Disambiguate some type printing.

Functions of functions use parens for grouping.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/compiler/scala/reflect/internal/Types.scala b/src/compiler/scala/reflect/internal/Types.scala
index 6d4332216c..fa62d00c6a 100644
--- a/src/compiler/scala/reflect/internal/Types.scala
+++ b/src/compiler/scala/reflect/internal/Types.scala
@@ -2095,8 +2095,11 @@ trait Types extends api.Types { self: SymbolTable =>
           // ...but only if it's not a tuple, so ((T1, T2)) => R is distinguishable
           // from (T1, T2) => R.
           targs match {
-            case in :: out :: Nil if !isTupleTypeOrSubtype(in)  =>
-              "" + in + " => " + out
+            case in :: out :: Nil if !isTupleTypeOrSubtype(in) =>
+              // A => B => C should be (A => B) => C or A => (B => C)
+              val in_s  = if (isFunctionType(in)) "(" + in + ")" else "" + in
+              val out_s = if (isFunctionType(out)) "(" + out + ")" else "" + out
+              in_s + " => " + out_s
             case xs =>
               xs.init.mkString("(", ", ", ")") + " => " + xs.last
           }