Add append operator to Tuple

library/src/scala/Tuple.scala

@@ -21,6 +21,11 @@ sealed trait Tuple extends Product {
   inline def toIArray: IArray[Object] =
     runtime.Tuples.toIArray(this)
 
+  /** Return a copy of `this` tuple with an element appended */
+  @experimental
+  inline def :* [This >: this.type <: Tuple, L] (x: L): Append[This, L] =
+    runtime.Tuples.append(x, this).asInstanceOf[Append[This, L]]
+
   /** Return a new tuple by prepending the element to `this` tuple.
    *  This operation is O(this.size)
    */
@@ -78,6 +83,13 @@ sealed trait Tuple extends Product {
 
 object Tuple {
 
+  /** Type of a tuple with an element appended */
+  @experimental
+  type Append[X <: Tuple, Y] <: Tuple = X match {
+    case EmptyTuple => Y *: EmptyTuple
+    case x *: xs => x *: Append[xs, Y]
+  }
+
   /** Type of the head of a tuple */
   type Head[X <: NonEmptyTuple] = X match {
     case x *: _ => x

library/src/scala/runtime/Tuples.scala

@@ -357,6 +357,82 @@ object Tuples {
     case _ => specialCaseTail(self)
   }
 
+  // Append for TupleXXL
+  private def xxlAppend(x: Any, xxl: TupleXXL): TupleXXL = {
+    val arr = new Array[Object](xxl.productArity + 1)
+    arr(xxl.productArity) = x.asInstanceOf[Object]
+    System.arraycopy(xxl.elems, 0, arr, 0, xxl.productArity)
+    TupleXXL.fromIArray(arr.asInstanceOf[IArray[Object]])
+  }
+
+  // Append for Tuple1 to Tuple22
+  private def specialCaseAppend(x: Any, self: Tuple): Tuple = {
+    (self: Any) match {
+      case EmptyTuple =>
+        Tuple1(x)
+      case self: Tuple1[_] =>
+        Tuple2(self._1, x)
+      case self: Tuple2[_, _] =>
+        Tuple3(self._1, self._2, x)
+      case self: Tuple3[_, _, _] =>
+        Tuple4(self._1, self._2, self._3, x)
+      case self: Tuple4[_, _, _, _] =>
+        Tuple5(self._1, self._2, self._3, self._4, x)
+      case self: Tuple5[_, _, _, _, _] =>
+        Tuple6(self._1, self._2, self._3, self._4, self._5, x)
+      case self: Tuple6[_, _, _, _, _, _] =>
+        Tuple7(self._1, self._2, self._3, self._4, self._5, self._6, x)
+      case self: Tuple7[_, _, _, _, _, _, _] =>
+        Tuple8(self._1, self._2, self._3, self._4, self._5, self._6, self._7, x)
+      case self: Tuple8[_, _, _, _, _, _, _, _] =>
+        Tuple9(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, x)
+      case self: Tuple9[_, _, _, _, _, _, _, _, _] =>
+        Tuple10(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, x)
+      case self: Tuple10[_, _, _, _, _, _, _, _, _, _] =>
+        Tuple11(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, x)
+      case self: Tuple11[_, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple12(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, x)
+      case self: Tuple12[_, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple13(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, x)
+      case self: Tuple13[_, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple14(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, x)
+      case self: Tuple14[_, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple15(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, x)
+      case self: Tuple15[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple16(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, x)
+      case self: Tuple16[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple17(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, self._16, x)
+      case self: Tuple17[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple18(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, self._16, self._17, x)
+      case self: Tuple18[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple19(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, self._16, self._17, self._18, x)
+      case self: Tuple19[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple20(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, self._16, self._17, self._18, self._19, x)
+      case self: Tuple20[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple21(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, self._16, self._17, self._18, self._19, self._20, x)
+      case self: Tuple21[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        Tuple22(self._1, self._2, self._3, self._4, self._5, self._6, self._7, self._8, self._9, self._10, self._11, self._12, self._13, self._14, self._15, self._16, self._17, self._18, self._19, self._20, self._21, x)
+      case self: Tuple22[_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _] =>
+        val arr: Array[Object] = Array(
+          self._1.asInstanceOf[Object], self._2.asInstanceOf[Object],
+          self._3.asInstanceOf[Object], self._4.asInstanceOf[Object], self._5.asInstanceOf[Object],
+          self._6.asInstanceOf[Object], self._7.asInstanceOf[Object], self._8.asInstanceOf[Object],
+          self._9.asInstanceOf[Object], self._10.asInstanceOf[Object], self._11.asInstanceOf[Object],
+          self._12.asInstanceOf[Object], self._13.asInstanceOf[Object], self._14.asInstanceOf[Object],
+          self._15.asInstanceOf[Object], self._16.asInstanceOf[Object], self._17.asInstanceOf[Object],
+          self._18.asInstanceOf[Object], self._19.asInstanceOf[Object], self._20.asInstanceOf[Object],
+          self._21.asInstanceOf[Object], self._22.asInstanceOf[Object], x.asInstanceOf[Object]
+        )
+        TupleXXL.fromIArray(arr.asInstanceOf[IArray[Object]]).asInstanceOf[Tuple]
+    }
+  }
+
+  @experimental
+  def append(x: Any, self: Tuple): Tuple = (self: Any) match {
+    case xxl: TupleXXL => xxlAppend(x, xxl).asInstanceOf[Tuple]
+    case _ => specialCaseAppend(x, self)
+  }
+
   // Init for TupleXXL
   private def xxlInit(xxl: TupleXXL): Tuple = {
     if (xxl.productArity == 23) {

