SML example importHEADmaster

1 files changed, 87 insertions, 0 deletions

diff --git a/examples/sml/checks.sml b/examples/sml/checks.sml
new file mode 100644
index 0000000..d5b7262
--- /dev/null
+++ b/examples/sml/checks.sml
@@ -0,0 +1,87 @@
+(* Copyright (C) 2017-2018 Ryan Kavanagh <rkavanagh@cs.cmu.edu>   *)
+(* Distributed under the ISC license, see COPYING for details.    *)
+
+(* This is a hypothetical assignment where students have to       *)
+(* implement addition. There are two Autolab problems testing     *)
+(* their implementation on "easy" and "hard" pairs of input.      *)
+(* The scoreboard just keeps track of how many bonuses problems   *)
+(* their implementation solves.                                   *)
+(* Because addition can be very lengthy, we timeout the execution *)
+(* after a fixed amount of time.                                  *)
+
+functor ChecksHelper (structure H : HELPER) : CHECKS where type checks = H.checks =
+struct
+
+datatype checks = datatype H.checks
+
+(*****************************************************)
+(**********       CONFIGURE ME HERE            *******)
+(*****************************************************)
+
+structure Student : ADDER = Adder
+
+(* Run function f with arguments a with timeout of n seconds. *)
+fun try n f a = Timeout.runWithTimeout (Time.fromSeconds n) f a
+
+(* test data is of the form *)
+(* ("autolab exercise name", maxScore, [(input,expected),...]) *)
+val testSums = [("easy", 4, [((1,1),2), ((1,2),3), ((2,2),4), ((3,5),8)]),
+		("hard", 8, [((152,203),355), ((1212,2121),3333)])]
+
+(* Bonus problems that get used for score board *)
+val bonusSums = [((10,~10),0)]
+(* Pretty print problem input *)
+fun inputToString (x,y) = (Int.toString x) ^ " + " ^ (Int.toString y)
+
+(* Compare student output to expected output with a timeout, and *)
+(* compute the % of correct answers. *)
+fun compare tests =
+  let fun c (input,expected) =
+	let val testStr = inputToString input in
+	    case try 10 Student.add input of
+		(* No timeout *)
+		SOME b => if b = expected then
+			      ( H.printLn ("Passed: " ^ testStr)
+			      ; (1, 0))
+			  else
+			      ( H.printLn ("Failed: " ^ testStr)
+			      ; H.printLn ("        Expected "
+					   ^ (Int.toString expected)
+					   ^ " but got " ^ (Int.toString b))
+			      ; (0, 1) )
+	      | NONE => ( H.printLn ("Timed out after 10s on " ^ testStr)
+			; (0, 1))
+	end
+      fun addp (a, b) (c, d) = (a + c, b + d)
+      val (same,diff) = List.foldl (fn (p,acc) => addp (c p) acc)
+				   (0, 0)
+				   tests
+  in real same / real (same + diff) end
+
+val checks = List.map (fn (name,max,tests) =>
+			  H.Problem (name, fn _ => real max * compare tests))
+		      testSums
+
+fun scoreboard score =
+  ( H.printLn "Checking bonuses..."
+  ; SOME [List.foldl
+	      (fn ((p,b),acc) =>
+		  if try 2 Student.add p = SOME b then
+		      ( H.printLn ("Got bonus " ^ (inputToString p))
+		      ; H.printLn ("Well done!")
+		      ; acc + 1
+		      )
+		  else
+		      ( H.printLn ("Failed to add bonus " ^ (inputToString p))
+		      ; H.printLn ("in under 2 seconds. Skipping.")
+		      ; acc
+		      )
+	      )
+	      0
+	      bonusSums] )
+
+(*****************************************************)
+(**********        END CONFIGURATION           *******)
+(*****************************************************)
+
+end