Implement basic mima-run functionality

Bugs fixed:
- Print correct file name when load/save error occurs
- Correctly identify invalid file formats

mima-run/Main.hs

@@ -1,10 +1,31 @@
 module Main where
 
-import Options.Applicative
+import           Control.Monad.IO.Class
+import qualified Data.Text.IO           as T
+import           Options.Applicative
 
-import Mima.MimaRun.Options
+import           Mima.Format
+import           Mima.MimaRun.Options
+import           Mima.Run
+import           Mima.Vm.State
+import           Mima.Vm.Storage
 
 main :: IO ()
-main = do
-  opts <- execParser parserInfo
-  putStrLn $ "The options are: " ++ show opts
+main = runOrExit 2 $ do
+  opts <- liftIO $ execParser parserInfo
+  initialState <- loadMimaState $ inputFile opts
+  finalState <- liftIO $ case steps opts of
+    Nothing -> do
+      let (finalState, abortReason, stepsMade) = execute initialState
+      putStrLn $ "Stopped after " ++ show stepsMade ++ " steps, reason:"
+      T.putStrLn $ toText abortReason
+      pure finalState
+    Just n -> do
+      let (finalState, mAbortReason, stepsMade) = executeN n initialState
+      putStrLn $ "Stopped after " ++ show stepsMade ++ " steps, reason:"
+      case mAbortReason of
+        Nothing          -> putStrLn "Ran out of steps"
+        Just abortReason -> T.putStrLn $ toText abortReason
+      pure finalState
+  liftIO $ putStrLn ""
+  liftIO $ print finalState

mima-run/Mima/MimaRun/Options.hs

@@ -3,16 +3,16 @@ module Mima.MimaRun.Options
   , parserInfo
   ) where
 
-import Options.Applicative
+import           Options.Applicative
 
 data Options = Options
   { inputFile :: FilePath
-  , steps :: Maybe Integer
+  , steps     :: Maybe Integer
   } deriving (Show)
 
 parser :: Parser Options
 parser = Options
-  <$> strOption
+  <$> strArgument
       (  help "The .mima file to use"
       <> metavar "INPUTFILE"
       )