Copyright	Copyright © 2015 PivotCloud Inc.
License	MIT
Maintainer	Lars Kuhtz <lkuhtz@pivotmail.com>
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Configuration.Utils.CommandLine

Contents

Misc Utils

Description

This module provides tools for defining command line parsers for configuration types.

Unlike normal command line parsers the parsers for configuration types are expected to yield an update function that takes a value and updates the value with the settings from the command line.

Assuming that

all configuration types are nested Haskell records or simple types and
that there are lenses for all record fields

usually the operators .:: and %:: are all that is needed from this module.

The module Configuration.Utils.Monoid provides tools for the case that a simple type is a container with a monoid instance, such as List or HashMap.

The module Configuration.Utils.Maybe explains the usage of optional Maybe values in configuration types.

Synopsis

type MParser a = Parser (a -> a)
(.::) :: (Alternative f, Applicative f) => Lens' a b -> f b -> f (a -> a)
(%::) :: (Alternative f, Applicative f) => Lens' a b -> f (b -> b) -> f (a -> a)
boolReader :: (Eq a, Show a, FoldCase a, IsString a, IsString e, Monoid e) => a -> Either e Bool
boolOption :: Mod OptionFields Bool -> Parser Bool
boolOption_ :: Mod FlagFields Bool -> Parser Bool
enableDisableFlag :: Mod FlagFields Bool -> Parser Bool
fileOption :: Mod OptionFields String -> Parser FilePath
eitherReadP :: Text -> ReadP a -> Text -> Either Text a
jsonOption :: FromJSON a => Mod OptionFields a -> Parser a
jsonReader :: FromJSON a => ReadM a
(<$) :: Functor f => a -> f b -> f a
class Functor f => Applicative (f :: Type -> Type) where
- pure :: a -> f a
- (<*>) :: f (a -> b) -> f a -> f b
- liftA2 :: (a -> b -> c) -> f a -> f b -> f c
- (*>) :: f a -> f b -> f b
- (<*) :: f a -> f b -> f a
mappend :: Monoid a => a -> a -> a
class Applicative f => Alternative (f :: Type -> Type) where
- empty :: f a
- (<|>) :: f a -> f a -> f a
- some :: f a -> f [a]
- many :: f a -> f [a]
(<$>) :: Functor f => (a -> b) -> f a -> f b
optional :: Alternative f => f a -> f (Maybe a)
newtype WrappedMonad (m :: Type -> Type) a = WrapMonad {
- unwrapMonad :: m a
}
newtype WrappedArrow (a :: Type -> Type -> Type) b c = WrapArrow {
- unwrapArrow :: a b c
}
newtype ZipList a = ZipList {
- getZipList :: [a]
}
newtype Const a (b :: k) = Const {
- getConst :: a
}
liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d
liftA :: Applicative f => (a -> b) -> f a -> f b
(<**>) :: Applicative f => f a -> f (a -> b) -> f b
renderFailure :: ParserFailure ParserHelp -> String -> (String, ExitCode)
parserFailure :: ParserPrefs -> ParserInfo a -> ParseError -> [Context] -> ParserFailure ParserHelp
execParserPure :: ParserPrefs -> ParserInfo a -> [String] -> ParserResult a
getParseResult :: ParserResult a -> Maybe a
handleParseResult :: ParserResult a -> IO a
customExecParser :: ParserPrefs -> ParserInfo a -> IO a
execParser :: ParserInfo a -> IO a
hsubparser :: Mod CommandFields a -> Parser a
helper :: Parser (a -> a)
defaultPrefs :: ParserPrefs
idm :: Monoid m => m
prefs :: PrefsMod -> ParserPrefs
helpShowGlobals :: PrefsMod
helpLongEquals :: PrefsMod
columns :: Int -> PrefsMod
subparserInline :: PrefsMod
noBacktrack :: PrefsMod
showHelpOnEmpty :: PrefsMod
showHelpOnError :: PrefsMod
disambiguate :: PrefsMod
multiSuffix :: String -> PrefsMod
info :: Parser a -> InfoMod a -> ParserInfo a
forwardOptions :: InfoMod a
noIntersperse :: InfoMod a
failureCode :: Int -> InfoMod a
progDescDoc :: Maybe Doc -> InfoMod a
progDesc :: String -> InfoMod a
footerDoc :: Maybe Doc -> InfoMod a
footer :: String -> InfoMod a
headerDoc :: Maybe Doc -> InfoMod a
header :: String -> InfoMod a
briefDesc :: InfoMod a
fullDesc :: InfoMod a
option :: ReadM a -> Mod OptionFields a -> Parser a
strOption :: IsString s => Mod OptionFields s -> Parser s
infoOption :: String -> Mod OptionFields (a -> a) -> Parser (a -> a)
abortOption :: ParseError -> Mod OptionFields (a -> a) -> Parser (a -> a)
switch :: Mod FlagFields Bool -> Parser Bool
flag' :: a -> Mod FlagFields a -> Parser a
flag :: a -> a -> Mod FlagFields a -> Parser a
strArgument :: IsString s => Mod ArgumentFields s -> Parser s
argument :: ReadM a -> Mod ArgumentFields a -> Parser a
subparser :: Mod CommandFields a -> Parser a
completer :: forall (f :: Type -> Type) a. HasCompleter f => Completer -> Mod f a
action :: forall (f :: Type -> Type) a. HasCompleter f => String -> Mod f a
completeWith :: forall (f :: Type -> Type) a. HasCompleter f => [String] -> Mod f a
commandGroup :: String -> Mod CommandFields a
command :: String -> ParserInfo a -> Mod CommandFields a
style :: forall (f :: Type -> Type) a. (Doc -> Doc) -> Mod f a
hidden :: forall (f :: Type -> Type) a. Mod f a
metavar :: forall (f :: Type -> Type) a. HasMetavar f => String -> Mod f a
noArgError :: ParseError -> Mod OptionFields a
helpDoc :: forall (f :: Type -> Type) a. Maybe Doc -> Mod f a
help :: forall (f :: Type -> Type) a. String -> Mod f a
showDefault :: forall a (f :: Type -> Type). Show a => Mod f a
showDefaultWith :: forall a (f :: Type -> Type). (a -> String) -> Mod f a
value :: forall (f :: Type -> Type) a. HasValue f => a -> Mod f a
long :: forall (f :: Type -> Type) a. HasName f => String -> Mod f a
short :: forall (f :: Type -> Type) a. HasName f => Char -> Mod f a
disabled :: ReadM a
maybeReader :: (String -> Maybe a) -> ReadM a
eitherReader :: (String -> Either String a) -> ReadM a
str :: IsString s => ReadM s
auto :: Read a => ReadM a
data InfoMod a
data PrefsMod
bashCompleter :: String -> Completer
listCompleter :: [String] -> Completer
listIOCompleter :: IO [String] -> Completer
internal :: forall (f :: Type -> Type) a. Mod f a
data OptionFields a
data FlagFields a
data CommandFields a
data ArgumentFields a
class HasName (f :: Type -> Type)
class HasCompleter (f :: Type -> Type)
class HasValue (f :: Type -> Type)
class HasMetavar (f :: Type -> Type)
data Mod (f :: Type -> Type) a
overFailure :: (ParserHelp -> ParserHelp) -> ParserResult a -> ParserResult a
mkCompleter :: (String -> IO [String]) -> Completer
readerError :: String -> ReadM a
readerAbort :: ParseError -> ReadM a
data ParseError
- = ErrorMsg String
- | InfoMsg String
- | ShowHelpText (Maybe String)
- | UnknownError
- | MissingError IsCmdStart SomeParser
- | ExpectsArgError String
- | UnexpectedError String SomeParser
data ParserInfo a = ParserInfo {
- infoParser :: Parser a
- infoFullDesc :: Bool
- infoProgDesc :: Chunk Doc
- infoHeader :: Chunk Doc
- infoFooter :: Chunk Doc
- infoFailureCode :: Int
- infoPolicy :: ArgPolicy
}
data ParserPrefs = ParserPrefs {
- prefMultiSuffix :: String
- prefDisambiguate :: Bool
- prefShowHelpOnError :: Bool
- prefShowHelpOnEmpty :: Bool
- prefBacktrack :: Backtracking
- prefColumns :: Int
- prefHelpLongEquals :: Bool
- prefHelpShowGlobal :: Bool
}
data ReadM a
data Completer
newtype CompletionResult = CompletionResult {
- execCompletion :: String -> IO String
}
newtype ParserFailure h = ParserFailure {
- execFailure :: String -> (h, ExitCode, Int)
}
data ParserResult a
- = Failure (ParserFailure ParserHelp)
- | CompletionInvoked CompletionResult
data ParserHelp = ParserHelp {
- helpError :: Chunk Doc
- helpSuggestions :: Chunk Doc
- helpHeader :: Chunk Doc
- helpUsage :: Chunk Doc
- helpBody :: Chunk Doc
- helpGlobals :: Chunk Doc
- helpFooter :: Chunk Doc
}

Documentation

type MParser a = Parser (a -> a) Source #

Type of option parsers that yield a modification function.

(.::) :: (Alternative f, Applicative f) => Lens' a b -> f b -> f (a -> a) infixr 5 Source #

An operator for applying a setter to an option parser that yields a value.

Example usage:

data Auth = Auth
    { _user ∷ !String
    , _pwd ∷ !String
    }

user ∷ Functor f ⇒ (String → f String) → Auth → f Auth
user f s = (\u → s { _user = u }) <$> f (_user s)

pwd ∷ Functor f ⇒ (String → f String) → Auth → f Auth
pwd f s = (\p → s { _pwd = p }) <$> f (_pwd s)

-- or with lenses and TemplateHaskell just:
-- $(makeLenses ''Auth)

pAuth ∷ MParser Auth
pAuth = id
   <$< user .:: strOption
       % long "user"
       ⊕ short 'u'
       ⊕ help "user name"
   <*< pwd .:: strOption
       % long "pwd"
       ⊕ help "password for user"

(%::) :: (Alternative f, Applicative f) => Lens' a b -> f (b -> b) -> f (a -> a) infixr 5 Source #

An operator for applying a setter to an option parser that yields a modification function.

Example usage:

data HttpURL = HttpURL
    { _auth ∷ !Auth
    , _domain ∷ !String
    }

auth ∷ Functor f ⇒ (Auth → f Auth) → HttpURL → f HttpURL
auth f s = (\u → s { _auth = u }) <$> f (_auth s)

domain ∷ Functor f ⇒ (String → f String) → HttpURL → f HttpURL
domain f s = (\u → s { _domain = u }) <$> f (_domain s)

path ∷ Functor f ⇒ (String → f String) → HttpURL → f HttpURL
path f s = (\u → s { _path = u }) <$> f (_path s)

-- or with lenses and TemplateHaskell just:
-- $(makeLenses ''HttpURL)

pHttpURL ∷ MParser HttpURL
pHttpURL = id
    <$< auth %:: pAuth
    <*< domain .:: strOption
        % long "domain"
        ⊕ short 'd'
        ⊕ help "HTTP domain"

Misc Utils

boolReader :: (Eq a, Show a, FoldCase a, IsString a, IsString e, Monoid e) => a -> Either e Bool Source #

boolOption :: Mod OptionFields Bool -> Parser Bool Source #

The boolOption is an alternative to switch.

Using switch with command line parsers that overwrite settings from a configuration file is problematic: the absence of the switch is interpreted as setting the respective configuration value to False. So there is no way to specify on the command line that the value from the configuration file shall be used. Some command line UIs use two different options for those values, for instance --enable-feature and --disable-feature. This option instead expects a Boolean value. Beside that it behaves like any other option.

boolOption_ :: Mod FlagFields Bool -> Parser Bool Source #

An alternative syntax for boolOption for options with long names.

Instead of taking a boolean argument the presence of the option acts as a switch to set the respective configuration setting to True. If the option is not present the setting is left unchanged.

In addition for long option names a respective unset flag is provided. For instance for a flag --verbose there will also be a flag --no-verbose.

This can still be used with short option names only, but no unset flag would be provided.

enableDisableFlag :: Mod FlagFields Bool -> Parser Bool Source #

An option parser for flags that are enabled via the flag name prefixed with --enable- and disabled via the flag name prefix --disable-. The prefixes are applied to all long option names. Short option names are parsed unchanged and cause the flag to be enabled.

This resembles the style of flags that is used for instances with Cabal.

fileOption :: Mod OptionFields String -> Parser FilePath Source #

An option that expects a file name.

eitherReadP :: Text -> ReadP a -> Text -> Either Text a Source #

Create an either-reader from a ReadP parser.

jsonOption :: FromJSON a => Mod OptionFields a -> Parser a Source #

An option that expects a JSON value as argument.

jsonReader :: FromJSON a => ReadM a Source #

An option reader for a JSON value.

(<$) :: Functor f => a -> f b -> f a infixl 4 #

Replace all locations in the input with the same value. The default definition is fmap . const, but this may be overridden with a more efficient version.

Using ApplicativeDo: 'a <$ bs' can be understood as the do expression

do bs
   pure a

with an inferred Functor constraint.

class Functor f => Applicative (f :: Type -> Type) where #

A functor with application, providing operations to

embed pure expressions (pure), and
sequence computations and combine their results (<*> and liftA2).

A minimal complete definition must include implementations of pure and of either <*> or liftA2. If it defines both, then they must behave the same as their default definitions:

(<*>) = liftA2 id

liftA2 f x y = f <$> x <*> y

Further, any definition must satisfy the following:

Identity

pure id <*> v = v

Composition

pure (.) <*> u <*> v <*> w = u <*> (v <*> w)

Homomorphism

pure f <*> pure x = pure (f x)

Interchange

u <*> pure y = pure ($ y) <*> u

The other methods have the following default definitions, which may be overridden with equivalent specialized implementations:

```
u *> v = (id <$ u) <*> v
```
```
u <* v = liftA2 const u v
```

As a consequence of these laws, the Functor instance for f will satisfy

```
fmap f x = pure f <*> x
```

It may be useful to note that supposing

forall x y. p (q x y) = f x . g y

it follows from the above that

liftA2 p (liftA2 q u v) = liftA2 f u . liftA2 g v

If f is also a Monad, it should satisfy

```
pure = return
```

m1 <*> m2 = m1 >>= (x1 -> m2 >>= (x2 -> return (x1 x2)))

```
(*>) = (>>)
```

(which implies that pure and <*> satisfy the applicative functor laws).

Minimal complete definition

pure, ((<*>) | liftA2)

Methods

pure :: a -> f a #

Lift a value.

(<*>) :: f (a -> b) -> f a -> f b infixl 4 #

Sequential application.

A few functors support an implementation of <*> that is more efficient than the default one.

Using ApplicativeDo: 'fs <*> as' can be understood as the do expression

do f <- fs
   a <- as
   pure (f a)

liftA2 :: (a -> b -> c) -> f a -> f b -> f c #

Lift a binary function to actions.

Some functors support an implementation of liftA2 that is more efficient than the default one. In particular, if fmap is an expensive operation, it is likely better to use liftA2 than to fmap over the structure and then use <*>.

This became a typeclass method in 4.10.0.0. Prior to that, it was a function defined in terms of <*> and fmap.

Using ApplicativeDo: 'liftA2 f as bs' can be understood as the do expression

do a <- as
   b <- bs
   pure (f a b)

(*>) :: f a -> f b -> f b infixl 4 #

Sequence actions, discarding the value of the first argument.

'as *> bs' can be understood as the do expression

do as
   bs

This is a tad complicated for our ApplicativeDo extension which will give it a Monad constraint. For an Applicative constraint we write it of the form

do _ <- as
   b <- bs
   pure b

(<*) :: f a -> f b -> f a infixl 4 #

Sequence actions, discarding the value of the second argument.

