move askNumber to utils

PollardPminus1.hs

@@ -1,6 +1,7 @@
 import Text.Read (readMaybe)
 import System.Exit (exitSuccess)
 import Data.Bits
+import Utils (askNumber)
 
 main :: IO ()
 main = do
@@ -16,16 +17,6 @@ main = do
         Nothing -> do
             putStrLn "Failed to find a factor using Pollard p-1 method. n could be prime or different parameters needed."
 
-askNumber :: String -> IO Integer
-askNumber s = do
-    putStrLn s
-    input <- getLine
-    case readMaybe input of
-        Just n | n > 1 -> return n
-        _ -> do
-            putStrLn "Not a valid integer"
-            exitSuccess
-
 -- Pollard p-1 factorization algorithm
 pollardP1 :: Integer -> Integer -> Maybe Integer
 pollardP1 n b = tryBases [2..5]

Utils.hs

@@ -0,0 +1,15 @@
+module Utils (askNumber) where
+
+import Text.Read (readMaybe)
+import System.Exit (exitSuccess)
+
+-- Ask user for an integer > 1, or exit on invalid input
+askNumber :: String -> IO Integer
+askNumber s = do
+    putStrLn s
+    input <- getLine
+    case readMaybe input of
+        Just n | n > 1 -> return n
+        _ -> do
+            putStrLn "Not a valid integer"
+            exitSuccess

fermat-factorization.hs

@@ -1,10 +1,10 @@
 import Text.Read (readMaybe)
 import System.Exit (exitSuccess)
-
+import Utils (askNumber)
 
 main :: IO ()
 main = do
-    n <- askNumber
+    n <- askNumber "Enter an integer:"
     let (d, root) = findIntegerSqrt n
         q = (root - d)
         p = (root + d)
@@ -12,19 +12,8 @@ main = do
     putStrLn ("Found d = " ++ show d ++ ", sqrt(n + d^2) = " ++ show root)
     putStrLn ("q = " ++ show q ++ ", p = " ++ show p)
 
-
-askNumber :: IO Int
-askNumber = do
-    putStrLn "Enter an integer:"
-    input <- getLine
-    case readMaybe input :: Maybe Int of
-        Just n  -> return n
-        Nothing -> do
-            putStrLn "Not a valid integer!"
-            exitSuccess
-
 -- Find the smallest integer d >= 0 such that sqrt(n + d^2) is an integer
-findIntegerSqrt :: Int -> (Int, Int)
+findIntegerSqrt :: Integer -> (Integer, Integer)
 findIntegerSqrt n = go 0
   where
     go d =