Exposed rule application order and version 2a parsing at command line

1 files changed, 33 insertions, 9 deletions

diff --git a/src/thue.hs b/src/thue.hs
index 89afcc3..ac935a4 100644
--- a/src/thue.hs
+++ b/src/thue.hs
@@ -1,27 +1,51 @@
 
 import System.Environment( getArgs )
+import System.Console.GetOpt
 import Control.Exception( ErrorCall(..), Handler(..), catches )
 import Thue.Parser
 import Thue.Interpreter
 
 
 
+data Flag = LeftInterpret | RightInterpret | RandomInterpret | Version1 | Version2a
+    deriving (Eq)
+
+
+
+
+options :: [OptDescr Flag]
+options =
+    [ Option ['l'] ["left"] (NoArg LeftInterpret) "Apply rules in a list from left to right"
+    , Option ['r'] ["right"] (NoArg RightInterpret) "Apply rules in a list from right to left"
+    , Option ['a'] ["random"] (NoArg RandomInterpret) "Apply rules randomly"
+    , Option ['1'] ["ver1"] (NoArg Version1) "Use version 1 parser"
+    , Option ['2'] ["ver2a"] (NoArg Version2a) "Use version 2a parser, with quoted strings and escaped characters" ]
+
+
 
 usageString :: String
-usageString = "Usage: thue <program file>"
+usageString = "Usage: thue [OPTION..] <program file>"
 
 
 
 program :: IO ()
 program = do
-	args <- getArgs
-	fileContents <- if (length args /= 1)
-		            then error usageString
-		            else readFile (head args)
-
-	case (parseThue fileContents) of
-		Left x -> putStrLn (show x)
-		Right x -> (thue x) >>= (putStrLn . show)
+    args <- getArgs
+    let (actions, nonOptions, errors) = getOpt Permute options args
+
+        parse = if (Version2a `elem` actions) then parseThue2a else parseThue
+
+        order = if (LeftInterpret `elem` actions)
+                then Just First
+                else if (RightInterpret `elem` actions) then Just Last else Nothing
+
+    fileContents <- if (length nonOptions /= 1)
+                    then error usageString
+                    else readFile (head nonOptions)
+
+    case (parse fileContents) of
+        Left x -> putStrLn (show x)
+        Right x -> (thue x order) >>= (putStrLn . show)