Using ApplicativeDo: 'as <* bs' can be understood as the do expression

do a <- as
   bs
   pure a

Instances

Instances details

Applicative []	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> [a] # (<>) :: [a -> b] -> [a] -> [b] # liftA2 :: (a -> b -> c) -> [a] -> [b] -> [c] # (>) :: [a] -> [b] -> [b] # (<*) :: [a] -> [b] -> [a] #
Applicative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> Maybe a # (<>) :: Maybe (a -> b) -> Maybe a -> Maybe b # liftA2 :: (a -> b -> c) -> Maybe a -> Maybe b -> Maybe c # (>) :: Maybe a -> Maybe b -> Maybe b # (<*) :: Maybe a -> Maybe b -> Maybe a #
Applicative IO	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> IO a # (<>) :: IO (a -> b) -> IO a -> IO b # liftA2 :: (a -> b -> c) -> IO a -> IO b -> IO c # (>) :: IO a -> IO b -> IO b # (<*) :: IO a -> IO b -> IO a #
Applicative Par1	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> Par1 a # (<>) :: Par1 (a -> b) -> Par1 a -> Par1 b # liftA2 :: (a -> b -> c) -> Par1 a -> Par1 b -> Par1 c # (>) :: Par1 a -> Par1 b -> Par1 b # (<*) :: Par1 a -> Par1 b -> Par1 a #
Applicative Q
Instance details Defined in Language.Haskell.TH.Syntax Methods pure :: a -> Q a # (<>) :: Q (a -> b) -> Q a -> Q b # liftA2 :: (a -> b -> c) -> Q a -> Q b -> Q c # (>) :: Q a -> Q b -> Q b # (<*) :: Q a -> Q b -> Q a #
Applicative First	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> First a # (<>) :: First (a -> b) -> First a -> First b # liftA2 :: (a -> b -> c) -> First a -> First b -> First c # (>) :: First a -> First b -> First b # (<*) :: First a -> First b -> First a #
Applicative Last	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Last a # (<>) :: Last (a -> b) -> Last a -> Last b # liftA2 :: (a -> b -> c) -> Last a -> Last b -> Last c # (>) :: Last a -> Last b -> Last b # (<*) :: Last a -> Last b -> Last a #
Applicative Flag
Instance details Defined in Distribution.Simple.Flag Methods pure :: a -> Flag a # (<>) :: Flag (a -> b) -> Flag a -> Flag b # liftA2 :: (a -> b -> c) -> Flag a -> Flag b -> Flag c # (>) :: Flag a -> Flag b -> Flag b # (<*) :: Flag a -> Flag b -> Flag a #
Applicative Condition
Instance details Defined in Distribution.Types.Condition Methods pure :: a -> Condition a # (<>) :: Condition (a -> b) -> Condition a -> Condition b # liftA2 :: (a -> b -> c) -> Condition a -> Condition b -> Condition c # (>) :: Condition a -> Condition b -> Condition b # (<*) :: Condition a -> Condition b -> Condition a #
Applicative NonEmpty	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods pure :: a -> NonEmpty a # (<>) :: NonEmpty (a -> b) -> NonEmpty a -> NonEmpty b # liftA2 :: (a -> b -> c) -> NonEmpty a -> NonEmpty b -> NonEmpty c # (>) :: NonEmpty a -> NonEmpty b -> NonEmpty b # (<*) :: NonEmpty a -> NonEmpty b -> NonEmpty a #
Applicative Identity	Since: base-4.8.0.0
Instance details Defined in Data.Functor.Identity Methods pure :: a -> Identity a # (<>) :: Identity (a -> b) -> Identity a -> Identity b # liftA2 :: (a -> b -> c) -> Identity a -> Identity b -> Identity c # (>) :: Identity a -> Identity b -> Identity b # (<*) :: Identity a -> Identity b -> Identity a #
Applicative IResult
Instance details Defined in Data.Aeson.Types.Internal Methods pure :: a -> IResult a # (<>) :: IResult (a -> b) -> IResult a -> IResult b # liftA2 :: (a -> b -> c) -> IResult a -> IResult b -> IResult c # (>) :: IResult a -> IResult b -> IResult b # (<*) :: IResult a -> IResult b -> IResult a #
Applicative Result
Instance details Defined in Data.Aeson.Types.Internal Methods pure :: a -> Result a # (<>) :: Result (a -> b) -> Result a -> Result b # liftA2 :: (a -> b -> c) -> Result a -> Result b -> Result c # (>) :: Result a -> Result b -> Result b # (<*) :: Result a -> Result b -> Result a #
Applicative Parser
Instance details Defined in Data.Aeson.Types.Internal Methods pure :: a -> Parser a # (<>) :: Parser (a -> b) -> Parser a -> Parser b # liftA2 :: (a -> b -> c) -> Parser a -> Parser b -> Parser c # (>) :: Parser a -> Parser b -> Parser b # (<*) :: Parser a -> Parser b -> Parser a #
Applicative Complex	Since: base-4.9.0.0
Instance details Defined in Data.Complex Methods pure :: a -> Complex a # (<>) :: Complex (a -> b) -> Complex a -> Complex b # liftA2 :: (a -> b -> c) -> Complex a -> Complex b -> Complex c # (>) :: Complex a -> Complex b -> Complex b # (<*) :: Complex a -> Complex b -> Complex a #
Applicative Min	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Min a # (<>) :: Min (a -> b) -> Min a -> Min b # liftA2 :: (a -> b -> c) -> Min a -> Min b -> Min c # (>) :: Min a -> Min b -> Min b # (<*) :: Min a -> Min b -> Min a #
Applicative Max	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Max a # (<>) :: Max (a -> b) -> Max a -> Max b # liftA2 :: (a -> b -> c) -> Max a -> Max b -> Max c # (>) :: Max a -> Max b -> Max b # (<*) :: Max a -> Max b -> Max a #
Applicative Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods pure :: a -> Option a # (<>) :: Option (a -> b) -> Option a -> Option b # liftA2 :: (a -> b -> c) -> Option a -> Option b -> Option c # (>) :: Option a -> Option b -> Option b # (<*) :: Option a -> Option b -> Option a #
Applicative ZipList	f <$> ZipList xs1 <> ... <> ZipList xsN = ZipList (zipWithN f xs1 ... xsN) where `zipWithN` refers to the `zipWith` function of the appropriate arity (`zipWith`, `zipWith3`, `zipWith4`, ...). For example: (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <> ZipList "567" <> ZipList [1..] = ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..]) = ZipList {getZipList = ["a5","b6b6","c7c7c7"]} Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> ZipList a # (<>) :: ZipList (a -> b) -> ZipList a -> ZipList b # liftA2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c # (>) :: ZipList a -> ZipList b -> ZipList b # (<*) :: ZipList a -> ZipList b -> ZipList a #
Applicative First	Since: base-4.8.0.0
Instance details Defined in Data.Monoid Methods pure :: a -> First a # (<>) :: First (a -> b) -> First a -> First b # liftA2 :: (a -> b -> c) -> First a -> First b -> First c # (>) :: First a -> First b -> First b # (<*) :: First a -> First b -> First a #
Applicative Last	Since: base-4.8.0.0
Instance details Defined in Data.Monoid Methods pure :: a -> Last a # (<>) :: Last (a -> b) -> Last a -> Last b # liftA2 :: (a -> b -> c) -> Last a -> Last b -> Last c # (>) :: Last a -> Last b -> Last b # (<*) :: Last a -> Last b -> Last a #
Applicative Dual	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Dual a # (<>) :: Dual (a -> b) -> Dual a -> Dual b # liftA2 :: (a -> b -> c) -> Dual a -> Dual b -> Dual c # (>) :: Dual a -> Dual b -> Dual b # (<*) :: Dual a -> Dual b -> Dual a #
Applicative Sum	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Sum a # (<>) :: Sum (a -> b) -> Sum a -> Sum b # liftA2 :: (a -> b -> c) -> Sum a -> Sum b -> Sum c # (>) :: Sum a -> Sum b -> Sum b # (<*) :: Sum a -> Sum b -> Sum a #
Applicative Product	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Product a # (<>) :: Product (a -> b) -> Product a -> Product b # liftA2 :: (a -> b -> c) -> Product a -> Product b -> Product c # (>) :: Product a -> Product b -> Product b # (<*) :: Product a -> Product b -> Product a #
Applicative Down	Since: base-4.11.0.0
Instance details Defined in Data.Ord Methods pure :: a -> Down a # (<>) :: Down (a -> b) -> Down a -> Down b # liftA2 :: (a -> b -> c) -> Down a -> Down b -> Down c # (>) :: Down a -> Down b -> Down b # (<*) :: Down a -> Down b -> Down a #
Applicative ReadPrec	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadPrec Methods pure :: a -> ReadPrec a # (<>) :: ReadPrec (a -> b) -> ReadPrec a -> ReadPrec b # liftA2 :: (a -> b -> c) -> ReadPrec a -> ReadPrec b -> ReadPrec c # (>) :: ReadPrec a -> ReadPrec b -> ReadPrec b # (<*) :: ReadPrec a -> ReadPrec b -> ReadPrec a #
Applicative ReadP	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods pure :: a -> ReadP a # (<>) :: ReadP (a -> b) -> ReadP a -> ReadP b # liftA2 :: (a -> b -> c) -> ReadP a -> ReadP b -> ReadP c # (>) :: ReadP a -> ReadP b -> ReadP b # (<*) :: ReadP a -> ReadP b -> ReadP a #
Applicative Put
Instance details Defined in Data.ByteString.Builder.Internal Methods pure :: a -> Put a # (<>) :: Put (a -> b) -> Put a -> Put b # liftA2 :: (a -> b -> c) -> Put a -> Put b -> Put c # (>) :: Put a -> Put b -> Put b # (<*) :: Put a -> Put b -> Put a #
Applicative Tree
Instance details Defined in Data.Tree Methods pure :: a -> Tree a # (<>) :: Tree (a -> b) -> Tree a -> Tree b # liftA2 :: (a -> b -> c) -> Tree a -> Tree b -> Tree c # (>) :: Tree a -> Tree b -> Tree b # (<*) :: Tree a -> Tree b -> Tree a #
Applicative Seq	Since: containers-0.5.4
Instance details Defined in Data.Sequence.Internal Methods pure :: a -> Seq a # (<>) :: Seq (a -> b) -> Seq a -> Seq b # liftA2 :: (a -> b -> c) -> Seq a -> Seq b -> Seq c # (>) :: Seq a -> Seq b -> Seq b # (<*) :: Seq a -> Seq b -> Seq a #
Applicative DNonEmpty
Instance details Defined in Data.DList.DNonEmpty.Internal Methods pure :: a -> DNonEmpty a # (<>) :: DNonEmpty (a -> b) -> DNonEmpty a -> DNonEmpty b # liftA2 :: (a -> b -> c) -> DNonEmpty a -> DNonEmpty b -> DNonEmpty c # (>) :: DNonEmpty a -> DNonEmpty b -> DNonEmpty b # (<*) :: DNonEmpty a -> DNonEmpty b -> DNonEmpty a #
Applicative DList
Instance details Defined in Data.DList.Internal Methods pure :: a -> DList a # (<>) :: DList (a -> b) -> DList a -> DList b # liftA2 :: (a -> b -> c) -> DList a -> DList b -> DList c # (>) :: DList a -> DList b -> DList b # (<*) :: DList a -> DList b -> DList a #
Applicative ReadM
Instance details Defined in Options.Applicative.Types Methods pure :: a -> ReadM a # (<>) :: ReadM (a -> b) -> ReadM a -> ReadM b # liftA2 :: (a -> b -> c) -> ReadM a -> ReadM b -> ReadM c # (>) :: ReadM a -> ReadM b -> ReadM b # (<*) :: ReadM a -> ReadM b -> ReadM a #
Applicative Parser
Instance details Defined in Options.Applicative.Types Methods pure :: a -> Parser a # (<>) :: Parser (a -> b) -> Parser a -> Parser b # liftA2 :: (a -> b -> c) -> Parser a -> Parser b -> Parser c # (>) :: Parser a -> Parser b -> Parser b # (<*) :: Parser a -> Parser b -> Parser a #
Applicative ParserM
Instance details Defined in Options.Applicative.Types Methods pure :: a -> ParserM a # (<>) :: ParserM (a -> b) -> ParserM a -> ParserM b # liftA2 :: (a -> b -> c) -> ParserM a -> ParserM b -> ParserM c # (>) :: ParserM a -> ParserM b -> ParserM b # (<*) :: ParserM a -> ParserM b -> ParserM a #
Applicative ParserResult
Instance details Defined in Options.Applicative.Types Methods pure :: a -> ParserResult a # (<>) :: ParserResult (a -> b) -> ParserResult a -> ParserResult b # liftA2 :: (a -> b -> c) -> ParserResult a -> ParserResult b -> ParserResult c # (>) :: ParserResult a -> ParserResult b -> ParserResult b # (<*) :: ParserResult a -> ParserResult b -> ParserResult a #
Applicative Chunk
Instance details Defined in Options.Applicative.Help.Chunk Methods pure :: a -> Chunk a # (<>) :: Chunk (a -> b) -> Chunk a -> Chunk b # liftA2 :: (a -> b -> c) -> Chunk a -> Chunk b -> Chunk c # (>) :: Chunk a -> Chunk b -> Chunk b # (<*) :: Chunk a -> Chunk b -> Chunk a #
Applicative SmallArray
Instance details Defined in Data.Primitive.SmallArray Methods pure :: a -> SmallArray a # (<>) :: SmallArray (a -> b) -> SmallArray a -> SmallArray b # liftA2 :: (a -> b -> c) -> SmallArray a -> SmallArray b -> SmallArray c # (>) :: SmallArray a -> SmallArray b -> SmallArray b # (<*) :: SmallArray a -> SmallArray b -> SmallArray a #
Applicative Array
Instance details Defined in Data.Primitive.Array Methods pure :: a -> Array a # (<>) :: Array (a -> b) -> Array a -> Array b # liftA2 :: (a -> b -> c) -> Array a -> Array b -> Array c # (>) :: Array a -> Array b -> Array b # (<*) :: Array a -> Array b -> Array a #
Applicative Vector
Instance details Defined in Data.Vector Methods pure :: a -> Vector a # (<>) :: Vector (a -> b) -> Vector a -> Vector b # liftA2 :: (a -> b -> c) -> Vector a -> Vector b -> Vector c # (>) :: Vector a -> Vector b -> Vector b # (<*) :: Vector a -> Vector b -> Vector a #
Applicative Id
Instance details Defined in Data.Vector.Fusion.Util Methods pure :: a -> Id a # (<>) :: Id (a -> b) -> Id a -> Id b # liftA2 :: (a -> b -> c) -> Id a -> Id b -> Id c # (>) :: Id a -> Id b -> Id b # (<*) :: Id a -> Id b -> Id a #
Applicative Box
Instance details Defined in Data.Vector.Fusion.Util Methods pure :: a -> Box a # (<>) :: Box (a -> b) -> Box a -> Box b # liftA2 :: (a -> b -> c) -> Box a -> Box b -> Box c # (>) :: Box a -> Box b -> Box b # (<*) :: Box a -> Box b -> Box a #
Applicative P	Since: base-4.5.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods pure :: a -> P a # (<>) :: P (a -> b) -> P a -> P b # liftA2 :: (a -> b -> c) -> P a -> P b -> P c # (>) :: P a -> P b -> P b # (<*) :: P a -> P b -> P a #
Applicative (Either e)	Since: base-3.0
Instance details Defined in Data.Either Methods pure :: a -> Either e a # (<>) :: Either e (a -> b) -> Either e a -> Either e b # liftA2 :: (a -> b -> c) -> Either e a -> Either e b -> Either e c # (>) :: Either e a -> Either e b -> Either e b # (<*) :: Either e a -> Either e b -> Either e a #
Applicative (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> U1 a # (<>) :: U1 (a -> b) -> U1 a -> U1 b # liftA2 :: (a -> b -> c) -> U1 a -> U1 b -> U1 c # (>) :: U1 a -> U1 b -> U1 b # (<*) :: U1 a -> U1 b -> U1 a #
Monoid a => Applicative ((,) a)	For tuples, the `Monoid` constraint on `a` determines how the first values merge. For example, `String`s concatenate: ("hello ", (+15)) <> ("world!", 2002) ("hello world!",2017) Since: base-2.1*
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, a0) # (<>) :: (a, a0 -> b) -> (a, a0) -> (a, b) # liftA2 :: (a0 -> b -> c) -> (a, a0) -> (a, b) -> (a, c) # (>) :: (a, a0) -> (a, b) -> (a, b) # (<*) :: (a, a0) -> (a, b) -> (a, a0) #
Applicative (Proxy :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Proxy Methods pure :: a -> Proxy a # (<>) :: Proxy (a -> b) -> Proxy a -> Proxy b # liftA2 :: (a -> b -> c) -> Proxy a -> Proxy b -> Proxy c # (>) :: Proxy a -> Proxy b -> Proxy b # (<*) :: Proxy a -> Proxy b -> Proxy a #
Applicative (Parser i)
Instance details Defined in Data.Attoparsec.Internal.Types Methods pure :: a -> Parser i a # (<>) :: Parser i (a -> b) -> Parser i a -> Parser i b # liftA2 :: (a -> b -> c) -> Parser i a -> Parser i b -> Parser i c # (>) :: Parser i a -> Parser i b -> Parser i b # (<*) :: Parser i a -> Parser i b -> Parser i a #
Monad m => Applicative (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> WrappedMonad m a # (<>) :: WrappedMonad m (a -> b) -> WrappedMonad m a -> WrappedMonad m b # liftA2 :: (a -> b -> c) -> WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m c # (>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # (<*) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m a #
Arrow a => Applicative (ArrowMonad a)	Since: base-4.6.0.0
Instance details Defined in Control.Arrow Methods pure :: a0 -> ArrowMonad a a0 # (<>) :: ArrowMonad a (a0 -> b) -> ArrowMonad a a0 -> ArrowMonad a b # liftA2 :: (a0 -> b -> c) -> ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a c # (>) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a b # (<*) :: ArrowMonad a a0 -> ArrowMonad a b -> ArrowMonad a a0 #
(Functor m, Monad m) => Applicative (MaybeT m)
Instance details Defined in Control.Monad.Trans.Maybe Methods pure :: a -> MaybeT m a # (<>) :: MaybeT m (a -> b) -> MaybeT m a -> MaybeT m b # liftA2 :: (a -> b -> c) -> MaybeT m a -> MaybeT m b -> MaybeT m c # (>) :: MaybeT m a -> MaybeT m b -> MaybeT m b # (<*) :: MaybeT m a -> MaybeT m b -> MaybeT m a #
Monad m => Applicative (ZipSource m)
Instance details Defined in Data.Conduit.Internal.Conduit Methods pure :: a -> ZipSource m a # (<>) :: ZipSource m (a -> b) -> ZipSource m a -> ZipSource m b # liftA2 :: (a -> b -> c) -> ZipSource m a -> ZipSource m b -> ZipSource m c # (>) :: ZipSource m a -> ZipSource m b -> ZipSource m b # (<*) :: ZipSource m a -> ZipSource m b -> ZipSource m a #
Applicative m => Applicative (ResourceT m)
Instance details Defined in Control.Monad.Trans.Resource.Internal Methods pure :: a -> ResourceT m a # (<>) :: ResourceT m (a -> b) -> ResourceT m a -> ResourceT m b # liftA2 :: (a -> b -> c) -> ResourceT m a -> ResourceT m b -> ResourceT m c # (>) :: ResourceT m a -> ResourceT m b -> ResourceT m b # (<*) :: ResourceT m a -> ResourceT m b -> ResourceT m a #
Applicative m => Applicative (ListT m)
Instance details Defined in Control.Monad.Trans.List Methods pure :: a -> ListT m a # (<>) :: ListT m (a -> b) -> ListT m a -> ListT m b # liftA2 :: (a -> b -> c) -> ListT m a -> ListT m b -> ListT m c # (>) :: ListT m a -> ListT m b -> ListT m b # (<*) :: ListT m a -> ListT m b -> ListT m a #
Semigroup a => Applicative (These a)
Instance details Defined in Data.These Methods pure :: a0 -> These a a0 # (<>) :: These a (a0 -> b) -> These a a0 -> These a b # liftA2 :: (a0 -> b -> c) -> These a a0 -> These a b -> These a c # (>) :: These a a0 -> These a b -> These a b # (<*) :: These a a0 -> These a b -> These a a0 #
Applicative f => Applicative (WrappedApplicative f)
Instance details Defined in Data.Functor.Bind.Class Methods pure :: a -> WrappedApplicative f a # (<>) :: WrappedApplicative f (a -> b) -> WrappedApplicative f a -> WrappedApplicative f b # liftA2 :: (a -> b -> c) -> WrappedApplicative f a -> WrappedApplicative f b -> WrappedApplicative f c # (>) :: WrappedApplicative f a -> WrappedApplicative f b -> WrappedApplicative f b # (<*) :: WrappedApplicative f a -> WrappedApplicative f b -> WrappedApplicative f a #
