----------------------------------------------------------------------------- -- | -- Module : Distribution.Simple.Command -- Copyright : Duncan Coutts 2007 -- -- Maintainer : cabal-devel@haskell.org -- Portability : portable -- -- This is to do with command line handling. The Cabal command line is -- organised into a number of named sub-commands (much like darcs). The -- 'CommandUI' abstraction represents one of these sub-commands, with a name, -- description, a set of flags. Commands can be associated with actions and -- run. It handles some common stuff automatically, like the @--help@ and -- command line completion flags. It is designed to allow other tools make -- derived commands. This feature is used heavily in @cabal-install@. {- All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither the name of Isaac Jones nor the names of other contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -} module Distribution.Simple.Command ( -- * Command interface CommandUI(..), commandShowOptions, CommandParse(..), commandParseArgs, -- ** Constructing commands ShowOrParseArgs(..), makeCommand, hiddenCommand, -- ** Associating actions with commands Command, commandAddAction, noExtraFlags, -- ** Running commands commandsRun, -- * Option Fields OptionField(..), Name, -- ** Constructing Option Fields option, multiOption, -- ** Liftings & Projections liftOption, viewAsFieldDescr, -- * Option Descriptions OptDescr(..), Description, SFlags, LFlags, OptFlags, ArgPlaceHolder, -- ** OptDescr 'smart' constructors MkOptDescr, reqArg, reqArg', optArg, optArg', noArg, boolOpt, boolOpt', choiceOpt, choiceOptFromEnum ) where import Control.Monad import Data.Char (isAlpha, toLower) import Data.List (sortBy) import Data.Maybe import Data.Monoid import qualified Distribution.GetOpt as GetOpt import Distribution.Text ( Text(disp, parse) ) import Distribution.ParseUtils import Distribution.ReadE import Distribution.Simple.Utils (die, intercalate) import Text.PrettyPrint ( punctuate, cat, comma, text, empty) data CommandUI flags = CommandUI { -- | The name of the command as it would be entered on the command line. -- For example @\"build\"@. commandName :: String, -- | A short, one line description of the command to use in help texts. commandSynopsis :: String, -- | A function that maps a program name to a usage summary for this -- command. commandUsage :: String -> String, -- | Additional explanation of the command to use in help texts. commandDescription :: Maybe (String -> String), -- | Initial \/ empty flags commandDefaultFlags :: flags, -- | All the Option fields for this command commandOptions :: ShowOrParseArgs -> [OptionField flags] } data ShowOrParseArgs = ShowArgs | ParseArgs type Name = String type Description = String -- | We usually have a datatype for storing configuration values, where -- every field stores a configuration option, and the user sets -- the value either via command line flags or a configuration file. -- An individual OptionField models such a field, and we usually -- build a list of options associated to a configuration datatype. data OptionField a = OptionField { optionName :: Name, optionDescr :: [OptDescr a] } -- | An OptionField takes one or more OptDescrs, describing the command line -- interface for the field. data OptDescr a = ReqArg Description OptFlags ArgPlaceHolder (ReadE (a->a)) (a -> [String]) | OptArg Description OptFlags ArgPlaceHolder (ReadE (a->a)) (a->a) (a -> [Maybe String]) | ChoiceOpt [(Description, OptFlags, a->a, a -> Bool)] | BoolOpt Description OptFlags{-True-} OptFlags{-False-} (Bool -> a -> a) (a-> Maybe Bool) -- | Short command line option strings type SFlags = [Char] -- | Long command line option strings type LFlags = [String] type OptFlags = (SFlags,LFlags) type ArgPlaceHolder = String -- | Create an option taking a single OptDescr. -- No explicit Name is given for the Option, the name is the first LFlag given. option :: SFlags -> LFlags -> Description -> get -> set -> MkOptDescr get set a -> OptionField a option sf lf@(n:_) d get set arg = OptionField n [arg sf lf d get set] option _ _ _ _ _ _ = error $ "Distribution.command.option: " ++ "An OptionField must have at least one LFlag" -- | Create an option taking several OptDescrs. -- You will have to give the flags and description individually to the -- OptDescr constructor. multiOption :: Name -> get -> set -> [get -> set -> OptDescr a] -- ^MkOptDescr constructors partially -- applied to flags and description. -> OptionField a multiOption n get set args = OptionField n [arg get set | arg <- args] type MkOptDescr get set a = SFlags -> LFlags -> Description -> get -> set -> OptDescr a -- | Create a string-valued command line interface. reqArg :: Monoid b => ArgPlaceHolder -> ReadE b -> (b -> [String]) -> MkOptDescr (a -> b) (b -> a -> a) a reqArg ad mkflag showflag sf lf d get set = ReqArg d (sf,lf) ad (fmap (\a b -> set (get b `mappend` a) b) mkflag) (showflag . get) -- | Create a string-valued command line interface with a default value. optArg :: Monoid b => ArgPlaceHolder -> ReadE b -> b -> (b -> [Maybe String]) -> MkOptDescr (a -> b) (b -> a -> a) a optArg ad mkflag def showflag sf lf d get set = OptArg d (sf,lf) ad (fmap (\a b -> set (get b `mappend` a) b) mkflag) (\b -> set (get b `mappend` def) b) (showflag . get) -- | (String -> a) variant of "reqArg" reqArg' :: Monoid b => ArgPlaceHolder -> (String -> b) -> (b -> [String]) -> MkOptDescr (a -> b) (b -> a -> a) a reqArg' ad mkflag showflag = reqArg ad (succeedReadE mkflag) showflag -- | (String -> a) variant of "optArg" optArg' :: Monoid b => ArgPlaceHolder -> (Maybe String -> b) -> (b -> [Maybe String]) -> MkOptDescr (a -> b) (b -> a -> a) a optArg' ad mkflag showflag = optArg ad (succeedReadE (mkflag . Just)) def showflag where def = mkflag Nothing noArg :: (Eq b, Monoid b) => b -> MkOptDescr (a -> b) (b -> a -> a) a noArg flag sf lf d = choiceOpt [(flag, (sf,lf), d)] sf lf d boolOpt :: (b -> Maybe Bool) -> (Bool -> b) -> SFlags -> SFlags -> MkOptDescr (a -> b) (b -> a -> a) a boolOpt g s sfT sfF _sf _lf@(n:_) d get set = BoolOpt d (sfT, ["enable-"++n]) (sfF, ["disable-"++n]) (set.s) (g.get) boolOpt _ _ _ _ _ _ _ _ _ = error "Distribution.Simple.Setup.boolOpt: unreachable" boolOpt' :: (b -> Maybe Bool) -> (Bool -> b) -> OptFlags -> OptFlags -> MkOptDescr (a -> b) (b -> a -> a) a boolOpt' g s ffT ffF _sf _lf d get set = BoolOpt d ffT ffF (set.s) (g . get) -- | create a Choice option choiceOpt :: Eq b => [(b,OptFlags,Description)] -> MkOptDescr (a -> b) (b -> a -> a) a choiceOpt aa_ff _sf _lf _d get set = ChoiceOpt alts where alts = [(d,flags, set alt, (==alt) . get) | (alt,flags,d) <- aa_ff] -- | create a Choice option out of an enumeration type. -- As long flags, the Show