become a proper stack project

1 files changed, 32 insertions, 0 deletions

diff --git a/src/Utils.hs b/src/Utils.hs
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index 0000000..21ee67b
--- /dev/null
+++ b/src/Utils.hs
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+{-
+ - Copyright 2015 Egor Tensin <Egor.Tensin@gmail.com>
+ - This file is licensed under the terms of the MIT License.
+ - See LICENSE.txt for details.
+-}
+
+module Utils where
+
+import Control.Monad ( liftM )
+import Data.Char ( toLower )
+import System.IO ( hFlush, stdout )
+
+prompt :: String -> IO String
+prompt banner = do
+  putStr banner
+  hFlush stdout
+  getLine
+
+promptYesNo :: String -> IO Bool
+promptYesNo banner = do
+  response <- liftM (map toLower) $ prompt banner
+  if response `elem` yeses
+    then return True
+    else if response `elem` noes
+      then return False
+      else promptToContinue
+  where
+    yeses = ["y", "yes"]
+    noes = ["n", "no"]
+
+promptToContinue :: IO Bool
+promptToContinue = promptYesNo "Continue? (y/n) "