initial skeleton

src/BC/Config.hs

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+module Bc.Prompt where
+
+versionStr = "0.1.0.0"
+
+prompt = "> "

src/BC/Prompt.hs

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+module BC.Prompt (startPrompt) where
+
+import BC.Config
+
+printHeader :: IO ()
+printHeader = do
+  putStrLn "bc (better calculator) version " ++ versionStr
+  putStrLn "Copyright 2017 Veit Heller"
+  putStrLn "This is free software with ABSOLUTELY NO WARRANTY.\n"
+
+
+prompt :: IO ()
+prompt = runInputT settings $ poll prompt
+  where poll p = do
+        input <- getInputLine p
+        case input of
+          Nothing -> return ""
+          Just str -> return str
+
+
+startPrompt :: IO ()
+startPrompt = do
+  printHeader
+  prompt

src/Main.hs

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+module Main where
+
+import BC.Prompt
+
+main :: IO ()
+main = startPrompt