From 3bae104c3218ca0ee0f724464083d303fb745453 Mon Sep 17 00:00:00 2001
From: Camil Staps
Date: Fri, 3 Jun 2016 12:29:24 +0200
Subject: Rewrite eval for AExpr

---
 paper/While/WhileCommon.icl | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

(limited to 'paper/While/WhileCommon.icl')

diff --git a/paper/While/WhileCommon.icl b/paper/While/WhileCommon.icl
index ce4f8fe..1fbebc3 100644
--- a/paper/While/WhileCommon.icl
+++ b/paper/While/WhileCommon.icl
@@ -46,13 +46,10 @@ where
 		= eval a1 st >>= \r1 ->
 		  eval a2 st >>= app op r1
 	where
-		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))
+		app :: Operator Int Int -> Either Error Int
+		app Div i 0 = Left (Runtime "Division by 0")
+		app op  i j = Right $ (case op of
+			Add = (+); Sub = (-); Mul = (*); Div = (/)) i j
 
 instance eval BExpr Bool
 where
-- 
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