Apply f => Applicative (MaybeApply f)
Instance details Defined in Data.Functor.Bind.Class Methods pure :: a -> MaybeApply f a # (<>) :: MaybeApply f (a -> b) -> MaybeApply f a -> MaybeApply f b # liftA2 :: (a -> b -> c) -> MaybeApply f a -> MaybeApply f b -> MaybeApply f c # (>) :: MaybeApply f a -> MaybeApply f b -> MaybeApply f b # (<*) :: MaybeApply f a -> MaybeApply f b -> MaybeApply f a #
Semigroup a => Applicative (These a)
Instance details Defined in Data.Strict.These Methods pure :: a0 -> These a a0 # (<>) :: These a (a0 -> b) -> These a a0 -> These a b # liftA2 :: (a0 -> b -> c) -> These a a0 -> These a b -> These a c # (>) :: These a a0 -> These a b -> These a b # (<*) :: These a a0 -> These a b -> These a a0 #
Applicative (SetM s)
Instance details Defined in Data.Graph Methods pure :: a -> SetM s a # (<>) :: SetM s (a -> b) -> SetM s a -> SetM s b # liftA2 :: (a -> b -> c) -> SetM s a -> SetM s b -> SetM s c # (>) :: SetM s a -> SetM s b -> SetM s b # (<*) :: SetM s a -> SetM s b -> SetM s a #
Applicative f => Applicative (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> Rec1 f a # (<>) :: Rec1 f (a -> b) -> Rec1 f a -> Rec1 f b # liftA2 :: (a -> b -> c) -> Rec1 f a -> Rec1 f b -> Rec1 f c # (>) :: Rec1 f a -> Rec1 f b -> Rec1 f b # (<*) :: Rec1 f a -> Rec1 f b -> Rec1 f a #
(Monoid a, Monoid b) => Applicative ((,,) a b)	Since: base-4.14.0.0
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, b, a0) # (<>) :: (a, b, a0 -> b0) -> (a, b, a0) -> (a, b, b0) # liftA2 :: (a0 -> b0 -> c) -> (a, b, a0) -> (a, b, b0) -> (a, b, c) # (>) :: (a, b, a0) -> (a, b, b0) -> (a, b, b0) # (<*) :: (a, b, a0) -> (a, b, b0) -> (a, b, a0) #
Arrow a => Applicative (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a0 -> WrappedArrow a b a0 # (<>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # liftA2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c # (>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<*) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 #
Applicative m => Applicative (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Methods pure :: a0 -> Kleisli m a a0 # (<>) :: Kleisli m a (a0 -> b) -> Kleisli m a a0 -> Kleisli m a b # liftA2 :: (a0 -> b -> c) -> Kleisli m a a0 -> Kleisli m a b -> Kleisli m a c # (>) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a b # (<*) :: Kleisli m a a0 -> Kleisli m a b -> Kleisli m a a0 #
Monoid m => Applicative (Const m :: Type -> Type)	Since: base-2.0.1
Instance details Defined in Data.Functor.Const Methods pure :: a -> Const m a # (<>) :: Const m (a -> b) -> Const m a -> Const m b # liftA2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c # (>) :: Const m a -> Const m b -> Const m b # (<*) :: Const m a -> Const m b -> Const m a #
Applicative f => Applicative (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods pure :: a -> Ap f a # (<>) :: Ap f (a -> b) -> Ap f a -> Ap f b # liftA2 :: (a -> b -> c) -> Ap f a -> Ap f b -> Ap f c # (>) :: Ap f a -> Ap f b -> Ap f b # (<*) :: Ap f a -> Ap f b -> Ap f a #
Applicative f => Applicative (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods pure :: a -> Alt f a # (<>) :: Alt f (a -> b) -> Alt f a -> Alt f b # liftA2 :: (a -> b -> c) -> Alt f a -> Alt f b -> Alt f c # (>) :: Alt f a -> Alt f b -> Alt f b # (<*) :: Alt f a -> Alt f b -> Alt f a #
Biapplicative p => Applicative (Join p)
Instance details Defined in Data.Bifunctor.Join Methods pure :: a -> Join p a # (<>) :: Join p (a -> b) -> Join p a -> Join p b # liftA2 :: (a -> b -> c) -> Join p a -> Join p b -> Join p c # (>) :: Join p a -> Join p b -> Join p b # (<*) :: Join p a -> Join p b -> Join p a #
Applicative m => Applicative (IdentityT m)
Instance details Defined in Control.Monad.Trans.Identity Methods pure :: a -> IdentityT m a # (<>) :: IdentityT m (a -> b) -> IdentityT m a -> IdentityT m b # liftA2 :: (a -> b -> c) -> IdentityT m a -> IdentityT m b -> IdentityT m c # (>) :: IdentityT m a -> IdentityT m b -> IdentityT m b # (<*) :: IdentityT m a -> IdentityT m b -> IdentityT m a #
(Monoid w, Applicative m) => Applicative (WriterT w m)
Instance details Defined in Control.Monad.Trans.Writer.Strict Methods pure :: a -> WriterT w m a # (<>) :: WriterT w m (a -> b) -> WriterT w m a -> WriterT w m b # liftA2 :: (a -> b -> c) -> WriterT w m a -> WriterT w m b -> WriterT w m c # (>) :: WriterT w m a -> WriterT w m b -> WriterT w m b # (<*) :: WriterT w m a -> WriterT w m b -> WriterT w m a #
(Monoid w, Applicative m) => Applicative (WriterT w m)
Instance details Defined in Control.Monad.Trans.Writer.Lazy Methods pure :: a -> WriterT w m a # (<>) :: WriterT w m (a -> b) -> WriterT w m a -> WriterT w m b # liftA2 :: (a -> b -> c) -> WriterT w m a -> WriterT w m b -> WriterT w m c # (>) :: WriterT w m a -> WriterT w m b -> WriterT w m b # (<*) :: WriterT w m a -> WriterT w m b -> WriterT w m a #
(Functor m, Monad m) => Applicative (StateT s m)
Instance details Defined in Control.Monad.Trans.State.Strict Methods pure :: a -> StateT s m a # (<>) :: StateT s m (a -> b) -> StateT s m a -> StateT s m b # liftA2 :: (a -> b -> c) -> StateT s m a -> StateT s m b -> StateT s m c # (>) :: StateT s m a -> StateT s m b -> StateT s m b # (<*) :: StateT s m a -> StateT s m b -> StateT s m a #
(Functor m, Monad m) => Applicative (StateT s m)
Instance details Defined in Control.Monad.Trans.State.Lazy Methods pure :: a -> StateT s m a # (<>) :: StateT s m (a -> b) -> StateT s m a -> StateT s m b # liftA2 :: (a -> b -> c) -> StateT s m a -> StateT s m b -> StateT s m c # (>) :: StateT s m a -> StateT s m b -> StateT s m b # (<*) :: StateT s m a -> StateT s m b -> StateT s m a #
Applicative m => Applicative (ReaderT r m)
Instance details Defined in Control.Monad.Trans.Reader Methods pure :: a -> ReaderT r m a # (<>) :: ReaderT r m (a -> b) -> ReaderT r m a -> ReaderT r m b # liftA2 :: (a -> b -> c) -> ReaderT r m a -> ReaderT r m b -> ReaderT r m c # (>) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m b # (<*) :: ReaderT r m a -> ReaderT r m b -> ReaderT r m a #
(Functor m, Monad m) => Applicative (ExceptT e m)
Instance details Defined in Control.Monad.Trans.Except Methods pure :: a -> ExceptT e m a # (<>) :: ExceptT e m (a -> b) -> ExceptT e m a -> ExceptT e m b # liftA2 :: (a -> b -> c) -> ExceptT e m a -> ExceptT e m b -> ExceptT e m c # (>) :: ExceptT e m a -> ExceptT e m b -> ExceptT e m b # (<*) :: ExceptT e m a -> ExceptT e m b -> ExceptT e m a #
Monad m => Applicative (ZipSink i m)
Instance details Defined in Data.Conduit.Internal.Conduit Methods pure :: a -> ZipSink i m a # (<>) :: ZipSink i m (a -> b) -> ZipSink i m a -> ZipSink i m b # liftA2 :: (a -> b -> c) -> ZipSink i m a -> ZipSink i m b -> ZipSink i m c # (>) :: ZipSink i m a -> ZipSink i m b -> ZipSink i m b # (<*) :: ZipSink i m a -> ZipSink i m b -> ZipSink i m a #
(Applicative f, Monad f) => Applicative (WhenMissing f x)	Equivalent to `ReaderT k (ReaderT x (MaybeT f))`. Since: containers-0.5.9
Instance details Defined in Data.IntMap.Internal Methods pure :: a -> WhenMissing f x a # (<>) :: WhenMissing f x (a -> b) -> WhenMissing f x a -> WhenMissing f x b # liftA2 :: (a -> b -> c) -> WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x c # (>) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x b # (<*) :: WhenMissing f x a -> WhenMissing f x b -> WhenMissing f x a #
(Functor m, Monad m) => Applicative (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods pure :: a -> ErrorT e m a # (<>) :: ErrorT e m (a -> b) -> ErrorT e m a -> ErrorT e m b # liftA2 :: (a -> b -> c) -> ErrorT e m a -> ErrorT e m b -> ErrorT e m c # (>) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m b # (<*) :: ErrorT e m a -> ErrorT e m b -> ErrorT e m a #
(Profunctor p, Arrow p) => Applicative (Closure p a)
Instance details Defined in Data.Profunctor.Closed Methods pure :: a0 -> Closure p a a0 # (<>) :: Closure p a (a0 -> b) -> Closure p a a0 -> Closure p a b # liftA2 :: (a0 -> b -> c) -> Closure p a a0 -> Closure p a b -> Closure p a c # (>) :: Closure p a a0 -> Closure p a b -> Closure p a b # (<*) :: Closure p a a0 -> Closure p a b -> Closure p a a0 #
(Profunctor p, Arrow p) => Applicative (Tambara p a)
Instance details Defined in Data.Profunctor.Strong Methods pure :: a0 -> Tambara p a a0 # (<>) :: Tambara p a (a0 -> b) -> Tambara p a a0 -> Tambara p a b # liftA2 :: (a0 -> b -> c) -> Tambara p a a0 -> Tambara p a b -> Tambara p a c # (>) :: Tambara p a a0 -> Tambara p a b -> Tambara p a b # (<*) :: Tambara p a a0 -> Tambara p a b -> Tambara p a a0 #
Applicative (Tagged s)
Instance details Defined in Data.Tagged Methods pure :: a -> Tagged s a # (<>) :: Tagged s (a -> b) -> Tagged s a -> Tagged s b # liftA2 :: (a -> b -> c) -> Tagged s a -> Tagged s b -> Tagged s c # (>) :: Tagged s a -> Tagged s b -> Tagged s b # (<*) :: Tagged s a -> Tagged s b -> Tagged s a #
Applicative (Mag a b)
Instance details Defined in Data.Biapplicative Methods pure :: a0 -> Mag a b a0 # (<>) :: Mag a b (a0 -> b0) -> Mag a b a0 -> Mag a b b0 # liftA2 :: (a0 -> b0 -> c) -> Mag a b a0 -> Mag a b b0 -> Mag a b c # (>) :: Mag a b a0 -> Mag a b b0 -> Mag a b b0 # (<*) :: Mag a b a0 -> Mag a b b0 -> Mag a b a0 #
Applicative ((->) r :: Type -> Type)	Since: base-2.1
Instance details Defined in GHC.Base Methods pure :: a -> r -> a # (<>) :: (r -> (a -> b)) -> (r -> a) -> r -> b # liftA2 :: (a -> b -> c) -> (r -> a) -> (r -> b) -> r -> c # (>) :: (r -> a) -> (r -> b) -> r -> b # (<*) :: (r -> a) -> (r -> b) -> r -> a #
Monoid c => Applicative (K1 i c :: Type -> Type)	Since: base-4.12.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> K1 i c a # (<>) :: K1 i c (a -> b) -> K1 i c a -> K1 i c b # liftA2 :: (a -> b -> c0) -> K1 i c a -> K1 i c b -> K1 i c c0 # (>) :: K1 i c a -> K1 i c b -> K1 i c b # (<*) :: K1 i c a -> K1 i c b -> K1 i c a #
(Applicative f, Applicative g) => Applicative (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> (f :: g) a # (<>) :: (f :: g) (a -> b) -> (f :: g) a -> (f :: g) b # liftA2 :: (a -> b -> c) -> (f :: g) a -> (f :: g) b -> (f :: g) c # (>) :: (f :: g) a -> (f :: g) b -> (f :: g) b # (<) :: (f :: g) a -> (f :: g) b -> (f :: g) a #
(Monoid a, Monoid b, Monoid c) => Applicative ((,,,) a b c)	Since: base-4.14.0.0
Instance details Defined in GHC.Base Methods pure :: a0 -> (a, b, c, a0) # (<>) :: (a, b, c, a0 -> b0) -> (a, b, c, a0) -> (a, b, c, b0) # liftA2 :: (a0 -> b0 -> c0) -> (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, c0) # (>) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, b0) # (<*) :: (a, b, c, a0) -> (a, b, c, b0) -> (a, b, c, a0) #
(Applicative f, Applicative g) => Applicative (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods pure :: a -> Product f g a # (<>) :: Product f g (a -> b) -> Product f g a -> Product f g b # liftA2 :: (a -> b -> c) -> Product f g a -> Product f g b -> Product f g c # (>) :: Product f g a -> Product f g b -> Product f g b # (<*) :: Product f g a -> Product f g b -> Product f g a #
Applicative (Cokleisli w a)
Instance details Defined in Control.Comonad Methods pure :: a0 -> Cokleisli w a a0 # (<>) :: Cokleisli w a (a0 -> b) -> Cokleisli w a a0 -> Cokleisli w a b # liftA2 :: (a0 -> b -> c) -> Cokleisli w a a0 -> Cokleisli w a b -> Cokleisli w a c # (>) :: Cokleisli w a a0 -> Cokleisli w a b -> Cokleisli w a b # (<*) :: Cokleisli w a a0 -> Cokleisli w a b -> Cokleisli w a a0 #
Applicative (ConduitT i o m)
Instance details Defined in Data.Conduit.Internal.Conduit Methods pure :: a -> ConduitT i o m a # (<>) :: ConduitT i o m (a -> b) -> ConduitT i o m a -> ConduitT i o m b # liftA2 :: (a -> b -> c) -> ConduitT i o m a -> ConduitT i o m b -> ConduitT i o m c # (>) :: ConduitT i o m a -> ConduitT i o m b -> ConduitT i o m b # (<*) :: ConduitT i o m a -> ConduitT i o m b -> ConduitT i o m a #
Monad m => Applicative (ZipConduit i o m)
Instance details Defined in Data.Conduit.Internal.Conduit Methods pure :: a -> ZipConduit i o m a # (<>) :: ZipConduit i o m (a -> b) -> ZipConduit i o m a -> ZipConduit i o m b # liftA2 :: (a -> b -> c) -> ZipConduit i o m a -> ZipConduit i o m b -> ZipConduit i o m c # (>) :: ZipConduit i o m a -> ZipConduit i o m b -> ZipConduit i o m b # (<*) :: ZipConduit i o m a -> ZipConduit i o m b -> ZipConduit i o m a #
(Monad f, Applicative f) => Applicative (WhenMatched f x y)	Equivalent to `ReaderT Key (ReaderT x (ReaderT y (MaybeT f)))` Since: containers-0.5.9
Instance details Defined in Data.IntMap.Internal Methods pure :: a -> WhenMatched f x y a # (<>) :: WhenMatched f x y (a -> b) -> WhenMatched f x y a -> WhenMatched f x y b # liftA2 :: (a -> b -> c) -> WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y c # (>) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y b # (<*) :: WhenMatched f x y a -> WhenMatched f x y b -> WhenMatched f x y a #
(Applicative f, Monad f) => Applicative (WhenMissing f k x)	Equivalent to `ReaderT k (ReaderT x (MaybeT f))` . Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods pure :: a -> WhenMissing f k x a # (<>) :: WhenMissing f k x (a -> b) -> WhenMissing f k x a -> WhenMissing f k x b # liftA2 :: (a -> b -> c) -> WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x c # (>) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x b # (<*) :: WhenMissing f k x a -> WhenMissing f k x b -> WhenMissing f k x a #
Applicative (ContT r m)
Instance details Defined in Control.Monad.Trans.Cont Methods pure :: a -> ContT r m a # (<>) :: ContT r m (a -> b) -> ContT r m a -> ContT r m b # liftA2 :: (a -> b -> c) -> ContT r m a -> ContT r m b -> ContT r m c # (>) :: ContT r m a -> ContT r m b -> ContT r m b # (<*) :: ContT r m a -> ContT r m b -> ContT r m a #
Applicative f => Applicative (Star f a)
Instance details Defined in Data.Profunctor.Types Methods pure :: a0 -> Star f a a0 # (<>) :: Star f a (a0 -> b) -> Star f a a0 -> Star f a b # liftA2 :: (a0 -> b -> c) -> Star f a a0 -> Star f a b -> Star f a c # (>) :: Star f a a0 -> Star f a b -> Star f a b # (<*) :: Star f a a0 -> Star f a b -> Star f a a0 #
Applicative (Costar f a)
Instance details Defined in Data.Profunctor.Types Methods pure :: a0 -> Costar f a a0 # (<>) :: Costar f a (a0 -> b) -> Costar f a a0 -> Costar f a b # liftA2 :: (a0 -> b -> c) -> Costar f a a0 -> Costar f a b -> Costar f a c # (>) :: Costar f a a0 -> Costar f a b -> Costar f a b # (<*) :: Costar f a a0 -> Costar f a b -> Costar f a a0 #
Applicative f => Applicative (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> M1 i c f a # (<>) :: M1 i c f (a -> b) -> M1 i c f a -> M1 i c f b # liftA2 :: (a -> b -> c0) -> M1 i c f a -> M1 i c f b -> M1 i c f c0 # (>) :: M1 i c f a -> M1 i c f b -> M1 i c f b # (<*) :: M1 i c f a -> M1 i c f b -> M1 i c f a #
(Applicative f, Applicative g) => Applicative (f :.: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods pure :: a -> (f :.: g) a # (<>) :: (f :.: g) (a -> b) -> (f :.: g) a -> (f :.: g) b # liftA2 :: (a -> b -> c) -> (f :.: g) a -> (f :.: g) b -> (f :.: g) c # (>) :: (f :.: g) a -> (f :.: g) b -> (f :.: g) b # (<*) :: (f :.: g) a -> (f :.: g) b -> (f :.: g) a #
(Applicative f, Applicative g) => Applicative (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods pure :: a -> Compose f g a # (<>) :: Compose f g (a -> b) -> Compose f g a -> Compose f g b # liftA2 :: (a -> b -> c) -> Compose f g a -> Compose f g b -> Compose f g c # (>) :: Compose f g a -> Compose f g b -> Compose f g b # (<*) :: Compose f g a -> Compose f g b -> Compose f g a #
(Monoid w, Functor m, Monad m) => Applicative (RWST r w s m)
Instance details Defined in Control.Monad.Trans.RWS.Strict Methods pure :: a -> RWST r w s m a # (<>) :: RWST r w s m (a -> b) -> RWST r w s m a -> RWST r w s m b # liftA2 :: (a -> b -> c) -> RWST r w s m a -> RWST r w s m b -> RWST r w s m c # (>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b # (<*) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m a #
(Monoid w, Functor m, Monad m) => Applicative (RWST r w s m)
Instance details Defined in Control.Monad.Trans.RWS.Lazy Methods pure :: a -> RWST r w s m a # (<>) :: RWST r w s m (a -> b) -> RWST r w s m a -> RWST r w s m b # liftA2 :: (a -> b -> c) -> RWST r w s m a -> RWST r w s m b -> RWST r w s m c # (>) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m b # (<*) :: RWST r w s m a -> RWST r w s m b -> RWST r w s m a #
(Monad f, Applicative f) => Applicative (WhenMatched f k x y)	Equivalent to `ReaderT k (ReaderT x (ReaderT y (MaybeT f)))` Since: containers-0.5.9
Instance details Defined in Data.Map.Internal Methods pure :: a -> WhenMatched f k x y a # (<>) :: WhenMatched f k x y (a -> b) -> WhenMatched f k x y a -> WhenMatched f k x y b # liftA2 :: (a -> b -> c) -> WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y c # (>) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y b # (<*) :: WhenMatched f k x y a -> WhenMatched f k x y b -> WhenMatched f k x y a #
Monad m => Applicative (Pipe l i o u m)
Instance details Defined in Data.Conduit.Internal.Pipe Methods pure :: a -> Pipe l i o u m a # (<>) :: Pipe l i o u m (a -> b) -> Pipe l i o u m a -> Pipe l i o u m b # liftA2 :: (a -> b -> c) -> Pipe l i o u m a -> Pipe l i o u m b -> Pipe l i o u m c # (>) :: Pipe l i o u m a -> Pipe l i o u m b -> Pipe l i o u m b # (<*) :: Pipe l i o u m a -> Pipe l i o u m b -> Pipe l i o u m a #

