Re: [pcre-dev] \u in JavaScript compat mode

On Fri, 11 Nov 2011, Zoltán Herczeg wrote:

> I recently got a notification that PCRE does not support \u in
> PCRE_JAVASCRIPT_COMPAT mode.

\u in Perl means "upper case the next character". PCRE does not support
it at all. The documentation (pcrecompat) says this:

5. The following Perl escape sequences are not supported: \l, \u, \L,
\U, and \N when followed by a character name or Unicode value. (\N on
its own, matching a non-newline character, is supported.) In fact
these are implemented by Perl's general string-handling and are not
part of its pattern matching engine. If any of these are encountered
by PCRE, an error is generated.

> So \u is simply converted to u, and \x as x if not followed by enough
> hex characters.
>
> Philip, could we follow the standard here?

The JAVASCRIPT_COMPAT mode was never meant to make PCRE fully JAVASCRIPT
compatible, as I suspect that is probably impossible. However, it looks
as if adding support \u in that mode won't break anything else, so I
guess it could be done.

Philip

--
Philip Hazel