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 )
22 = NoArg (m ()) -- flag with no argument
23 | HasArg (String -> m ()) -- flag has an argument (maybe prefix)
24 | SepArg (String -> m ()) -- flag has a separate argument
25 | Prefix (String -> m ()) -- flag is a prefix only
26 | OptPrefix (String -> m ()) -- flag may be a prefix
27 | AnySuffix (String -> m ()) -- flag is a prefix, pass whole arg to fn
28 | PassFlag (String -> m ()) -- flag with no arg, pass flag to fn
29 | PrefixPred (String -> Bool) (String -> m ())
30 | AnySuffixPred (String -> Bool) (String -> m ())
32 processArgs :: Monad m
33 => [(String, OptKind m)] -- cmdline parser spec
36 [String], -- spare args
39 processArgs spec args = process spec args [] []
41 process _spec [] spare errs =
42 return (reverse spare, reverse errs)
44 process spec args@(('-':arg):args') spare errs =
45 case findArg spec arg of
47 case processOneArg action rest args of
48 Left err -> process spec args' spare (err:errs)
49 Right (action,rest) -> do
50 action >> process spec rest spare errs
52 process spec args' (('-':arg):spare) errs
54 process spec (arg:args) spare errs =
55 process spec args (arg:spare) errs
58 processOneArg :: OptKind m -> String -> [String]
59 -> Either String (m (), [String])
60 processOneArg action rest (dash_arg@('-':arg):args) =
62 NoArg a -> ASSERT(null rest) Right (a, args)
66 then Right (f rest, args)
68 [] -> missingArgErr dash_arg
69 (arg1:args1) -> Right (f arg1, args1)
73 [] -> unknownFlagErr dash_arg
74 (arg1:args1) -> Right (f arg1, args1)
78 then Right (f rest, args)
79 else unknownFlagErr dash_arg
83 then Right (f rest, args)
84 else unknownFlagErr dash_arg
86 OptPrefix f -> Right (f rest, args)
88 AnySuffix f -> Right (f dash_arg, args)
90 AnySuffixPred p f -> Right (f dash_arg, args)
94 then unknownFlagErr dash_arg
95 else Right (f dash_arg, args)
98 findArg :: [(String,OptKind a)] -> String -> Maybe (String,OptKind a)
100 = case [ (removeSpaces rest, k)
102 Just rest <- [maybePrefixMatch pat arg],
108 arg_ok (NoArg _) rest arg = null rest
109 arg_ok (HasArg _) rest arg = True
110 arg_ok (SepArg _) rest arg = null rest
111 arg_ok (Prefix _) rest arg = notNull rest
112 arg_ok (PrefixPred p _) rest arg = notNull rest && p rest
113 arg_ok (OptPrefix _) rest arg = True
114 arg_ok (PassFlag _) rest arg = null rest
115 arg_ok (AnySuffix _) rest arg = True
116 arg_ok (AnySuffixPred p _) rest arg = p arg
118 unknownFlagErr :: String -> Either String a
119 unknownFlagErr f = Left ("unrecognised flag: " ++ f)
121 missingArgErr :: String -> Either String a
122 missingArgErr f = Left ("missing argument for flag: " ++ f)
124 -- -----------------------------------------------------------------------------
125 -- A state monad for use in the command-line parser
127 newtype CmdLineP s a = CmdLineP { runCmdLine :: s -> (a, s) }
129 instance Monad (CmdLineP s) where
130 return a = CmdLineP $ \s -> (a, s)
131 m >>= k = CmdLineP $ \s -> let
132 (a, s') = runCmdLine m s
133 in runCmdLine (k a) s'
135 getCmdLineState = CmdLineP $ \s -> (s,s)
136 putCmdLineState s = CmdLineP $ \_ -> ((),s)