in hphp/runtime/base/zend-string.cpp [1930:2224]
String string_metaphone(const char *input, int word_len, long max_phonemes,
int traditional) {
unsigned char *word = (unsigned char *)input;
int w_idx = 0; /* point in the phonization we're at. */
int max_buffer_len = 0; /* maximum length of the destination buffer */
/*-- Parameter checks --*/
/* Negative phoneme length is meaningless */
if (max_phonemes < 0)
return String();
/* Empty/null string is meaningless */
/* Overly paranoid */
/* always_assert(word != NULL && word[0] != '\0'); */
if (word == nullptr)
return String();
/*-- Allocate memory for our phoned_phrase --*/
if (max_phonemes == 0) { /* Assume largest possible */
max_buffer_len = word_len;
} else {
max_buffer_len = max_phonemes;
}
StringBuffer buffer(max_buffer_len);
/*-- 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') {
return buffer.detach(); /* 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 */
return buffer.detach();
}