First version almost finished

1 files changed, 21 insertions, 16 deletions

diff --git a/paper/While/WhileCommon.icl b/paper/While/WhileCommon.icl
index a76458f..ce4f8fe 100644
--- a/paper/While/WhileCommon.icl
+++ b/paper/While/WhileCommon.icl
@@ -9,7 +9,8 @@ import Yard
 
 derive gEq AExpr, Operator, BExpr, Comparator
 
-instance zero State where zero = \v -> Left (Runtime "Undefined variable")
+instance zero State
+where zero = \v -> Left (Runtime "Undefined")
 
 instance toString AExpr
 where
@@ -38,32 +39,36 @@ where
 
 instance eval AExpr Int
 where
+	eval :: AExpr State -> Either Error Int
 	eval (Var v) st = st v
-	eval (Lit i) st = pure i
-	eval (Op a1 op a2) st = eval a1 st >>= \r1 -> eval a2 st >>= toOp op r1
+	eval (Lit i) _  = pure i
+	eval (Op a1 op a2) st
+		= eval a1 st >>= \r1 ->
+		  eval a2 st >>= app op r1
 	where
-		toOp :: Operator -> Int Int -> Either Error Int
-		toOp Add = \i j -> pure (i + j)
-		toOp Sub = \i j -> pure (i - j)
-		toOp Mul = \i j -> pure (i * j)
-		toOp Div = \i j ->
-			if (j == 0) (Left (Runtime "Division by 0")) (pure (i / j))
+		app :: Operator -> Int Int -> Either Error Int
+		app Add = pure on (+)
+		app Sub = pure on (-)
+		app Mul = pure on (*)
+		app Div = \i j -> if (j == 0)
+			(Left (Runtime "Division by 0"))
+			(pure (i / j))
 
 instance eval BExpr Bool
 where
 	eval (Bool b) st = pure b
-	eval (Not b) st = eval b st >>= pure o not
+	eval (Not b) st = not <$> eval b st
 	eval (And b1 b2) st = liftM2 (&&) (eval b1 st) (eval b2 st)
 	eval (Or b1 b2) st = liftM2 (||) (eval b1 st) (eval b2 st)
 	eval (Comp a1 cmp a2) st = liftM2 (toCmp cmp) (eval a1 st) (eval a2 st)
 	where
 		toCmp :: Comparator -> Int Int -> Bool
-		toCmp Eq = \i j -> i == j
-		toCmp Ne = \i j -> i <> j
-		toCmp Le = \i j -> i <= j
-		toCmp Lt = \i j -> i < j
-		toCmp Ge = \i j -> i >= j
-		toCmp Gt = \i j -> i > j
+		toCmp Eq = (==)
+		toCmp Ne = (<>)
+		toCmp Le = (<=)
+		toCmp Lt = (<)
+		toCmp Ge = (>=)
+		toCmp Gt = (>)
 
 pbexpr :: Parser Token BExpr
 pbexpr = liftM2 Or pbconj (item OrToken *> pbexpr) <|> pbconj