Add regression tests for Tuple and code some cleanup

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -197,6 +197,7 @@ class CompilationTests extends ParallelTesting {
       compileFile("tests/run-custom-args/i5256.scala", allowDeepSubtypes),
       compileFile("tests/run-custom-args/fors.scala", defaultOptions and "-strict"),
       compileFile("tests/run-custom-args/no-useless-forwarders.scala", defaultOptions and "-Xmixin-force-forwarders:false"),
+      compileFilesInDir("tests/run-deep-subtype", allowDeepSubtypes),
       compileFilesInDir("tests/run", defaultOptions)
     ).checkRuns()
   }

library/src-3.x/scala/Tuple.scala

@@ -3,13 +3,15 @@ import annotation.showAsInfix
 import compiletime._
 import internal._
 
+import scala.runtime.DynamicTuple
+
 sealed trait Tuple extends Any {
   import Tuple._
 
   inline def toArray: Array[Object] =
     inline constValueOpt[BoundedSize[this.type]] match {
       case Some(0) =>
-        scala.runtime.DynamicTuple.empty$Array
+        DynamicTuple.empty$Array
       case Some(1) =>
         val t = asInstanceOf[Tuple1[Object]]
         Array(t._1)
@@ -22,12 +24,12 @@ sealed trait Tuple extends Any {
       case Some(4) =>
         val t = asInstanceOf[Tuple4[Object, Object, Object, Object]]
         Array(t._1, t._2, t._3, t._4)
-      case Some(n) if n <= scala.runtime.DynamicTuple.MaxSpecialized =>
-        to$Array(this, n)
+      case Some(n) if n <= DynamicTuple.MaxSpecialized =>
+        DynamicTuple.to$Array(this, n)
       case Some(n) =>
         asInstanceOf[TupleXXL].elems
       case None =>
-        runtime.DynamicTuple.dynamicToArray(this)
+        DynamicTuple.dynamicToArray(this)
     }
 
   inline def *: [H, This >: this.type <: Tuple] (x: H): H *: This = {
@@ -47,9 +49,9 @@ sealed trait Tuple extends Any {
         val t = asInstanceOf[Tuple4[_, _, _, _]]
         Tuple5(x, t._1, t._2, t._3, t._4).asInstanceOf[Result]
       case Some(n) =>
-        knownTupleFromArray[H *: this.type](cons$Array(x, toArray))
+        knownTupleFromArray[H *: this.type](DynamicTuple.cons$Array(x, toArray))
       case _ =>
-        runtime.DynamicTuple.dynamic_*:[This, H](this, x)
+        DynamicTuple.dynamic_*:[This, H](this, x)
     }
   }
 
@@ -72,7 +74,7 @@ sealed trait Tuple extends Any {
             val u = that.asInstanceOf[Tuple2[_, _]]
             Tuple4(t._1, t._2, u._1, u._2).asInstanceOf[Result]
           case _ =>
-            genericConcat[Result](this, that).asInstanceOf[Result]
+            knownTupleFromArray[Result](this.toArray ++ that.toArray)
         }
       case Some(3) =>
         val t = asInstanceOf[Tuple3[_, _, _]]
@@ -82,24 +84,21 @@ sealed trait Tuple extends Any {
             val u = that.asInstanceOf[Tuple1[_]]
             Tuple4(t._1, t._2, t._3, u._1).asInstanceOf[Result]
           case _ =>
-            genericConcat[Result](this, that).asInstanceOf[Result]
+            knownTupleFromArray[Result](this.toArray ++ that.toArray)
         }
       case Some(_) =>
         if (constValue[BoundedSize[that.type]] == 0) this.asInstanceOf[Result]
-        else genericConcat[Result](this, that).asInstanceOf[Result]
+        else knownTupleFromArray[Result](this.toArray ++ that.toArray)
       case None =>
-        runtime.DynamicTuple.dynamic_++[This, that.type](this, that)
+        DynamicTuple.dynamic_++[This, that.type](this, that)
     }
   }
 
