Re: [PATCH 6/6] RelNotes: add more notes about PCRE in 2.14

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 20, 2017, 19:11 UTC
Message-ID: <xmqqbmoely9l.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <20170720141927.18274-7-avarab@gmail.com>

Ævar Arnfjörð Bjarmason  <avarab@gmail.com> writes:

Show 6 quoted lines

> We were missing any mention that:
>
>  - PCRE is now faster with JIT
>  - That it's now faster than the other regex backends
>  - That therefore you might want to use it by default, but beware of
>    the incompatible syntax.

Hmph. All of that has been more or less deliberate, as I want the release notes to be more like table of contents, one bullet per item with short description, not a novelette with one paragraph per item.

These should already be in the documentation when they do want to decide if they want to use JIT; somebody who downloads 2.15 or later and wants to decide if they want JIT shouldn't have to dig down to earlier release notes that introduced the option for the first time.

Show 27 quoted lines

> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>  Documentation/RelNotes/2.14.0.txt | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/RelNotes/2.14.0.txt b/Documentation/RelNotes/2.14.0.txt
> index fb6a3dba31..a6a1cb963b 100644
> --- a/Documentation/RelNotes/2.14.0.txt
> +++ b/Documentation/RelNotes/2.14.0.txt
> @@ -88,7 +88,16 @@ UI, Workflows & Features
>     learned to say "it's a pathspec" a bit more often when the syntax
>     looks like so.
>  
> - * Update "perl-compatible regular expression" support to enable JIT.
> + * Update "perl-compatible regular expression" support to enable
> +   JIT.
> +
> +   This makes grep.patternType=perl (and -P and --perl-regexp) much
> +   faster for "git grep" and "git log", and is generally faster than
> +   the system's POSIX regular expression implementation. Users
> +   concerned with "git grep" performance or "git log --grep"
> +   performance might want to try setting grep.patternType=perl. Note
> +   that the syntax isn't compatible with git's default of
> +   grep.patternType=basic.
>  
>   * "filter-branch" learned a pseudo filter "--setup" that can be used
>     to define common functions/variables that can be used by other