Merge pull request scala#6762 from pathikrit/2.13.x

DRY up some common remove utils from mutable.Queue to ArrayDeque

Author: szeiger

src/library/scala/collection/mutable/ArrayDeque.scala

@@ -367,6 +367,43 @@ class ArrayDeque[A] protected (
     elems.result()
   }
 
+  /** Returns the first element which satisfies the given predicate after or at some start index
+    * and removes this element from the collections
+    *
+    *  @param p   the predicate used for choosing the first element
+    *  @param from the start index
+    *  @return the first element of the queue for which p yields true
+    */
+  def removeFirst(p: A => Boolean, from: Int = 0): Option[A] = {
+    val i = indexWhere(p, from)
+    if (i < 0) None else Some(remove(i))
+  }
+
+  /** Returns all elements in this collection which satisfy the given predicate
+    * and removes those elements from this collections.
+    *
+    *  @param p   the predicate used for choosing elements
+    *  @return    a sequence of all elements in the queue for which
+    *             p yields true.
+    */
+  def removeAll(p: A => Boolean): scala.collection.immutable.Seq[A] = {
+    val res = scala.collection.immutable.Seq.newBuilder[A]
+    var i, j = 0
+    while (i < size) {
+      if (p(this(i))) {
+        res += this(i)
+      } else {
+        if (i != j) {
+          this(j) = this(i)
+        }
+        j += 1
+      }
+      i += 1
+    }
+    if (i != j) takeInPlace(j)
+    res.result()
+  }
+
   override def reverse: IterableCC[A] = {
     val n = length
     val arr = ArrayDeque.alloc(n)
@@ -399,7 +436,7 @@ class ArrayDeque[A] protected (
   }
 
   /**
-    * clears this buffer and shrinks to @param size
+    * Clears this buffer and shrinks to @param size
     *
     * @param size
     * @return

src/library/scala/collection/mutable/Queue.scala

@@ -76,41 +76,25 @@ class Queue[A] protected (array: Array[AnyRef], start: Int, end: Int)
     *  @return the first element of the queue for which p yields true
     */
   def dequeueFirst(p: A => Boolean): Option[A] =
-    if (isEmpty) None
-    else if (p(head)) {
-      val res = Some(head)
-      removeHead()
-      res
-    } else {
-      val i = indexWhere(p)
-      if (i < 0) None
-      else Some(remove(i))
-    }
-
-   /** Returns all elements in the queue which satisfy the
-   *  given predicate, and removes those elements from the queue.
-   *
-   *  @param p   the predicate used for choosing elements
-   *  @return    a sequence of all elements in the queue for which
-   *             p yields true.
-   */
-  def dequeueAll(p: A => Boolean): scala.collection.immutable.Seq[A] = {
-    val res = scala.collection.immutable.Seq.newBuilder[A]
-    var i, j = 0
-    while (i < size) {
-      if (p(apply(i))) {
-        res += this(i)
-      } else {
-        if (i != j) {
-          this(j) = this(i)
-        }
-        j += 1
-      }
-      i += 1
-    }
-    if (i != j) takeInPlace(j)
-    res.result()
-  }
+    removeFirst(p)
+
+  /** Returns all elements in the queue which satisfy the
+    *  given predicate, and removes those elements from the queue.
+    *
+    *  @param p   the predicate used for choosing elements
+    *  @return    a sequence of all elements in the queue for which
+    *             p yields true.
+    */
+  def dequeueAll(p: A => Boolean): scala.collection.immutable.Seq[A] =
+    removeAll(p)
+
+  /**
+    * Returns and dequeues all elements from the queue which satisfy the given predicate
+    *
+    *  @param f   the predicate used for choosing elements
+    *  @return The removed elements
+    */
+  def dequeueWhile(f: A => Boolean): scala.collection.Seq[A] = removeHeadWhile(f)
 
   /** Returns the first element in the queue, or throws an error if there
     *  is no element contained in the queue.