-  inline def genericConcat[T <: Tuple](xs: Tuple, ys: Tuple): Tuple =
-    knownTupleFromArray[T](xs.toArray ++ ys.toArray)
-
   inline def size[This >: this.type <: Tuple]: Size[This] = {
     type Result = Size[This]
     inline constValueOpt[BoundedSize[this.type]] match {
       case Some(n) => n.asInstanceOf[Result]
-      case _ => runtime.DynamicTuple.dynamicSize(this)
+      case _ => DynamicTuple.dynamicSize(this)
     }
   }
 
@@ -144,25 +143,7 @@ object Tuple {
 
   private[scala] type BoundedSize[X] = BoundedSizeRecur[X, 23]
 
-  val $emptyArray = Array[Object]()
-
-  def to$Array(xs: Tuple, n: Int) = {
-    val arr = new Array[Object](n)
-    var i = 0
-    var it = xs.asInstanceOf[Product].productIterator
-    while (i < n) {
-      arr(i) = it.next().asInstanceOf[Object]
-      i += 1
-    }
-    arr
-  }
-
-  def cons$Array[H](x: H, elems: Array[Object]): Array[Object] = {
-    val elems1 = new Array[Object](elems.length + 1)
-    elems1(0) = x.asInstanceOf[Object]
-    System.arraycopy(elems, 0, elems1, 1, elems.length)
-    elems1
-  }
+  private[scala] val $emptyArray = Array[Object]()
 
   private[scala] inline def knownTupleFromArray[T <: Tuple](xs: Array[Object]): T =
     inline constValue[BoundedSize[T]] match {
@@ -197,7 +178,7 @@ object Tuple {
       case xs: Array[Object] => xs
       case xs => xs.map(_.asInstanceOf[Object])
     }
-    runtime.DynamicTuple.dynamicFromArray[Tuple](xs2)
+    DynamicTuple.dynamicFromArray[Tuple](xs2)
   }
 
 }
@@ -220,13 +201,13 @@ sealed trait NonEmptyTuple extends Tuple {
       case Some(4) =>
         val t = asInstanceOf[Tuple4[_, _, _, _]]
         t._1
-      case Some(n) if n > 4 && n <= scala.runtime.DynamicTuple.MaxSpecialized =>
+      case Some(n) if n > 4 && n <= DynamicTuple.MaxSpecialized =>
         asInstanceOf[Product].productElement(0)
-      case Some(n) if n > scala.runtime.DynamicTuple.MaxSpecialized =>
+      case Some(n) if n > DynamicTuple.MaxSpecialized =>
         val t = asInstanceOf[TupleXXL]
         t.elems(0)
       case None =>
-        scala.runtime.DynamicTuple.dynamicHead[this.type](this)
+        DynamicTuple.dynamicHead[this.type](this)
     }
     resVal.asInstanceOf[Result]
   }
@@ -251,14 +232,14 @@ sealed trait NonEmptyTuple extends Tuple {
       case Some(n) if n > 5 =>
         knownTupleFromArray[Result](toArray.tail)
       case None =>
-        runtime.DynamicTuple.dynamicTail[This](this)
+        DynamicTuple.dynamicTail[This](this)
     }
   }
 
   inline def fallbackApply(n: Int) =
     inline constValueOpt[n.type] match {
       case Some(n: Int) => error("index out of bounds: ", n)
-      case None => runtime.DynamicTuple.dynamicApply[this.type, n.type](this, n)
+      case None => DynamicTuple.dynamicApply[this.type, n.type](this, n)
     }
 
   inline def apply[This >: this.type <: NonEmptyTuple](n: Int): Elem[This, n.type] = {
@@ -294,13 +275,13 @@ sealed trait NonEmptyTuple extends Tuple {
           case Some(3) => t._4.asInstanceOf[Result]
           case _ => fallbackApply(n).asInstanceOf[Result]
         }
-      case Some(s) if s > 4 && s <= scala.runtime.DynamicTuple.MaxSpecialized =>
+      case Some(s) if s > 4 && s <= DynamicTuple.MaxSpecialized =>
         val t = asInstanceOf[Product]
         inline constValueOpt[n.type] match {
           case Some(n) if n >= 0 && n < s => t.productElement(n).asInstanceOf[Result]
           case _ => fallbackApply(n).asInstanceOf[Result]
         }
-      case Some(s) if s > scala.runtime.DynamicTuple.MaxSpecialized =>
+      case Some(s) if s > DynamicTuple.MaxSpecialized =>
         val t = asInstanceOf[TupleXXL]
         inline constValueOpt[n.type] match {
           case Some(n) if n >= 0 && n < s => t.elems(n).asInstanceOf[Result]

