Move scala.deriving to src-{non-}bootstrapped library

Author: nicolasstucki

library/src/scala/deriving.scala renamed to library/src-bootstrapped/scala/deriving.scala

@@ -0,0 +1,74 @@
+package scala
+
+// non bootstrapped
+
+object deriving {
+
+  /** Mirrors allows typelevel access to enums, case classes and objects, and their sealed parents.
+   */
+  sealed trait Mirror {
+
+    /** The mirrored *-type */
+    type MirroredMonoType
+
+    /** The name of the type */
+    type MirroredLabel <: String
+
+    /** The names of the product elements */
+    type MirroredElemLabels <: Tuple
+  }
+
+  object Mirror {
+
+    /** The Mirror for a sum type */
+    trait Sum extends Mirror { self =>
+      /** The ordinal number of the case class of `x`. For enums, `ordinal(x) == x.ordinal` */
+      def ordinal(x: MirroredMonoType): Int
+    }
+
+    /** The Mirror for a product type */
+    trait Product extends Mirror {
+
+      /** Create a new instance of type `T` with elements taken from product `p`. */
+      def fromProduct(p: scala.Product): MirroredMonoType
+    }
+
+    trait Singleton extends Product {
+      type MirroredMonoType = this.type
+      type MirroredType = this.type
+      type MirroredElemTypes = Unit
+      type MirroredElemLabels = Unit
+      def fromProduct(p: scala.Product) = this
+    }
+
+    /** A proxy for Scala 2 singletons, which do not inherit `Singleton` directly */
+    class SingletonProxy(val value: AnyRef) extends Product {
+      type MirroredMonoType = value.type
+      type MirroredType = value.type
+      type MirroredElemTypes = Unit
+      type MirroredElemLabels = Unit
+      def fromProduct(p: scala.Product) = value
+    }
+
+    type Of[T]        = Mirror { type MirroredType = T; type MirroredMonoType = T ; type MirroredElemTypes <: Tuple }
+    type ProductOf[T] = Mirror.Product { type MirroredType = T; type MirroredMonoType = T ; type MirroredElemTypes <: Tuple }
+    type SumOf[T]     = Mirror.Sum { type MirroredType = T; type MirroredMonoType = T; type MirroredElemTypes <: Tuple }
+  }
+
+  /** Helper class to turn arrays into products */
+  class ArrayProduct(val elems: Array[AnyRef]) extends Product {
+    def this(size: Int) = this(new Array[AnyRef](size))
+    def canEqual(that: Any): Boolean = true
+    def productElement(n: Int) = elems(n)
+    def productArity = elems.length
+    override def productIterator: Iterator[Any] = elems.iterator
+    def update(n: Int, x: Any) = elems(n) = x.asInstanceOf[AnyRef]
+  }
+
+  /** The empty product */
+  object EmptyProduct extends ArrayProduct(Array.emptyObjectArray)
+
+  /** Helper method to select a product element */
+  def productElement[T](x: Any, idx: Int) =
+    x.asInstanceOf[Product].productElement(idx).asInstanceOf[T]
+}