Parse only flag

1 files changed, 14 insertions, 7 deletions

diff --git a/src/Main.hs b/src/Main.hs
index 8959329..6e57ba4 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -17,23 +17,30 @@ import System.IO (hPutStr, hPutStrLn, stderr, stdout)
 version = "0.1.0"
 
 data Options = Options
-  { optHelp :: Bool,
+  { optParse :: Bool,
+    optHelp :: Bool,
     optVersion :: Bool
   }
 
 defOptions =
   Options
-    { optHelp = False,
+    { optParse = False,
+      optHelp = False,
       optVersion = False
     }
 
 options :: [OptDescr (Options -> Options)]
 options =
   [ Option
+      ['p']
+      ["parse"]
+      (NoArg (\opts -> opts {optParse = True}))
+      "only parse, reporting any errors",
+    Option
       ['h']
       ["help"]
       (NoArg (\opts -> opts {optHelp = True}))
-      "show help and exit",
+      "show help",
     Option
       ['v']
       ["version"]
@@ -57,15 +64,15 @@ usage progName errs
     helpText =
       usageInfo header options
 
-compileFile :: String -> IO ()
-compileFile filename = do
+compileFile :: String -> Bool -> IO ()
+compileFile filename onlyParse = do
   res <- parseFromFile (scan parse) filename
   case res of
     Left err -> hPutStrLn stderr (showParserError err) >> exitFailure
     Right ast -> do
       res <- return $ evalState (compileAll ast) startState
       case res of
-        Right _ -> print ast
+        Right _ -> if onlyParse then exitSuccess else print ast
         Left errs -> hPutStr stderr (showErrorList errs) >> exitFailure
 
 main :: IO ()
@@ -78,7 +85,7 @@ main = do
         when (optHelp opts) $ usage progName []
         when (optVersion opts) $ putStrLn (progName ++ " " ++ version) >> exitSuccess
         case n of
-          [filename] -> compileFile filename
+          [filename] -> compileFile filename $ optParse opts
           _ -> usage progName []
       where
         opts = foldl (flip id) defOptions o