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

@@ -0,0 +1,170 @@
+import scala.reflect.ClassTag
+
+object Test {
+  def main(args: Array[String]): Unit = {
+
+    assert(1 == Tuple1(1).apply(0))
+    assert(1 == (1, 2).apply(0))
+    assert(2 == (1, 2).apply(1))
+    assert(1 == (1, 2, 3).apply(0))
+    assert(2 == (1, 2, 3).apply(1))
+    assert(3 == (1, 2, 3).apply(2))
+    assert(1 == (1, 2, 3, 4).apply(0))
+    assert(2 == (1, 2, 3, 4).apply(1))
+    assert(3 == (1, 2, 3, 4).apply(2))
+    assert(4 == (1, 2, 3, 4).apply(3))
+    assert(1 == (1, 2, 3, 4, 5).apply(0))
+    assert(2 == (1, 2, 3, 4, 5).apply(1))
+    assert(3 == (1, 2, 3, 4, 5).apply(2))
+    assert(4 == (1, 2, 3, 4, 5).apply(3))
+    assert(5 == (1, 2, 3, 4, 5).apply(4))
+    // TODO improve performace
+//    assert(1 == (1, 2, 3, 4, 5, 6).apply(0))
+//    assert(2 == (1, 2, 3, 4, 5, 6).apply(1))
+//    assert(3 == (1, 2, 3, 4, 5, 6).apply(2))
+//    assert(4 == (1, 2, 3, 4, 5, 6).apply(3))
+//    assert(5 == (1, 2, 3, 4, 5, 6).apply(4))
+//    assert(6 == (1, 2, 3, 4, 5, 6).apply(5))
+//    assert(1 == (1, 2, 3, 4, 5, 6, 7).apply(0))
+//    assert(2 == (1, 2, 3, 4, 5, 6, 7).apply(1))
+//    assert(3 == (1, 2, 3, 4, 5, 6, 7).apply(2))
+//    assert(4 == (1, 2, 3, 4, 5, 6, 7).apply(3))
+//    assert(5 == (1, 2, 3, 4, 5, 6, 7).apply(4))
+//    assert(6 == (1, 2, 3, 4, 5, 6, 7).apply(5))
+//    assert(7 == (1, 2, 3, 4, 5, 6, 7).apply(6))
+//    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8).apply(0))
+//    assert(2 == (1, 2, 3, 4, 5, 6, 7, 8).apply(1))
+//    assert(3 == (1, 2, 3, 4, 5, 6, 7, 8).apply(2))
+//    assert(4 == (1, 2, 3, 4, 5, 6, 7, 8).apply(3))
+//    assert(5 == (1, 2, 3, 4, 5, 6, 7, 8).apply(4))
+//    assert(6 == (1, 2, 3, 4, 5, 6, 7, 8).apply(5))
+//    assert(7 == (1, 2, 3, 4, 5, 6, 7, 8).apply(6))
+//    assert(8 == (1, 2, 3, 4, 5, 6, 7, 8).apply(7))
+//    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(0))
+//    assert(2 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(1))
+//    assert(3 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(2))
+//    assert(4 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(3))
+//    assert(5 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(4))
+//    assert(6 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(5))
+//    assert(7 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(6))
+//    assert(8 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(7))
+//    assert(9 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(8))
+//    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(0))
+//    assert(2 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(1))
+//    assert(3 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(2))
+//    assert(4 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(3))
+//    assert(5 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(4))
+//    assert(6 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(5))
+//    assert(7 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(6))
+//    assert(8 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(7))
+//    assert(9 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(8))
+//    assert(10 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(9))
+
+    assert(1 == Tuple1(1).apply(0))
+    assert(1 == (1, 2).apply(0))
+    assert(1 == (1, 2, 3).apply(0))
+    assert(1 == (1, 2, 3, 4).apply(0))
+    assert(1 == (1, 2, 3, 4, 5).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23).apply(0))
+    assert(1 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24).apply(0))
+    assert(1 == (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).apply(0))
+
+    assert(1 == Tuple1(1).apply(0))
+    assert(2 == (1, 2).apply(1))
+    assert(3 == (1, 2, 3).apply(2))
+    assert(4 == (1, 2, 3, 4).apply(3))
+    assert(5 == (1, 2, 3, 4, 5).apply(4))
+    assert(6 == (1, 2, 3, 4, 5, 6).apply(5))
+    assert(7 == (1, 2, 3, 4, 5, 6, 7).apply(6))
+    assert(8 == (1, 2, 3, 4, 5, 6, 7, 8).apply(7))
+    assert(9 == (1, 2, 3, 4, 5, 6, 7, 8, 9).apply(8))