mappend :: Monoid a => a -> a -> a #

An associative operation

NOTE: This method is redundant and has the default implementation mappend = (<>) since base-4.11.0.0. Should it be implemented manually, since mappend is a synonym for (<>), it is expected that the two functions are defined the same way. In a future GHC release mappend will be removed from Monoid.

class Applicative f => Alternative (f :: Type -> Type) where #

A monoid on applicative functors.

If defined, some and many should be the least solutions of the equations:

```
some v = (:) <$> v <*> many v
```
```
many v = some v <|> pure []
```

Minimal complete definition

empty, (<|>)

Methods

empty :: f a #

The identity of <|>

(<|>) :: f a -> f a -> f a infixl 3 #

An associative binary operation

some :: f a -> f [a] #

One or more.

many :: f a -> f [a] #

Zero or more.

Instances

Instances details

Alternative []	Since: base-2.1
Instance details Defined in GHC.Base Methods empty :: [a] # (<\|>) :: [a] -> [a] -> [a] # some :: [a] -> [[a]] # many :: [a] -> [[a]] #
Alternative Maybe	Since: base-2.1
Instance details Defined in GHC.Base Methods empty :: Maybe a # (<\|>) :: Maybe a -> Maybe a -> Maybe a # some :: Maybe a -> Maybe [a] # many :: Maybe a -> Maybe [a] #
Alternative IO	Since: base-4.9.0.0
Instance details Defined in GHC.Base Methods empty :: IO a # (<\|>) :: IO a -> IO a -> IO a # some :: IO a -> IO [a] # many :: IO a -> IO [a] #
Alternative Condition
Instance details Defined in Distribution.Types.Condition Methods empty :: Condition a # (<\|>) :: Condition a -> Condition a -> Condition a # some :: Condition a -> Condition [a] # many :: Condition a -> Condition [a] #
Alternative IResult
Instance details Defined in Data.Aeson.Types.Internal Methods empty :: IResult a # (<\|>) :: IResult a -> IResult a -> IResult a # some :: IResult a -> IResult [a] # many :: IResult a -> IResult [a] #
Alternative Result
Instance details Defined in Data.Aeson.Types.Internal Methods empty :: Result a # (<\|>) :: Result a -> Result a -> Result a # some :: Result a -> Result [a] # many :: Result a -> Result [a] #
Alternative Parser
Instance details Defined in Data.Aeson.Types.Internal Methods empty :: Parser a # (<\|>) :: Parser a -> Parser a -> Parser a # some :: Parser a -> Parser [a] # many :: Parser a -> Parser [a] #
Alternative Option	Since: base-4.9.0.0
Instance details Defined in Data.Semigroup Methods empty :: Option a # (<\|>) :: Option a -> Option a -> Option a # some :: Option a -> Option [a] # many :: Option a -> Option [a] #
Alternative ZipList	Since: base-4.11.0.0
Instance details Defined in Control.Applicative Methods empty :: ZipList a # (<\|>) :: ZipList a -> ZipList a -> ZipList a # some :: ZipList a -> ZipList [a] # many :: ZipList a -> ZipList [a] #
Alternative ReadPrec	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadPrec Methods empty :: ReadPrec a # (<\|>) :: ReadPrec a -> ReadPrec a -> ReadPrec a # some :: ReadPrec a -> ReadPrec [a] # many :: ReadPrec a -> ReadPrec [a] #
Alternative ReadP	Since: base-4.6.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods empty :: ReadP a # (<\|>) :: ReadP a -> ReadP a -> ReadP a # some :: ReadP a -> ReadP [a] # many :: ReadP a -> ReadP [a] #
Alternative Seq	Since: containers-0.5.4
Instance details Defined in Data.Sequence.Internal Methods empty :: Seq a # (<\|>) :: Seq a -> Seq a -> Seq a # some :: Seq a -> Seq [a] # many :: Seq a -> Seq [a] #
Alternative DList
Instance details Defined in Data.DList.Internal Methods empty :: DList a # (<\|>) :: DList a -> DList a -> DList a # some :: DList a -> DList [a] # many :: DList a -> DList [a] #
Alternative ReadM
Instance details Defined in Options.Applicative.Types Methods empty :: ReadM a # (<\|>) :: ReadM a -> ReadM a -> ReadM a # some :: ReadM a -> ReadM [a] # many :: ReadM a -> ReadM [a] #
Alternative Parser
Instance details Defined in Options.Applicative.Types Methods empty :: Parser a # (<\|>) :: Parser a -> Parser a -> Parser a # some :: Parser a -> Parser [a] # many :: Parser a -> Parser [a] #
Alternative Chunk
Instance details Defined in Options.Applicative.Help.Chunk Methods empty :: Chunk a # (<\|>) :: Chunk a -> Chunk a -> Chunk a # some :: Chunk a -> Chunk [a] # many :: Chunk a -> Chunk [a] #
Alternative SmallArray
Instance details Defined in Data.Primitive.SmallArray Methods empty :: SmallArray a # (<\|>) :: SmallArray a -> SmallArray a -> SmallArray a # some :: SmallArray a -> SmallArray [a] # many :: SmallArray a -> SmallArray [a] #
Alternative Array
Instance details Defined in Data.Primitive.Array Methods empty :: Array a # (<\|>) :: Array a -> Array a -> Array a # some :: Array a -> Array [a] # many :: Array a -> Array [a] #
Alternative Vector
Instance details Defined in Data.Vector Methods empty :: Vector a # (<\|>) :: Vector a -> Vector a -> Vector a # some :: Vector a -> Vector [a] # many :: Vector a -> Vector [a] #
Alternative P	Since: base-4.5.0.0
Instance details Defined in Text.ParserCombinators.ReadP Methods empty :: P a # (<\|>) :: P a -> P a -> P a # some :: P a -> P [a] # many :: P a -> P [a] #
Alternative (U1 :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: U1 a # (<\|>) :: U1 a -> U1 a -> U1 a # some :: U1 a -> U1 [a] # many :: U1 a -> U1 [a] #
Alternative (Proxy :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Proxy Methods empty :: Proxy a # (<\|>) :: Proxy a -> Proxy a -> Proxy a # some :: Proxy a -> Proxy [a] # many :: Proxy a -> Proxy [a] #
Alternative (Parser i)
Instance details Defined in Data.Attoparsec.Internal.Types Methods empty :: Parser i a # (<\|>) :: Parser i a -> Parser i a -> Parser i a # some :: Parser i a -> Parser i [a] # many :: Parser i a -> Parser i [a] #
MonadPlus m => Alternative (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods empty :: WrappedMonad m a # (<\|>) :: WrappedMonad m a -> WrappedMonad m a -> WrappedMonad m a # some :: WrappedMonad m a -> WrappedMonad m [a] # many :: WrappedMonad m a -> WrappedMonad m [a] #
ArrowPlus a => Alternative (ArrowMonad a)	Since: base-4.6.0.0
Instance details Defined in Control.Arrow Methods empty :: ArrowMonad a a0 # (<\|>) :: ArrowMonad a a0 -> ArrowMonad a a0 -> ArrowMonad a a0 # some :: ArrowMonad a a0 -> ArrowMonad a [a0] # many :: ArrowMonad a a0 -> ArrowMonad a [a0] #
(Functor m, Monad m) => Alternative (MaybeT m)
Instance details Defined in Control.Monad.Trans.Maybe Methods empty :: MaybeT m a # (<\|>) :: MaybeT m a -> MaybeT m a -> MaybeT m a # some :: MaybeT m a -> MaybeT m [a] # many :: MaybeT m a -> MaybeT m [a] #
Alternative m => Alternative (ResourceT m)	Since 1.1.5
Instance details Defined in Control.Monad.Trans.Resource.Internal Methods empty :: ResourceT m a # (<\|>) :: ResourceT m a -> ResourceT m a -> ResourceT m a # some :: ResourceT m a -> ResourceT m [a] # many :: ResourceT m a -> ResourceT m [a] #
Applicative m => Alternative (ListT m)
Instance details Defined in Control.Monad.Trans.List Methods empty :: ListT m a # (<\|>) :: ListT m a -> ListT m a -> ListT m a # some :: ListT m a -> ListT m [a] # many :: ListT m a -> ListT m [a] #
Alternative f => Alternative (WrappedApplicative f)
Instance details Defined in Data.Functor.Bind.Class Methods empty :: WrappedApplicative f a # (<\|>) :: WrappedApplicative f a -> WrappedApplicative f a -> WrappedApplicative f a # some :: WrappedApplicative f a -> WrappedApplicative f [a] # many :: WrappedApplicative f a -> WrappedApplicative f [a] #
Alternative f => Alternative (Rec1 f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: Rec1 f a # (<\|>) :: Rec1 f a -> Rec1 f a -> Rec1 f a # some :: Rec1 f a -> Rec1 f [a] # many :: Rec1 f a -> Rec1 f [a] #
(ArrowZero a, ArrowPlus a) => Alternative (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods empty :: WrappedArrow a b a0 # (<\|>) :: WrappedArrow a b a0 -> WrappedArrow a b a0 -> WrappedArrow a b a0 # some :: WrappedArrow a b a0 -> WrappedArrow a b [a0] # many :: WrappedArrow a b a0 -> WrappedArrow a b [a0] #
Alternative m => Alternative (Kleisli m a)	Since: base-4.14.0.0
Instance details Defined in Control.Arrow Methods empty :: Kleisli m a a0 # (<\|>) :: Kleisli m a a0 -> Kleisli m a a0 -> Kleisli m a a0 # some :: Kleisli m a a0 -> Kleisli m a [a0] # many :: Kleisli m a a0 -> Kleisli m a [a0] #
Alternative f => Alternative (Ap f)	Since: base-4.12.0.0
Instance details Defined in Data.Monoid Methods empty :: Ap f a # (<\|>) :: Ap f a -> Ap f a -> Ap f a # some :: Ap f a -> Ap f [a] # many :: Ap f a -> Ap f [a] #
Alternative f => Alternative (Alt f)	Since: base-4.8.0.0
Instance details Defined in Data.Semigroup.Internal Methods empty :: Alt f a # (<\|>) :: Alt f a -> Alt f a -> Alt f a # some :: Alt f a -> Alt f [a] # many :: Alt f a -> Alt f [a] #
Alternative m => Alternative (IdentityT m)
Instance details Defined in Control.Monad.Trans.Identity Methods empty :: IdentityT m a # (<\|>) :: IdentityT m a -> IdentityT m a -> IdentityT m a # some :: IdentityT m a -> IdentityT m [a] # many :: IdentityT m a -> IdentityT m [a] #
(Monoid w, Alternative m) => Alternative (WriterT w m)
Instance details Defined in Control.Monad.Trans.Writer.Strict Methods empty :: WriterT w m a # (<\|>) :: WriterT w m a -> WriterT w m a -> WriterT w m a # some :: WriterT w m a -> WriterT w m [a] # many :: WriterT w m a -> WriterT w m [a] #
(Monoid w, Alternative m) => Alternative (WriterT w m)
Instance details Defined in Control.Monad.Trans.Writer.Lazy Methods empty :: WriterT w m a # (<\|>) :: WriterT w m a -> WriterT w m a -> WriterT w m a # some :: WriterT w m a -> WriterT w m [a] # many :: WriterT w m a -> WriterT w m [a] #
(Functor m, MonadPlus m) => Alternative (StateT s m)
Instance details Defined in Control.Monad.Trans.State.Strict Methods empty :: StateT s m a # (<\|>) :: StateT s m a -> StateT s m a -> StateT s m a # some :: StateT s m a -> StateT s m [a] # many :: StateT s m a -> StateT s m [a] #
(Functor m, MonadPlus m) => Alternative (StateT s m)
Instance details Defined in Control.Monad.Trans.State.Lazy Methods empty :: StateT s m a # (<\|>) :: StateT s m a -> StateT s m a -> StateT s m a # some :: StateT s m a -> StateT s m [a] # many :: StateT s m a -> StateT s m [a] #
Alternative m => Alternative (ReaderT r m)
Instance details Defined in Control.Monad.Trans.Reader Methods empty :: ReaderT r m a # (<\|>) :: ReaderT r m a -> ReaderT r m a -> ReaderT r m a # some :: ReaderT r m a -> ReaderT r m [a] # many :: ReaderT r m a -> ReaderT r m [a] #
(Functor m, Monad m, Monoid e) => Alternative (ExceptT e m)
Instance details Defined in Control.Monad.Trans.Except Methods empty :: ExceptT e m a # (<\|>) :: ExceptT e m a -> ExceptT e m a -> ExceptT e m a # some :: ExceptT e m a -> ExceptT e m [a] # many :: ExceptT e m a -> ExceptT e m [a] #
(Functor m, Monad m, Error e) => Alternative (ErrorT e m)
Instance details Defined in Control.Monad.Trans.Error Methods empty :: ErrorT e m a # (<\|>) :: ErrorT e m a -> ErrorT e m a -> ErrorT e m a # some :: ErrorT e m a -> ErrorT e m [a] # many :: ErrorT e m a -> ErrorT e m [a] #
(Profunctor p, ArrowPlus p) => Alternative (Closure p a)
Instance details Defined in Data.Profunctor.Closed Methods empty :: Closure p a a0 # (<\|>) :: Closure p a a0 -> Closure p a a0 -> Closure p a a0 # some :: Closure p a a0 -> Closure p a [a0] # many :: Closure p a a0 -> Closure p a [a0] #
(Profunctor p, ArrowPlus p) => Alternative (Tambara p a)
Instance details Defined in Data.Profunctor.Strong Methods empty :: Tambara p a a0 # (<\|>) :: Tambara p a a0 -> Tambara p a a0 -> Tambara p a a0 # some :: Tambara p a a0 -> Tambara p a [a0] # many :: Tambara p a a0 -> Tambara p a [a0] #
(Alternative f, Alternative g) => Alternative (f :*: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: (f :: g) a # (<\|>) :: (f :: g) a -> (f :: g) a -> (f :: g) a # some :: (f :: g) a -> (f :: g) [a] # many :: (f :: g) a -> (f :: g) [a] #
(Alternative f, Alternative g) => Alternative (Product f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Product Methods empty :: Product f g a # (<\|>) :: Product f g a -> Product f g a -> Product f g a # some :: Product f g a -> Product f g [a] # many :: Product f g a -> Product f g [a] #
Alternative f => Alternative (Star f a)
Instance details Defined in Data.Profunctor.Types Methods empty :: Star f a a0 # (<\|>) :: Star f a a0 -> Star f a a0 -> Star f a a0 # some :: Star f a a0 -> Star f a [a0] # many :: Star f a a0 -> Star f a [a0] #
Alternative f => Alternative (M1 i c f)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: M1 i c f a # (<\|>) :: M1 i c f a -> M1 i c f a -> M1 i c f a # some :: M1 i c f a -> M1 i c f [a] # many :: M1 i c f a -> M1 i c f [a] #
(Alternative f, Applicative g) => Alternative (f :.: g)	Since: base-4.9.0.0
Instance details Defined in GHC.Generics Methods empty :: (f :.: g) a # (<\|>) :: (f :.: g) a -> (f :.: g) a -> (f :.: g) a # some :: (f :.: g) a -> (f :.: g) [a] # many :: (f :.: g) a -> (f :.: g) [a] #
(Alternative f, Applicative g) => Alternative (Compose f g)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Compose Methods empty :: Compose f g a # (<\|>) :: Compose f g a -> Compose f g a -> Compose f g a # some :: Compose f g a -> Compose f g [a] # many :: Compose f g a -> Compose f g [a] #
(Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m)
Instance details Defined in Control.Monad.Trans.RWS.Strict Methods empty :: RWST r w s m a # (<\|>) :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a # some :: RWST r w s m a -> RWST r w s m [a] # many :: RWST r w s m a -> RWST r w s m [a] #
(Monoid w, Functor m, MonadPlus m) => Alternative (RWST r w s m)
Instance details Defined in Control.Monad.Trans.RWS.Lazy Methods empty :: RWST r w s m a # (<\|>) :: RWST r w s m a -> RWST r w s m a -> RWST r w s m a # some :: RWST r w s m a -> RWST r w s m [a] # many :: RWST r w s m a -> RWST r w s m [a] #

