From: Mart Lubbers <mart@martlubbers.net>
Date: Mon, 31 Aug 2015 18:06:42 +0000 (+0200)
Subject: rose now works
X-Git-Tag: assignment2~11
X-Git-Url: https://git.martlubbers.net/?a=commitdiff_plain;h=319efa41e84489a7367e8595ecda5033d1033f5e;p=ap2015.git

rose now works
---

diff --git a/a1/mart/skeleton1.icl b/a1/mart/skeleton1.icl
index bcb57fe..18dac9a 100644
--- a/a1/mart/skeleton1.icl
+++ b/a1/mart/skeleton1.icl
@@ -51,6 +51,10 @@ instance >< Bool where		// False is smaller than True
 	(><) _     _     = Equal
 
 /**************** End Prelude *************************/
+isEqual :: Ordering -> Bool
+isEqual Equal = True
+isEqual _ = False
+
 // 1. Ordering by overloading
 instance >< Color where
 	(><) Red Red = Equal
@@ -61,35 +65,32 @@ instance >< Color where
 	(><) Blue Blue = Equal
 	(><) _ _ = Smaller
 
-instance >< (Tree a) | >< a & == a where
+instance >< (Tree a) | >< a where
 	(><) Tip Tip = Equal
 	(><) (Bin _ _ _) Tip = Bigger
 	(><) Tip (Bin _ _ _) = Smaller
 	(><) (Bin x ltx rtx) (Bin y lty rty)
-	| x == y = case ltx >< lty of
-		Equal = rtx >< rty
-		otherwise = ltx >< lty
-	| otherwise = x >< y
-
-instance >< (Rose a) | >< a & == a where
-	(><) (Rose _ _) (Rose _ []) = Bigger
-	(><) (Rose _ []) (Rose _ _) = Smaller
-	(><) (Rose x xs) (Rose y ys)
-	| x == y = xs >< ys
+	| isEqual (x >< y)
+		| isEqual (ltx >< lty) = rtx >< rty
+		| otherwise = ltx >< lty
 	| otherwise = x >< y
 
-instance >< [a] | Ord a & == a where
+instance >< [a] | >< a where
 	(><) [] [] = Equal
 	(><) [] _ = Smaller
 	(><) _ [] = Bigger
 	(><) [x:xs] [y:ys]
-	| x == y = xs >< ys
-	| x < y = Smaller
-	| otherwise = Bigger
+	| isEqual (x >< y) = xs >< ys
+	| otherwise = x >< y
+
+instance >< (Rose a) | >< a where
+	(><) (Rose x xs) (Rose y ys)
+	| isEqual (x >< y) = xs >< ys
+	| otherwise = x >< y
 
-instance >< (a, b) | >< a & >< b & == a where
+instance >< (a, b) | >< a & >< b where
 	(><) (xa, xb) (ya, yb)
-	| xa == ya = xb >< yb
+	| isEqual (xa >< ya) = xb >< yb
 	| otherwise = xa >< ya
 
 //2. Generic representation