project/MiMaFilters.scala

@@ -6,6 +6,7 @@ object MiMaFilters {
   val Library: Seq[ProblemFilter] = Seq(
     // Experimental APIs that can be added in 3.2.0
     ProblemFilters.exclude[DirectMissingMethodProblem]("scala.runtime.Tuples.init"),
-    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.runtime.Tuples.last")
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.runtime.Tuples.last"),
+    ProblemFilters.exclude[DirectMissingMethodProblem]("scala.runtime.Tuples.append")
   )
 }

tests/run-deep-subtype/Tuple-append.check

@@ -0,0 +1,76 @@
+(0)
+(0,1)
+(0,1,2)
+(0,1,2,3)
+(0,1,2,3,4)
+(0,1,2,3,4,5)
+(0,1,2,3,4,5,6)
+(0,1,2,3,4,5,6,7)
+(0,1,2,3,4,5,6,7,8)
+(0,1,2,3,4,5,6,7,8,9)
+(0,1,2,3,4,5,6,7,8,9,10)
+(0,1,2,3,4,5,6,7,8,9,10,11)
+(0,1,2,3,4,5,6,7,8,9,10,11,12)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24)
+(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25)
+(1)
+(1,2)
+(1,2,3)
+(1,2,3,4)
+(1,2,3,4,5)
+(1,2,3,4,5,6)
+(1,2,3,4,5,6,7)
+(1,2,3,4,5,6,7,8)
+(1,2,3,4,5,6,7,8,9)
+(1,2,3,4,5,6,7,8,9,10)
+(1,2,3,4,5,6,7,8,9,10,11)
+(1,2,3,4,5,6,7,8,9,10,11,12)
+(1,2,3,4,5,6,7,8,9,10,11,12,13)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25)
+(1)
+(1,2)
+(1,2,3)
+(1,2,3,4)
+(1,2,3,4,5)
+(1,2,3,4,5,6)
+(1,2,3,4,5,6,7)
+(1,2,3,4,5,6,7,8)
+(1,2,3,4,5,6,7,8,9)
+(1,2,3,4,5,6,7,8,9,10)
+(1,2,3,4,5,6,7,8,9,10,11)
+(1,2,3,4,5,6,7,8,9,10,11,12)
+(1,2,3,4,5,6,7,8,9,10,11,12,13)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24)
+(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25)

tests/run-deep-subtype/Tuple-append.scala

@@ -0,0 +1,65 @@
+import scala.reflect.ClassTag
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    def testArray[T: ClassTag](n: Int, elem: Int => T): Unit = {
+      val t: Tuple = Tuple.fromArray(Array.tabulate(n)(elem))
+      println(t :* n)
+    }
+
+    for (i <- 0 to 25)
+      testArray(i, j => j)
+
+    println(Tuple() :* 1)
+    println(Tuple1(1) :* 2)
+    println((1, 2) :* 3)
+    println((1, 2, 3) :* 4)
+    println((1, 2, 3, 4) :* 5)
+    println((1, 2, 3, 4, 5) :* 6)
+    println((1, 2, 3, 4, 5, 6) :* 7)
+    println((1, 2, 3, 4, 5, 6, 7) :* 8)
+    println((1, 2, 3, 4, 5, 6, 7, 8) :* 9)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9) :* 10)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10) :* 11)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11) :* 12)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) :* 13)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13) :* 14)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14) :* 15)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15) :* 16)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16) :* 17)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17) :* 18)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18) :* 19)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19) :* 20)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20) :* 21)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21) :* 22)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22) :* 23)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23) :* 24)
+    println((1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24) :* 25)
+
+    println(EmptyTuple :* 1)
+    println((1 *: Tuple()) :* 2)
+    println((1 *: 2 *: Tuple()) :* 3)
+    println((1 *: 2 *: 3 *: Tuple()) :* 4)
+    println((1 *: 2 *: 3 *: 4 *: Tuple()) :* 5)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: Tuple()) :* 6)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: Tuple()) :* 7)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: Tuple()) :* 8)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: Tuple()) :* 9)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: Tuple()) :* 10)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: Tuple()) :* 11)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: Tuple()) :* 12)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: Tuple()) :* 13)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: Tuple()) :* 14)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: Tuple()) :* 15)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: Tuple()) :* 16)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: Tuple()) :* 17)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: Tuple()) :* 18)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: Tuple()) :* 19)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: Tuple()) :* 20)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: Tuple()) :* 21)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: Tuple()) :* 22)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: Tuple()) :* 23)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: 23 *: Tuple()) :* 24)
+    println((1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: 23 *: 24 *: Tuple()) :* 25)
+  }
+}