Reinstate closures.brat accidentally zapped by #117

Author: acl-cqc

brat/test/compilation/closures.brat

@@ -1,2 +1,17 @@
 f(Nat) -> { Nat -> Nat }
 f(x) = { y => x + y }
+
+g(Nat) -> { Nat -> { Nat -> Nat } }
+g(x) = { y => { z => x + y + z } }
+
+
+h(Nat) -> { Nat -> Nat }
+h(x) = let y = x in { z => x + y + z }
+
+ff(Vec(Nat,2)) -> { Nat -> Nat }
+ff([a,b]) = { y => a + b*y }
+
+ext "to_float" i2f :: {Int -> Float}
+
+fi(Float) -> { Int -> Float }
+fi(x) = { y => x + i2f(y) }