/* +----------------------------------------------------------------------+ | PHP Version 5 | +----------------------------------------------------------------------+ | Copyright (c) 1997-2008 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> | +----------------------------------------------------------------------+ */ /* $Id: metaphone.c,v 1.28.2.1.2.7 2008/02/27 01:10:56 felipe Exp $ */ /* 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, int word_len, long max_phonemes, char **phoned_word, int traditional); /* {{{ proto string metaphone(string text[, int phones]) Break english phrases down into their phonemes */ PHP_FUNCTION(metaphone) { char *str; char *result = 0; int str_len; long phones = 0; if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s|l", &str, &str_len, &phones) == FAILURE) { return; } if (metaphone((unsigned char *)str, str_len, phones, &result, 1) == 0) { RETVAL_STRING(result, 0); } else { if (result) { efree(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... */ 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 dipthongs 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(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 = safe_erealloc(*phoned_word, 2, sizeof(char), max_buffer_len); \ max_buffer_len += 2; \ } \ (*phoned_word)[p_idx++] = c; \ } /* Slap a null character on the end of the phoned word */ #define End_Phoned_Word { \ if (p_idx == max_buffer_len) { \ *phoned_word = safe_erealloc(*phoned_word, 1, sizeof(char), max_buffer_len); \ } \ (*phoned_word)[p_idx] = '\0'; \ } /* 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, int word_len, long max_phonemes, char **phoned_word, int traditional) { int w_idx = 0; /* point in the phonization we're at. */ int p_idx = 0; /* end of the phoned phrase */ int 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 = safe_emalloc(sizeof(char), word_len, 1); } else { max_buffer_len = max_phonemes; *phoned_word = safe_emalloc(sizeof(char), max_phonemes, 1); } /*-- 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 H, WR becomes R W if followed by a vowel */ case 'W': if (Next_Letter == 'H' || Next_Letter == 'R') { Phonize(Next_Letter); w_idx += 2; } else if (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 < 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 { 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 */