From: "Mattias Engdegård" <mattiase@acm.org>
To: Lars Ingebrigtsen <larsi@gnus.org>
Cc: 43598@debbugs.gnu.org
Subject: bug#43598: replace-in-string: finishing touches
Date: Sun, 27 Sep 2020 13:12:04 +0200 [thread overview]
Message-ID: <9EAF49DE-5B51-4F8D-B5F1-50D853FCA4B9@acm.org> (raw)
In-Reply-To: <878scwaxw6.fsf@gnus.org>
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27 sep. 2020 kl. 02.03 skrev Lars Ingebrigtsen <larsi@gnus.org>:
> *phew*
Not bad! This seems to work all right.
Here are some minor optimisations:
- Do the fast all-ASCII test (bytes == chars) before iterating through the bytes to check for non-ASCII chars.
- Faster check for non-ASCII non-raw bytes (no need for the complex code in string_char_advance).
It is tempting to vectorise the all-ASCII loop. Maybe another day...
The patch also adds some more test cases for completeness.
[-- Attachment #2: string-search-tweaks.diff --]
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diff --git a/src/fns.c b/src/fns.c
index 0f76871154..f626fe11b2 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -5457,16 +5457,11 @@ DEFUN ("buffer-hash", Fbuffer_hash, Sbuffer_hash, 0, 1, 0,
static bool
string_ascii_p (Lisp_Object string)
{
- if (STRING_MULTIBYTE (string))
- return SBYTES (string) == SCHARS (string);
- else
- {
- ptrdiff_t nbytes = SBYTES (string);
- for (ptrdiff_t i = 0; i < nbytes; i++)
- if (SREF (string, i) > 127)
- return false;
- return true;
- }
+ ptrdiff_t nbytes = SBYTES (string);
+ for (ptrdiff_t i = 0; i < nbytes; i++)
+ if (SREF (string, i) > 127)
+ return false;
+ return true;
}
DEFUN ("string-search", Fstring_search, Sstring_search, 2, 3, 0,
@@ -5505,9 +5500,14 @@ DEFUN ("string-search", Fstring_search, Sstring_search, 2, 3, 0,
haystart = SSDATA (haystack) + start_byte;
haybytes = SBYTES (haystack) - start_byte;
- if (STRING_MULTIBYTE (haystack) == STRING_MULTIBYTE (needle)
- || string_ascii_p (needle)
- || string_ascii_p (haystack))
+ /* We can do a direct byte-string search if both strings have the
+ same multibyteness, or if at least one of them consists of ASCII
+ characters only. */
+ if (STRING_MULTIBYTE (haystack)
+ ? (STRING_MULTIBYTE (needle)
+ || SCHARS (haystack) == SBYTES (haystack) || string_ascii_p (needle))
+ : (!STRING_MULTIBYTE (needle)
+ || SCHARS (needle) == SBYTES (needle) || string_ascii_p (haystack)))
res = memmem (haystart, haybytes,
SSDATA (needle), SBYTES (needle));
else if (STRING_MULTIBYTE (haystack)) /* unibyte needle */
@@ -5521,26 +5521,21 @@ DEFUN ("string-search", Fstring_search, Sstring_search, 2, 3, 0,
/* The only possible way we can find the multibyte needle in the
unibyte stack (since we know that neither are pure-ASCII) is
if they contain "raw bytes" (and no other non-ASCII chars.) */
- ptrdiff_t chars = SCHARS (needle);
- const unsigned char *src = SDATA (needle);
-
- for (ptrdiff_t i = 0; i < chars; i++)
- {
- int c = string_char_advance (&src);
-
- if (!CHAR_BYTE8_P (c)
- && !ASCII_CHAR_P (c))
- /* Found a char that can't be in the haystack. */
- return Qnil;
- }
+ ptrdiff_t nbytes = SBYTES (needle);
+ for (ptrdiff_t i = 0; i < nbytes; i++)
+ {
+ int c = SREF (needle, i);
+ if (CHAR_BYTE8_HEAD_P (c))
+ i++; /* Skip raw byte. */
+ else if (!ASCII_CHAR_P (c))
+ return Qnil; /* Found a char that can't be in the haystack. */
+ }
- {
- /* "Raw bytes" (aka eighth-bit) are represented differently in
- multibyte and unibyte strings. */
- Lisp_Object uni_needle = Fstring_to_unibyte (needle);
- res = memmem (haystart, haybytes,
- SSDATA (uni_needle), SBYTES (uni_needle));
- }
+ /* "Raw bytes" (aka eighth-bit) are represented differently in
+ multibyte and unibyte strings. */
+ Lisp_Object uni_needle = Fstring_to_unibyte (needle);
+ res = memmem (haystart, haybytes,
+ SSDATA (uni_needle), SBYTES (uni_needle));
}
if (! res)
diff --git a/test/src/fns-tests.el b/test/src/fns-tests.el
index 41969f2af2..d3c22f966e 100644
--- a/test/src/fns-tests.el
+++ b/test/src/fns-tests.el
@@ -913,6 +913,7 @@ string-search
(should (equal (string-search "ab\0" "ab") nil))
(should (equal (string-search "ab" "abababab" 3) 4))
(should (equal (string-search "ab" "ababac" 3) nil))
+ (should (equal (string-search "aaa" "aa") nil))
(let ((case-fold-search t))
(should (equal (string-search "ab" "AB") nil)))
@@ -936,14 +937,16 @@ string-search
(should (equal (string-search (string-to-multibyte "\377") "ab\377c") 2))
(should (equal (string-search "\303" "aøb") nil))
(should (equal (string-search "\270" "aøb") nil))
- ;; This test currently fails, but it shouldn't!
