package eu.eudat.logic.utilities.helpers;

import org.springframework.stereotype.Component;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Function;
import java.util.function.Predicate;

@Component
public class ListHelper {

	public <T> Predicate<T> distinctByKey(Function<? super T, ?> keyExtractor) {
		Map<Object, Boolean> seen = new ConcurrentHashMap<>();
		return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
	}
}