[DNSOP] Microphone question on back-references - BULK RR

Brian Dickson <brian.peter.dickson@gmail.com> Fri, 31 March 2017 00:07 UTC

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From: Brian Dickson <brian.peter.dickson@gmail.com>
Date: Thu, 30 Mar 2017 19:07:28 -0500
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Subject: [DNSOP] Microphone question on back-references - BULK RR
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>
> Apologies but I did not hear the full question regarding BULK RR’s and the
> perl like back-references.  If you could please repeat the question we
> would be happy to comment.
>
>
>
>
>
> Thanks,
>
> John
>

Sorry for the delayed response.

The question was:

Given the use of perl-style back-references ( like "${1}" ) - would it not
make sense to use the same perl syntax to provide well-defined targets for
those back-references?

E.g. "my-special-(<regex-thing>)-(<regex-thing>)-with-suffix" and then
there is no ambiguity as to what ${1} and ${2} point at?

Perl regex rules are IMHO very clean and clever, and avoid ambiguity very
nicely.
(Also historical shout-out to Henry Spencer, whose regex mods served as the
source for perl's.)

Things inside parentheses are the target of back-refs.
In Perl, there is no need to escape the parentheses within regexes.

Brian