-- Hoogle documentation, generated by Haddock -- See Hoogle, http://www.haskell.org/hoogle/ -- | Command line flag parser, very similar to Google's gflags -- -- The HFlags library supports easy definition of command line -- flags, reimplementing the ideas from Google's gflags -- (http://code.google.com/p/gflags). -- -- Command line flags can be declared in any file at the toplevel, using -- defineFlag. At runtime, the actual values are assigned to the -- toplevel flags_name constants. Those can be used purely -- throughout the program. -- -- At the beginning of the main function, $initHFlags -- program description has to be called to initialize the -- flags. All flags will be initialized that are transitively reachable -- via imports from main. This means, that any Haskell package -- can easily define command line flags with HFlags. This -- feature is demonstrated by -- http://github.com/errge/hflags/blob/master/examples/ImportExample.hs -- and -- http://github.com/errge/hflags/tree/master/examples/package. -- -- A simple example (more in the -- http://github.com/errge/hflags/tree/master/examples directory): -- -- 
--   #!/usr/bin/env runhaskell
--   
--   {-# LANGUAGE TemplateHaskell #-}
--   
--   import HFlags
--   
--   defineFlag "name" "Indiana Jones" "Who to greet."
--   defineFlag "r:repeat" (3 + 4 :: Int) "Number of times to repeat the message."
--   
--   main = do s <- $initHFlags "Simple program v0.1"
--             sequence_ $ replicate flags_repeat greet
--             putStrLn $ "Your additional arguments were: " ++ show s
--             putStrLn $ "Which is the same as: " ++ show HFlags.arguments
--     where
--       greet = putStrLn $ "Hello " ++ flags_name ++ ", very nice to meet you!"
--
-- -- At initHFlags time, the library also tries to gather flags -- out of environment variables. HFLAGS_verbose=True is -- equivalent to specify --verbose=True. This environment feature only -- works with long options and the user has to specify a value even for -- Bools. -- -- Since version 0.2, you mustn't put the initHFlags in a parentheses -- with the program description. Just $initHFlags, it's -- cleaner. -- -- Changes in version 0.2 -- -- @package hflags @version 0.2 -- | The HFlags library supports easy definition of command line -- flags, reimplementing the ideas from Google's gflags -- (http://code.google.com/p/gflags). -- -- Command line flags can be declared in any file at the toplevel, using -- defineFlag. At runtime, the actual values are assigned to the -- toplevel flags_name constants. Those can be used purely -- throughout the program. -- -- At the beginning of the main function, $initHFlags -- program description has to be called to initialize the -- flags. All flags will be initialized that are transitively reachable -- via imports from main. This means, that any Haskell package -- can easily define command line flags with HFlags. This -- feature is demonstrated by -- http://github.com/errge/hflags/blob/master/examples/ImportExample.hs -- and -- http://github.com/errge/hflags/tree/master/examples/package. -- -- A simple example (more in the -- http://github.com/errge/hflags/tree/master/examples directory): -- -- 
--   #!/usr/bin/env runhaskell
--   
--   {-# LANGUAGE TemplateHaskell #-}
--   
--   import HFlags
--   
--   defineFlag "name" "Indiana Jones" "Who to greet."
--   defineFlag "r:repeat" (3 + 4 :: Int) "Number of times to repeat the message."
--   
--   main = do s <- $initHFlags "Simple program v0.1"
--             sequence_ $ replicate flags_repeat greet
--             putStrLn $ "Your additional arguments were: " ++ show s
--             putStrLn $ "Which is the same as: " ++ show HFlags.arguments
--     where
--       greet = putStrLn $ "Hello " ++ flags_name ++ ", very nice to meet you!"
--
-- -- At initHFlags time, the library also tries to gather flags -- out of environment variables. HFLAGS_verbose=True is -- equivalent to specify --verbose=True. This environment feature only -- works with long options and the user has to specify a value even for -- Bools. -- -- Since version 0.2, you mustn't put the initHFlags in a parentheses -- with the program description. Just $initHFlags, it's -- cleaner. module HFlags -- | The most flexible way of defining a flag. For an example see -- http://github.com/errge/hflags/blob/master/examples/ComplexExample.hs. -- For most things defineFlag should be enough instead. -- -- The parameters: -- -- defineCustomFlag :: String -> ExpQ -> String -> ExpQ -> ExpQ -> String -> Q [Dec] -- | This just forwards to defineCustomFlag with [| read |] -- and [| show |]. Useful for flags where the type is not an -- instance of FlagType. For examples, see -- http://github.com/errge/hflags/blob/master/examples/ComplexExample.hs. -- -- The parameters: -- -- defineEQFlag :: String -> ExpQ -> String -> String -> Q [Dec] -- | Class of types for which the easy defineFlag syntax is -- supported. class FlagType t defineFlag :: FlagType t => String -> t -> String -> Q [Dec] -- | Has to be called from the main before doing anything else: -- -- 
--   main = do args <- $initHFlags Simple program v0.1
--             ...
--
-- -- Since version 0.2, you mustn't put the initHFlags in a parentheses -- with the program description. Just $initHFlags, it's -- cleaner. -- -- Internally, it uses Template Haskell trickery to gather all the -- instances of the Flag class and then generates a call to -- initFlags with the appropriate data gathered together from -- those instances to a list. -- -- Type after splicing is String -> IO [String]. initHFlags :: ExpQ -- | Same as initHFlags, but makes it possible to introduce programmatic -- defaults based on user supplied flag values. -- -- The second parameter has to be a function that gets the following -- alists: -- -- -- -- Has to return an alist that contains the additional defaults that will -- override the default flag values (but not the user supplied values: -- environment or command line). -- -- Type after splicing is String -> DependentDefaults -> IO -- [String]. Where: -- -- initHFlagsDependentDefaults :: ExpQ -- | Contains the non-parsed, non-option parts of the command line, the -- arguments. Can only be used after initHFlags has been called. arguments :: [String] -- | Every flag the program supports has to be defined through a new -- phantom datatype and the Flag instance of that datatype. -- -- But users of the library shouldn't worry about this class or the -- implementation details behind these functions, just use the -- defineFlag Template Haskell function for defining new flags. class Flag a getFlagData :: Flag a => a -> FlagData -- | A global IORef for the communication between -- initHFlags and flags_*. This is a map between flag -- name and current value. globalHFlags :: IORef (Maybe (Map String String)) -- | A global IORef for the easy access to the arguments. globalArguments :: IORef (Maybe [String]) instance FlagType Text instance FlagType Double instance FlagType String instance FlagType Integer instance FlagType Int instance FlagType Bool instance Show FlagData