From 77983153f9e891f1199c8faa16dcb2a0e8bcbbb9 Mon Sep 17 00:00:00 2001
From: Adam Vogt <vogt.adam@gmail.com>
Date: Wed, 7 May 2014 04:49:30 +0200
Subject: make the check for overflow cleaner

Ignore-this: c12448f9219c8a29f2707526691acfda

darcs-hash:20140507024930-1499c-52860fb59794c3f370f27158b0936f845fce6ded.gz
---
 tests/Utils.hs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'tests/Utils.hs')

diff --git a/tests/Utils.hs b/tests/Utils.hs
index 2d9df81..e3eef0f 100644
--- a/tests/Utils.hs
+++ b/tests/Utils.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE RankNTypes #-}
 module Utils where
 
 import XMonad.StackSet hiding (filter)
@@ -35,5 +36,12 @@ applyN Nothing f v = v
 applyN (Just 0) f v = v
 applyN (Just n) f v = applyN (Just $ n-1) f (f v)
 
-
 tags x = map tag $ workspaces x
+
+
+-- | noOverflows op a b is True if @a `op` fromIntegral b@ overflows (or
+-- otherwise gives the same answer when done using Integer
+noOverflows :: (Integral b, Integral c) =>
+  (forall a. Integral a => a -> a -> a) -> b -> c -> Bool
+noOverflows op a b = toInteger (a `op` fromIntegral b) == toInteger a `op` toInteger b
+
-- 
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