X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMisc.hs;h=4b285e4cc3b0cff1f8344aa09c905ed6b0c3fe99;hb=40a354da29b99d773fc18c4c4ad0d136a93d7264;hp=b9220cbbcefa7bf52ea9ec6c76b5f5d09467d4b6;hpb=42e5b4cc8b2dbd76ba4567b73967de974831c666;p=spline3.git

diff --git a/src/Misc.hs b/src/Misc.hs
index b9220cb..4b285e4 100644
--- a/src/Misc.hs
+++ b/src/Misc.hs
@@ -1,9 +1,15 @@
+{-# LANGUAGE BangPatterns #-}
 -- | The Misc module contains helper functions that seem out of place
 --   anywhere else.
 module Misc
 where
 
-import Data.List (intersect)
+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 (Assertion, assertEqual)
+import Test.QuickCheck
 
 
 -- | The standard factorial function. See
@@ -19,11 +25,12 @@ import Data.List (intersect)
 --   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.
@@ -61,17 +68,49 @@ all_equal xs =
       other_elements = tail xs
 
 
--- | Returns 'True' if the lists xs and ys are disjoint, 'False'
+-- | Returns 'True' if the vectors xs and ys are disjoint, 'False'
 --   otherwise.
 --
 --   Examples:
 --
---   >>> disjoint [1,2,3] [4,5,6]
+--   >>> let xs = Data.Vector.fromList [1,2,3]
+--   >>> let ys = Data.Vector.fromList [4,5,6]
+--   >>> disjoint xs ys
 --   True
 --
---   >>>  disjoint [1,2,3] [3,4,5]
+--   >>> let ys = Data.Vector.fromList [3,4,5]
+--   >>> disjoint xs ys
 --   False
 --
-disjoint :: (Eq a) => [a] -> [a] -> Bool
+disjoint :: (Eq a) => V.Vector a -> V.Vector a -> Bool
 disjoint xs ys =
-    intersect xs ys == []
+  intersect xs ys == V.empty
+  where
+    intersect :: (Eq a) => V.Vector a -> V.Vector a -> V.Vector a
+    intersect ws zs =
+      V.filter (`V.elem` zs) ws
+
+prop_factorial_greater :: Int -> Property
+prop_factorial_greater n =
+    n <= 20 ==> factorial n >= n
+
+
+test_flatten1 :: Assertion
+test_flatten1 =
+    assertEqual "flatten actually works" expected_list actual_list
+    where
+      target = [[[1::Int]], [[2, 3]]]
+      expected_list = [1, 2, 3]
+      actual_list = flatten target
+
+
+misc_tests :: Test.Framework.Test
+misc_tests =
+    testGroup "Misc Tests" [
+      testCase "flatten (1)" test_flatten1 ]
+
+
+misc_properties :: Test.Framework.Test
+misc_properties =
+    testGroup "Misc Properties" [
+      testProperty "factorial greater" prop_factorial_greater ]