X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fstr-kmp.h;h=74c8bd44f63a17f5cbe60246cd9479297dcfd2b5;hb=0aa49ea72a8764e3065ebbfc55459232ca8fb021;hp=76668cf8f2b47fa71c6df6586e77bd4af09dc532;hpb=b2e2010c7c902235b5efb5bd3c6529f61b093aa4;p=gnulib.git diff --git a/lib/str-kmp.h b/lib/str-kmp.h index 76668cf8f..74c8bd44f 100644 --- a/lib/str-kmp.h +++ b/lib/str-kmp.h @@ -1,6 +1,6 @@ -/* Substring search in a NUL terminated string of 'char' elements, +/* Substring search in a NUL terminated string of UNIT elements, using the Knuth-Morris-Pratt algorithm. - Copyright (C) 2005-2010 Free Software Foundation, Inc. + Copyright (C) 2005-2012 Free Software Foundation, Inc. Written by Bruno Haible , 2005. This program is free software; you can redistribute it and/or modify @@ -14,25 +14,29 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software Foundation, - Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ + along with this program; if not, see . */ /* Before including this file, you need to define: + UNIT The element type of the needle and haystack. CANON_ELEMENT(c) A macro that canonicalizes an element right after - it has been fetched from one of the two strings. - The argument is an 'unsigned char'; the result - must be an 'unsigned char' as well. */ + it has been fetched from needle or haystack. + The argument is of type UNIT; the result must be + of type UNIT as well. */ /* Knuth-Morris-Pratt algorithm. See http://en.wikipedia.org/wiki/Knuth-Morris-Pratt_algorithm + HAYSTACK is the NUL terminated string in which to search for. + NEEDLE is the string to search for in HAYSTACK, consisting of NEEDLE_LEN + units. Return a boolean indicating success: Return true and set *RESULTP if the search was completed. Return false if it was aborted because not enough memory was available. */ static bool -knuth_morris_pratt_unibyte (const char *haystack, const char *needle, - const char **resultp) +knuth_morris_pratt (const UNIT *haystack, + const UNIT *needle, size_t needle_len, + const UNIT **resultp) { - size_t m = strlen (needle); + size_t m = needle_len; /* Allocate the table. */ size_t *table = (size_t *) nmalloca (m, sizeof (size_t)); @@ -66,14 +70,14 @@ knuth_morris_pratt_unibyte (const char *haystack, const char *needle, The inequality needle[x..i-1] != needle[0..i-1-x] is known to hold for x < table[i-1], by induction. Furthermore, if j>0: needle[i-1-j..i-2] = needle[0..j-1]. */ - unsigned char b = CANON_ELEMENT ((unsigned char) needle[i - 1]); + UNIT b = CANON_ELEMENT (needle[i - 1]); for (;;) { /* Invariants: The inequality needle[x..i-1] != needle[0..i-1-x] is known to hold for x < i-1-j. Furthermore, if j>0: needle[i-1-j..i-2] = needle[0..j-1]. */ - if (b == CANON_ELEMENT ((unsigned char) needle[j])) + if (b == CANON_ELEMENT (needle[j])) { /* Set table[i] := i-1-j. */ table[i] = i - ++j; @@ -108,17 +112,16 @@ knuth_morris_pratt_unibyte (const char *haystack, const char *needle, /* Search, using the table to accelerate the processing. */ { size_t j; - const char *rhaystack; - const char *phaystack; + const UNIT *rhaystack; + const UNIT *phaystack; *resultp = NULL; j = 0; rhaystack = haystack; phaystack = haystack; /* Invariant: phaystack = rhaystack + j. */ - while (*phaystack != '\0') - if (CANON_ELEMENT ((unsigned char) needle[j]) - == CANON_ELEMENT ((unsigned char) *phaystack)) + while (*phaystack != 0) + if (CANON_ELEMENT (needle[j]) == CANON_ELEMENT (*phaystack)) { j++; phaystack++;