Re: devel/pcre2: why --enable-newline-is-any?

lennart@getcoding.de writes:

> (not subscribed to the list)
>
> Ever since the initial revision of devel/pcre2/Makefile, PCRE2 is
> compiled with --enable-newline-is-any. Why is that? Does anything
> depend on it? Is that written down anywhere?

pcre2build(3): NEWLINE RECOGNITION
This explains --enable-newline-is-any as a flexibile combination of CR,
LF, CRLF, plus unicode newline sequences.

Whatever default line ending convention is selected when PCRE2 is built
can be overridden by applications that use the library. At build time
it is recommended to use the standard for your operating system.

It also says it can be overwritten. For example, pcre2grep (tool) and
pcre2_compile (function) both have ways to do it.

pcre2grep(1): -N newline-type, --newline=newline-type
When the PCRE2 library is built, a default line-ending
sequence is specified. This is normally the standard
sequence for the operating system. Unless otherwise specified
by this option, pcre2grep uses the library's default

pcre2_compile(3): NEWLINES and PCRE2 CONTEXTS
When PCRE2 is built, a default can be specified...
However, the newline convention can be changed by an
application when calling pcre2_compile(), or it can be specified by
special text at the start of the pattern itself;

A compile context is required if you want to provide an external
function for stack checking during compilation or to change the default
values of any of the following compile-time parameters:

What \R matches (Unicode newlines or CR, LF, CRLF only)
PCRE2's character tables
The newline character sequence

>
> MediaWiki, which I am trying to set up, complains about that.

mediawiki might have to be adapted. --enable-newline-is-any seems
reasonable as a default since it is flexible and can be overridden by
consumers.