1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
|
/* +++Date last modified: 09-Jun-1996 */
/*
** METAPHON.C - Phonetic string matching
**
** The Metaphone algorithm was developed by Lawrence Phillips. Like the
** Soundex algorithm, it compares words that sound alike but are spelled
** differently. Metaphone was designed to overcome difficulties encountered
** with Soundex.
**
** This implementation was written by Gary A. Parker and originally published
** in the June/July, 1991 (vol. 5 nr. 4) issue of C Gazette. As published,
** this code was explicitly placed in the public domain by the author.
*/
#include <ctype.h>
#include "metaphone.h"
/*
** Character coding array
*/
static char vsvfn[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 */
/*
** Macros to access the character coding array
*/
#define vowel(x) (vsvfn[(x) - 'A'] & 1) /* AEIOU */
#define same(x) (vsvfn[(x) - 'A'] & 2) /* FJLMNR */
#define varson(x) (vsvfn[(x) - 'A'] & 4) /* CGPST */
#define frontv(x) (vsvfn[(x) - 'A'] & 8) /* EIY */
#define noghf(x) (vsvfn[(x) - 'A'] & 16) /* BDH */
/*
** metaphone()
**
** Arguments: 1 - The word to be converted to a metaphone code.
** 2 - A MAXMETAPH+1 char field for the result.
** 3 - Function flag:
** If 0: Compute the Metaphone code for the first argument,
** then compare it to the Metaphone code passed in
** the second argument.
** If 1: Compute the Metaphone code for the first argument,
** then store the result in the area pointed to by the
** second argument.
**
** Returns: If function code is 0, returns 0 for a match, else 1.
** If function code is 1, returns 0
*/
unsigned short int metaphone(const char *Word, char *Metaph, unsigned short int Flag)
{
char *n, *n_start, *n_end; /* Pointers to string */
char *metaph, *metaph_end; /* Pointers to metaph */
char ntrans[512]; /* Word with uppercase letters */
char newm[MAXMETAPH + 4]; /* New metaph for comparison */
int KSflag; /* State flag for X translation */
/*
** Copy word to internal buffer, dropping non-alphabetic characters
** and converting to upper case.
*/
for (n = ntrans + 1, n_end = ntrans + sizeof(ntrans) - 2;
*Word && n < n_end; ++Word)
{
if (isalpha(*Word))
*n++ = toupper(*Word);
}
if (n == ntrans + 1)
return 1; /* Return if zero characters */
else n_end = n; /* Set end of string pointer */
/*
** Pad with NULs, front and rear
*/
*n++ = '\0';
*n = '\0';
n = ntrans;
*n++ = '\0';
/*
** If doing comparison, redirect pointers
*/
if (Flag == 0)
{
metaph = Metaph;
Metaph = newm;
}
/*
** Check for PN, KN, GN, WR, WH, and X at start
*/
switch (*n)
{
case 'P':
case 'K':
case 'G':
if ('N' == *(n + 1))
*n++ = '\0';
break;
case 'A':
if ('E' == *(n + 1))
*n++ = '\0';
break;
case 'W':
if ('R' == *(n + 1))
*n++ = '\0'
;
else if ('H' == *(n + 1))
{
*(n + 1) = *n;
*n++ = '\0';
}
break;
case 'X':
*n = 'S';
break;
}
/*
** Now loop through the string, stopping at the end of the string
** or when the computed Metaphone code is MAXMETAPH characters long.
*/
KSflag = 0; /* State flag for KStranslation */
for (metaph_end = Metaph + MAXMETAPH, n_start = n;
n <= n_end && Metaph < metaph_end; ++n)
{
if (KSflag)
{
KSflag = 0;
*Metaph++ = *n;
}
else
{
/* Drop duplicates except for CC */
if (*(n - 1) == *n && *n != 'C')
continue;
/* Check for F J L M N R or first letter vowel */
if (same(*n) || (n == n_start && vowel(*n)))
*Metaph++ = *n;
else switch (*n)
{
case 'B':
if (n < n_end || *(n - 1) != 'M')
*Metaph++ = *n;
break;
case 'C':
if (*(n - 1) != 'S' || !frontv(*(n + 1)))
{
if ('I' == *(n + 1) && 'A' == *(n + 2))
*Metaph++ = 'X';
else if (frontv(*(n + 1)))
*Metaph++ = 'S';
else if ('H' == *(n + 1))
*Metaph++ = ((n == n_start &&
!vowel(*(n + 2))) ||
'S' == *(n - 1)) ? 'K' : 'X';
else *Metaph++ = 'K';
}
break;
case 'D':
*Metaph++ = ('G' == *(n + 1) && frontv(*(n + 2))) ?
'J' : 'T';
break;
case 'G':
if ((*(n + 1) != 'H' || vowel(*(n + 2))) &&
(*(n + 1) != 'N' || ((n + 1) < n_end &&
(*(n + 2) != 'E' || *(n + 3) != 'D'))) &&
(*(n - 1) != 'D' || !frontv(*(n + 1))))
{
*Metaph++ = (frontv(*(n + 1)) &&
*(n + 2) != 'G') ? 'J' : 'K';
}
else if ('H' == *(n + 1) && !noghf(*(n - 3)) &&
*(n - 4) != 'H')
{
*Metaph++ = 'F';
}
break;
case 'H':
if (!varson(*(n - 1)) && (!vowel(*(n - 1)) ||
vowel(*(n + 1))))
{
*Metaph++ = 'H';
}
break;
case 'K':
if (*(n - 1) != 'C')
*Metaph++ = 'K';
break;
case 'P':
*Metaph++ = ('H' == *(n + 1)) ? 'F' : 'P';
break;
case 'Q':
*Metaph++ = 'K';
break;
case 'S':
*Metaph++ = ('H' == *(n + 1) || ('I' == *(n + 1) &&
('O' == *(n + 2) || 'A' == *(n + 2)))) ?
'X' : 'S';
break;
case 'T':
if ('I' == *(n + 1) && ('O' == *(n + 2) ||
'A' == *(n + 2)))
{
*Metaph++ = 'X';
}
else if ('H' == *(n + 1))
*Metaph++ = 'O';
else if (*(n + 1) != 'C' || *(n + 2) != 'H')
*Metaph++ = 'T';
break;
case 'V':
*Metaph++ = 'F';
break;
case 'W':
case 'Y':
if (vowel(*(n + 1)))
*Metaph++ = *n;
break;
case 'X':
if (n == n_start)
*Metaph++ = 'S';
else
{
*Metaph++ = 'K';
KSflag = 1;
}
break;
case 'Z':
*Metaph++ = 'S';
break;
}
}
/*
** Compare new Metaphone code with old
*/
if (Flag==0 &&
*(Metaph - 1) != metaph[(Metaph - newm) - 1])
{
return 1;
}
}
/*
** If comparing, check if Metaphone codes were equal in length
*/
if (Flag==0 && metaph[Metaph - newm])
return 1;
*Metaph = '\0';
return 0;
}
|
