+++ /dev/null
-A Haskell port of GNU's getopt library
-
-Sven Panne <Sven.Panne@informatik.uni-muenchen.de> Oct. 1996 (small
-changes Dec. 1997)
-
-Two rather obscure features are missing: The Bash 2.0 non-option hack
-(if you don't already know it, you probably don't want to hear about
-it...) and the recognition of long options with a single dash
-(e.g. '-help' is recognised as '--help', as long as there is no short
-option 'h').
-
-Other differences between GNU's getopt and this implementation: * To
-enforce a coherent description of options and arguments, there are
-explanation fields in the option/argument descriptor. * Error
-messages are now more informative, but no longer POSIX
-compliant... :-( And a final Haskell advertisement: The GNU C
-implementation uses well over 1100 lines, we need only 195 here,
-including a 46 line example! :-)
-
-\begin{code}
-module GetOpt (ArgOrder(..), OptDescr(..), ArgDescr(..), usageInfo, getOpt) where
-
-import List(isPrefixOf)
-
-data ArgOrder a -- what to do with options following non-options:
- = RequireOrder -- no option processing after first non-option
- | Permute -- freely intersperse options and non-options
- | ReturnInOrder (String -> a) -- wrap non-options into options
-
-data OptDescr a = -- description of a single options:
- Option [Char] -- list of short option characters
- [String] -- list of long option strings (without "--")
- (ArgDescr a) -- argument descriptor
- String -- explanation of option for user
-
-data ArgDescr a -- description of an argument option:
- = NoArg a -- no argument expected
- | ReqArg (String -> a) String -- option requires argument
- | OptArg (Maybe String -> a) String -- optional argument
-
-data OptKind a -- kind of cmd line arg (internal use only):
- = Opt a -- an option
- | NonOpt String -- a non-option
- | EndOfOpts -- end-of-options marker (i.e. "--")
- | OptErr String -- something went wrong...
-
-usageInfo :: String -- header
- -> [OptDescr a] -- option descriptors
- -> String -- nicely formatted decription of options
-usageInfo header optDescr = unlines (header:table)
- where (ss,ls,ds) = (unzip3 . map fmtOpt) optDescr
- table = zipWith3 paste (sameLen ss) (sameLen ls) (sameLen ds)
- paste x y z = " " ++ x ++ " " ++ y ++ " " ++ z
- sameLen xs = flushLeft ((maximum . map length) xs) xs
- flushLeft n xs = [ take n (x ++ repeat ' ') | x <- xs ]
-
-fmtOpt :: OptDescr a -> (String,String,String)
-fmtOpt (Option sos los ad descr) = (sepBy ',' (map (fmtShort ad) sos),
- sepBy ',' (map (fmtLong ad) los),
- descr)
- where sepBy _ [] = ""
- sepBy _ [x] = x
- sepBy ch (x:xs) = x ++ ch:' ':sepBy ch xs
-
-fmtShort :: ArgDescr a -> Char -> String
-fmtShort (NoArg _ ) so = "-" ++ [so]
-fmtShort (ReqArg _ ad) so = "-" ++ [so] ++ " " ++ ad
-fmtShort (OptArg _ ad) so = "-" ++ [so] ++ "[" ++ ad ++ "]"
-
-fmtLong :: ArgDescr a -> String -> String
-fmtLong (NoArg _ ) lo = "--" ++ lo
-fmtLong (ReqArg _ ad) lo = "--" ++ lo ++ "=" ++ ad
-fmtLong (OptArg _ ad) lo = "--" ++ lo ++ "[=" ++ ad ++ "]"
-
-getOpt :: ArgOrder a -- non-option handling
- -> [OptDescr a] -- option descriptors
- -> [String] -- the commandline arguments
- -> ([a],[String],[String]) -- (options,non-options,error messages)
-getOpt _ _ [] = ([],[],[])
-getOpt ordering optDescr (arg:args) = procNextOpt opt ordering
- where procNextOpt (Opt o) _ = (o:os,xs,es)
- procNextOpt (NonOpt x) RequireOrder = ([],x:rest,[])
- procNextOpt (NonOpt x) Permute = (os,x:xs,es)
- procNextOpt (NonOpt x) (ReturnInOrder f) = (f x :os, xs,es)
- procNextOpt EndOfOpts RequireOrder = ([],rest,[])
- procNextOpt EndOfOpts Permute = ([],rest,[])
- procNextOpt EndOfOpts (ReturnInOrder f) = (map f rest,[],[])
- procNextOpt (OptErr e) _ = (os,xs,e:es)
-
- (opt,rest) = getNext arg args optDescr
- (os,xs,es) = getOpt ordering optDescr rest
-
--- take a look at the next cmd line arg and decide what to do with it
-getNext :: String -> [String] -> [OptDescr a] -> (OptKind a,[String])
-getNext ('-':'-':[]) rest _ = (EndOfOpts,rest)
-getNext ('-':'-':xs) rest optDescr = longOpt xs rest optDescr
-getNext ('-': x :xs) rest optDescr = shortOpt x xs rest optDescr
-getNext a rest _ = (NonOpt a,rest)
-
