Added orElse to Type.

Tree and Symbol each have the analogous method, so consistency
calls along with utility for putting it on Type.

2 files changed, 8 insertions, 0 deletions

diff --git a/src/reflect/scala/reflect/api/Types.scala b/src/reflect/scala/reflect/api/Types.scala
index 1152f97350..0291d5d26f 100644
--- a/src/reflect/scala/reflect/api/Types.scala
+++ b/src/reflect/scala/reflect/api/Types.scala
@@ -209,6 +209,12 @@ trait Types {
 
     /******************* helpers *******************/
 
+    /** Provides an alternate if type is NoType.
+     *
+     *  @group Helpers
+     */
+    def orElse(alt: => Type): Type
+
     /** Substitute symbols in `to` for corresponding occurrences of references to
      *  symbols `from` in this type.
      */
diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala
index cd41f533bb..86115e7174 100644
--- a/src/reflect/scala/reflect/internal/Types.scala
+++ b/src/reflect/scala/reflect/internal/Types.scala
@@ -742,6 +742,8 @@ trait Types
       def map[T](f: Type => T): List[T]  = collect(Type.this) map f
     }
 
+    @inline final def orElse(alt: => Type): Type = if (this ne NoType) this else alt
+
     /** Returns optionally first type (in a preorder traversal) which satisfies predicate `p`,
      *  or None if none exists.
      */