Add higher-order-functions and some other goodies

  * The reads clause now needs to be self framing.

  * The requires clause now needs to be framed by the reads clause.

  * There are one-shot lambdas, with a single arrow, but they will probably be
    removed.

  * There is a {:heapQuantifier} attribute to quantifiers, but they will
    probably be removed.

  * Add smart handling of type variables

  * Add < and > for datatype & type parameter

1 files changed, 50 insertions, 0 deletions

diff --git a/Test/hofs/Classes.dfy b/Test/hofs/Classes.dfy
new file mode 100644
index 00000000..91d7e384
--- /dev/null
+++ b/Test/hofs/Classes.dfy
@@ -0,0 +1,50 @@
+// RUN: %dafny /compile:0 "%s" > "%t"
+// RUN: %diff "%s.expect" "%t"
+
+
+class C {
+  static function method Static() : bool
+  {
+    true
+  }
+}
+
+method K() {
+  var f := C.Static;
+  var o : object;
+  assert o !in f.reads();
+  assert f.requires();
+  assert f();
+}
+
+
+class T {
+  var h : int -> int;
+}
+
+function B(t : T) : int -> int
+  requires t != null;
+  reads t;
+{
+  t.h
+}
+
+function J(t : T) : int
+  requires t != null;
+  requires t.h.reads(0) == {};
+  reads t;
+  reads if t != null then t.h.reads(0) else {};
+{
+  if t.h.requires(0) then
+    B(t)(0)
+  else
+    B(t)(0)  // fail
+}
+
+method U(t : T)
+  requires t != null;
+  modifies t;
+{
+  t.h := x => x;
+  assert J(t) == 0; // ok
+}