[PATCH] regex: Add \A and \z synonyms to \` and \'

[Collin Funk]

Hi Paul,

Paul Eggert <eggert@cs.ucla.edu> writes:

>> If POSIX were to try to standardize \` and \' instead of \A and \z, it
>> would have the benefit of existing practice (glibc)
>
> Not just glibc. A quick search shows that FreeBSD[1] and Boost[2][3]
> both support \`...\' in POSIX-style BREs and EREs, as an extension.
> Surely there are other implementations.
>
> Let's standardize what already works instead of adding even more confusion.

I saw that there are proposed changes in Python regarding this
proposed standardization [1] [2]. But I am sympathetic to your argument
that \` and \' should be standardized instead since some implementations
already support it. I have linked them this thread so they know about it
before making any changes.

Collin

[1] https://github.com/python/cpython/issues/133306
[2] https://discuss.python.org/t/proposal-add-z-as-a-synonym-for-z-in-python-res-for-standardization/90378/11