From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 7 Jun 2011 21:00:54 +0000 (-0400)
Subject: Add the all_equal function to the Misc module.
X-Git-Tag: 0.0.1~287
X-Git-Url: http://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=5973e31fd84d4a91578185f649b3783fdae8a882;p=spline3.git

Add the all_equal function to the Misc module.
---

diff --git a/src/Misc.hs b/src/Misc.hs
index 6364e95..fd6dd39 100644
--- a/src/Misc.hs
+++ b/src/Misc.hs
@@ -18,3 +18,13 @@ factorial n
 --   one-dimensional one.
 flatten :: [[[a]]] -> [a]
 flatten xs = concat $ concat xs
+
+
+-- | Takes a list, and returns True if its elements are pairwise
+--   equal. Returns False otherwise.
+all_equal :: (Eq a) => [a] -> Bool
+all_equal xs =
+    and $ map (== first_element) other_elements
+    where
+      first_element  = head xs
+      other_elements = tail xs