(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4 #

An infix synonym for fmap.

The name of this operator is an allusion to $. Note the similarities between their types:

 ($)  ::              (a -> b) ->   a ->   b
(<$>) :: Functor f => (a -> b) -> f a -> f b

Whereas $ is function application, <$> is function application lifted over a Functor.

Examples

Expand

Convert from a Maybe Int to a Maybe String using show:

>>> show <$> Nothing
Nothing
>>> show <$> Just 3
Just "3"

Convert from an Either Int Int to an Either Int String using show:

>>> show <$> Left 17
Left 17
>>> show <$> Right 17
Right "17"

Double each element of a list:

>>> (*2) <$> [1,2,3]
[2,4,6]

Apply even to the second element of a pair:

>>> even <$> (2,2)
(2,True)

optional :: Alternative f => f a -> f (Maybe a) #

One or none.

newtype WrappedMonad (m :: Type -> Type) a #

Constructors

WrapMonad
Fields unwrapMonad :: m a

Instances

Instances details

Monad m => Monad (WrappedMonad m)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (>>=) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b # (>>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # return :: a -> WrappedMonad m a #
Monad m => Functor (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods fmap :: (a -> b) -> WrappedMonad m a -> WrappedMonad m b # (<$) :: a -> WrappedMonad m b -> WrappedMonad m a #
Monad m => Applicative (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> WrappedMonad m a # (<>) :: WrappedMonad m (a -> b) -> WrappedMonad m a -> WrappedMonad m b # liftA2 :: (a -> b -> c) -> WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m c # (>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # (<*) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m a #
MonadPlus m => Alternative (WrappedMonad m)	Since: base-2.1
Instance details Defined in Control.Applicative Methods empty :: WrappedMonad m a # (<\|>) :: WrappedMonad m a -> WrappedMonad m a -> WrappedMonad m a # some :: WrappedMonad m a -> WrappedMonad m [a] # many :: WrappedMonad m a -> WrappedMonad m [a] #
MonadPlus m => Alt (WrappedMonad m)
Instance details Defined in Data.Functor.Alt Methods (<!>) :: WrappedMonad m a -> WrappedMonad m a -> WrappedMonad m a # some :: Applicative (WrappedMonad m) => WrappedMonad m a -> WrappedMonad m [a] # many :: Applicative (WrappedMonad m) => WrappedMonad m a -> WrappedMonad m [a] #
Monad m => Apply (WrappedMonad m)
Instance details Defined in Data.Functor.Bind.Class Methods (<.>) :: WrappedMonad m (a -> b) -> WrappedMonad m a -> WrappedMonad m b # (.>) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m b # (<.) :: WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m a # liftF2 :: (a -> b -> c) -> WrappedMonad m a -> WrappedMonad m b -> WrappedMonad m c #
Monad m => Bind (WrappedMonad m)
Instance details Defined in Data.Functor.Bind.Class Methods (>>-) :: WrappedMonad m a -> (a -> WrappedMonad m b) -> WrappedMonad m b # join :: WrappedMonad m (WrappedMonad m a) -> WrappedMonad m a #
Generic1 (WrappedMonad m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 (WrappedMonad m) :: k -> Type # Methods from1 :: forall (a :: k). WrappedMonad m a -> Rep1 (WrappedMonad m) a # to1 :: forall (a :: k). Rep1 (WrappedMonad m) a -> WrappedMonad m a #
Generic (WrappedMonad m a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (WrappedMonad m a) :: Type -> Type # Methods from :: WrappedMonad m a -> Rep (WrappedMonad m a) x # to :: Rep (WrappedMonad m a) x -> WrappedMonad m a #
type Rep1 (WrappedMonad m :: Type -> Type)
Instance details Defined in Control.Applicative type Rep1 (WrappedMonad m :: Type -> Type) = D1 ('MetaData "WrappedMonad" "Control.Applicative" "base" 'True) (C1 ('MetaCons "WrapMonad" 'PrefixI 'True) (S1 ('MetaSel ('Just "unwrapMonad") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 m)))
type Rep (WrappedMonad m a)
Instance details Defined in Control.Applicative type Rep (WrappedMonad m a) = D1 ('MetaData "WrappedMonad" "Control.Applicative" "base" 'True) (C1 ('MetaCons "WrapMonad" 'PrefixI 'True) (S1 ('MetaSel ('Just "unwrapMonad") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (m a))))

newtype WrappedArrow (a :: Type -> Type -> Type) b c #

Constructors

WrapArrow
Fields unwrapArrow :: a b c

Instances

Instances details

Generic1 (WrappedArrow a b :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 (WrappedArrow a b) :: k -> Type # Methods from1 :: forall (a0 :: k). WrappedArrow a b a0 -> Rep1 (WrappedArrow a b) a0 # to1 :: forall (a0 :: k). Rep1 (WrappedArrow a b) a0 -> WrappedArrow a b a0 #
Arrow a => Functor (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods fmap :: (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # (<$) :: a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 #
Arrow a => Applicative (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a0 -> WrappedArrow a b a0 # (<>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # liftA2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c # (>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<*) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 #
(ArrowZero a, ArrowPlus a) => Alternative (WrappedArrow a b)	Since: base-2.1
Instance details Defined in Control.Applicative Methods empty :: WrappedArrow a b a0 # (<\|>) :: WrappedArrow a b a0 -> WrappedArrow a b a0 -> WrappedArrow a b a0 # some :: WrappedArrow a b a0 -> WrappedArrow a b [a0] # many :: WrappedArrow a b a0 -> WrappedArrow a b [a0] #
ArrowPlus a => Alt (WrappedArrow a b)
Instance details Defined in Data.Functor.Alt Methods (<!>) :: WrappedArrow a b a0 -> WrappedArrow a b a0 -> WrappedArrow a b a0 # some :: Applicative (WrappedArrow a b) => WrappedArrow a b a0 -> WrappedArrow a b [a0] # many :: Applicative (WrappedArrow a b) => WrappedArrow a b a0 -> WrappedArrow a b [a0] #
Arrow a => Apply (WrappedArrow a b)
Instance details Defined in Data.Functor.Bind.Class Methods (<.>) :: WrappedArrow a b (a0 -> b0) -> WrappedArrow a b a0 -> WrappedArrow a b b0 # (.>) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b b0 # (<.) :: WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b a0 # liftF2 :: (a0 -> b0 -> c) -> WrappedArrow a b a0 -> WrappedArrow a b b0 -> WrappedArrow a b c #
Generic (WrappedArrow a b c)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (WrappedArrow a b c) :: Type -> Type # Methods from :: WrappedArrow a b c -> Rep (WrappedArrow a b c) x # to :: Rep (WrappedArrow a b c) x -> WrappedArrow a b c #
type Rep1 (WrappedArrow a b :: Type -> Type)
Instance details Defined in Control.Applicative type Rep1 (WrappedArrow a b :: Type -> Type) = D1 ('MetaData "WrappedArrow" "Control.Applicative" "base" 'True) (C1 ('MetaCons "WrapArrow" 'PrefixI 'True) (S1 ('MetaSel ('Just "unwrapArrow") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 (a b))))
type Rep (WrappedArrow a b c)
Instance details Defined in Control.Applicative type Rep (WrappedArrow a b c) = D1 ('MetaData "WrappedArrow" "Control.Applicative" "base" 'True) (C1 ('MetaCons "WrapArrow" 'PrefixI 'True) (S1 ('MetaSel ('Just "unwrapArrow") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (a b c))))

newtype ZipList a #

Lists, but with an Applicative functor based on zipping.