+    assert(10 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10).apply(9))
+    assert(11 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11).apply(10))
+    assert(12 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12).apply(11))
+    assert(13 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13).apply(12))
+    assert(14 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14).apply(13))
+    assert(15 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15).apply(14))
+    assert(16 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16).apply(15))
+    assert(17 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17).apply(16))
+    assert(18 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18).apply(17))
+    assert(19 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19).apply(18))
+    assert(20 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20).apply(19))
+    assert(21 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21).apply(20))
+    assert(22 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22).apply(21))
+    assert(23 == (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23).apply(22))
+    assert(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).apply(23))
+    assert(25 == (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).apply(24))
+
+    assert(1 == (1 *: ()).apply(0))
+    assert(1 == (1 *: 2 *: ()).apply(0))
+    assert(1 == (1 *: 2 *: 3 *: ()).apply(0))
+    assert(1 == (1 *: 2 *: 3 *: 4 *: ()).apply(0))
+    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: ()).apply(0))
+    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: ()).apply(0))
+    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: ()).apply(0))
+    // FIXME performace
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: 23 *: ()).apply(0))
+//    assert(1 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: 23 *: 24 *: ()).apply(0))
+//    assert(1 == (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 *: ()).apply(0))
+
+    assert(1 == (1 *: ()).apply(0))
+    assert(2 == (1 *: 2 *: ()).apply(1))
+    assert(3 == (1 *: 2 *: 3 *: ()).apply(2))
+    assert(4 == (1 *: 2 *: 3 *: 4 *: ()).apply(3))
+    assert(5 == (1 *: 2 *: 3 *: 4 *: 5 *: ()).apply(4))
+    assert(6 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: ()).apply(5))
+    assert(7 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: ()).apply(6))
+    // FIXME performace
+//    assert(8 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: ()).apply(7))
+//    assert(9 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: ()).apply(8))
+//    assert(10 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: ()).apply(9))
+//    assert(11 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: ()).apply(10))
+//    assert(12 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: ()).apply(11))
+//    assert(13 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: ()).apply(12))
+//    assert(14 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: ()).apply(13))
+//    assert(15 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: ()).apply(14))
+//    assert(16 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: ()).apply(15))
+//    assert(17 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: ()).apply(16))
+//    assert(18 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: ()).apply(17))
+//    assert(19 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: ()).apply(18))
+//    assert(20 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: ()).apply(19))
+//    assert(21 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: ()).apply(20))
+//    assert(22 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: ()).apply(21))
+//    assert(23 == (1 *: 2 *: 3 *: 4 *: 5 *: 6 *: 7 *: 8 *: 9 *: 10 *: 11 *: 12 *: 13 *: 14 *: 15 *: 16 *: 17 *: 18 *: 19 *: 20 *: 21 *: 22 *: 23 *: ()).apply(22))
+//    assert(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 *: ()).apply(23))
+//    assert(25 == (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 *: ()).apply(24))
+
+  }
+}