complete word completion in the shell. works for commands, flags, options, abstract syntax identifiers and NL strings

src-3.0/GF/Command/Abstract.hs

@@ -26,3 +26,23 @@ data Argument
   = AExp Exp
   | ANoArg
   deriving (Eq,Ord,Show)
+
+valIdOpts :: String -> String -> [Option] -> String
+valIdOpts flag def opts = case valOpts flag (VId def) opts of
+  VId v -> v
+  _     -> def
+
+valIntOpts :: String -> Integer -> [Option] -> Int
+valIntOpts flag def opts = fromInteger $ case valOpts flag (VInt def) opts of
+  VInt v -> v
+  _      -> def
+
+valOpts :: String -> Value -> [Option] -> Value
+valOpts flag def opts = case lookup flag flags of
+  Just v -> v
+  _ -> def
+ where
+   flags = [(f,v) | OFlag f v <- opts]
+
+isOpt :: String -> [Option] -> Bool
+isOpt o opts = elem o [x | OOpt x <- opts]