output is used. As short flags, the first character -- which does not conflict with a previous one is used. choiceOptFromEnum :: (Bounded b, Enum b, Show b, Eq b) => MkOptDescr (a -> b) (b -> a -> a) a choiceOptFromEnum _sf _lf d get = choiceOpt [ (x, (sf, [map toLower $ show x]), d') | (x, sf) <- sflags' , let d' = d ++ show x] _sf _lf d get where sflags' = foldl f [] [firstOne..] f prev x = let prevflags = concatMap snd prev in prev ++ take 1 [(x, [toLower sf]) | sf <- show x, isAlpha sf , toLower sf `notElem` prevflags] firstOne = minBound `asTypeOf` get undefined commandGetOpts :: ShowOrParseArgs -> CommandUI flags -> [GetOpt.OptDescr (flags -> flags)] commandGetOpts showOrParse command = concatMap viewAsGetOpt (commandOptions command showOrParse) viewAsGetOpt :: OptionField a -> [GetOpt.OptDescr (a->a)] viewAsGetOpt (OptionField _n aa) = concatMap optDescrToGetOpt aa where optDescrToGetOpt (ReqArg d (cs,ss) arg_desc set _) = [GetOpt.Option cs ss (GetOpt.ReqArg set' arg_desc) d] where set' = readEOrFail set optDescrToGetOpt (OptArg d (cs,ss) arg_desc set def _) = [GetOpt.Option cs ss (GetOpt.OptArg set' arg_desc) d] where set' Nothing = def set' (Just txt) = readEOrFail set txt optDescrToGetOpt (ChoiceOpt alts) = [GetOpt.Option sf lf (GetOpt.NoArg set) d | (d,(sf,lf),set,_) <- alts ] optDescrToGetOpt (BoolOpt d (sfT,lfT) (sfF, lfF) set _) = [ GetOpt.Option sfT lfT (GetOpt.NoArg (set True)) ("Enable " ++ d) , GetOpt.Option sfF lfF (GetOpt.NoArg (set False)) ("Disable " ++ d) ] -- | to view as a FieldDescr, we sort the list of interfaces (Req > Bool > -- Choice > Opt) and consider only the first one. viewAsFieldDescr :: OptionField a -> FieldDescr a viewAsFieldDescr (OptionField _n []) = error "Distribution.command.viewAsFieldDescr: unexpected" viewAsFieldDescr (OptionField n dd) = FieldDescr n get set where optDescr = head $ sortBy cmp dd cmp :: OptDescr a -> OptDescr a -> Ordering ReqArg{} `cmp` ReqArg{} = EQ ReqArg{} `cmp` _ = GT BoolOpt{} `cmp` ReqArg{} = LT BoolOpt{} `cmp` BoolOpt{} = EQ BoolOpt{} `cmp` _ = GT ChoiceOpt{} `cmp` ReqArg{} = LT ChoiceOpt{} `cmp` BoolOpt{} = LT ChoiceOpt{} `cmp` ChoiceOpt{} = EQ ChoiceOpt{} `cmp` _ = GT OptArg{} `cmp` OptArg{} = EQ OptArg{} `cmp` _ = LT -- get :: a -> Doc get t = case optDescr of ReqArg _ _ _ _ ppr -> (cat . punctuate comma . map text . ppr) t OptArg _ _ _ _ _ ppr -> case ppr t of [] -> empty (Nothing : _) -> text "True" (Just a : _) -> text a ChoiceOpt alts -> fromMaybe empty $ listToMaybe [ text lf | (_,(_,lf:_), _,enabled) <- alts, enabled t] BoolOpt _ _ _ _ enabled -> (maybe empty disp . enabled) t -- set :: LineNo -> String -> a -> ParseResult a set line val a = case optDescr of ReqArg _ _ _ readE _ -> ($ a) `liftM` runE line n readE val -- We parse for a single value instead of a -- list, as one can't really implement -- parseList :: ReadE a -> ReadE [a] with -- the current ReadE definition ChoiceOpt{} -> case getChoiceByLongFlag optDescr val of Just f -> return (f a) _ -> syntaxError line val BoolOpt _ _ _ setV _ -> (`setV` a) `liftM` runP line n parse val OptArg _ _ _ readE _ _ -> ($ a) `liftM` runE line n readE val -- Optional arguments are parsed just like -- required arguments here; we don't -- provide a method to set an OptArg field -- to the default value. getChoiceByLongFlag :: OptDescr b -> String -> Maybe (b->b) getChoiceByLongFlag (ChoiceOpt