php-src/ext/standard/metaphone.c
Peter Kokot 8d3f8ca12a Remove unused Git attributes ident
The $Id$ keywords were used in Subversion where they can be substituted
with filename, last revision number change, last changed date, and last
user who changed it.

In Git this functionality is different and can be done with Git attribute
ident. These need to be defined manually for each file in the
.gitattributes file and are afterwards replaced with 40-character
hexadecimal blob object name which is based only on the particular file
contents.

This patch simplifies handling of $Id$ keywords by removing them since
they are not used anymore.
2018-07-25 00:53:25 +02:00

482 lines
12 KiB
C

/*
+----------------------------------------------------------------------+
| PHP Version 7 |
+----------------------------------------------------------------------+
| Copyright (c) 1997-2018 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 3.01 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available through the world-wide-web at the following url: |
| http://www.php.net/license/3_01.txt |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Author: Thies C. Arntzen <thies@thieso.net> |
+----------------------------------------------------------------------+
*/
/*
Based on CPANs "Text-Metaphone-1.96" by Michael G Schwern <schwern@pobox.com>
*/
#include "php.h"
#include "php_metaphone.h"
static int metaphone(unsigned char *word, size_t word_len, zend_long max_phonemes, zend_string **phoned_word, int traditional);
/* {{{ proto string metaphone(string text[, int phones])
Break english phrases down into their phonemes */
PHP_FUNCTION(metaphone)
{
zend_string *str;
zend_string *result = NULL;
zend_long phones = 0;
ZEND_PARSE_PARAMETERS_START(1, 2)
Z_PARAM_STR(str)
Z_PARAM_OPTIONAL
Z_PARAM_LONG(phones)
ZEND_PARSE_PARAMETERS_END();
if (metaphone((unsigned char *)ZSTR_VAL(str), ZSTR_LEN(str), phones, &result, 1) == 0) {
RETVAL_STR(result);
} else {
if (result) {
zend_string_free(result);
}
RETURN_FALSE;
}
}
/* }}} */
/*
this is now the original code by Michael G Schwern:
i've changed it just a slightly bit (use emalloc,
get rid of includes etc)
- thies - 13.09.1999
*/
/*----------------------------- */
/* this used to be "metaphone.h" */
/*----------------------------- */
/* Special encodings */
#define SH 'X'
#define TH '0'
/*----------------------------- */
/* end of "metaphone.h" */
/*----------------------------- */
/*----------------------------- */
/* this used to be "metachar.h" */
/*----------------------------- */
/* Metachar.h ... little bits about characters for metaphone */
/*-- Character encoding array & accessing macros --*/
/* Stolen directly out of the book... */
static const char _codes[26] =
{
1, 16, 4, 16, 9, 2, 4, 16, 9, 2, 0, 2, 2, 2, 1, 4, 0, 2, 4, 4, 1, 0, 0, 0, 8, 0
/* a b c d e f g h i j k l m n o p q r s t u v w x y z */
};
#define ENCODE(c) (isalpha(c) ? _codes[((toupper(c)) - 'A')] : 0)
#define isvowel(c) (ENCODE(c) & 1) /* AEIOU */
/* These letters are passed through unchanged */
#define NOCHANGE(c) (ENCODE(c) & 2) /* FJMNR */
/* These form diphthongs when preceding H */
#define AFFECTH(c) (ENCODE(c) & 4) /* CGPST */
/* These make C and G soft */
#define MAKESOFT(c) (ENCODE(c) & 8) /* EIY */
/* These prevent GH from becoming F */
#define NOGHTOF(c) (ENCODE(c) & 16) /* BDH */
/*----------------------------- */
/* end of "metachar.h" */
/*----------------------------- */
/* I suppose I could have been using a character pointer instead of
* accesssing the array directly... */
/* Look at the next letter in the word */
#define Next_Letter (toupper(word[w_idx+1]))
/* Look at the current letter in the word */
#define Curr_Letter (toupper(word[w_idx]))
/* Go N letters back. */
#define Look_Back_Letter(n) (w_idx >= n ? toupper(word[w_idx-n]) : '\0')
/* Previous letter. I dunno, should this return null on failure? */
#define Prev_Letter (Look_Back_Letter(1))
/* Look two letters down. It makes sure you don't walk off the string. */
