Type parameters in method/function signatures are no longer auto-declared. Although

convenient and concise, the auto-declare behavior has on many occasions caused
confusion when a type name has accidentally been mistyped (and Dafny had then
accepted and auto-declared the name).
Note, the behavior of filling in missing type parameters is still supported.  This
mode, although unusual (even original?) in languages, is different from the auto-
declare behavior.  For auto-declare, identifiers could be used in the program
without having a declaration.  For fill-in parameters, the implicitly declared
type parameters remain anonymous.

1 files changed, 1 insertions, 1 deletions

diff --git a/Test/dafny0/NestedMatch.dfy b/Test/dafny0/NestedMatch.dfy
index e6e7c489..81319b4a 100644
--- a/Test/dafny0/NestedMatch.dfy
+++ b/Test/dafny0/NestedMatch.dfy
@@ -28,7 +28,7 @@ function last<T>(xs: List<T>): T
   case Cons(y, Cons(z, zs)) => last(Cons(z, zs))

 }

 

-method checkLast(y: T) {

+method checkLast<T>(y: T) {

   assert last(Cons(y, Nil)) == y;

   assert last(Cons(y, Cons(y, Nil))) == last(Cons(y, Nil));

 }