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[netmod] regular expression flavours (again)

Ladislav Lhotka <lhotka@nic.cz> Wed, 12 June 2019 08:02 UTC

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From: Ladislav Lhotka <lhotka@nic.cz>
To: NETMOD WG <netmod@ietf.org>
Date: Wed, 12 Jun 2019 10:01:30 +0200
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Subject: [netmod] regular expression flavours (again)
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Hi,

I think it is very unfortunate that OpenConfig folks use POSIX regular
expressions instead of XSD. This of course causes confusion, see e.g. this PR:

https://github.com/CZ-NIC/yangson/pull/22

Given the popularity of OpenConfig models, it seems to me that it would be
better if YANG somehow accomodates such (largely cosmetic) differences.

One option would be that each YANG module declares the regex flavour used in its
patterns. Yes, it is a complication, but having separate forks of YANG is much
worse.

ISO Schematron adopted a similar approach with "query language binding" that can
be declared with the schema element, for example

<schema xmlns="http://purl.oclc.org/dsdl/schematron" queryBinding="exslt">

Any thoughts on this?

Lada

-- 
Ladislav Lhotka
Head, CZ.NIC Labs
PGP Key ID: 0xB8F92B08A9F76C67

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