/**
* Returns a list of suggestions if the word is not in the dictionary.
*
* @param word the wrong spelled word. Can't be null.
* @return a list of class Suggestion.
* @see Suggestion
*/
public List<Suggestion> searchSuggestions(final String word) {
if (word.length() == 0 || exist(word)) {
return new ArrayList<Suggestion>();
}
final Suggestions suggesions = new Suggestions(Math.min(20, 4 + word.length()));
idx = 0;
searchSuggestions(suggesions, word, 0, 0, 0);
final List<Suggestion> list = suggesions.getlist();
Collections.sort(list);
return list;
}
private void searchSuggestionsLonger(
final Suggestions list,
final CharSequence chars,
final int originalLength,
final int lastIdx,
final int diff) {
idx = lastIdx;
while (idx < size && tree[idx] < LAST_CHAR) {
if (isWordMatch()) {
list.add(new Suggestion(chars.toString() + tree[idx], diff));
}
idx += 3;
}
}
/**
* Es wird nach verschiedenen Regeln nach aehnlichen Woertern gesucht. Je nach Regel gibt es einen
* anderen diff. Jekleiner der diff desto aehnlicher. Diese Methode ruft sich rekursiv auf.
*
* @param list Kontainer fuer die gefundenen Woerter
* @param chars bis zur charPosition bereits gemappte Buchstaben, danach noch zu mappende des
* orignal Wortes
* @param charPosition Zeichenposition im char array
* @param lastIdx Position im Suchindex der zur aktuellen Zeichenposition zeigt.
* @param diff Die Unaehnlichkeit bis zur aktuellen Zeichenposition
*/
private void searchSuggestions(
final Suggestions list,
final CharSequence chars,
final int charPosition,
final int lastIdx,
final int diff) {
if (diff > list.getMaxDissimilarity()) {
return;
}
// First with the correct letters to go on
idx = lastIdx;
char currentChar = chars.charAt(charPosition);
if (searchChar(currentChar)) {
if (isWordMatch()) {
if (charPosition + 1 == chars.length()) {
// exact match at this character position
list.add(new Suggestion(chars, diff));
} else {
// a shorter match, we need to cut the string
final int length = charPosition + 1;
final CharSequence chars2 = chars.subSequence(0, length);
list.add(new Suggestion(chars2, diff + (chars.length() - length) * 5));
}
}
idx = readIndex();
if (idx <= 0) {
// no more characters in the tree
return;
}
if (charPosition + 1 == chars.length()) {
searchSuggestionsLonger(list, chars, chars.length(), idx, diff + 5);
return;
}
searchSuggestions(list, chars, charPosition + 1, idx, diff);
}
// transposed letters and additional letter
if (charPosition + 1 < chars.length()) {
idx = lastIdx;
currentChar = chars.charAt(charPosition + 1);
if (searchChar(currentChar)) {
final int tempIdx = idx;
// transposed letters (German - Buchstabendreher)
idx = readIndex();
if (idx > 0) {
final StringBuilder buffer = new StringBuilder(chars);
buffer.setCharAt(charPosition + 1, chars.charAt(charPosition));
buffer.setCharAt(charPosition, currentChar);
searchSuggestions(list, buffer, charPosition + 1, idx, diff + 3);
}
// Additional character in the misspelled word
idx = tempIdx;
final StringBuilder buffer = new StringBuilder();
buffer.append(chars, 0, charPosition);
buffer.append(chars, charPosition + 1, chars.length());
searchSuggestions(list, buffer, charPosition, lastIdx, diff + 5);
}
}
// Missing letters, we need to add one character
{
int tempIdx = idx = lastIdx;
while (idx < size && tree[idx] < LAST_CHAR) {
final char newChar = tree[idx];
idx = readIndex();
if (idx > 0 && newChar != currentChar) {
final StringBuilder buffer = new StringBuilder(chars);
buffer.insert(charPosition, newChar);
searchSuggestions(list, buffer, charPosition + 1, idx, diff + 5);
}
idx = tempIdx += 3;
}
}
// Typos - wrong letters (One character is replaced with any character)
if (charPosition < chars.length()) {
currentChar = chars.charAt(charPosition);
int tempIdx = idx = lastIdx;
while (idx < size && tree[idx] < LAST_CHAR) {
if (isWordMatch()) {
final StringBuilder buffer = new StringBuilder();
buffer.append(chars, 0, charPosition);
buffer.append(tree[idx]);
list.add(new Suggestion(buffer, diff + 5 + (chars.length() - buffer.length()) * 5));
}
if (charPosition + 1 < chars.length()) {
final char newChar = tree[idx];
idx = readIndex();
if (idx > 0 && newChar != currentChar) {
final StringBuilder buffer = new StringBuilder(chars);
buffer.setCharAt(charPosition, newChar);
searchSuggestions(
list, buffer, charPosition + 1, idx, diff + charDiff(currentChar, newChar));
}
}
idx = tempIdx += 3;
}
}
}
