Solutions

README.md

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+### Docs
+
+```shell
+# dune build @docs
+
+# open _build/default/_doc/_html/index.html
+```
+
+### Tests
+
+```
+# dune test
+```
+

dune

@@ -1 +1,4 @@
-(library (name camellito) (public_name camellito))
+(library (name camellito) (wrapped false) (public_name camellito) (modules task))
+
+(test (name test) (libraries camellito ounit2) (modules test))
+

task.ml

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+let ignore _ = ()
+
+let map f u =
+  let rec loop acc = function
+  | [] -> acc
+  | x :: u -> loop (f x :: acc) u in
+  List.rev (loop [] u)
+
+let range lo =
+  let rec loop u i = if i < lo then u else loop (i :: u) (i - 1) in loop []

task.mli

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+(** Module [Tasks] contains the functions that need to be implemented.
+
+    The file [task.mli] contains the signature and description of the functions.
+    It should not be modiled.
+
+    Write your functions in the file [task.ml]. Replace the dummy content
+    [failwith "Not yet implemented"] by your code.
+
+    The [[@warning "-27"]] pragma can be removed once a function is implemented.
+*)
+
+val ignore : 'a -> unit
+(** Discards the value of its argument and returns the unit value [()]. For
+  instance, [ignore (f x)] discards the result of the function [f]. Side effects
+  triggered by the evaluation of the argument are unchanged. *)
+
+val map : ('a -> 'b) -> 'a list -> 'b list
+(** [map f [a1; ...; an]] applies function [f] to [[a1, ..., an]], and builds
+  the list [[f a1; ...; f an]] with the results returned by [f].
+ *)
+
+val range : int -> int -> int list
+(** [range lo hi] returns a list of integers [[lo; lo + 1; ...; hi]]. It
+  returns an empty list if [hi < lo]. This function is tail-recursive. *)

test.ml

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+open OUnit2
+
+let sq x = x * x
+
+let ignore = [
+  "unit" >:: (fun _ -> assert_equal () (Task.ignore ()));
+  "42" >:: (fun _ -> assert_equal () (Task.ignore 42));
+  "apply" >:: (fun _ -> assert_equal () (Task.ignore (sq 3)));
+  "print" >:: (fun _ -> assert_equal () (Task.ignore (print_newline ())));
+]
+
+let map = [
+  "nil" >:: (fun _ -> assert_equal [] (Task.map sq []));
+  "sq" >:: (fun _ -> assert_equal [1; 4; 9] (Task.map sq [1; 2; 3]));
+  "id" >:: (fun _ -> assert_equal [1; 2; 3] (Task.map Fun.id [1; 2; 3]));
+  "then" >:: (fun _ -> assert_equal ([1; 2; 3] |> Task.map (( + ) 1) |> Task.map sq) (Task.map (fun x -> x |> ( + ) 1 |> sq) [1; 2; 3]));
+]
+
+let range = [
+  "nil" >:: (fun _ -> assert_equal [] (Task.range 7 3));
+  "cons" >:: (fun _ -> assert_equal [3; 4; 5] (Task.range 3 5));
+]
+
+let () = "Task" >::: [
+  "ignore" >::: ignore;
+  "map" >::: map;
+  "range" >::: range
+] |> run_test_tt_main