/**
* This was the method found in the {@link com.cybozu.labs.langdetect.Detector} class, it was used
* to extract grams from the to-analyze text.
*
* <p>NOTE: although it adds the first ngram with space, it does not add the last n-gram with
* space. example: "foo" gives " fo" but not "oo "!. It is not clear yet whether this is desired
* (and why) or a bug.
*
* <p>TODO replace this algorithm with a simpler, faster one that uses less memory: only by
* position shifting. also, the returned list size can be computed before making it (based on text
* length and number of n-grams).
*
* @author Nakatani Shuyo
*/
@NotNull
@Deprecated
public static List<String> extractNGrams(@NotNull CharSequence text, @Nullable Filter filter) {
List<String> list = new ArrayList<>();
NGram ngram = new NGram();
for (int i = 0; i < text.length(); ++i) {
ngram.addChar(text.charAt(i));
for (int n = 1; n <= NGram.N_GRAM; ++n) {
String w = ngram.get(n);
if (w != null) { // TODO this null check is ugly
if (filter == null || filter.use(w)) {
list.add(w);
}
}
}
}
return list;
}