alts) val = listToMaybe [ set | (_,(_sf,lf:_), set, _) <- alts , lf == val] getChoiceByLongFlag _ _ = error "Distribution.command.getChoiceByLongFlag: expected a choice option" getCurrentChoice :: OptDescr a -> a -> [String] getCurrentChoice (ChoiceOpt alts) a = [ lf | (_,(_sf,lf:_), _, currentChoice) <- alts, currentChoice a] getCurrentChoice _ _ = error "Command.getChoice: expected a Choice OptDescr" liftOption :: (b -> a) -> (a -> (b -> b)) -> OptionField a -> OptionField b liftOption get' set' opt = opt { optionDescr = liftOptDescr get' set' `map` optionDescr opt} liftOptDescr :: (b -> a) -> (a -> (b -> b)) -> OptDescr a -> OptDescr b liftOptDescr get' set' (ChoiceOpt opts) = ChoiceOpt [ (d, ff, liftSet get' set' set , (get . get')) | (d, ff, set, get) <- opts] liftOptDescr get' set' (OptArg d ff ad set def get) = OptArg d ff ad (liftSet get' set' `fmap` set) (liftSet get' set' def) (get . get') liftOptDescr get' set' (ReqArg d ff ad set get) = ReqArg d ff ad (liftSet get' set' `fmap` set) (get . get') liftOptDescr get' set' (BoolOpt d ffT ffF set get) = BoolOpt d ffT ffF (liftSet get' set' . set) (get . get') liftSet :: (b -> a) -> (a -> (b -> b)) -> (a -> a) -> b -> b liftSet get' set' set x = set' (set $ get' x) x -- | Show flags in the standard long option command line format commandShowOptions :: CommandUI flags -> flags -> [String] commandShowOptions command v = concat [ showOptDescr v od | o <- commandOptions command ParseArgs , od <- optionDescr o] where showOptDescr :: a -> OptDescr a -> [String] showOptDescr x (BoolOpt _ (_,lfT:_) (_,lfF:_) _ enabled) = case enabled x of Nothing -> [] Just True -> ["--" ++ lfT] Just False -> ["--" ++ lfF] showOptDescr x c@ChoiceOpt{} = ["--" ++ val | val <- getCurrentChoice c x] showOptDescr x (ReqArg _ (_ssff,lf:_) _ _ showflag) = [ "--"++lf++"="++flag | flag <- showflag x ] showOptDescr x (OptArg _ (_ssff,lf:_) _ _ _ showflag) = [ case flag of Just s -> "--"++lf++"="++s Nothing -> "--"++lf | flag <- showflag x ] showOptDescr _ _ = error "Distribution.Simple.Command.showOptDescr: unreachable" commandListOptions :: CommandUI flags -> [String] commandListOptions command = concatMap listOption $ addCommonFlags ShowArgs $ -- This is a slight hack, we don't want -- "--list-options" showing up in the -- list options output, so use ShowArgs commandGetOpts ShowArgs command where listOption (GetOpt.Option shortNames longNames _ _) = [ "-" ++ [name] | name <- shortNames ] ++ [ "--" ++ name | name <- longNames ] -- | The help text for this command with descriptions of all the options. commandHelp :: CommandUI flags -> String -> String commandHelp command pname = commandUsage command pname ++ (GetOpt.usageInfo "" . addCommonFlags ShowArgs $ commandGetOpts ShowArgs command) ++ case commandDescription command of Nothing -> "" Just desc -> '\n': desc pname -- | Make a Command from standard 'GetOpt' options. makeCommand :: String -- ^ name -> String -- ^ short description -> Maybe (String -> String) -- ^ long description -> flags -- ^ initial\/empty flags -> (ShowOrParseArgs -> [OptionField flags]) -- ^ options -> CommandUI flags makeCommand name shortDesc longDesc defaultFlags options = CommandUI { commandName = name, commandSynopsis = shortDesc, commandDescription = longDesc, commandUsage = usage, commandDefaultFlags = defaultFlags, commandOptions = options } where usage pname = "Usage: " ++ pname ++ " " ++ name ++ " [FLAGS]\n\n" ++ "Flags for " ++ name ++ ":" -- | Common flags that apply to every command data CommonFlag = HelpFlag | ListOptionsFlag commonFlags :: ShowOrParseArgs -> [GetOpt.OptDescr CommonFlag] commonFlags showOrParseArgs = case showOrParseArgs of ShowArgs -> [help] ParseArgs -> [help, list] where help = GetOpt.Option helpShortFlags ["help"] (GetOpt.NoArg HelpFlag) "Show this help text" helpShortFlags = case showOrParseArgs of ShowArgs -> ['h'] ParseArgs -> ['h', '?'] list = GetOpt.Option [] ["list-options"] (GetOpt.NoArg ListOptionsFlag) "Print a list of command line flags" addCommonFlags :: ShowOrParseArgs -> [GetOpt.OptDescr a] -> [GetOpt.OptDescr (Either CommonFlag a)] addCommonFlags showOrParseArgs options = map (fmapOptDesc Left) (commonFlags showOrParseArgs) ++ map (fmapOptDesc Right) options where fmapOptDesc f (GetOpt.Option s l d m) = GetOpt.Option s l (fmapArgDesc f d) m fmapArgDesc f (GetOpt.NoArg a) = GetOpt.NoArg (f a) fmapArgDesc f (GetOpt.ReqArg s d) = GetOpt.ReqArg (f . s) d fmapArgDesc f (GetOpt.OptArg s d) = GetOpt.OptArg (f . s) d -- | Parse a bunch of command line arguments -- commandParseArgs :: CommandUI flags -> Bool -- ^ Is the command a global or subcommand? -> [String] -> CommandParse (flags -> flags, [String]) commandParseArgs command global args = let options = addCommonFlags ParseArgs $ commandGetOpts ParseArgs command order | global = GetOpt.RequireOrder | otherwise = GetOpt.Permute in case GetOpt.getOpt' order options args of (flags, _, _, _) | any listFlag flags -> CommandList (commandListOptions command) | any helpFlag flags -> CommandHelp (commandHelp command) where listFlag (Left ListOptionsFlag) = True; listFlag _ = False helpFlag (Left HelpFlag) = True; helpFlag _ = False (flags, opts, opts', []) | global || null opts' -> CommandReadyToGo (accum flags, mix opts opts') | otherwise -> CommandErrors (unrecognised opts') (_, _, _, errs) -> CommandErrors errs where -- Note: It is crucial to use reverse function composition here or to -- reverse the flags here as we want to process the flags left to right -- but data flow in function compsition is right to left. accum flags = foldr (flip (.)) id [ f | Right f <- flags ] unrecognised opts = [ "unrecognized option `" ++ opt ++ "'\n" | opt <- opts ] -- For unrecognised global flags we put them in the position just after -- the command, if there is one. This gives us a chance to parse them -- as sub-command rather than global flags. mix [] ys = ys mix (x:xs) ys = x:ys++xs data CommandParse flags = CommandHelp (String -> String) | CommandList [String] | CommandErrors [String] | CommandReadyToGo flags instance Functor CommandParse where fmap _ (CommandHelp help) = CommandHelp help fmap _ (CommandList opts) = CommandList opts fmap _ (CommandErrors errs) = CommandErrors errs fmap f (CommandReadyToGo flags) = CommandReadyToGo (f flags) data CommandType = NormalCommand | HiddenCommand data Command action = Command String String ([String] -> CommandParse action) CommandType -- | Mark command as hidden. Hidden commands don't show up in the 'progname -- help' or 'progname --help' output. hiddenCommand :: Command action -> Command action hiddenCommand (Command name synopsys f _cmdType) = Command name synopsys f HiddenCommand commandAddAction :: CommandUI flags -> (flags -> [String] -> action) -> Command