search method
It does an search on a list of User
and returns users with
id
or name
containing the query
.
Results are returned sorted by their edit distance from the searched string, distance is calculated using the levenshtein algorithm.
Implementation
List<User> search(String query) {
String normalize(String input) => input.toLowerCase().diacriticsInsensitive;
final normalizedQuery = normalize(query);
final matchingUsers = <User, int>{}; // User:lDistance
for (final user in this) {
final normalizedId = normalize(user.id);
final normalizedUserName = normalize(user.name);
final lDistance = normalizedUserName.levenshteinDistance(normalizedQuery);
final containsId = normalizedId.contains(normalizedQuery);
final containsName = normalizedUserName.contains(normalizedQuery);
if (lDistance < 3 || containsId || containsName) {
matchingUsers[user] = lDistance;
}
}
final entries = matchingUsers.entries.toList(growable: false)
..sort((prev, curr) {
bool containsQuery(User user) =>
normalize(user.id).contains(normalizedQuery) ||
normalize(user.name).contains(normalizedQuery);
final containsInPrev = containsQuery(prev.key);
final containsInCurr = containsQuery(curr.key);
if (containsInPrev && !containsInCurr) {
return -1;
} else if (!containsInPrev && containsInCurr) {
return 1;
}
return prev.value.compareTo(curr.value);
});
return entries.map((e) => e.key).toList(growable: false);
}