>
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Subject: Re: [Caml-list] Str, regular expressions, longest match

On 29/09/14 22:04, Tom Ridge wrote:
> I am trying to use the Str module to match regular expressions. I want to
> return the longest match.[...]  I don't want the order of
> the alternatives to matter. What am I doing wrong?

Nothing: it's just that Str has first-match semantics, not longest-match.

> What can I do to match the longest substring?

In this particular example, you can sort the string patterns in
decreasing lexicographic order before putting them in ...|...|...

In more general case, you might have more luck with other regexp
libraries (e.g. PCRE or Vouillon's RE, but I didn't check whether they
implement longest match).

Hope this helps,

- Xavier Leroy