| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
WithCli.Pure
Contents
Synopsis
- withCliPure :: WithCliPure function a => String -> [Modifier] -> [String] -> function -> Result a
- class WithCliPure function output
- data Result a
- = Success a
- | Errors String
- | OutputAndExit String
- handleResult :: Result a -> IO a
- class HasArguments a where
- atomicArgumentsParser :: forall a. Argument a => Modifiers -> Maybe String -> Result (Parser Unnormalized a)
- class Argument a where
- data Modifier
- class Generic a
- class Typeable (a :: k)
- data Proxy (t :: k) :: forall k. k -> * = Proxy
Documentation
Arguments
| :: WithCliPure function a | |
| => String | |
| -> [Modifier] | |
| -> [String] | |
| -> function | The |
| -> Result a |
Pure variant of withCliModified.
class WithCliPure function output Source #
Minimal complete definition
run
Instances
| WithCliPure output output Source # | |
| (HasArguments input, WithCliPure function output) => WithCliPure (input -> function) output Source # | |
Type to wrap results from withCliPure.
Constructors
| Success a | The CLI was used correctly and a value of type |
| Errors String | The CLI was used incorrectly. The It can also happen that the data type you're trying to use isn't supported. See the README for details. |
| OutputAndExit String | The CLI was used with |
handleResult :: Result a -> IO a Source #
Handles an input of type Result a
- On
Successaa. - On
OutputAndExitmessagestdoutand throwsExitSuccess. - On
Errorserrsstderrand throwsExitFailure1
This is used by withCli to handle parse results.
class HasArguments a where Source #
Everything that can be used as an argument to your main function
(see withCli) needs to have a HasArguments instance.
HasArguments also allows to conjure up instances for record types
to create more complex command line interfaces. Here's an example:
{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DeriveGeneric #-}
import WithCli
data Options
= Options {
port :: Int,
daemonize :: Bool,
config :: Maybe FilePath
}
deriving (Show, Generic, HasArguments)
main :: IO ()
main = withCli run
run :: Options -> IO ()
run = printIn a shell this program behaves like this:
$ program --port 8080 --config some/path
Options {port = 8080, daemonize = False, config = Just "some/path"}
$ program --port 8080 --daemonize
Options {port = 8080, daemonize = True, config = Nothing}
$ program --port foo
cannot parse as INTEGER: foo
# exit-code 1
$ program
missing option: --port=INTEGER
# exit-code 1
$ program --help
program [OPTIONS]
--port=INTEGER
--daemonize
--config=STRING (optional)
-h --help show help and exitMethods
argumentsParser :: Modifiers -> Maybe String -> Result (Parser Unnormalized a) Source #
argumentsParser :: (Generic a, GTo a, GDatatypeInfo a, All2 HasArguments (GCode a)) => Modifiers -> Maybe String -> Result (Parser Unnormalized a) Source #
Instances
| HasArguments Bool Source # | |
Defined in WithCli.HasArguments | |
| HasArguments Double Source # | |
Defined in WithCli.HasArguments | |
| HasArguments Float Source # | |
Defined in WithCli.HasArguments | |
| HasArguments Int Source # | |
Defined in WithCli.HasArguments | |
| HasArguments String Source # | |
Defined in WithCli.HasArguments | |
| Argument a => HasArguments [a] Source # | |
Defined in WithCli.HasArguments | |
| Argument a => HasArguments (Maybe a) Source # | |
Defined in WithCli.HasArguments | |
| (HasArguments a, HasArguments b) => HasArguments (a, b) Source # | |
Defined in WithCli.HasArguments | |
| (HasArguments a, HasArguments b, HasArguments c) => HasArguments (a, b, c) Source # | |
Defined in WithCli.HasArguments | |
atomicArgumentsParser :: forall a. Argument a => Modifiers -> Maybe String -> Result (Parser Unnormalized a) Source #
Useful for implementing your own instances of HasArguments on top
of a custom Argument instance.
class Argument a where Source #
Argument is a typeclass for things that can be parsed as atomic values from
single command line arguments, e.g. strings (and filenames) and numbers.
