Class: Fuzzy
- Inherits:
-
Object
- Object
- Fuzzy
- Defined in:
- ext/fuzzy_search.c,
ext/bitap_fuzzy_search.c
Class Method Summary collapse
Class Method Details
.equal ⇒ Object
76 77 78 79 80 81 82 83 84 85 86 87 |
# File 'ext/fuzzy_search.c', line 76
static VALUE
fuzzy_equal (VALUE self, VALUE text, VALUE pattern, VALUE errors_percent)
{
const char *t = StringValuePtr (text);
const char *p = StringValuePtr (pattern);
int errors = (errors_percent * maximun (strlen (t), strlen (p))) / 100;
int distance = levenshtein_distance (t, p);
// printf ("Allowed errors: %d - Levenshtein's distance: %d\n", errors, distance);
if (distance <= errors)
return INT2NUM (errors - distance);
return Qfalse;
}
|
.search ⇒ Object
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 |
# File 'ext/bitap_fuzzy_search.c', line 21
static VALUE
bitap_fuzzy_search (VALUE self, VALUE text, VALUE pattern, VALUE errors_percent)
{
char *p = downcase2 (StringValuePtr (pattern));
if (p[0] == '\0') return Qnil;
char *t = downcase2 (StringValuePtr (text));
int n = strlen (t);
int m = strlen (p);
if (abs (n - m) > 2) return Qnil;
const char *result = NULL;
unsigned long *R;
unsigned long bitmasks[CHAR_MAX + 1];
int i, d;
int errors = (FIX2INT (errors_percent) * m) / 100;
if (errors == 0) errors = 1;
/* Initialize the bit array R */
R = malloc ((errors + 1) * sizeof (*R));
for (i = 0; i <= errors; ++i)
R[i] = ~1;
/* Initialize the pattern bitmasks */
for (i = 0; i <= CHAR_MAX; ++i)
bitmasks[i] = ~0;
for (i = 0; i < m; ++i)
bitmasks[p[i]] &= ~(1UL << i);
for (i = 0; t[i] != '\0'; ++i)
{
/* Update the bit arrays */
unsigned long old_Rd1 = R[0];
R[0] |= bitmasks[t[i]];
R[0] <<= 1;
for (d = 1; d <= errors; ++d)
{
unsigned long tmp = R[d];
/* Substitution is all we care about */
R[d] = (old_Rd1 & (R[d] | bitmasks[t[i]])) << 1;
old_Rd1 = tmp;
}
if (0 == (R[errors] & (1UL << m)) && (i - m + 1) == 0)
{
result = (t + i - m) + 1;
break;
}
}
free (R);
free (p);
free (t);
if (result)
return rb_str_new2 (result);
return Qnil;
}
|