X-Git-Url: http://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2FMisc.hs;h=57dfd433e2ffc4b72cb8daa00f19f94443813404;hb=4a7ea6313df073bfd41fd69552a338c7d7cd6f47;hp=b2ebeef53c42e470af7e12c58e5e55fdeac74a10;hpb=c864b66c83f2be395fa590321ca313e227d79fab;p=spline3.git

diff --git a/src/Misc.hs b/src/Misc.hs
index b2ebeef..57dfd43 100644
--- a/src/Misc.hs
+++ b/src/Misc.hs
@@ -3,10 +3,26 @@
 module Misc
 where
 
+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.QuickCheck
+
 
 -- | The standard factorial function. See
 --   <http://www.willamette.edu/~fruehr/haskell/evolution.html> for
 --   possible improvements.
+--
+--   Examples:
+--
+--   >>> factorial 0
+--   1
+--
+--   >>> factorial 4
+--   24
+--
 factorial :: Int -> Int
 factorial n
     | n <= 1 = 1
@@ -16,10 +32,30 @@ factorial n
 
 -- | Takes a three-dimensional list, and flattens it into a
 --   one-dimensional one.
+--
+--  Examples:
+--
+--  >>> flatten [ [[1,2], [3,4]], [[5,6], [7,8]] ]
+--  [1,2,3,4,5,6,7,8]
+--
 flatten :: [[[a]]] -> [a]
 flatten xs = concat $ concat xs
 
 
+-- | Switch the x and z dimensions of a three-dimensional list.
+transpose_xz :: [[[a]]] -> [[[a]]]
+transpose_xz [] = []
+transpose_xz [[]] = [[]]
+transpose_xz [[[]]] = [[[]]]
+transpose_xz m =
+    [[[ m !! x !! y !! z | x <- [0..xsize]]
+                      | y <- [0..ysize]]
+                      | z <- [0..zsize]]
+    where
+      zsize = (length m) - 1
+      ysize = length (head m) - 1
+      xsize = length (head $ head m) - 1
+
 -- | Takes a list, and returns True if its elements are pairwise
 --   equal. Returns False otherwise.
 all_equal :: (Eq a) => [a] -> Bool
@@ -28,3 +64,51 @@ all_equal xs =
     where
       first_element  = head xs
       other_elements = tail xs
+
+
+-- | Returns 'True' if the vectors xs and ys are disjoint, 'False'
+--   otherwise.
+--
+--   Examples:
+--
+--   >>> let xs = Data.Vector.fromList [1,2,3]
+--   >>> let ys = Data.Vector.fromList [4,5,6]
+--   >>> disjoint xs ys
+--   True
+--
+--   >>> let ys = Data.Vector.fromList [3,4,5]
+--   >>> disjoint xs ys
+--   False
+--
+disjoint :: (Eq a) => V.Vector a -> V.Vector a -> Bool
+disjoint 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 ]