diff options
author | Ian Lynagh <igloo@earth.li> | 2008-08-24 02:02:13 +0000 |
---|---|---|
committer | Ian Lynagh <igloo@earth.li> | 2008-08-24 02:02:13 +0000 |
commit | 1943bef914ea256ba4d3b208c268e76bfb041963 (patch) | |
tree | 7e231dcb038e5cc59db1fb716fb5435beac6ca2d /libraries/base/System/Console | |
parent | 75097ac2585560aa580563d4c7be0b1944a41911 (diff) | |
download | haskell-1943bef914ea256ba4d3b208c268e76bfb041963.tar.gz |
Split getopt off into its own package
Diffstat (limited to 'libraries/base/System/Console')
-rw-r--r-- | libraries/base/System/Console/GetOpt.hs | 393 |
1 files changed, 0 insertions, 393 deletions
diff --git a/libraries/base/System/Console/GetOpt.hs b/libraries/base/System/Console/GetOpt.hs deleted file mode 100644 index 92ebd52055..0000000000 --- a/libraries/base/System/Console/GetOpt.hs +++ /dev/null @@ -1,393 +0,0 @@ ------------------------------------------------------------------------------ --- | --- Module : System.Console.GetOpt --- Copyright : (c) Sven Panne 2002-2005 --- License : BSD-style (see the file libraries/base/LICENSE) --- --- Maintainer : libraries@haskell.org --- Stability : experimental --- Portability : portable --- --- This library provides facilities for parsing the command-line options --- in a standalone program. It is essentially a Haskell port of the GNU --- @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! -:-) --} - -module System.Console.GetOpt ( - -- * GetOpt - getOpt, getOpt', - usageInfo, - ArgOrder(..), - OptDescr(..), - ArgDescr(..), - - -- * Examples - - -- |To hopefully illuminate the role of the different data structures, - -- here are the command-line options for a (very simple) compiler, - -- done in two different ways. - -- The difference arises because the type of 'getOpt' is - -- parameterized by the type of values derived from flags. - - -- ** Interpreting flags as concrete values - -- $example1 - - -- ** Interpreting flags as transformations of an options record - -- $example2 -) where - -import Prelude -- necessary to get dependencies right - -import Data.List ( isPrefixOf, find ) - --- |What to do with options following non-options -data ArgOrder a - = RequireOrder -- ^ no option processing after first non-option - | Permute -- ^ freely intersperse options and non-options - | ReturnInOrder (String -> a) -- ^ wrap non-options into options - -{-| -Each 'OptDescr' describes a single option. - -The arguments to 'Option' are: - -* list of short option characters - -* list of long option strings (without \"--\") - -* argument descriptor - -* explanation of option for user --} -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 - --- |Describes whether an option takes an argument or not, and if so --- how the argument is injected into a value of type @a@. -data ArgDescr a - = 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 - | UnreqOpt String -- an un-recognized option - | NonOpt String -- a non-option - | EndOfOpts -- end-of-options marker (i.e. "--") - | OptErr String -- something went wrong... - --- | Return a string describing the usage of a command, derived from --- the header (first argument) and the options described by the --- second argument. -usageInfo :: String -- header - -> [OptDescr a] -- option descriptors - -> String -- nicely formatted decription of options -usageInfo header optDescr = unlines (header:table) - where (ss,ls,ds) = (unzip3 . concatMap fmtOpt) optDescr - table = zipWith3 paste (sameLen ss) (sameLen ls) 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) = - case lines descr of - [] -> [(sosFmt,losFmt,"")] - (d:ds) -> (sosFmt,losFmt,d) : [ ("","",d') | d' <- ds ] - where sepBy _ [] = "" - sepBy _ [x] = x - sepBy ch (x:xs) = x ++ ch:' ':sepBy ch xs - sosFmt = sepBy ',' (map (fmtShort ad) sos) - losFmt = sepBy ',' (map (fmtLong ad) los) - -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 ++ "]" - -{-| -Process the command-line, and return the list of values that matched -(and those that didn\'t). The arguments are: - -* The order requirements (see 'ArgOrder') - -* The option descriptions (see 'OptDescr') - -* The actual command line arguments (presumably got from - 'System.Environment.getArgs'). - -'getOpt' returns a triple consisting of the option arguments, a list -of non-options, and a list of error messages. --} -getOpt :: ArgOrder a -- non-option handling - -> [OptDescr a] -- option descriptors - -> [String] -- the command-line arguments - -> ([a],[String],[String]) -- (options,non-options,error messages) -getOpt ordering optDescr args = (os,xs,es ++ map errUnrec us) - where (os,xs,us,es) = getOpt' ordering optDescr args - -{-| -This is almost the same as 'getOpt', but returns a quadruple -consisting of the option arguments, a list of non-options, a list of -unrecognized options, and a list of error messages. --} -getOpt' :: ArgOrder a -- non-option handling - -> [OptDescr a] -- option