Load metadata file if it exists

mima-run/Main.hs

@@ -1,27 +1,38 @@
 module Main where
 
 import           Control.Monad.IO.Class
+import qualified Data.Text              as T
 import qualified Data.Text.IO           as T
 import           Options.Applicative
 
 import           Mima.Format
 import           Mima.MimaRun.Options
 import           Mima.Run
+import           Mima.Vm.Flags
+import           Mima.Vm.Metadata
 import           Mima.Vm.State
 import           Mima.Vm.Storage
 
+loadMetadataOrEmpty :: FilePath -> Run Metadata
+loadMetadataOrEmpty path = catch (loadMetadata path) (\error -> do
+  liftIO $ putStrLn $ "Metafile could not be loaded. " ++ T.unpack error
+  pure mempty)
+
 main :: IO ()
 main = runOrExit 2 $ do
   opts <- liftIO $ execParser parserInfo
   initialState <- loadMimaState $ inputFile opts
+  metadata <- loadMetadataOrEmpty $ metadataFile opts
+  let flags = flagsFromMetadata metadata
+
   finalState <- liftIO $ case steps opts of
     Nothing -> do
-      let (finalState, abortReason, stepsMade) = execute mempty initialState
+      let (finalState, abortReason, stepsMade) = execute flags initialState
       putStrLn $ "Stopped after " ++ show stepsMade ++ " steps, reason:"
       T.putStrLn $ toText abortReason
       pure finalState
     Just n -> do
-      let (finalState, mAbortReason, stepsMade) = executeN n mempty initialState
+      let (finalState, mAbortReason, stepsMade) = executeN n flags initialState
       putStrLn $ "Stopped after " ++ show stepsMade ++ " steps, reason:"
       case mAbortReason of
         Nothing          -> putStrLn "Ran out of steps"