Made the additions to Predef described in #3762.

reminding me or someone to deprecate in 2.9. No review.

2 files changed, 33 insertions, 22 deletions

diff --git a/src/library/scala/Predef.scala b/src/library/scala/Predef.scala
index 2c60a8e8a8..491d9e3901 100644
--- a/src/library/scala/Predef.scala
+++ b/src/library/scala/Predef.scala
@@ -6,8 +6,6 @@
 **                          |/                                          **
 \*                                                                      */
 
-
-
 package scala
 
 import scala.collection.{ mutable, immutable, generic }
@@ -41,25 +39,32 @@ object Predef extends LowPriorityImplicits {
   val Map         = immutable.Map
   val Set         = immutable.Set
 
-  type Manifest[T] = scala.reflect.Manifest[T]
+  // Manifest types, companions, and incantations for summoning
   type ClassManifest[T] = scala.reflect.ClassManifest[T]
-  def implicitly[T](implicit e: T) = e
-  def manifest[T](implicit m: Manifest[T]) = m
-  def classManifest[T](implicit m: ClassManifest[T]) = m
+  type Manifest[T]      = scala.reflect.Manifest[T]
+  type OptManifest[T]   = scala.reflect.OptManifest[T]
+  val ClassManifest     = scala.reflect.ClassManifest
+  val Manifest          = scala.reflect.Manifest
+  val NoManifest        = scala.reflect.NoManifest
 
-  // @see `conforms` for the implicit version
-  def identity[A](x: A): A = x
-
-  def currentThread = java.lang.Thread.currentThread()
+  def manifest[T](implicit m: Manifest[T])           = m
+  def classManifest[T](implicit m: ClassManifest[T]) = m
+  def optManifest[T](implicit m: OptManifest[T])     = m
 
-  @inline def locally[T](x: T): T = x
+  // Minor variations on identity functions
+  def identity[A](x: A): A         = x    // @see `conforms` for the implicit version
+  def implicitly[T](implicit e: T) = e    // for summoning implicit values from the nether world
+  @inline def locally[T](x: T): T  = x    // to communicate intent and avoid unmoored statements
 
   // errors and asserts -------------------------------------------------
 
+  // @deprecated("Throw your own exceptions") // deprecation waiting for 2.9
   def error(message: String): Nothing = throw new RuntimeException(message)
 
+  // @deprecated("Use System.exit instead") // deprecation waiting for 2.9
   def exit(): Nothing = exit(0)
 
+  // @deprecated("Use System.exit(status) instead") // deprecation waiting for 2.9
   def exit(status: Int): Nothing = {
     java.lang.System.exit(status)
     throw new Throwable()
@@ -180,6 +185,8 @@ object Predef extends LowPriorityImplicits {
   def println() = Console.println()
   def println(x: Any) = Console.println(x)
   def printf(text: String, xs: Any*) = Console.print(format(text, xs: _*))
+  // deprecation waiting for 2.9
+  // @deprecated("Use formatString.format(args: _*) or arg.formatted(formatString) instead")
   def format(text: String, xs: Any*) = augmentString(text).format(xs: _*)
 
   def readLine(): String = Console.readLine()
@@ -211,18 +218,18 @@ object Predef extends LowPriorityImplicits {
       def foreach[U](f: ((El1, El2, El3)) => U): Unit = zz foreach Function.untupled(f)
     }
 
-  implicit def genericArrayOps[T](xs: Array[T]): ArrayOps[T] = (xs: AnyRef) match { // !!! drop the AnyRef and get unreachable code errors!
-    case x: Array[AnyRef] => refArrayOps[AnyRef](x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Int] => intArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Double] => doubleArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Long] => longArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Float] => floatArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Char] => charArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Byte] => byteArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Short] => shortArrayOps(x).asInstanceOf[ArrayOps[T]]
+  implicit def genericArrayOps[T](xs: Array[T]): ArrayOps[T] = xs match {
+    case x: Array[AnyRef]  => refArrayOps[AnyRef](x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Int]     => intArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Double]  => doubleArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Long]    => longArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Float]   => floatArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Char]    => charArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Byte]    => byteArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case x: Array[Short]   => shortArrayOps(x).asInstanceOf[ArrayOps[T]]
     case x: Array[Boolean] => booleanArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case x: Array[Unit] => unitArrayOps(x).asInstanceOf[ArrayOps[T]]
-    case null => null
+    case x: Array[Unit]    => unitArrayOps(x).asInstanceOf[ArrayOps[T]]
+    case null              => null
   }
 
   implicit def refArrayOps[T <: AnyRef](xs: Array[T]): ArrayOps[T] = new ArrayOps.ofRef[T](xs)
@@ -348,6 +355,8 @@ object Predef extends LowPriorityImplicits {
   }
 
   // less useful due to #2781
+  // @deprecated("Use From => To instead")
+  // ...intended for 2.9 unless someone can point out anything <%< offers over =>
   sealed abstract class <%<[-From, +To] extends (From => To)
   object <%< {
     implicit def conformsOrViewsAs[A <% B, B]: A <%< B = new (A <%< B) {def apply(x: A) = x}
diff --git a/src/library/scala/package.scala b/src/library/scala/package.scala
index 69966d003b..2931722dba 100644
--- a/src/library/scala/package.scala
+++ b/src/library/scala/package.scala
@@ -71,6 +71,8 @@ package object scala {
   // Migrated from Predef
 
   val $scope = scala.xml.TopScope
+
+  // @deprecated("Use Thread.currentThread instead") // waiting for 2.9
   def currentThread = java.lang.Thread.currentThread()
 
   // Numeric types which were moved into scala.math.*