bug#58992: 28.2; "lax space matching" no longer works

[Andreas Schwab]

On Nov 04 2022, Vincent Lefevre wrote:

> On 2022-11-04 14:25:20 +0100, Andreas Schwab wrote:
>> On Nov 04 2022, Vincent Lefevre wrote:
>> 
>> > On 2022-11-04 12:38:14 +0100, Andreas Schwab wrote:
>> >> On Nov 04 2022, Vincent Lefevre wrote:
>> >> 
>> >> > Wow! This is really confusing! [:space:] is defined by POSIX,
>> >> 
>> >> Emacs regexps are _not_ defined by POSIX.
>> >> 
>> >> >     A character alternative can also specify named character classes
>> >> >     (*note Char Classes::).  This is a POSIX feature.  [...]
>> >                                  ^^^^^^^^^^^^^^^^^^^^^^^
>> >
>> >> Did you read the referenced node?
>> >
>> > Did you read what the manual says?
>> 
>> Yes, I did.
>
> No, you didn't.
>
>> ‘[:space:]’
>>      This matches any character that has whitespace syntax (*note Syntax
>>      Class Table::).
>
> This is NOT a POSIX feature!!!

Yes, it is.  POSIX has introduced that syntax, and Emacs copied it.

-- 
Andreas Schwab, schwab@linux-m68k.org
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