Norihiro Tanaka wrote:
Hmm, how about the following test cases, although it is extreame?
I don't think we need to worry about performance for the case when -w is given, and a pattern matches data that contains non-word characters. In practice, such cases are rare. I expect that most users would be surprised that -w can match non-word characters, and that users wouldn't object to -w rejecting such matches (if this wouldn't hurt performance significantly).
While looking into this I did find a very small performance tweak for the test case, and installed the attached.
From 7ad36793e6bc43b98a37b1512b057a7a03ed10b2 Mon Sep 17 00:00:00 2001 From: Paul Eggert <egg...@cs.ucla.edu> Date: Mon, 26 Dec 2016 09:42:29 -0800 Subject: [PATCH] grep: minor performance tweak for pure functions * src/search.h (wordchars_size, wordchar_next, wordchar_prev): Declare to be pure. --- src/search.h | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/src/search.h b/src/search.h index 469fc9c..1aa2f94 100644 --- a/src/search.h +++ b/src/search.h @@ -48,9 +48,10 @@ typedef signed char mb_len_map_t; /* searchutils.c */ extern void wordinit (void); extern kwset_t kwsinit (bool); -extern size_t wordchars_size (char const *, char const *); -extern size_t wordchar_next (char const *, char const *); -extern size_t wordchar_prev (char const *, char const *, char const *); +extern size_t wordchars_size (char const *, char const *) _GL_ATTRIBUTE_PURE; +extern size_t wordchar_next (char const *, char const *) _GL_ATTRIBUTE_PURE; +extern size_t wordchar_prev (char const *, char const *, char const *) + _GL_ATTRIBUTE_PURE; extern ptrdiff_t mb_goback (char const **, char const *, char const *); /* dfasearch.c */ -- 2.7.4