descriptors - -> [String] -- the command-line arguments - -> ([a],[String], [String] ,[String]) -- (options,non-options,unrecognized,error messages) -getOpt' _ _ [] = ([],[],[],[]) -getOpt' ordering optDescr (arg:args) = procNextOpt opt ordering - where procNextOpt (Opt o) _ = (o:os,xs,us,es) - procNextOpt (UnreqOpt u) _ = (os,xs,u:us,es) - procNextOpt (NonOpt x) RequireOrder = ([],x:rest,[],[]) - procNextOpt (NonOpt x) Permute = (os,x:xs,us,es) - procNextOpt (NonOpt x) (ReturnInOrder f) = (f x :os, xs,us,es) - procNextOpt EndOfOpts RequireOrder = ([],rest,[],[]) - procNextOpt EndOfOpts Permute = ([],rest,[],[]) - procNextOpt EndOfOpts (ReturnInOrder f) = (map f rest,[],[],[]) - procNextOpt (OptErr e) _ = (os,xs,us,e:es) - - (opt,rest) = getNext arg args optDescr - (os,xs,us,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 - getWith p = [ o | o@(Option _ xs _ _) <- optDescr - , find (p opt) xs /= Nothing ] - exact = getWith (==) - options = if null exact then getWith isPrefixOf else exact - 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 = (UnreqOpt ("--"++ls),rest) - --- handle short option -shortOpt :: Char -> String -> [String] -> [OptDescr a] -> (OptKind a,[String]) -shortOpt y ys rs optDescr = short ads ys rs - where options = [ o | o@(Option ss _ _ _) <- optDescr, s <- ss, y == s ] - ads = [ ad | Option _ _ ad _ <- options ] - optStr = '-':[y] - - 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 = (UnreqOpt optStr,rest) - short [] xs rest = (UnreqOpt 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 -> String -errUnrec optStr = "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 ------------------------------------------------------------------------------------------ --} - -{- $example1 - -A simple choice for the type associated with flags is to define a type -@Flag@ as an algebraic type representing the possible flags and their -arguments: - -> module Opts1 where -> -> import System.Console.GetOpt -> import Data.Maybe ( fromMaybe ) -> -> data Flag -> = Verbose | Version -> | Input String | Output String | LibDir String -> deriving Show -> -> options :: [OptDescr Flag] -> options = -> [ Option ['v'] ["verbose"] (NoArg Verbose) "chatty output on stderr" -> , Option ['V','?'] ["version"] (NoArg Version) "show version number" -> , Option ['o'] ["output"] (OptArg outp "FILE") "output FILE" -> , Option ['c'] [] (OptArg inp "FILE") "input FILE" -> , Option ['L'] ["libdir"] (ReqArg LibDir "DIR") "library directory" -> ] -> -> inp,outp :: Maybe String -> Flag -> outp = Output . fromMaybe "stdout" -> inp = Input . fromMaybe "stdin" -> -> compilerOpts :: [String] -> IO ([Flag], [String]) -> compilerOpts argv = -> case getOpt Permute options argv of -> (o,n,[] ) -> return (o,n) -> (_,_,errs) -> ioError (userError (concat errs ++ usageInfo header options)) -> where header = "Usage: ic [OPTION...] files..." - -Then the rest of the program will use the constructed list of flags -to determine it\'s behaviour. - --} - -{- $example2 - -A different approach is to group the option values in a record of type -@Options@, and have each flag yield a function of type -@Options -> Options@ transforming this record. - -> module Opts2 where -> -> import System.Console.GetOpt -> import Data.Maybe ( fromMaybe ) -> -> data Options = Options -> { optVerbose :: Bool -> , optShowVersion :: Bool -> , optOutput :: Maybe FilePath -> , optInput :: Maybe FilePath -> , optLibDirs :: [FilePath] -> } deriving Show -> -> defaultOptions = Options -> { optVerbose = False -> , optShowVersion = False -> , optOutput = Nothing -> , optInput = Nothing -> , optLibDirs = [] -> } -> -> options :: [OptDescr (Options -> Options)] -> options = -> [ Option ['v'] ["verbose"] -> (NoArg (\ opts -> opts { optVerbose = True })) -> "chatty output on stderr" -> , Option ['V','?'] ["version"] -> (NoArg (\ opts -> opts { optShowVersion = True })) -> "show version number" -> , Option ['o'] ["output"] -> (OptArg ((\ f opts -> opts { optOutput = Just f }) . fromMaybe "output") -> "FILE") -> "output FILE" -> , Option ['c'] [] -> (OptArg ((\ f opts -> opts { optInput = Just f }) . fromMaybe "input") -> "FILE") -> "input FILE" -> , Option ['L'] ["libdir"] -> (ReqArg (\ d opts -> opts { optLibDirs = optLibDirs opts ++ [d] }) "DIR") -> "library directory" -> ] -> -> compilerOpts :: [String] -> IO (Options, [String]) -> compilerOpts argv = -> case getOpt Permute options argv of -> (o,n,[] ) -> return (foldl (flip id) defaultOptions o, n) -> (_,_,errs) -> ioError (userError (concat errs ++ usageInfo header options)) -> where header = "Usage: ic [OPTION...] files..." - -Similarly, each flag could yield a monadic function transforming a record, -of type @Options -> IO Options@ (or any other monad), allowing option -processing to perform actions of the chosen monad, e.g. printing help or -version messages, checking that file arguments exist, etc. - --} |