Finish(?) assignment 12

1 files changed, 27 insertions, 2 deletions

diff --git a/assignment-12/cashModel.icl b/assignment-12/cashModel.icl
index c1200be..c9dfc55 100644
--- a/assignment-12/cashModel.icl
+++ b/assignment-12/cashModel.icl
@@ -50,8 +50,9 @@ model list (Rem p)
 | otherwise       = (list,[])
 model list Pay = ([],[euro list])
 
-derive gen Euro
-derive string Euro
+derive gEq Action
+derive gen Euro, Action, Product, []
+derive string Euro, Action, Product, []
 derive bimap []
 
 /**
@@ -98,3 +99,27 @@ where
 
 	prop_neg_distributes_over_plus :: Euro Euro -> Property
 	prop_neg_distributes_over_plus a b = ~(a + b) =.= ~a + ~b
+
+/**
+ * Passed
+ *
+ * NB: this only checks Rem (as requested). The same property holds for Add.
+ * For Pay, the output of the model should be negated.
+ */
+Start = test fairness
+where
+	fairness :: [Product] Product -> Property
+	fairness ps p = value newps =.= value ps + value out
+	where (newps, out) = model ps (Rem p)
+
+class value a :: (a -> Real)
+instance value Real where value = id
+instance value [a] | value a where value = sum o map value
+instance value Euro where value = \e -> toReal e.euro * 100.0 + toReal (sign e.euro * e.cent)
+instance value Product where value = value o euro
+instance value Action
+where
+	value = \a -> case a of
+		Add p -> value p
+		Rem p -> ~(value p)
+		Pay   -> 0.0