- ;;(should (equal (string-search "ø" "\303\270") nil))
+ (should (equal (string-search "ø" "\303\270") nil))
+
+ (should (equal (string-search "a\U00010f98z" "a\U00010f98a\U00010f98z") 2))
(should-error (string-search "a" "abc" -1))
(should-error (string-search "a" "abc" 4))
(should-error (string-search "a" "abc" 100000000000))
(should (equal (string-search "a" "aaa" 3) nil))
+ (should (equal (string-search "aa" "aa" 1) nil))
(should (equal (string-search "\0" "") nil))
(should (equal (string-search "" "") 0))
@@ -955,6 +958,21 @@ string-search
(should-error (string-search "" "abc" -1))
(should-not (string-search "ø" "foo\303\270"))
+ (should-not (string-search "\303\270" "ø"))
+ (should-not (string-search "\370" "ø"))
+ (should-not (string-search (string-to-multibyte "\370") "ø"))
+ (should-not (string-search "ø" "\370"))
+ (should-not (string-search "ø" (string-to-multibyte "\370")))
+ (should-not (string-search "\303\270" "\370"))
+ (should-not (string-search (string-to-multibyte "\303\270") "\370"))
+ (should-not (string-search "\303\270" (string-to-multibyte "\370")))
+ (should-not (string-search (string-to-multibyte "\303\270")
+ (string-to-multibyte "\370")))
+ (should-not (string-search "\370" "\303\270"))
+ (should-not (string-search (string-to-multibyte "\370") "\303\270"))
+ (should-not (string-search "\370" (string-to-multibyte "\303\270")))
+ (should-not (string-search (string-to-multibyte "\370")
+ (string-to-multibyte "\303\270")))
(should (equal (string-search (string-to-multibyte "o\303\270") "foo\303\270")
2))
(should (equal (string-search "\303\270" "foo\303\270") 3)))
next prev parent reply other threads:[~2020-09-27 11:12 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-24 20:52 bug#43598: replace-in-string: finishing touches Mattias Engdegård
2020-09-24 21:12 ` Lars Ingebrigtsen
2020-09-24 21:19 ` Lars Ingebrigtsen
2020-09-24 23:18 ` Lars Ingebrigtsen
2020-09-25 9:21 ` Eli Zaretskii
2020-09-25 10:09 ` Lars Ingebrigtsen
2020-09-24 23:54 ` Lars Ingebrigtsen
2020-09-25 10:42 ` Mattias Engdegård
2020-09-25 11:11 ` Lars Ingebrigtsen
2020-09-25 11:22 ` Mattias Engdegård
2020-09-25 11:32 ` Lars Ingebrigtsen
2020-09-27 0:03 ` Lars Ingebrigtsen
2020-09-27 0:34 ` Lars Ingebrigtsen
2020-09-27 8:45 ` Mattias Engdegård
2020-09-28 3:41 ` Richard Stallman
2020-09-28 9:40 ` Mattias Engdegård
2020-09-29 3:29 ` Richard Stallman
2020-09-29 4:12 ` Eli Zaretskii
2020-09-27 11:12 ` Mattias Engdegård [this message]
2020-09-27 11:48 ` Lars Ingebrigtsen
2020-09-27 11:57 ` Mattias Engdegård
2020-09-27 12:02 ` Lars Ingebrigtsen
2020-09-27 16:14 ` Mattias Engdegård
2020-09-27 16:19 ` Eli Zaretskii
2020-09-27 16:41 ` Lars Ingebrigtsen
2020-09-27 16:48 ` Eli Zaretskii
2020-09-26 22:44 ` Lars Ingebrigtsen
2020-09-26 22:25 ` Lars Ingebrigtsen
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