--- handle long option
-longOpt :: String -> [String] -> [OptDescr a] -> (OptKind a,[String])
-longOpt ls rs optDescr = long ads arg rs
- where (opt,arg) = break (=='=') ls
- options = [ o | o@(Option _ ls _ _) <- optDescr, l <- ls, opt `isPrefixOf` l ]
- ads = [ ad | Option _ _ ad _ <- options ]
- optStr = ("--"++opt)
-
- long (_:_:_) _ rest = (errAmbig options optStr,rest)
- long [NoArg a ] [] rest = (Opt a,rest)
- long [NoArg _ ] ('=':_) rest = (errNoArg optStr,rest)
- long [ReqArg _ d] [] [] = (errReq d optStr,[])
- long [ReqArg f _] [] (r:rest) = (Opt (f r),rest)
- long [ReqArg f _] ('=':xs) rest = (Opt (f xs),rest)
- long [OptArg f _] [] rest = (Opt (f Nothing),rest)
- long [OptArg f _] ('=':xs) rest = (Opt (f (Just xs)),rest)
- long _ _ rest = (errUnrec optStr,rest)
-
--- handle short option
-shortOpt :: Char -> String -> [String] -> [OptDescr a] -> (OptKind a,[String])
-shortOpt x xs rest optDescr = short ads xs rest
- where options = [ o | o@(Option ss _ _ _) <- optDescr, s <- ss, x == s ]
- ads = [ ad | Option _ _ ad _ <- options ]
- optStr = '-':[x]
-
- short (_:_:_) _ rest = (errAmbig options optStr,rest)
- short (NoArg a :_) [] rest = (Opt a,rest)
- short (NoArg a :_) xs rest = (Opt a,('-':xs):rest)
- short (ReqArg _ d:_) [] [] = (errReq d optStr,[])
- short (ReqArg f _:_) [] (r:rest) = (Opt (f r),rest)
- short (ReqArg f _:_) xs rest = (Opt (f xs),rest)
- short (OptArg f _:_) [] rest = (Opt (f Nothing),rest)
- short (OptArg f _:_) xs rest = (Opt (f (Just xs)),rest)
- short [] [] rest = (errUnrec optStr,rest)
- short [] xs rest = (errUnrec optStr,('-':xs):rest)
-
--- miscellaneous error formatting
-
-errAmbig :: [OptDescr a] -> String -> OptKind a
-errAmbig ods optStr = OptErr (usageInfo header ods)
- where header = "option `" ++ optStr ++ "' is ambiguous; could be one of:"
-
-errReq :: String -> String -> OptKind a
-errReq d optStr = OptErr ("option `" ++ optStr ++ "' requires an argument " ++ d ++ "\n")
-
-errUnrec :: String -> OptKind a
-errUnrec optStr = OptErr ("unrecognized option `" ++ optStr ++ "'\n")
-
-errNoArg :: String -> OptKind a
-errNoArg optStr = OptErr ("option `" ++ optStr ++ "' doesn't allow an argument\n")
-
-{-
------------------------------------------------------------------------------------------
--- and here a small and hopefully enlightening example:
-
-data Flag = Verbose | Version | Name String | Output String | Arg String deriving Show
-
-options :: [OptDescr Flag]
-options =
- [Option ['v'] ["verbose"] (NoArg Verbose) "verbosely list files",
- Option ['V','?'] ["version","release"] (NoArg Version) "show version info",
- Option ['o'] ["output"] (OptArg out "FILE") "use FILE for dump",
- Option ['n'] ["name"] (ReqArg Name "USER") "only dump USER's files"]
-
-out :: Maybe String -> Flag
-out Nothing = Output "stdout"
-out (Just o) = Output o
-
-test :: ArgOrder Flag -> [String] -> String
-test order cmdline = case getOpt order options cmdline of
- (o,n,[] ) -> "options=" ++ show o ++ " args=" ++ show n ++ "\n"
- (_,_,errs) -> concat errs ++ usageInfo header options
- where header = "Usage: foobar [OPTION...] files..."
-
--- example runs:
--- putStr (test RequireOrder ["foo","-v"])
--- ==> options=[] args=["foo", "-v"]
--- putStr (test Permute ["foo","-v"])
--- ==> options=[Verbose] args=["foo"]
--- putStr (test (ReturnInOrder Arg) ["foo","-v"])
--- ==> options=[Arg "foo", Verbose] args=[]
--- putStr (test Permute ["foo","--","-v"])
--- ==> options=[] args=["foo", "-v"]
--- putStr (test Permute ["-?o","--name","bar","--na=baz"])
--- ==> options=[Version, Output "stdout", Name "bar", Name "baz"] args=[]
--- putStr (test Permute ["--ver","foo"])
--- ==> option `--ver' is ambiguous; could be one of:
--- -v --verbose verbosely list files
--- -V, -? --version, --release show version info
--- Usage: foobar [OPTION...] files...
--- -v --verbose verbosely list files
--- -V, -? --version, --release show version info
--- -o[FILE] --output[=FILE] use FILE for dump
--- -n USER --name=USER only dump USER's files
------------------------------------------------------------------------------------------
--}
-\end{code}
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