Constructors

ZipList
Fields getZipList :: [a]

Instances

Instances details

Functor ZipList	Since: base-2.1
Instance details Defined in Control.Applicative Methods fmap :: (a -> b) -> ZipList a -> ZipList b # (<$) :: a -> ZipList b -> ZipList a #
Applicative ZipList	f <$> ZipList xs1 <> ... <> ZipList xsN = ZipList (zipWithN f xs1 ... xsN) where `zipWithN` refers to the `zipWith` function of the appropriate arity (`zipWith`, `zipWith3`, `zipWith4`, ...). For example: (\a b c -> stimes c [a, b]) <$> ZipList "abcd" <> ZipList "567" <> ZipList [1..] = ZipList (zipWith3 (\a b c -> stimes c [a, b]) "abcd" "567" [1..]) = ZipList {getZipList = ["a5","b6b6","c7c7c7"]} Since: base-2.1
Instance details Defined in Control.Applicative Methods pure :: a -> ZipList a # (<>) :: ZipList (a -> b) -> ZipList a -> ZipList b # liftA2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c # (>) :: ZipList a -> ZipList b -> ZipList b # (<*) :: ZipList a -> ZipList b -> ZipList a #
Foldable ZipList	Since: base-4.9.0.0
Instance details Defined in Control.Applicative Methods fold :: Monoid m => ZipList m -> m # foldMap :: Monoid m => (a -> m) -> ZipList a -> m # foldMap' :: Monoid m => (a -> m) -> ZipList a -> m # foldr :: (a -> b -> b) -> b -> ZipList a -> b # foldr' :: (a -> b -> b) -> b -> ZipList a -> b # foldl :: (b -> a -> b) -> b -> ZipList a -> b # foldl' :: (b -> a -> b) -> b -> ZipList a -> b # foldr1 :: (a -> a -> a) -> ZipList a -> a # foldl1 :: (a -> a -> a) -> ZipList a -> a # toList :: ZipList a -> [a] # null :: ZipList a -> Bool # length :: ZipList a -> Int # elem :: Eq a => a -> ZipList a -> Bool # maximum :: Ord a => ZipList a -> a # minimum :: Ord a => ZipList a -> a # sum :: Num a => ZipList a -> a # product :: Num a => ZipList a -> a #
Traversable ZipList	Since: base-4.9.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> ZipList a -> f (ZipList b) # sequenceA :: Applicative f => ZipList (f a) -> f (ZipList a) # mapM :: Monad m => (a -> m b) -> ZipList a -> m (ZipList b) # sequence :: Monad m => ZipList (m a) -> m (ZipList a) #
Alternative ZipList	Since: base-4.11.0.0
Instance details Defined in Control.Applicative Methods empty :: ZipList a # (<\|>) :: ZipList a -> ZipList a -> ZipList a # some :: ZipList a -> ZipList [a] # many :: ZipList a -> ZipList [a] #
NFData1 ZipList	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a -> ()) -> ZipList a -> () #
Apply ZipList
Instance details Defined in Data.Functor.Bind.Class Methods (<.>) :: ZipList (a -> b) -> ZipList a -> ZipList b # (.>) :: ZipList a -> ZipList b -> ZipList b # (<.) :: ZipList a -> ZipList b -> ZipList a # liftF2 :: (a -> b -> c) -> ZipList a -> ZipList b -> ZipList c #
IsList (ZipList a)	Since: base-4.15.0.0
Instance details Defined in GHC.Exts Associated Types type Item (ZipList a) # Methods fromList :: [Item (ZipList a)] -> ZipList a # fromListN :: Int -> [Item (ZipList a)] -> ZipList a # toList :: ZipList a -> [Item (ZipList a)] #
Eq a => Eq (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods (==) :: ZipList a -> ZipList a -> Bool # (/=) :: ZipList a -> ZipList a -> Bool #
Ord a => Ord (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods compare :: ZipList a -> ZipList a -> Ordering # (<) :: ZipList a -> ZipList a -> Bool # (<=) :: ZipList a -> ZipList a -> Bool # (>) :: ZipList a -> ZipList a -> Bool # (>=) :: ZipList a -> ZipList a -> Bool # max :: ZipList a -> ZipList a -> ZipList a # min :: ZipList a -> ZipList a -> ZipList a #
Read a => Read (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods readsPrec :: Int -> ReadS (ZipList a) # readList :: ReadS [ZipList a] # readPrec :: ReadPrec (ZipList a) # readListPrec :: ReadPrec [ZipList a] #
Show a => Show (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Methods showsPrec :: Int -> ZipList a -> ShowS # show :: ZipList a -> String # showList :: [ZipList a] -> ShowS #
Generic (ZipList a)	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep (ZipList a) :: Type -> Type # Methods from :: ZipList a -> Rep (ZipList a) x # to :: Rep (ZipList a) x -> ZipList a #
NFData a => NFData (ZipList a)	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: ZipList a -> () #
Generic1 ZipList	Since: base-4.7.0.0
Instance details Defined in Control.Applicative Associated Types type Rep1 ZipList :: k -> Type # Methods from1 :: forall (a :: k). ZipList a -> Rep1 ZipList a # to1 :: forall (a :: k). Rep1 ZipList a -> ZipList a #
type Rep (ZipList a)
Instance details Defined in Control.Applicative type Rep (ZipList a) = D1 ('MetaData "ZipList" "Control.Applicative" "base" 'True) (C1 ('MetaCons "ZipList" 'PrefixI 'True) (S1 ('MetaSel ('Just "getZipList") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 [a])))
type Item (ZipList a)
Instance details Defined in GHC.Exts type Item (ZipList a) = a
type Rep1 ZipList
Instance details Defined in Control.Applicative type Rep1 ZipList = D1 ('MetaData "ZipList" "Control.Applicative" "base" 'True) (C1 ('MetaCons "ZipList" 'PrefixI 'True) (S1 ('MetaSel ('Just "getZipList") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec1 [])))

newtype Const a (b :: k) #

The Const functor.

Constructors

Const
Fields getConst :: a

Instances

Instances details

Generic1 (Const a :: k -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Associated Types type Rep1 (Const a) :: k -> Type # Methods from1 :: forall (a0 :: k0). Const a a0 -> Rep1 (Const a) a0 # to1 :: forall (a0 :: k0). Rep1 (Const a) a0 -> Const a a0 #
Unbox a => Vector Vector (Const a b)
Instance details Defined in Data.Vector.Unboxed.Base Methods basicUnsafeFreeze :: PrimMonad m => Mutable Vector (PrimState m) (Const a b) -> m (Vector (Const a b)) # basicUnsafeThaw :: PrimMonad m => Vector (Const a b) -> m (Mutable Vector (PrimState m) (Const a b)) # basicLength :: Vector (Const a b) -> Int # basicUnsafeSlice :: Int -> Int -> Vector (Const a b) -> Vector (Const a b) # basicUnsafeIndexM :: Monad m => Vector (Const a b) -> Int -> m (Const a b) # basicUnsafeCopy :: PrimMonad m => Mutable Vector (PrimState m) (Const a b) -> Vector (Const a b) -> m () # elemseq :: Vector (Const a b) -> Const a b -> b0 -> b0 #
Unbox a => MVector MVector (Const a b)
Instance details Defined in Data.Vector.Unboxed.Base Methods basicLength :: MVector s (Const a b) -> Int # basicUnsafeSlice :: Int -> Int -> MVector s (Const a b) -> MVector s (Const a b) # basicOverlaps :: MVector s (Const a b) -> MVector s (Const a b) -> Bool # basicUnsafeNew :: PrimMonad m => Int -> m (MVector (PrimState m) (Const a b)) # basicInitialize :: PrimMonad m => MVector (PrimState m) (Const a b) -> m () # basicUnsafeReplicate :: PrimMonad m => Int -> Const a b -> m (MVector (PrimState m) (Const a b)) # basicUnsafeRead :: PrimMonad m => MVector (PrimState m) (Const a b) -> Int -> m (Const a b) # basicUnsafeWrite :: PrimMonad m => MVector (PrimState m) (Const a b) -> Int -> Const a b -> m () # basicClear :: PrimMonad m => MVector (PrimState m) (Const a b) -> m () # basicSet :: PrimMonad m => MVector (PrimState m) (Const a b) -> Const a b -> m () # basicUnsafeCopy :: PrimMonad m => MVector (PrimState m) (Const a b) -> MVector (PrimState m) (Const a b) -> m () # basicUnsafeMove :: PrimMonad m => MVector (PrimState m) (Const a b) -> MVector (PrimState m) (Const a b) -> m () # basicUnsafeGrow :: PrimMonad m => MVector (PrimState m) (Const a b) -> Int -> m (MVector (PrimState m) (Const a b)) #
ToJSON2 (Const :: Type -> Type -> Type)
Instance details Defined in Data.Aeson.Types.ToJSON Methods liftToJSON2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> Const a b -> Value # liftToJSONList2 :: (a -> Value) -> ([a] -> Value) -> (b -> Value) -> ([b] -> Value) -> [Const a b] -> Value # liftToEncoding2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> Const a b -> Encoding # liftToEncodingList2 :: (a -> Encoding) -> ([a] -> Encoding) -> (b -> Encoding) -> ([b] -> Encoding) -> [Const a b] -> Encoding #
FromJSON2 (Const :: Type -> Type -> Type)
Instance details Defined in Data.Aeson.Types.FromJSON Methods liftParseJSON2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser (Const a b) # liftParseJSONList2 :: (Value -> Parser a) -> (Value -> Parser [a]) -> (Value -> Parser b) -> (Value -> Parser [b]) -> Value -> Parser [Const a b] #
Bifunctor (Const :: Type -> Type -> Type)	Since: base-4.8.0.0
Instance details Defined in Data.Bifunctor Methods bimap :: (a -> b) -> (c -> d) -> Const a c -> Const b d # first :: (a -> b) -> Const a c -> Const b c # second :: (b -> c) -> Const a b -> Const a c #
Bifoldable (Const :: Type -> Type -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Bifoldable Methods bifold :: Monoid m => Const m m -> m # bifoldMap :: Monoid m => (a -> m) -> (b -> m) -> Const a b -> m # bifoldr :: (a -> c -> c) -> (b -> c -> c) -> c -> Const a b -> c # bifoldl :: (c -> a -> c) -> (c -> b -> c) -> c -> Const a b -> c #
Eq2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq2 :: (a -> b -> Bool) -> (c -> d -> Bool) -> Const a c -> Const b d -> Bool #
Ord2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare2 :: (a -> b -> Ordering) -> (c -> d -> Ordering) -> Const a c -> Const b d -> Ordering #
Read2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> Int -> ReadS (Const a b) # liftReadList2 :: (Int -> ReadS a) -> ReadS [a] -> (Int -> ReadS b) -> ReadS [b] -> ReadS [Const a b] # liftReadPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec (Const a b) # liftReadListPrec2 :: ReadPrec a -> ReadPrec [a] -> ReadPrec b -> ReadPrec [b] -> ReadPrec [Const a b] #
Show2 (Const :: Type -> Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> Int -> Const a b -> ShowS # liftShowList2 :: (Int -> a -> ShowS) -> ([a] -> ShowS) -> (Int -> b -> ShowS) -> ([b] -> ShowS) -> [Const a b] -> ShowS #
Biapplicative (Const :: Type -> Type -> Type)
Instance details Defined in Data.Biapplicative Methods bipure :: a -> b -> Const a b # (<<>>) :: Const (a -> b) (c -> d) -> Const a c -> Const b d # biliftA2 :: (a -> b -> c) -> (d -> e -> f) -> Const a d -> Const b e -> Const c f # (>>) :: Const a b -> Const c d -> Const c d # (<<*) :: Const a b -> Const c d -> Const a b #
NFData2 (Const :: Type -> Type -> Type)	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf2 :: (a -> ()) -> (b -> ()) -> Const a b -> () #
Hashable2 (Const :: Type -> Type -> Type)
Instance details Defined in Data.Hashable.Class Methods liftHashWithSalt2 :: (Int -> a -> Int) -> (Int -> b -> Int) -> Int -> Const a b -> Int #
Biapply (Const :: Type -> Type -> Type)
Instance details Defined in Data.Functor.Bind.Class Methods (<<.>>) :: Const (a -> b) (c -> d) -> Const a c -> Const b d # (.>>) :: Const a b -> Const c d -> Const c d # (<<.) :: Const a b -> Const c d -> Const a b #
Bifoldable1 (Const :: Type -> Type -> Type)
Instance details Defined in Data.Semigroup.Foldable.Class Methods bifold1 :: Semigroup m => Const m m -> m # bifoldMap1 :: Semigroup m => (a -> m) -> (b -> m) -> Const a b -> m #
Functor (Const m :: Type -> Type)	Since: base-2.1
Instance details Defined in Data.Functor.Const Methods fmap :: (a -> b) -> Const m a -> Const m b # (<$) :: a -> Const m b -> Const m a #
Monoid m => Applicative (Const m :: Type -> Type)	Since: base-2.0.1
Instance details Defined in Data.Functor.Const Methods pure :: a -> Const m a # (<>) :: Const m (a -> b) -> Const m a -> Const m b # liftA2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c # (>) :: Const m a -> Const m b -> Const m b # (<*) :: Const m a -> Const m b -> Const m a #
Foldable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Functor.Const Methods fold :: Monoid m0 => Const m m0 -> m0 # foldMap :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldMap' :: Monoid m0 => (a -> m0) -> Const m a -> m0 # foldr :: (a -> b -> b) -> b -> Const m a -> b # foldr' :: (a -> b -> b) -> b -> Const m a -> b # foldl :: (b -> a -> b) -> b -> Const m a -> b # foldl' :: (b -> a -> b) -> b -> Const m a -> b # foldr1 :: (a -> a -> a) -> Const m a -> a # foldl1 :: (a -> a -> a) -> Const m a -> a # toList :: Const m a -> [a] # null :: Const m a -> Bool # length :: Const m a -> Int # elem :: Eq a => a -> Const m a -> Bool # maximum :: Ord a => Const m a -> a # minimum :: Ord a => Const m a -> a # sum :: Num a => Const m a -> a # product :: Num a => Const m a -> a #
Traversable (Const m :: Type -> Type)	Since: base-4.7.0.0
Instance details Defined in Data.Traversable Methods traverse :: Applicative f => (a -> f b) -> Const m a -> f (Const m b) # sequenceA :: Applicative f => Const m (f a) -> f (Const m a) # mapM :: Monad m0 => (a -> m0 b) -> Const m a -> m0 (Const m b) # sequence :: Monad m0 => Const m (m0 a) -> m0 (Const m a) #
ToJSON a => ToJSON1 (Const a :: Type -> Type)
Instance details Defined in Data.Aeson.Types.ToJSON Methods liftToJSON :: (a0 -> Value) -> ([a0] -> Value) -> Const a a0 -> Value # liftToJSONList :: (a0 -> Value) -> ([a0] -> Value) -> [Const a a0] -> Value # liftToEncoding :: (a0 -> Encoding) -> ([a0] -> Encoding) -> Const a a0 -> Encoding # liftToEncodingList :: (a0 -> Encoding) -> ([a0] -> Encoding) -> [Const a a0] -> Encoding #
FromJSON a => FromJSON1 (Const a :: Type -> Type)
Instance details Defined in Data.Aeson.Types.FromJSON Methods liftParseJSON :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser (Const a a0) # liftParseJSONList :: (Value -> Parser a0) -> (Value -> Parser [a0]) -> Value -> Parser [Const a a0] #
Contravariant (Const a :: Type -> Type)
Instance details Defined in Data.Functor.Contravariant Methods contramap :: (a0 -> b) -> Const a b -> Const a a0 # (>$) :: b -> Const a b -> Const a a0 #
Eq a => Eq1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftEq :: (a0 -> b -> Bool) -> Const a a0 -> Const a b -> Bool #
Ord a => Ord1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftCompare :: (a0 -> b -> Ordering) -> Const a a0 -> Const a b -> Ordering #
Read a => Read1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftReadsPrec :: (Int -> ReadS a0) -> ReadS [a0] -> Int -> ReadS (Const a a0) # liftReadList :: (Int -> ReadS a0) -> ReadS [a0] -> ReadS [Const a a0] # liftReadPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec (Const a a0) # liftReadListPrec :: ReadPrec a0 -> ReadPrec [a0] -> ReadPrec [Const a a0] #
Show a => Show1 (Const a :: Type -> Type)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Classes Methods liftShowsPrec :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> Int -> Const a a0 -> ShowS # liftShowList :: (Int -> a0 -> ShowS) -> ([a0] -> ShowS) -> [Const a a0] -> ShowS #
NFData a => NFData1 (Const a :: Type -> Type)	Since: deepseq-1.4.3.0
Instance details Defined in Control.DeepSeq Methods liftRnf :: (a0 -> ()) -> Const a a0 -> () #
Hashable a => Hashable1 (Const a :: Type -> Type)
Instance details Defined in Data.Hashable.Class Methods liftHashWithSalt :: (Int -> a0 -> Int) -> Int -> Const a a0 -> Int #
Semigroup m => Apply (Const m :: Type -> Type)	A `Const m` is not `Applicative` unless its `m` is a `Monoid`, but it is an instance of `Apply`
Instance details Defined in Data.Functor.Bind.Class Methods (<.>) :: Const m (a -> b) -> Const m a -> Const m b # (.>) :: Const m a -> Const m b -> Const m b # (<.) :: Const m a -> Const m b -> Const m a # liftF2 :: (a -> b -> c) -> Const m a -> Const m b -> Const m c #
Bounded a => Bounded (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods minBound :: Const a b # maxBound :: Const a b #
Enum a => Enum (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods succ :: Const a b -> Const a b # pred :: Const a b -> Const a b # toEnum :: Int -> Const a b # fromEnum :: Const a b -> Int # enumFrom :: Const a b -> [Const a b] # enumFromThen :: Const a b -> Const a b -> [Const a b] # enumFromTo :: Const a b -> Const a b -> [Const a b] # enumFromThenTo :: Const a b -> Const a b -> Const a b -> [Const a b] #
Eq a => Eq (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (==) :: Const a b -> Const a b -> Bool # (/=) :: Const a b -> Const a b -> Bool #
Floating a => Floating (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods pi :: Const a b # exp :: Const a b -> Const a b # log :: Const a b -> Const a b # sqrt :: Const a b -> Const a b # (**) :: Const a b -> Const a b -> Const a b # logBase :: Const a b -> Const a b -> Const a b # sin :: Const a b -> Const a b # cos :: Const a b -> Const a b # tan :: Const a b -> Const a b # asin :: Const a b -> Const a b # acos :: Const a b -> Const a b # atan :: Const a b -> Const a b # sinh :: Const a b -> Const a b # cosh :: Const a b -> Const a b # tanh :: Const a b -> Const a b # asinh :: Const a b -> Const a b # acosh :: Const a b -> Const a b # atanh :: Const a b -> Const a b # log1p :: Const a b -> Const a b # expm1 :: Const a b -> Const a b # log1pexp :: Const a b -> Const a b # log1mexp :: Const a b -> Const a b #
Fractional a => Fractional (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (/) :: Const a b -> Const a b -> Const a b # recip :: Const a b -> Const a b # fromRational :: Rational -> Const a b #
Integral a => Integral (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods quot :: Const a b -> Const a b -> Const a b # rem :: Const a b -> Const a b -> Const a b # div :: Const a b -> Const a b -> Const a b # mod :: Const a b -> Const a b -> Const a b # quotRem :: Const a b -> Const a b -> (Const a b, Const a b) # divMod :: Const a b -> Const a b -> (Const a b, Const a b) # toInteger :: Const a b -> Integer #
Num a => Num (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (+) :: Const a b -> Const a b -> Const a b # (-) :: Const a b -> Const a b -> Const a b # (*) :: Const a b -> Const a b -> Const a b # negate :: Const a b -> Const a b # abs :: Const a b -> Const a b # signum :: Const a b -> Const a b # fromInteger :: Integer -> Const a b #
Ord a => Ord (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods compare :: Const a b -> Const a b -> Ordering # (<) :: Const a b -> Const a b -> Bool # (<=) :: Const a b -> Const a b -> Bool # (>) :: Const a b -> Const a b -> Bool # (>=) :: Const a b -> Const a b -> Bool # max :: Const a b -> Const a b -> Const a b # min :: Const a b -> Const a b -> Const a b #
Read a => Read (Const a b)	This instance would be equivalent to the derived instances of the `Const` newtype if the `getConst` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Const Methods readsPrec :: Int -> ReadS (Const a b) # readList :: ReadS [Const a b] # readPrec :: ReadPrec (Const a b) # readListPrec :: ReadPrec [Const a b] #
Real a => Real (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods toRational :: Const a b -> Rational #
RealFloat a => RealFloat (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods floatRadix :: Const a b -> Integer # floatDigits :: Const a b -> Int # floatRange :: Const a b -> (Int, Int) # decodeFloat :: Const a b -> (Integer, Int) # encodeFloat :: Integer -> Int -> Const a b # exponent :: Const a b -> Int # significand :: Const a b -> Const a b # scaleFloat :: Int -> Const a b -> Const a b # isNaN :: Const a b -> Bool # isInfinite :: Const a b -> Bool # isDenormalized :: Const a b -> Bool # isNegativeZero :: Const a b -> Bool # isIEEE :: Const a b -> Bool # atan2 :: Const a b -> Const a b -> Const a b #
RealFrac a => RealFrac (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods properFraction :: Integral b0 => Const a b -> (b0, Const a b) # truncate :: Integral b0 => Const a b -> b0 # round :: Integral b0 => Const a b -> b0 # ceiling :: Integral b0 => Const a b -> b0 # floor :: Integral b0 => Const a b -> b0 #
Show a => Show (Const a b)	This instance would be equivalent to the derived instances of the `Const` newtype if the `getConst` field were removed Since: base-4.8.0.0
Instance details Defined in Data.Functor.Const Methods showsPrec :: Int -> Const a b -> ShowS # show :: Const a b -> String # showList :: [Const a b] -> ShowS #
Ix a => Ix (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods range :: (Const a b, Const a b) -> [Const a b] # index :: (Const a b, Const a b) -> Const a b -> Int # unsafeIndex :: (Const a b, Const a b) -> Const a b -> Int # inRange :: (Const a b, Const a b) -> Const a b -> Bool # rangeSize :: (Const a b, Const a b) -> Int # unsafeRangeSize :: (Const a b, Const a b) -> Int #
IsString a => IsString (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.String Methods fromString :: String -> Const a b #
Generic (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Associated Types type Rep (Const a b) :: Type -> Type # Methods from :: Const a b -> Rep (Const a b) x # to :: Rep (Const a b) x -> Const a b #
Semigroup a => Semigroup (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (<>) :: Const a b -> Const a b -> Const a b # sconcat :: NonEmpty (Const a b) -> Const a b # stimes :: Integral b0 => b0 -> Const a b -> Const a b #
Monoid a => Monoid (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods mempty :: Const a b # mappend :: Const a b -> Const a b -> Const a b # mconcat :: [Const a b] -> Const a b #
NFData a => NFData (Const a b)	Since: deepseq-1.4.0.0
Instance details Defined in Control.DeepSeq Methods rnf :: Const a b -> () #
Hashable a => Hashable (Const a b)
Instance details Defined in Data.Hashable.Class Methods hashWithSalt :: Int -> Const a b -> Int # hash :: Const a b -> Int #
ToJSON a => ToJSON (Const a b)
Instance details Defined in Data.Aeson.Types.ToJSON Methods toJSON :: Const a b -> Value # toEncoding :: Const a b -> Encoding # toJSONList :: [Const a b] -> Value # toEncodingList :: [Const a b] -> Encoding #
(ToJSON a, ToJSONKey a) => ToJSONKey (Const a b)
Instance details Defined in Data.Aeson.Types.ToJSON Methods toJSONKey :: ToJSONKeyFunction (Const a b) # toJSONKeyList :: ToJSONKeyFunction [Const a b] #
FromJSON a => FromJSON (Const a b)
Instance details Defined in Data.Aeson.Types.FromJSON Methods parseJSON :: Value -> Parser (Const a b) # parseJSONList :: Value -> Parser [Const a b] #
(FromJSON a, FromJSONKey a) => FromJSONKey (Const a b)
Instance details Defined in Data.Aeson.Types.FromJSON Methods fromJSONKey :: FromJSONKeyFunction (Const a b) # fromJSONKeyList :: FromJSONKeyFunction [Const a b] #
Storable a => Storable (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods sizeOf :: Const a b -> Int # alignment :: Const a b -> Int # peekElemOff :: Ptr (Const a b) -> Int -> IO (Const a b) # pokeElemOff :: Ptr (Const a b) -> Int -> Const a b -> IO () # peekByteOff :: Ptr b0 -> Int -> IO (Const a b) # pokeByteOff :: Ptr b0 -> Int -> Const a b -> IO () # peek :: Ptr (Const a b) -> IO (Const a b) # poke :: Ptr (Const a b) -> Const a b -> IO () #
Bits a => Bits (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods (.&.) :: Const a b -> Const a b -> Const a b # (.\|.) :: Const a b -> Const a b -> Const a b # xor :: Const a b -> Const a b -> Const a b # complement :: Const a b -> Const a b # shift :: Const a b -> Int -> Const a b # rotate :: Const a b -> Int -> Const a b # zeroBits :: Const a b # bit :: Int -> Const a b # setBit :: Const a b -> Int -> Const a b # clearBit :: Const a b -> Int -> Const a b # complementBit :: Const a b -> Int -> Const a b # testBit :: Const a b -> Int -> Bool # bitSizeMaybe :: Const a b -> Maybe Int # bitSize :: Const a b -> Int # isSigned :: Const a b -> Bool # shiftL :: Const a b -> Int -> Const a b # unsafeShiftL :: Const a b -> Int -> Const a b # shiftR :: Const a b -> Int -> Const a b # unsafeShiftR :: Const a b -> Int -> Const a b # rotateL :: Const a b -> Int -> Const a b # rotateR :: Const a b -> Int -> Const a b # popCount :: Const a b -> Int #
FiniteBits a => FiniteBits (Const a b)	Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods finiteBitSize :: Const a b -> Int # countLeadingZeros :: Const a b -> Int # countTrailingZeros :: Const a b -> Int #
Prim a => Prim (Const a b)	Since: primitive-0.6.5.0
Instance details Defined in Data.Primitive.Types Methods sizeOf# :: Const a b -> Int# # alignment# :: Const a b -> Int# # indexByteArray# :: ByteArray# -> Int# -> Const a b # readByteArray# :: MutableByteArray# s -> Int# -> State# s -> (# State# s, Const a b #) # writeByteArray# :: MutableByteArray# s -> Int# -> Const a b -> State# s -> State# s # setByteArray# :: MutableByteArray# s -> Int# -> Int# -> Const a b -> State# s -> State# s # indexOffAddr# :: Addr# -> Int# -> Const a b # readOffAddr# :: Addr# -> Int# -> State# s -> (# State# s, Const a b #) # writeOffAddr# :: Addr# -> Int# -> Const a b -> State# s -> State# s # setOffAddr# :: Addr# -> Int# -> Int# -> Const a b -> State# s -> State# s #
Unbox a => Unbox (Const a b)
Instance details Defined in Data.Vector.Unboxed.Base
type Rep1 (Const a :: k -> Type)
Instance details Defined in Data.Functor.Const type Rep1 (Const a :: k -> Type) = D1 ('MetaData "Const" "Data.Functor.Const" "base" 'True) (C1 ('MetaCons "Const" 'PrefixI 'True) (S1 ('MetaSel ('Just "getConst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
newtype MVector s (Const a b)
Instance details Defined in Data.Vector.Unboxed.Base newtype MVector s (Const a b) = MV_Const (MVector s a)
type Rep (Const a b)
Instance details Defined in Data.Functor.Const type Rep (Const a b) = D1 ('MetaData "Const" "Data.Functor.Const" "base" 'True) (C1 ('MetaCons "Const" 'PrefixI 'True) (S1 ('MetaSel ('Just "getConst") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 a)))
newtype Vector (Const a b)
Instance details Defined in Data.Vector.Unboxed.Base newtype Vector (Const a b) = V_Const (Vector a)