Occasionally you might want to declare your own instance for additional type safety and for providing a more informative command argument type. Here's an example:
{-# LANGUAGE DeriveDataTypeable #-}
import WithCli
data File = File FilePath
deriving (Show, Typeable)
instance Argument File where
argumentType Proxy = "custom-file-type"
parseArgument f = Just (File f)
instance HasArguments File where
argumentsParser = atomicArgumentsParser
main :: IO ()
main = withCli run
run :: File -> IO ()
run = printAnd this is how the above program behaves:
$ program --help program [OPTIONS] custom-file-type -h --help show help and exit $ program some/file File "some/file"
Minimal complete definition
Instances
| Argument Double Source # | |
Defined in WithCli.Argument | |
| Argument Float Source # | |
Defined in WithCli.Argument | |
| Argument Int Source # | |
Defined in WithCli.Argument | |
| Argument Integer Source # | |
Defined in WithCli.Argument | |
| Argument String Source # | |
Defined in WithCli.Argument | |
Modifiers
Modifiers can be used to customize the command line parser.
Constructors
| AddShortOption String Char |
|
| RenameOption String String |
|
| RenameOptions (String -> Maybe String) |
Can be used together with |
| UseForPositionalArguments String String |
|
| AddOptionHelp String String |
|
| AddVersionFlag String |
|
Useful Re-exports
Representable types of kind *.
This class is derivable in GHC with the DeriveGeneric flag on.
A Generic instance must satisfy the following laws:
from.to≡idto.from≡id
Instances
The class Typeable allows a concrete representation of a type to
be calculated.
Minimal complete definition
typeRep#
data Proxy (t :: k) :: forall k. k -> * #
Proxy is a type that holds no data, but has a phantom parameter of
arbitrary type (or even kind). Its use is to provide type information, even
though there is no value available of that type (or it may be too costly to
create one).
Historically, Proxy :: Proxy a'undefined :: a' idiom.
>>>Proxy :: Proxy (Void, Int -> Int)Proxy
Proxy can even hold types of higher kinds,
>>>Proxy :: Proxy EitherProxy
>>>Proxy :: Proxy FunctorProxy
>>>Proxy :: Proxy complicatedStructureProxy
Constructors
| Proxy |
Instances
| Generic1 (Proxy :: k -> *) | |
| Monad (Proxy :: * -> *) | Since: base-4.7.0.0 |
| Functor (Proxy :: * -> *) | Since: base-4.7.0.0 |
| Applicative (Proxy :: * -> *) | Since: base-4.7.0.0 |
| Foldable (Proxy :: * -> *) | Since: base-4.7.0.0 |
Defined in Data.Foldable Methods fold :: Monoid m => Proxy m -> m # foldMap :: Monoid m => (a -> m) -> Proxy a -> m # foldr :: (a -> b -> b) -> b -> Proxy a -> b # foldr' :: (a -> b -> b) -> b -> Proxy a -> b # foldl :: (b -> a -> b) -> b -> Proxy a -> b # foldl' :: (b -> a -> b) -> b -> Proxy a -> b # foldr1 :: (a -> a -> a) -> Proxy a -> a # foldl1 :: (a -> a -> a) -> Proxy a -> a # elem :: Eq a => a -> Proxy a -> Bool # maximum :: Ord a => Proxy a -> a # minimum :: Ord a => Proxy a -> a # | |
| Traversable (Proxy :: * -> *) | Since: base-4.7.0.0 |
| Alternative (Proxy :: * -> *) | Since: base-4.9.0.0 |
| MonadPlus (Proxy :: * -> *) | Since: base-4.9.0.0 |
| Bounded (Proxy t) | |
| Enum (Proxy s) | Since: base-4.7.0.0 |
| Eq (Proxy s) | Since: base-4.7.0.0 |
| Ord (Proxy s) | Since: base-4.7.0.0 |
| Read (Proxy t) | Since: base-4.7.0.0 |
| Show (Proxy s) | Since: base-4.7.0.0 |
| Ix (Proxy s) | Since: base-4.7.0.0 |
Defined in Data.Proxy | |
| Generic (Proxy t) | |
| Semigroup (Proxy s) | Since: base-4.9.0.0 |
| Monoid (Proxy s) | Since: base-4.7.0.0 |
| type Rep1 (Proxy :: k -> *) | |
| type Rep (Proxy t) | |
| type Code (Proxy t) | |
Defined in Generics.SOP.Instances | |
| type DatatypeInfoOf (Proxy t) | |
Defined in Generics.SOP.Instances type DatatypeInfoOf (Proxy t) = ADT "Data.Proxy" "Proxy" (Constructor "Proxy" ': ([] :: [ConstructorInfo])) | |