Initial commit

1 files changed, 45 insertions, 0 deletions

diff --git a/src/Eval.hs b/src/Eval.hs
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--- /dev/null
+++ b/src/Eval.hs
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+module Eval
+  ( evalMain
+  ) where
+
+import           Control.Exception
+import           Control.Monad.State
+import           System.Console.Haskeline
+import           System.Environment
+import           System.Exit
+import           System.IO
+
+type Environment = [String]
+
+eval :: String -> IO ()
+eval code = putStrLn "ok"
+
+evalFile :: String -> IO ()
+evalFile path = do
+  file <- try $ readFile path :: IO (Either IOError String)
+  case file of
+    Left  exception -> print (exception :: IOError)
+    Right file      -> eval file
+
+evalRepl :: String -> Environment -> InputT IO Environment
+evalRepl line env = outputStrLn (show env) >> pure env
+
+repl :: Environment -> InputT IO ()
+repl env =
+  getInputLine ":: "
+    >>= (\case
+          Nothing   -> pure ()
+          Just line -> evalRepl line env >>= repl
+        )
+
+usage :: IO ()
+usage = putStrLn "Invalid arguments. Use 'bruijn [file]' instead"
+
+evalMain :: IO ()
+evalMain = do
+  args <- getArgs
+  case args of
+    [] -> runInputT defaultSettings { historyFile = Just ".brown-history" }
+      $ repl []
+    [path] -> evalFile path
+    _      -> usage