Add separate ProjectEuler.hs module

Haskell/ProjectEuler.hs

@@ -0,0 +1,12 @@
+module ProjectEuler
+( isPrime
+) where
+
+isPrime :: (Integral n) => n -> Bool
+isPrime 1 = False
+isPrime 2 = True
+isPrime 3 = True
+isPrime n =
+    n `mod` 2 /= 0 && n `mod` 3 /= 0 && null [ x | x <- candidates, n `mod` x == 0 || n `mod` (x+2) == 0 ]
+    where candidates = [5,11..limit]
+          limit = floor(sqrt(fromIntegral n)) + 1

Haskell/p003.hs

@@ -1,14 +1,6 @@
 -- The prime factors of 13195 are 5, 7, 13 and 29.  --
 -- What is the largest prime factor of the number 600851475143?
-
+import ProjectEuler
-isPrime :: (Integral n) => n -> Bool
-isPrime 1 = False
-isPrime 2 = True
-isPrime 3 = True
-isPrime n =
-    n `mod` 2 /= 0 && n `mod` 3 /= 0 && null [ x | x <- candidates, n `mod` x == 0 || n `mod` (x+2) == 0 ]
-    where candidates = [5,11..limit]
-          limit = floor(sqrt(fromIntegral n)) + 1
 
 maxPrimeFactor :: (Integral n) => n -> n
 maxPrimeFactor n