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, 2 insertions, 2 deletions

diff --git a/Test/hofs/Twice.dfy b/Test/hofs/Twice.dfy
index add7e83c..5d948a58 100644
--- a/Test/hofs/Twice.dfy
+++ b/Test/hofs/Twice.dfy
@@ -1,7 +1,7 @@
 // RUN: %dafny /print:"%t.print" "%s" > "%t"
 // RUN: %diff "%s.expect" "%t"
 
-function method Twice(f : A -> A): A -> A
+function method Twice<A>(f : A -> A): A -> A
 {
   x requires f.requires(x) && f.requires(f(x))
     reads f.reads(x) reads if f.requires(x) then f.reads(f(x)) else {}
@@ -29,7 +29,7 @@ method WithReads() {
 }
 
 
-function method Twice_bad(f : A -> A): A -> A
+function method Twice_bad<A>(f : A -> A): A -> A
 {
   x requires f.requires(x) && f.requires(f(x))
     reads f.reads(x) + f.reads(f(x))