[Python-Dev] Regular expressions: splitting on zero-width patterns

[MRAB]

On 2017-11-28 22:27, Guido van Rossum wrote:
> On Tue, Nov 28, 2017 at 2:23 PM, MRAB <python at mrabarnett.plus.com 
> <mailto:python at mrabarnett.plus.com>> wrote:
>
>     On 2017-11-28 20:04, Serhiy Storchaka wrote:
>
>         The two largest problems in the re module are splitting on
>         zero-width
>         patterns and complete and correct support of the Unicode
>         standard. These
>         problems are solved in regex. regex has many other features,
>         but they
>         are less important.
>
>         I want to tell the problem of splitting on zero-width patterns. It
>         already was discussed on Python-Dev 13 years ago [3] and maybe
>         later.
>         See also issues: [4], [5], [6], [7], [8].
>
>     [snip]
>     After some thought, I've decided that if this happens in the re
>     module in Python 3.7, then, for the sake of compatibility (and
>     because the edge cases are debatable anyway), I'll have the regex
>     module do the same when used on Python 3.7.
>
>
> Maybe it should also be selectable with a version flag?
>
Well, when anyone who uses re updates to Python 3.7, they'll be faced 
with the change anyway.