Wrote tests for take and drop

Author: Antoine Brunner

library/src/scala/runtime/DynamicTuple.scala

@@ -265,27 +265,36 @@ object DynamicTuple {
   }
 
   def dynamicTake[This <: Tuple, N <: Int](self: This, n: N): Take[This, N] = {
+    if (n < 0) throw new IndexOutOfBoundsException(n.toString)
+    val actualN = Math.min(n, self.size)
+
     type Result = Take[This, N]
     val arr = (self: Any) match {
+      case () => Array.empty[Object]
       case xxl: TupleXXL =>
-        xxl.elems.asInstanceOf[Array[Object]].take(n)
+        xxl.elems.asInstanceOf[Array[Object]].take(actualN)
       case _ =>
-        val arr = new Array[Object](n)
-        itToArray(self.asInstanceOf[Product].productIterator, n, arr, 0)
+        val arr = new Array[Object](actualN)
+        itToArray(self.asInstanceOf[Product].productIterator, actualN, arr, 0)
         arr
     }
     dynamicFromIArray(arr.asInstanceOf[IArray[Object]]).asInstanceOf[Result]
   }
 
   def dynamicDrop[This <: Tuple, N <: Int](self: This, n: N): Drop[This, N] = {
+    if (n < 0) throw new IndexOutOfBoundsException(n.toString)
+    val size = self.size
+    val actualN = Math.min(n, size)
+
     type Result = Drop[This, N]
     val arr = (self: Any) match {
+      case () => Array.empty[Object]
       case xxl: TupleXXL =>
-        xxl.elems.asInstanceOf[Array[Object]].drop(n)
+        xxl.elems.asInstanceOf[Array[Object]].drop(actualN)
       case _ =>
-        val size = self.asInstanceOf[Product].productArity - n
-        val arr = new Array[Object](size)
-        itToArray(self.asInstanceOf[Product].productIterator.drop(n), size, arr, 0)
+        val rem = size - actualN
+        val arr = new Array[Object](rem)
+        itToArray(self.asInstanceOf[Product].productIterator.drop(actualN), rem, arr, 0)
         arr
     }
     dynamicFromIArray(arr.asInstanceOf[IArray[Object]]).asInstanceOf[Result]
@@ -294,6 +303,7 @@ object DynamicTuple {
   def dynamicSplitAt[This <: Tuple, N <: Int](self: This, n: N): Split[This, N] = {
     type Result = Split[This, N]
     val (arr1, arr2) = (self: Any) match {
+      case () => (Array.empty[Object], Array.empty[Object])
       case xxl: TupleXXL =>
         xxl.elems.asInstanceOf[Array[Object]].splitAt(n)
       case _ =>

tests/run/tuple-drop.check

@@ -0,0 +1,14 @@
+()
+()
+()
+(1,2,3,4,5)
+(2,3,4,5)
+(4,5)
+()
+()
+(11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35)
+(12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35)
+(21,22,23,24,25,26,27,28,29,30,31,32,33,34,35)
+(31,32,33,34,35)
+()
+()

tests/run/tuple-drop.scala

@@ -0,0 +1,23 @@
+
+object Test extends App {
+  val emptyTuple: Tuple = ()
+  val tuple: Tuple = ("1", "2", "3", "4", "5")
+  val tupleXXL: Tuple = ("11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35")
+
+  println(emptyTuple.drop(0))
+  println(emptyTuple.drop(1))
+  println(emptyTuple.drop(10))
+
+  println(tuple.drop(0))
+  println(tuple.drop(1))
+  println(tuple.drop(3))
+  println(tuple.drop(5))
+  println(tuple.drop(10))
+
+  println(tupleXXL.drop(0))
+  println(tupleXXL.drop(1))
+  println(tupleXXL.drop(10))
+  println(tupleXXL.drop(20))
+  println(tupleXXL.drop(25))
+  println(tupleXXL.drop(30))
+}

tests/run/tuple-take.check

@@ -0,0 +1,15 @@
+()
+()
+()
+()
+()
+(1)
+(1,2,3)
+(1,2,3,4,5)
+(1,2,3,4,5)
+()
+(11)
+(11,12,13,14,15,16,17,18,19,20)
+(11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30)
+(11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35)
+(11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35)

tests/run/tuple-take.scala

@@ -0,0 +1,24 @@
+
+object Test extends App {
+  val emptyTuple: Tuple = ()
+  val tuple: Tuple = ("1", "2", "3", "4", "5")
+  val tupleXXL: Tuple = ("11", "12", "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34", "35")
+
+  println(emptyTuple.take(0))
+  println(emptyTuple.take(0))
+  println(emptyTuple.take(1))
+  println(emptyTuple.take(10))
+
+  println(tuple.take(0))
+  println(tuple.take(1))
+  println(tuple.take(3))
+  println(tuple.take(5))
+  println(tuple.take(10))
+
+  println(tupleXXL.take(0))
+  println(tupleXXL.take(1))
+  println(tupleXXL.take(10))
+  println(tupleXXL.take(20))
+  println(tupleXXL.take(25))
+  println(tupleXXL.take(30))
+}