Amend

src/main/java/org/jianzhao/sugar/Sugar.java

@@ -85,6 +85,21 @@ public static <T> void forEach(List<T> list, Consumer<? super T> action) {
  list.forEach(action);
  }
 
+ public static <T> T findFirst(List<T> list, Predicate<? super T> predicate) {
+ List<T> filtered = filter(list, predicate);
+ if (isEmpty(filtered)) {
+ return null;
+ }
+ return filtered.get(0);
+ }
+
+ public static <T> boolean every(List<T> list, Predicate<? super T> predicate) {
+ if (isEmpty(list)) {
+ return false;
+ }
+ return list.stream().allMatch(predicate);
+ }
+
  public static <T> List<T> distinct(List<T> list, Function<? super T, ?> keyExtractor) {
  Objects.requireNonNull(keyExtractor);
  Set<Object> seen = new HashSet<>();
@@ -174,10 +189,6 @@ public static <T, K, V> Map<K, List<V>> groupToMap(List<T> list,
  Collectors.groupingBy(keyExtractor, Collectors.mapping(valueExtractor, Collectors.toList())));
  }
 
- public static <T> boolean includes(List<T> list, T item) {
- return includes(list, Predicate.isEqual(item));
- }
-
  public static <T> boolean includes(List<T> list, Predicate<? super T> predicate) {
  if (isEmpty(list)) {
  return false;

src/test/java/org/jianzhao/sugar/SugarTest.java

@@ -137,9 +137,8 @@ public void testGroupToMap() {
  @Test
  public void testIncludes() {
  val list = listOf(3, 1, 4, 1, 5, 9, 2, 6);
- assertTrue(includes(list, 3));
- assertFalse(includes(list, 7));
- assertFalse(includes(list, (Predicate<Integer>) it -> it < 0));
+ assertTrue(includes(list, Predicate.isEqual(5)));
+ assertFalse(includes(list, it -> it < 0));
  }
 
  @Test
@@ -152,4 +151,17 @@ public void testCollectionShortcut() {
  );
  assertTrue(c.get(1).get("2").contains(Pair.of("c", "C")));
  }
+
+ @Test
+ public void testEvery() {
+ val list = listOf(3, 1, 4, 1, 5, 9);
+ assertTrue(every(list, it -> it > 0));
+ }
+
+ @Test
+ public void testFindFirst() {
+ val list = listOf(3, 1, 4, 1, 5, 9);
+ val first = findFirst(list, it -> it > 3);
+ assertEquals(4, first);
+ }
 }