A dictionary is responsible for finding words that match a prespecified pattern. Each dictionary is tied to a .xdict file that contains both words and index information to facilitate lookup. See the file xdict.c for information about the dictionary file format.
Here are two methods to locate words that match a specific pattern. The find method accepts general patterns. Limit restricts its search to a list of previous matches and finds all words that have a given letter in a given location.
*/
- find: (char *) pattern
{
id words;
if ((words = [cache find: pattern]) == nil)
words = [self findWithoutCache: pattern];
return words;
}
- find: (char *) pattern changeAt: (int) i
{
id words;
char c;
int n;
if ((words = [cache find: pattern]) == nil)
{
if ((c = pattern[i]) != WILDCARD)
{
n = strlen(pattern);
pattern[i] = WILDCARD;
words = [self find: pattern];
words = [self limit: words toLetter: c - 'a' at: i forLength: n ];
pattern[i] = c;
}
else words = [self findWithoutCache: pattern];
}
return words;
}
- findWithoutCache: (char *) pattern
{
char * string;
id words, match;
int i, n;
words = match = nil;
i = n = strlen(pattern);
while (i--) if (pattern[i] != WILDCARD)
{
match = words;
words = [self limit: match toLetter: pattern[i] - 'a' at: i forLength: n];
[match free];
}
string = (char *) malloc(strlen(pattern) + 1);
strcpy(string, pattern);
[cache add: string value: words];
return words;
}
- limit: match toLetter: (char) c at: (int) i forLength: (int) n
