Add lab8

esperimenti/Program.fs

@@ -21,3 +21,6 @@ printfn "%b" (isPippo(numOfStringsContainingAs [|"a";"a";"a";"a"|] |> numeroPipp
 printfn "%b" (isPippo(numOfStringsContainingAs [|"a";"a";"a"|] |> numeroPippo))
 printfn "%b" (isPippo(parolaPippo("pipo")))
 printfn "%b" (isPippo(parolaPippo("pippo")))
+
+let s = Seq.initInfinite (fun s -> s*s)
+Seq.toList (Seq.take 10 s)

lab8/Program.fs

@@ -0,0 +1,35 @@
+// identificatori
+type ide = string
+
+type aexp =
+  | AEint of int
+  | AEplus of (aexp * aexp)
+  | AEminus of (aexp * aexp)
+  | AElet of (ide * aexp * aexp)
+  | AEide of ide
+
+let rec aexp_to_string : aexp -> string =
+  fun e ->
+    match e with
+      AEint i -> sprintf "%d" i
+      | AEplus (e,f) -> sprintf "(%s + %s)" (aexp_to_string e) (aexp_to_string f)
+      | AEminus (e,f) -> sprintf "(%s - %s)" (aexp_to_string e) (aexp_to_string f)
+      | AElet (x, e, f) ->
+        Printf.sprintf "(let %s = %s in %s)" x (aexp_to_string e) (aexp_to_string f)
+      | AEide (x) -> x
+
+// error handling
+let unbound_identifier_error ide =
+  failwith (Printf.sprintf "unbound identifier %s" ide)
+
+// semantic domains
+type eval = int
+type dval = eval // denotable and expressible values coincide
+
+let eval_to_string : eval -> string =
+  fun e -> Printf.sprintf "%d" e
+
+// ambiente
+type env = ide -> dval
+
+let empty = fun v -> unbound_identifier_error v

ludo/Program.fs

@@ -36,7 +36,7 @@ let rec sumFirstFun f k =
 let rec fold g f k1 k2 z =
   if (k2 < k1) then z
   else g (fold g f (k1+1) k2 z) (f(k1))
->
+
 let sum x y = x + y
 let double x = 2*x