1 -----------------------------------------------------------------------------
5 -- This is an abstract command-line parser used by both StaticFlags and
8 -- (c) The University of Glasgow 2005
10 -----------------------------------------------------------------------------
12 module CmdLineParser (
13 processArgs, OptKind(..),
14 CmdLineP(..), getCmdLineState, putCmdLineState
17 #include "HsVersions.h"
19 import Util ( maybePrefixMatch, notNull, removeSpaces )
23 = NoArg (m ()) -- flag with no argument
24 | HasArg (String -> m ()) -- flag has an argument (maybe prefix)
25 | SepArg (String -> m ()) -- flag has a separate argument
26 | Prefix (String -> m ()) -- flag is a prefix only
27 | OptPrefix (String -> m ()) -- flag may be a prefix
28 | AnySuffix (String -> m ()) -- flag is a prefix, pass whole arg to fn
29 | PassFlag (String -> m ()) -- flag with no arg, pass flag to fn
30 | PrefixPred (String -> Bool) (String -> m ())
31 | AnySuffixPred (String -> Bool) (String -> m ())
33 processArgs :: Monad m
34 => [(String, OptKind m)] -- cmdline parser spec
37 [String], -- spare args
40 processArgs spec args = process spec args [] []
42 process _spec [] spare errs =
43 return (reverse spare, reverse errs)
45 process spec args@(('-':arg):args') spare errs =
46 case findArg spec arg of
48 case processOneArg action rest args of
49 Left err -> process spec args' spare (err:errs)
50 Right (action,rest) -> do
51 action >> process spec rest spare errs
53 process spec args' (('-':arg):spare) errs
55 process spec (arg:args) spare errs =
56 process spec args (arg:spare) errs
59 processOneArg :: OptKind m -> String -> [String]
60 -> Either String (m (), [String])
61 processOneArg action rest (dash_arg@('-':arg):args) =
63 NoArg a -> ASSERT(null rest) Right (a, args)
67 then Right (f rest, args)
69 [] -> missingArgErr dash_arg
70 (arg1:args1) -> Right (f arg1, args1)
74 [] -> unknownFlagErr dash_arg
75 (arg1:args1) -> Right (f arg1, args1)
79 then Right (f rest, args)
80 else unknownFlagErr dash_arg
84 then Right (f rest, args)
85 else unknownFlagErr dash_arg
87 OptPrefix f -> Right (f rest, args)
89 AnySuffix f -> Right (f dash_arg, args)
91 AnySuffixPred p f -> Right (f dash_arg, args)
95 then unknownFlagErr dash_arg
96 else Right (f dash_arg, args)
99 findArg :: [(String,OptKind a)] -> String -> Maybe (String,OptKind a)
101 = case [ (removeSpaces rest, k)
103 Just rest <- [maybePrefixMatch pat arg],
109 arg_ok (NoArg _) rest arg = null rest
110 arg_ok (HasArg _) rest arg = True
111 arg_ok (SepArg _) rest arg = null rest
112 arg_ok (Prefix _) rest arg = notNull rest
113 arg_ok (PrefixPred p _) rest arg = notNull rest && p rest
114 arg_ok (OptPrefix _) rest arg = True
115 arg_ok (PassFlag _) rest arg = null rest
116 arg_ok (AnySuffix _) rest arg = True
117 arg_ok (AnySuffixPred p _) rest arg = p arg
119 unknownFlagErr :: String -> Either String a
120 unknownFlagErr f = Left ("unrecognised flag: " ++ f)
122 missingArgErr :: String -> Either String a
123 missingArgErr f = Left ("missing argument for flag: " ++ f)
125 -- -----------------------------------------------------------------------------
126 -- A state monad for use in the command-line parser
128 newtype CmdLineP s a = CmdLineP { runCmdLine :: s -> (a, s) }
130 instance Monad (CmdLineP s) where
131 return a = CmdLineP $ \s -> (a, s)
132 m >>= k = CmdLineP $ \s -> let
133 (a, s') = runCmdLine m s
134 in runCmdLine (k a) s'
136 getCmdLineState = CmdLineP $ \s -> (s,s)
137 putCmdLineState s = CmdLineP $ \_ -> ((),s)