Re: [pcre-dev] Serialization format versioning

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Author: ph10
Date:  
To: Daniel Richard G.
CC: pcre-dev
Subject: Re: [pcre-dev] Serialization format versioning
On Wed, 20 Jun 2018, Daniel Richard G. wrote:

> Is it not feasible for the serialized form to be forward-compatible with
> later versions of PCRE2?


Zoltán may correct me on this, but basically we felt that this would be
too much of a constraint on future development. Changes to what is
compiled are not ruled out - in fact there's an item buried somewhere in
my "potential work" list to redesign how classes work because over the
years the code has got contorted and hard to understand. It may not
happen, but we wanted to be able to change the internal form of compiled
patterns without constraint.

Of course, in theory one could support old and new versions of
something, but this would involve tests and alternate paths and the
maintenance of old code, all of which I felt was too much of a
burden for the maintainer, even if performance wasn't hit.

I have no idea how widely the serializing feature is used.

I suppose we could invent the idea of a "format version" for the
compiled code. The serialization functions could check this instead of
the PCRE2 version number. Zoltán: (are you reading this?) What do you
think? That seems an easy solution.

Philip

--
Philip Hazel