lec01.ml

lecture/lec01/lec01.ml

+(* welcome to 341 *)
+
+(* a program is a sequence of bindings *)
+let x = 3
+let y : int = 4
+
+(* to run a program, use utop
+   - utop is a REPL
+   - load a program from file: #use "filename.ml";;
+*)
+
+(* what do programs mean? run them and see what happens
+   - two phases to execution: compile-time and run-time
+   - at compile-time, we do type checking
+   - at run-time, we run stuff
+
+*)
+
+let z = x + y
+let _ = x * (y + z)
+
+let _ = if z > 5 then 3 else 17
+
+(* another kind of binding: making a function *)
+
+(* let max((a: int), (b: int)): int = *)
+
+(* let max(a, b): int =  *)
+let max((a: int), (b: int)) =
+  if a < b then b else a
+
+let _ = max(10, 5)
+
+(* floats *)
+(* let _ = 1.5 + 1.5   *)
+let _ = 1.5 +. 1.5 *. 2. -. 1.
+let _ = 1.5 +. 1.5 *. 2. -. float_of_int(1)
+
+(* strings *)
+let msg = string_of_int(17)