#define After_Next_Letter (Next_Letter != '\0' ? toupper(word[w_idx+2]) \
: '\0')
#define Look_Ahead_Letter(n) (toupper(Lookahead((char *) word+w_idx, n)))
/* Allows us to safely look ahead an arbitrary # of letters */
/* I probably could have just used strlen... */
static char Lookahead(char *word, int how_far)
{
char letter_ahead = '\0'; /* null by default */
int idx;
for (idx = 0; word[idx] != '\0' && idx < how_far; idx++);
/* Edge forward in the string... */
letter_ahead = word[idx]; /* idx will be either == to how_far or
* at the end of the string
*/
return letter_ahead;
}
/* phonize one letter
* We don't know the buffers size in advance. On way to solve this is to just
* re-allocate the buffer size. We're using an extra of 2 characters (this
* could be one though; or more too). */
#define Phonize(c) { \
if (p_idx >= max_buffer_len) { \
*phoned_word = zend_string_extend(*phoned_word, 2 * sizeof(char) + max_buffer_len, 0); \
max_buffer_len += 2; \
} \
ZSTR_VAL(*phoned_word)[p_idx++] = c; \
ZSTR_LEN(*phoned_word) = p_idx; \
}
/* Slap a null character on the end of the phoned word */
#define End_Phoned_Word { \
if (p_idx == max_buffer_len) { \
*phoned_word = zend_string_extend(*phoned_word, 1 * sizeof(char) + max_buffer_len, 0); \
max_buffer_len += 1; \
} \
ZSTR_VAL(*phoned_word)[p_idx] = '\0'; \
ZSTR_LEN(*phoned_word) = p_idx; \
}
/* How long is the phoned word? */
#define Phone_Len (p_idx)
/* Note is a letter is a 'break' in the word */
#define Isbreak(c) (!isalpha(c))
/* {{{ metaphone
*/
static int metaphone(unsigned char *word, size_t word_len, zend_long max_phonemes, zend_string **phoned_word, int traditional)
{
int w_idx = 0; /* point in the phonization we're at. */
size_t p_idx = 0; /* end of the phoned phrase */
size_t max_buffer_len = 0; /* maximum length of the destination buffer */
/*-- Parameter checks --*/
/* Negative phoneme length is meaningless */
if (max_phonemes < 0)
return -1;
/* Empty/null string is meaningless */
/* Overly paranoid */
/* assert(word != NULL && word[0] != '\0'); */
if (word == NULL)
return -1;
/*-- Allocate memory for our phoned_phrase --*/
if (max_phonemes == 0) { /* Assume largest possible */
max_buffer_len = word_len;
*phoned_word = zend_string_alloc(sizeof(char) * word_len + 1, 0);
} else {
max_buffer_len = max_phonemes;
*phoned_word = zend_string_alloc(sizeof(char) * max_phonemes + 1, 0);
}
/*-- The first phoneme has to be processed specially. --*/
/* Find our first letter */
for (; !isalpha(Curr_Letter); w_idx++) {
/* On the off chance we were given nothing but crap... */
if (Curr_Letter == '\0') {
End_Phoned_Word
return SUCCESS; /* For testing */
}
}
switch (Curr_Letter) {
/* AE becomes E */
case 'A':
if (Next_Letter == 'E') {
Phonize('E');
w_idx += 2;
}
/* Remember, preserve vowels at the beginning */
else {
Phonize('A');
w_idx++;
}
break;
/* [GKP]N becomes N */
case 'G':
case 'K':
case 'P':
if (Next_Letter == 'N') {
Phonize('N');
w_idx += 2;
}
break;
/* WH becomes W,
WR becomes R
W if followed by a vowel */
case 'W':
if (Next_Letter == 'R') {
Phonize(Next_Letter);
w_idx += 2;
} else if (Next_Letter == 'H' || isvowel(Next_Letter)) {
Phonize('W');
w_idx += 2;
}
/* else ignore */
break;
/* X becomes S */
case 'X':
Phonize('S');
w_idx++;
break;
/* Vowels are kept */
/* We did A already
case 'A':
case 'a':
*/
case 'E':
case 'I':
case 'O':
case 'U':
Phonize(Curr_Letter);
w_idx++;
break;
default:
/* do nothing */
break;
}
/* On to the metaphoning */
for (; Curr_Letter != '\0' &&
(max_phonemes == 0 || Phone_Len < (size_t)max_phonemes);
w_idx++) {
/* How many letters to skip because an eariler encoding handled
* multiple letters */
unsigned short int skip_letter = 0;
/* THOUGHT: It would be nice if, rather than having things like...
* well, SCI. For SCI you encode the S, then have to remember
* to skip the C. So the phonome SCI invades both S and C. It would
* be better, IMHO, to skip the C from the S part of the encoding.
* Hell, I'm trying it.