liftA3 :: Applicative f => (a -> b -> c -> d) -> f a -> f b -> f c -> f d #

Lift a ternary function to actions.

Using ApplicativeDo: 'liftA3 f as bs cs' can be understood as the do expression

do a <- as
   b <- bs
   c <- cs
   pure (f a b c)

liftA :: Applicative f => (a -> b) -> f a -> f b #

Lift a function to actions. This function may be used as a value for fmap in a Functor instance.

| Using ApplicativeDo: 'liftA f as' can be understood as the do expression

do a <- as
   pure (f a)

with an inferred Functor constraint, weaker than Applicative.

(<**>) :: Applicative f => f a -> f (a -> b) -> f b infixl 4 #

A variant of <*> with the arguments reversed.

Using ApplicativeDo: 'as <**> fs' can be understood as the do expression

do a <- as
   f <- fs
   pure (f a)

renderFailure :: ParserFailure ParserHelp -> String -> (String, ExitCode) #

parserFailure :: ParserPrefs -> ParserInfo a -> ParseError -> [Context] -> ParserFailure ParserHelp #

Generate a ParserFailure from a ParseError in a given Context.

This function can be used, for example, to show the help text for a parser:

handleParseResult . Failure $ parserFailure pprefs pinfo ShowHelpText mempty

execParserPure #

Arguments

:: ParserPrefs	Global preferences for this parser
-> ParserInfo a	Description of the program to run
-> [String]	Program arguments
-> ParserResult a

The most general way to run a program description in pure code.

getParseResult :: ParserResult a -> Maybe a #

Extract the actual result from a ParserResult value.

This function returns Nothing in case of errors. Possible error messages or completion actions are simply discarded.

If you want to display error messages and invoke completion actions appropriately, use handleParseResult instead.

handleParseResult :: ParserResult a -> IO a #

Handle ParserResult.

customExecParser :: ParserPrefs -> ParserInfo a -> IO a #

Run a program description with custom preferences.

execParser :: ParserInfo a -> IO a #

Run a program description.

Parse command line arguments. Display help text and exit if any parse error occurs.

hsubparser :: Mod CommandFields a -> Parser a #

Builder for a command parser with a "helper" option attached. Used in the same way as subparser, but includes a "--help|-h" inside the subcommand.

helper :: Parser (a -> a) #

A hidden "helper" option which always fails.

A common usage pattern is to apply this applicatively when creating a ParserInfo

opts :: ParserInfo Sample
opts = info (sample <**> helper) mempty

defaultPrefs :: ParserPrefs #

Default preferences.

idm :: Monoid m => m #

Trivial option modifier.

prefs :: PrefsMod -> ParserPrefs #

Create a ParserPrefs given a modifier

helpShowGlobals :: PrefsMod #

Show global help information in subparser usage

helpLongEquals :: PrefsMod #

Show equals sign, rather than space, in usage and help text for options with long names.

columns :: Int -> PrefsMod #

Set the maximum width of the generated help text.

subparserInline :: PrefsMod #

Allow full mixing of subcommand and parent arguments by inlining selected subparsers into the parent parser.

NOTE: When this option is used, preferences for the subparser which effect the parser behaviour (such as noIntersperse) are ignored.

noBacktrack :: PrefsMod #

Turn off backtracking after subcommand is parsed.

showHelpOnEmpty :: PrefsMod #

Show the help text if the user enters only the program name or subcommand.

This will suppress a "Missing:" error and show the full usage instead if a user just types the name of the program.

showHelpOnError :: PrefsMod #

Show full help text on any error.

disambiguate :: PrefsMod #

Turn on disambiguation.

See https://github.com/pcapriotti/optparse-applicative#disambiguation

multiSuffix :: String -> PrefsMod #

Include a suffix to attach to the metavar when multiple values can be entered.

info :: Parser a -> InfoMod a -> ParserInfo a #

Create a ParserInfo given a Parser and a modifier.

forwardOptions :: InfoMod a #

Intersperse matched options and arguments normally, but allow unmatched options to be treated as positional arguments. This is sometimes useful if one is wrapping a third party cli tool and needs to pass options through, while also providing a handful of their own options. Not recommended in general as typos by the user may not yield a parse error and cause confusion.

noIntersperse :: InfoMod a #

Disable parsing of regular options after arguments. After a positional argument is parsed, all remaining options and arguments will be treated as a positional arguments. Not recommended in general as users often expect to be able to freely intersperse regular options and flags within command line options.

failureCode :: Int -> InfoMod a #

Specify an exit code if a parse error occurs.

progDescDoc :: Maybe Doc -> InfoMod a #

Specify a short program description as a Doc value.

progDesc :: String -> InfoMod a #

Specify a short program description.

footerDoc :: Maybe Doc -> InfoMod a #

Specify a footer for this parser as a Doc value.

footer :: String -> InfoMod a #

Specify a footer for this parser.

headerDoc :: Maybe Doc -> InfoMod a #

Specify a header for this parser as a Doc value.

header :: String -> InfoMod a #

Specify a header for this parser.

briefDesc :: InfoMod a #

Only show a brief description in the help text of this parser.

fullDesc :: InfoMod a #

Show a full description in the help text of this parser.

option :: ReadM a -> Mod OptionFields a -> Parser a #

Builder for an option using the given reader.

This is a regular option, and should always have either a long or short name specified in the modifiers (or both).

nameParser = option str ( long "name" <> short 'n' )

strOption :: IsString s => Mod OptionFields s -> Parser s #

Builder for an option taking a String argument.

infoOption :: String -> Mod OptionFields (a -> a) -> Parser (a -> a) #

An option that always fails and displays a message.

abortOption :: ParseError -> Mod OptionFields (a -> a) -> Parser (a -> a) #

An option that always fails.

When this option is encountered, the option parser immediately aborts with the given parse error. If you simply want to output a message, use infoOption instead.

switch :: Mod FlagFields Bool -> Parser Bool #

Builder for a boolean flag.

Note: Because this parser will never fail, it can not be used with combinators such as some or many, as these combinators continue until a failure occurs. See flag'.

switch = flag False True

flag' #

Arguments

:: a	active value
-> Mod FlagFields a	option modifier
-> Parser a

Builder for a flag parser without a default value.

Same as flag, but with no default value. In particular, this flag will never parse successfully by itself.

It still makes sense to use it as part of a composite parser. For example

length <$> many (flag' () (short 't'))

is a parser that counts the number of "-t" arguments on the command line, alternatively

flag' True (long "on") <|> flag' False (long "off")

will require the user to enter '--on' or '--off' on the command line.

flag #

Arguments

:: a	default value
-> a	active value
-> Mod FlagFields a	option modifier
-> Parser a

Builder for a flag parser.

A flag that switches from a "default value" to an "active value" when encountered. For a simple boolean value, use switch instead.

Note: Because this parser will never fail, it can not be used with combinators such as some or many, as these combinators continue until a failure occurs. See flag'.

strArgument :: IsString s => Mod ArgumentFields s -> Parser s #

Builder for a String argument.

argument :: ReadM a -> Mod ArgumentFields a -> Parser a #

Builder for an argument parser.

subparser :: Mod CommandFields a -> Parser a #

Builder for a command parser. The command modifier can be used to specify individual commands.

completer :: forall (f :: Type -> Type) a. HasCompleter f => Completer -> Mod f a #

Add a completer to an argument.

