X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMisc.hs;h=4b285e4cc3b0cff1f8344aa09c905ed6b0c3fe99;hb=40a354da29b99d773fc18c4c4ad0d136a93d7264;hp=57dfd433e2ffc4b72cb8daa00f19f94443813404;hpb=d2e1b5009ad0ae3595e874227586617aad068daa;p=spline3.git diff --git a/src/Misc.hs b/src/Misc.hs index 57dfd43..4b285e4 100644 --- a/src/Misc.hs +++ b/src/Misc.hs @@ -1,3 +1,4 @@ +{-# LANGUAGE BangPatterns #-} -- | The Misc module contains helper functions that seem out of place -- anywhere else. module Misc @@ -7,7 +8,7 @@ import qualified Data.Vector as V (Vector, elem, empty, filter) import Test.Framework (Test, testGroup) import Test.Framework.Providers.HUnit (testCase) import Test.Framework.Providers.QuickCheck2 (testProperty) -import Test.HUnit +import Test.HUnit (Assertion, assertEqual) import Test.QuickCheck @@ -24,11 +25,12 @@ import Test.QuickCheck -- 24 -- factorial :: Int -> Int -factorial n - | n <= 1 = 1 - | n > 20 = error "integer overflow in factorial function" - | otherwise = product [1..n] - +factorial !n + | n > 20 = error "integer overflow in factorial function" + | otherwise = go 1 n + where go !acc !i + | i <= 1 = acc + | otherwise = go (acc * i) (i - 1) -- | Takes a three-dimensional list, and flattens it into a -- one-dimensional one.