first commit

java/queue/Queue.java

@@ -0,0 +1,56 @@
+package queue;
+
+import java.util.function.Predicate;
+
+/**
+ * @author Doschennikov Nikita (me@fymio.us)
+ */
+public interface Queue {
+    void enqueue(Object element);
+
+    void push(Object element);
+
+    Object element();
+
+    Object peek();
+
+    Object dequeue();
+
+    Object remove();
+
+    int size();
+
+    boolean isEmpty();
+
+    void clear();
+
+    int count(Object element);
+
+    int countIf(Predicate<Object> predicate);
+
+    int indexIf(Predicate<Object> predicate);
+
+    int lastIndexIf(Predicate<Object> predicate);
+
+    int indexOf(Object element);
+
+    int lastIndexOf(Object element);
+
+    boolean contains(Object element);
+
+    boolean removeFirst(Object element);
+
+    Queue getNth(int n);
+
+    Queue removeNth(int n);
+
+    void dropNth(int n);
+
+    void removeIf(java.util.function.Predicate<Object> predicate);
+
+    void retainIf(java.util.function.Predicate<Object> predicate);
+
+    void removeAll(Object element);
+
+    void retainAll(Object element);
+}