A completer is a function String -> IO String which, given a partial argument, returns all possible completions for that argument.

action :: forall (f :: Type -> Type) a. HasCompleter f => String -> Mod f a #

Add a bash completion action. Common actions include file and directory. See http://www.gnu.org/software/bash/manual/html_node/Programmable-Completion-Builtins.html#Programmable-Completion-Builtins for a complete list.

completeWith :: forall (f :: Type -> Type) a. HasCompleter f => [String] -> Mod f a #

Add a list of possible completion values.

commandGroup :: String -> Mod CommandFields a #

Add a description to a group of commands.

Advanced feature for separating logical groups of commands on the parse line.

If using the same metavar for each group of commands, it may yield a more attractive usage text combined with hidden for some groups.

command :: String -> ParserInfo a -> Mod CommandFields a #

Add a command to a subparser option.

Suggested usage for multiple commands is to add them to a single subparser. e.g.

sample :: Parser Sample
sample = subparser
       ( command "hello"
         (info hello (progDesc "Print greeting"))
      <> command "goodbye"
         (info goodbye (progDesc "Say goodbye"))
       )

style :: forall (f :: Type -> Type) a. (Doc -> Doc) -> Mod f a #

Apply a function to the option description in the usage text.

import Options.Applicative.Help
flag' () (short 't' <> style bold)

NOTE: This builder is more flexible than its name and example allude. One of the motivating examples for its addition was to used const to completely replace the usage text of an option.

hidden :: forall (f :: Type -> Type) a. Mod f a #

Hide this option from the brief description.

Use internal to hide the option from the help text too.

metavar :: forall (f :: Type -> Type) a. HasMetavar f => String -> Mod f a #

Specify a metavariable for the argument.

Metavariables have no effect on the actual parser, and only serve to specify the symbolic name for an argument to be displayed in the help text.

noArgError :: ParseError -> Mod OptionFields a #

Specify the error to display when no argument is provided to this option.

helpDoc :: forall (f :: Type -> Type) a. Maybe Doc -> Mod f a #

Specify the help text for an option as a Doc value.

help :: forall (f :: Type -> Type) a. String -> Mod f a #

Specify the help text for an option.

showDefault :: forall a (f :: Type -> Type). Show a => Mod f a #

Show the default value for this option using its Show instance.

showDefaultWith :: forall a (f :: Type -> Type). (a -> String) -> Mod f a #

Specify a function to show the default value for an option.

value :: forall (f :: Type -> Type) a. HasValue f => a -> Mod f a #

Specify a default value for an option.

Note: Because this modifier means the parser will never fail, do not use it with combinators such as some or many, as these combinators continue until a failure occurs. Careless use will thus result in a hang.

To display the default value, combine with showDefault or showDefaultWith.

long :: forall (f :: Type -> Type) a. HasName f => String -> Mod f a #

Specify a long name for an option.

short :: forall (f :: Type -> Type) a. HasName f => Char -> Mod f a #

Specify a short name for an option.

disabled :: ReadM a #

Null Option reader. All arguments will fail validation.

maybeReader :: (String -> Maybe a) -> ReadM a #

Convert a function producing a Maybe into a reader.

eitherReader :: (String -> Either String a) -> ReadM a #

Convert a function producing an Either into a reader.

As an example, one can create a ReadM from an attoparsec Parser easily with

import qualified Data.Attoparsec.Text as A
import qualified Data.Text as T
attoparsecReader :: A.Parser a -> ReadM a
attoparsecReader p = eitherReader (A.parseOnly p . T.pack)

str :: IsString s => ReadM s #

String Option reader.

Polymorphic over the IsString type class since 0.14.

auto :: Read a => ReadM a #

Option reader based on the Read type class.

data InfoMod a #

Modifier for ParserInfo.

Instances

Instances details

Semigroup (InfoMod a)
Instance details Defined in Options.Applicative.Builder Methods (<>) :: InfoMod a -> InfoMod a -> InfoMod a # sconcat :: NonEmpty (InfoMod a) -> InfoMod a # stimes :: Integral b => b -> InfoMod a -> InfoMod a #
Monoid (InfoMod a)
Instance details Defined in Options.Applicative.Builder Methods mempty :: InfoMod a # mappend :: InfoMod a -> InfoMod a -> InfoMod a # mconcat :: [InfoMod a] -> InfoMod a #

data PrefsMod #

Instances

Instances details

Semigroup PrefsMod
Instance details Defined in Options.Applicative.Builder Methods (<>) :: PrefsMod -> PrefsMod -> PrefsMod # sconcat :: NonEmpty PrefsMod -> PrefsMod # stimes :: Integral b => b -> PrefsMod -> PrefsMod #
Monoid PrefsMod
Instance details Defined in Options.Applicative.Builder Methods mempty :: PrefsMod # mappend :: PrefsMod -> PrefsMod -> PrefsMod # mconcat :: [PrefsMod] -> PrefsMod #

bashCompleter :: String -> Completer #

Run a compgen completion action.

Common actions include file and directory. See http://www.gnu.org/software/bash/manual/html_node/Programmable-Completion-Builtins.html#Programmable-Completion-Builtins for a complete list.

listCompleter :: [String] -> Completer #

Create a Completer from a constant list of strings.

listIOCompleter :: IO [String] -> Completer #

Create a Completer from an IO action

internal :: forall (f :: Type -> Type) a. Mod f a #

Hide this option completely from the help text

Use hidden if the option should remain visible in the full description.

data OptionFields a #

Instances

Instances details

HasName OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods name :: OptName -> OptionFields a -> OptionFields a #
HasCompleter OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods modCompleter :: (Completer -> Completer) -> OptionFields a -> OptionFields a #
HasValue OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasValueDummy :: OptionFields a -> () #
HasMetavar OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasMetavarDummy :: OptionFields a -> () #

data FlagFields a #

Instances

Instances details

HasName FlagFields
Instance details Defined in Options.Applicative.Builder.Internal Methods name :: OptName -> FlagFields a -> FlagFields a #

data CommandFields a #

Instances

Instances details

HasMetavar CommandFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasMetavarDummy :: CommandFields a -> () #

data ArgumentFields a #

Instances

Instances details

HasCompleter ArgumentFields
Instance details Defined in Options.Applicative.Builder.Internal Methods modCompleter :: (Completer -> Completer) -> ArgumentFields a -> ArgumentFields a #
HasValue ArgumentFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasValueDummy :: ArgumentFields a -> () #
HasMetavar ArgumentFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasMetavarDummy :: ArgumentFields a -> () #

class HasName (f :: Type -> Type) #

Minimal complete definition

name

Instances

Instances details

HasName OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods name :: OptName -> OptionFields a -> OptionFields a #
HasName FlagFields
Instance details Defined in Options.Applicative.Builder.Internal Methods name :: OptName -> FlagFields a -> FlagFields a #

class HasCompleter (f :: Type -> Type) #

Minimal complete definition

modCompleter

Instances

Instances details

HasCompleter OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods modCompleter :: (Completer -> Completer) -> OptionFields a -> OptionFields a #
HasCompleter ArgumentFields
Instance details Defined in Options.Applicative.Builder.Internal Methods modCompleter :: (Completer -> Completer) -> ArgumentFields a -> ArgumentFields a #

class HasValue (f :: Type -> Type) #

Minimal complete definition

hasValueDummy

Instances

Instances details

HasValue OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasValueDummy :: OptionFields a -> () #
HasValue ArgumentFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasValueDummy :: ArgumentFields a -> () #

class HasMetavar (f :: Type -> Type) #

Minimal complete definition

hasMetavarDummy

Instances

Instances details

HasMetavar OptionFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasMetavarDummy :: OptionFields a -> () #
HasMetavar CommandFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasMetavarDummy :: CommandFields a -> () #
HasMetavar ArgumentFields
Instance details Defined in Options.Applicative.Builder.Internal Methods hasMetavarDummy :: ArgumentFields a -> () #

data Mod (f :: Type -> Type) a #

An option modifier.

Option modifiers are values that represent a modification of the properties of an option.

The type parameter a is the return type of the option, while f is a record containing its properties (e.g. OptionFields for regular options, FlagFields for flags, etc...).

An option modifier consists of 3 elements:

A field modifier, of the form f a -> f a. These are essentially (compositions of) setters for some of the properties supported by f.
An optional default value and function to display it.
A property modifier, of the form OptProperties -> OptProperties. This is just like the field modifier, but for properties applicable to any option.

Modifiers are instances of Monoid, and can be composed as such.

One rarely needs to deal with modifiers directly, as most of the times it is sufficient to pass them to builders (such as strOption or flag) to create options (see Builder).

Instances

Instances details

Semigroup (Mod f a)	Since: optparse-applicative-0.13.0.0
Instance details Defined in Options.Applicative.Builder.Internal Methods (<>) :: Mod f a -> Mod f a -> Mod f a # sconcat :: NonEmpty (Mod f a) -> Mod f a # stimes :: Integral b => b -> Mod f a -> Mod f a #
Monoid (Mod f a)
Instance details Defined in Options.Applicative.Builder.Internal Methods mempty :: Mod f a # mappend :: Mod f a -> Mod f a -> Mod f a # mconcat :: [Mod f a] -> Mod f a #

overFailure :: (ParserHelp -> ParserHelp) -> ParserResult a -> ParserResult a #

mkCompleter :: (String -> IO [String]) -> Completer #

Smart constructor for a Completer

readerError :: String -> ReadM a #

Abort option reader by exiting with an error message.

readerAbort :: ParseError -> ReadM a #

Abort option reader by exiting with a ParseError.

data ParseError #

Constructors

ErrorMsg String
InfoMsg String
ShowHelpText (Maybe String)
UnknownError
MissingError IsCmdStart SomeParser
ExpectsArgError String
UnexpectedError String SomeParser

Instances

Instances details

Semigroup ParseError
Instance details Defined in Options.Applicative.Types Methods (<>) :: ParseError -> ParseError -> ParseError # sconcat :: NonEmpty ParseError -> ParseError # stimes :: Integral b => b -> ParseError -> ParseError #
Monoid ParseError
Instance details Defined in Options.Applicative.Types Methods mempty :: ParseError # mappend :: ParseError -> ParseError -> ParseError # mconcat :: [ParseError] -> ParseError #

data ParserInfo a #

A full description for a runnable Parser for a program.

Constructors

ParserInfo

Fields

infoParser :: Parser a
the option parser for the program
infoFullDesc :: Bool
whether the help text should contain full documentation
infoProgDesc :: Chunk Doc
brief parser description
infoHeader :: Chunk Doc
header of the full parser description
infoFooter :: Chunk Doc
footer of the full parser description
infoFailureCode :: Int
exit code for a parser failure
infoPolicy :: ArgPolicy
allow regular options and flags to occur after arguments (default: InterspersePolicy)

Instances

Instances details

Functor ParserInfo
Instance details Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserInfo a -> ParserInfo b # (<$) :: a -> ParserInfo b -> ParserInfo a #

data ParserPrefs #

Global preferences for a top-level Parser.

Constructors

ParserPrefs

Fields

prefMultiSuffix :: String
metavar suffix for multiple options
prefDisambiguate :: Bool
automatically disambiguate abbreviations (default: False)
prefShowHelpOnError :: Bool
always show help text on parse errors (default: False)
prefShowHelpOnEmpty :: Bool
show the help text for a command or subcommand if it fails with no input (default: False)
prefBacktrack :: Backtracking
backtrack to parent parser when a subcommand fails (default: Backtrack)
prefColumns :: Int
number of columns in the terminal, used to format the help page (default: 80)
prefHelpLongEquals :: Bool
when displaying long names in usage and help, use an '=' sign for long names, rather than a single space (default: False)
prefHelpShowGlobal :: Bool
when displaying subparsers' usage help, show parent options under a "global options" section (default: True)

Instances

Instances details

Eq ParserPrefs
Instance details Defined in Options.Applicative.Types Methods (==) :: ParserPrefs -> ParserPrefs -> Bool # (/=) :: ParserPrefs -> ParserPrefs -> Bool #
Show ParserPrefs
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> ParserPrefs -> ShowS # show :: ParserPrefs -> String # showList :: [ParserPrefs] -> ShowS #

data ReadM a #

A newtype over 'ReaderT String Except', used by option readers.

Instances

Instances details

Monad ReadM
Instance details Defined in Options.Applicative.Types Methods (>>=) :: ReadM a -> (a -> ReadM b) -> ReadM b # (>>) :: ReadM a -> ReadM b -> ReadM b # return :: a -> ReadM a #
Functor ReadM
Instance details Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ReadM a -> ReadM b # (<$) :: a -> ReadM b -> ReadM a #
MonadFail ReadM
Instance details Defined in Options.Applicative.Types Methods fail :: String -> ReadM a #
Applicative ReadM
Instance details Defined in Options.Applicative.Types Methods pure :: a -> ReadM a # (<>) :: ReadM (a -> b) -> ReadM a -> ReadM b # liftA2 :: (a -> b -> c) -> ReadM a -> ReadM b -> ReadM c # (>) :: ReadM a -> ReadM b -> ReadM b # (<*) :: ReadM a -> ReadM b -> ReadM a #
MonadPlus ReadM
Instance details Defined in Options.Applicative.Types Methods mzero :: ReadM a # mplus :: ReadM a -> ReadM a -> ReadM a #
Alternative ReadM
Instance details Defined in Options.Applicative.Types Methods empty :: ReadM a # (<\|>) :: ReadM a -> ReadM a -> ReadM a # some :: ReadM a -> ReadM [a] # many :: ReadM a -> ReadM [a] #

data Completer #

A shell complete function.

Instances

Instances details

Semigroup Completer
Instance details Defined in Options.Applicative.Types Methods (<>) :: Completer -> Completer -> Completer # sconcat :: NonEmpty Completer -> Completer # stimes :: Integral b => b -> Completer -> Completer #
Monoid Completer
Instance details Defined in Options.Applicative.Types Methods mempty :: Completer # mappend :: Completer -> Completer -> Completer # mconcat :: [Completer] -> Completer #

newtype CompletionResult #

Constructors

CompletionResult
Fields execCompletion :: String -> IO String

Instances

Instances details

Show CompletionResult
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> CompletionResult -> ShowS # show :: CompletionResult -> String # showList :: [CompletionResult] -> ShowS #

newtype ParserFailure h #

Constructors

ParserFailure
Fields execFailure :: String -> (h, ExitCode, Int)

Instances

Instances details

Functor ParserFailure
Instance details Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserFailure a -> ParserFailure b # (<$) :: a -> ParserFailure b -> ParserFailure a #
Show h => Show (ParserFailure h)
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> ParserFailure h -> ShowS # show :: ParserFailure h -> String # showList :: [ParserFailure h] -> ShowS #

data ParserResult a #

Result of execParserPure.

Constructors

Failure (ParserFailure ParserHelp)
CompletionInvoked CompletionResult

Instances

Instances details

Monad ParserResult
Instance details Defined in Options.Applicative.Types Methods (>>=) :: ParserResult a -> (a -> ParserResult b) -> ParserResult b # (>>) :: ParserResult a -> ParserResult b -> ParserResult b # return :: a -> ParserResult a #
Functor ParserResult
Instance details Defined in Options.Applicative.Types Methods fmap :: (a -> b) -> ParserResult a -> ParserResult b # (<$) :: a -> ParserResult b -> ParserResult a #
Applicative ParserResult
Instance details Defined in Options.Applicative.Types Methods pure :: a -> ParserResult a # (<>) :: ParserResult (a -> b) -> ParserResult a -> ParserResult b # liftA2 :: (a -> b -> c) -> ParserResult a -> ParserResult b -> ParserResult c # (>) :: ParserResult a -> ParserResult b -> ParserResult b # (<*) :: ParserResult a -> ParserResult b -> ParserResult a #
Show a => Show (ParserResult a)
Instance details Defined in Options.Applicative.Types Methods showsPrec :: Int -> ParserResult a -> ShowS # show :: ParserResult a -> String # showList :: [ParserResult a] -> ShowS #

data ParserHelp #

Constructors

ParserHelp
Fields helpError :: Chunk Doc helpSuggestions :: Chunk Doc helpHeader :: Chunk Doc helpUsage :: Chunk Doc helpBody :: Chunk Doc helpGlobals :: Chunk Doc helpFooter :: Chunk Doc

Instances

Instances details

Show ParserHelp
Instance details Defined in Options.Applicative.Help.Types Methods showsPrec :: Int -> ParserHelp -> ShowS # show :: ParserHelp -> String # showList :: [ParserHelp] -> ShowS #
Semigroup ParserHelp
Instance details Defined in Options.Applicative.Help.Types Methods (<>) :: ParserHelp -> ParserHelp -> ParserHelp # sconcat :: NonEmpty ParserHelp -> ParserHelp # stimes :: Integral b => b -> ParserHelp -> ParserHelp #
Monoid ParserHelp
Instance details Defined in Options.Applicative.Help.Types Methods mempty :: ParserHelp # mappend :: ParserHelp -> ParserHelp -> ParserHelp # mconcat :: [ParserHelp] -> ParserHelp #