*/
/* Ignore non-alphas */
if (!isalpha(Curr_Letter))
continue;
/* Drop duplicates, except CC */
if (Curr_Letter == Prev_Letter &&
Curr_Letter != 'C')
continue;
switch (Curr_Letter) {
/* B -> B unless in MB */
case 'B':
if (Prev_Letter != 'M')
Phonize('B');
break;
/* 'sh' if -CIA- or -CH, but not SCH, except SCHW.
* (SCHW is handled in S)
* S if -CI-, -CE- or -CY-
* dropped if -SCI-, SCE-, -SCY- (handed in S)
* else K
*/
case 'C':
if (MAKESOFT(Next_Letter)) { /* C[IEY] */
if (After_Next_Letter == 'A' &&
Next_Letter == 'I') { /* CIA */
Phonize(SH);
}
/* SC[IEY] */
else if (Prev_Letter == 'S') {
/* Dropped */
} else {
Phonize('S');
}
} else if (Next_Letter == 'H') {
if ((!traditional) && (After_Next_Letter == 'R' || Prev_Letter == 'S')) { /* Christ, School */
Phonize('K');
} else {
Phonize(SH);
}
skip_letter++;
} else {
Phonize('K');
}
break;
/* J if in -DGE-, -DGI- or -DGY-
* else T
*/
case 'D':
if (Next_Letter == 'G' &&
MAKESOFT(After_Next_Letter)) {
Phonize('J');
skip_letter++;
} else
Phonize('T');
break;
/* F if in -GH and not B--GH, D--GH, -H--GH, -H---GH
* else dropped if -GNED, -GN,
* else dropped if -DGE-, -DGI- or -DGY- (handled in D)
* else J if in -GE-, -GI, -GY and not GG
* else K
*/
case 'G':
if (Next_Letter == 'H') {
if (!(NOGHTOF(Look_Back_Letter(3)) ||
Look_Back_Letter(4) == 'H')) {
Phonize('F');
skip_letter++;
} else {
/* silent */
}
} else if (Next_Letter == 'N') {
if (Isbreak(After_Next_Letter) ||
(After_Next_Letter == 'E' &&
Look_Ahead_Letter(3) == 'D')) {
/* dropped */
} else
Phonize('K');
} else if (MAKESOFT(Next_Letter) &&
Prev_Letter != 'G') {
Phonize('J');
} else {
Phonize('K');
}
break;
/* H if before a vowel and not after C,G,P,S,T */
case 'H':
if (isvowel(Next_Letter) &&
!AFFECTH(Prev_Letter))
Phonize('H');
break;
/* dropped if after C
* else K
*/
case 'K':
if (Prev_Letter != 'C')
Phonize('K');
break;
/* F if before H
* else P
*/
case 'P':
if (Next_Letter == 'H') {
Phonize('F');
} else {
Phonize('P');
}
break;
/* K
*/
case 'Q':
Phonize('K');
break;
/* 'sh' in -SH-, -SIO- or -SIA- or -SCHW-
* else S
*/
case 'S':
if (Next_Letter == 'I' &&
(After_Next_Letter == 'O' ||
After_Next_Letter == 'A')) {
Phonize(SH);
} else if (Next_Letter == 'H') {
Phonize(SH);
skip_letter++;
} else if ((!traditional) && (Next_Letter == 'C' && Look_Ahead_Letter(2) == 'H' && Look_Ahead_Letter(3) == 'W')) {
Phonize(SH);
skip_letter += 2;
} else {
Phonize('S');
}
break;
/* 'sh' in -TIA- or -TIO-
* else 'th' before H
* else T
*/
case 'T':
if (Next_Letter == 'I' &&
(After_Next_Letter == 'O' ||
After_Next_Letter == 'A')) {
Phonize(SH);
} else if (Next_Letter == 'H') {
Phonize(TH);
skip_letter++;
} else if (!(Next_Letter == 'C' && After_Next_Letter == 'H')) {
Phonize('T');
}
break;
/* F */
case 'V':
Phonize('F');
break;
/* W before a vowel, else dropped */
case 'W':
if (isvowel(Next_Letter))
Phonize('W');
break;
/* KS */
case 'X':
Phonize('K');
Phonize('S');
break;
/* Y if followed by a vowel */
case 'Y':
if (isvowel(Next_Letter))
Phonize('Y');
break;
/* S */
case 'Z':
Phonize('S');
break;
/* No transformation */
case 'F':
case 'J':
case 'L':
case 'M':
case 'N':
case 'R':
Phonize(Curr_Letter);
break;
default:
/* nothing */
break;
} /* END SWITCH */
w_idx += skip_letter;
} /* END FOR */
End_Phoned_Word;
return 0;
} /* END metaphone */
/* }}} */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: sw=4 ts=4 fdm=marker
* vim<600: sw=4 ts=4
*/