action commandAddAction command action = Command (commandName command) (commandSynopsis command) (fmap (uncurry applyDefaultArgs) . commandParseArgs command False) NormalCommand where applyDefaultArgs mkflags args = let flags = mkflags (commandDefaultFlags command) in action flags args commandsRun :: CommandUI a -> [Command action] -> [String] -> CommandParse (a, CommandParse action) commandsRun globalCommand commands args = case commandParseArgs globalCommand' True args of CommandHelp help -> CommandHelp help CommandList opts -> CommandList (opts ++ commandNames) CommandErrors errs -> CommandErrors errs CommandReadyToGo (mkflags, args') -> case args' of ("help":cmdArgs) -> handleHelpCommand cmdArgs (name:cmdArgs) -> case lookupCommand name of [Command _ _ action _] -> CommandReadyToGo (flags, action cmdArgs) _ -> CommandReadyToGo (flags, badCommand name) [] -> CommandReadyToGo (flags, noCommand) where flags = mkflags (commandDefaultFlags globalCommand) where lookupCommand cname = [ cmd | cmd@(Command cname' _ _ _) <- commands' , cname' == cname ] noCommand = CommandErrors ["no command given (try --help)\n"] badCommand cname = CommandErrors ["unrecognised command: " ++ cname ++ " (try --help)\n"] commands' = commands ++ [commandAddAction helpCommandUI undefined] commandNames = [ name | (Command name _ _ NormalCommand) <- commands' ] globalCommand' = globalCommand { commandUsage = \pname -> (case commandUsage globalCommand pname of "" -> "" original -> original ++ "\n") ++ "Usage: " ++ pname ++ " COMMAND [FLAGS]\n" ++ " or: " ++ pname ++ " [GLOBAL FLAGS]\n\n" ++ "Global flags:", commandDescription = Just $ \pname -> "Commands:\n" ++ unlines [ " " ++ align name ++ " " ++ description | Command name description _ NormalCommand <- commands' ] ++ case commandDescription globalCommand of Nothing -> "" Just desc -> '\n': desc pname } where maxlen = maximum [ length name | Command name _ _ NormalCommand <- commands' ] align str = str ++ replicate (maxlen - length str) ' ' -- A bit of a hack: support "prog help" as a synonym of "prog --help" -- furthermore, support "prog help command" as "prog command --help" handleHelpCommand cmdArgs = case commandParseArgs helpCommandUI True cmdArgs of CommandHelp help -> CommandHelp help CommandList list -> CommandList (list ++ commandNames) CommandErrors _ -> CommandHelp globalHelp CommandReadyToGo (_,[]) -> CommandHelp globalHelp CommandReadyToGo (_,(name:cmdArgs')) -> case lookupCommand name of [Command _ _ action _] -> case action ("--help":cmdArgs') of CommandHelp help -> CommandHelp help CommandList _ -> CommandList [] _ -> CommandHelp globalHelp _ -> badCommand name where globalHelp = commandHelp globalCommand' helpCommandUI = (makeCommand "help" "Help about commands." Nothing () (const [])) { commandUsage = \pname -> "Usage: " ++ pname ++ " help [FLAGS]\n" ++ " or: " ++ pname ++ " help COMMAND [FLAGS]\n\n" ++ "Flags for help:" } -- | Utility function, many commands do not accept additional flags. This -- action fails with a helpful error message if the user supplies any extra. -- noExtraFlags :: [String] -> IO () noExtraFlags [] = return () noExtraFlags extraFlags = die $ "Unrecognised flags: " ++ intercalate ", " extraFlags --TODO: eliminate this function and turn it into a variant on commandAddAction -- instead like commandAddActionNoArgs that doesn't supply the [String]