Moduleservant-0.20.2Haskell2010

Servant.Types.SourceT

2 types
14 values

Packageservant-0.20.2
Exports16
LanguageHaskell2010
LicenceBSD-3-Clause
SourceSourceT.hs

Example5 expressions

>>> :set -XNoOverloadedStrings>>> import Data.String (fromString)>>> import Control.Monad.Except (runExcept)>>> import Data.Foldable (toList)>>> import qualified Data.Attoparsec.ByteString.Char8 as A8

newtypenewtype SourceT (m :: Type -> Type) a

This is CPSised ListT.

Constructors

SourceT
- unSourceT :: forall b. (StepT m a -> m b) -> m b

Instances10MFunctor, FromSourceIO, ToSourceIO, Functor, Foldable, Show1, …

MFunctor SourceTDefined in servant-0.20.2 · Servant.Types.SourceT

Example1 expression

>>> hoist (Just . runIdentity) (source [1..3]) :: SourceT Maybe IntfromStepT (Effect (Just (Yield 1 (Yield 2 (Yield 3 Stop)))))

MonadIO m => FromSourceIO a (SourceT m a)Defined in servant-0.20.2 · Servant.API.Stream
SourceToSourceIO m => ToSourceIO chunk (SourceT m chunk)Defined in servant-0.20.2 · Servant.API.Stream
Relax to use auxiliary class, have m
Functor m => Functor (SourceT m)Defined in servant-0.20.2 · Servant.Types.SourceT
Identity ~ m => Foldable (SourceT m)Defined in servant-0.20.2 · Servant.Types.SourceT
Example1 expression
```
>>> toList (source [1::Int .. 10])[1,2,3,4,5,6,7,8,9,10]
```
(Applicative m, Show1 m) => Show1 (SourceT m)Defined in servant-0.20.2 · Servant.Types.SourceT
(Applicative m, Show1 m, Show a) => Show (SourceT m a)Defined in servant-0.20.2 · Servant.Types.SourceT

Functor m => Semigroup (SourceT m a)Defined in servant-0.20.2 · Servant.Types.SourceT

Example1 expression

>>> source "xy" <> source "z" :: SourceT Identity CharfromStepT (Effect (Identity (Yield 'x' (Yield 'y' (Yield 'z' Stop)))))

Functor m => Monoid (SourceT m a)Defined in servant-0.20.2 · Servant.Types.SourceT
Example1 expression
```
>>> mempty :: SourceT Maybe IntfromStepT (Effect (Just Stop))
```
(Arbitrary a, Monad m) => Arbitrary (SourceT m a)Defined in servant-0.20.2 · Servant.Types.SourceT
Doesn't generate Error constructors. SourceT doesn't shrink.

valuemapStepT :: (StepT m a -> StepT m b) -> SourceT m a -> SourceT m b

datadata StepT (m :: Type -> Type) a

ListT with additional constructors.

Constructors

Stop
Error String
Skip (StepT m a)
Yield a (StepT m a)
Effect (m (StepT m a))

Instances8MFunctor, Functor, Foldable, Show1, Show, Semigroup, …

MFunctor StepTDefined in servant-0.20.2 · Servant.Types.SourceT
Functor m => Functor (StepT m)Defined in servant-0.20.2 · Servant.Types.SourceT
Identity ~ m => Foldable (StepT m)Defined in servant-0.20.2 · Servant.Types.SourceT
(Applicative m, Show1 m) => Show1 (StepT m)Defined in servant-0.20.2 · Servant.Types.SourceT
(Applicative m, Show1 m, Show a) => Show (StepT m a)Defined in servant-0.20.2 · Servant.Types.SourceT
Functor m => Semigroup (StepT m a)Defined in servant-0.20.2 · Servant.Types.SourceT
Functor m => Monoid (StepT m a)Defined in servant-0.20.2 · Servant.Types.SourceT
Example1 expression
```
>>> mempty :: StepT [] IntStop
```
Example1 expression
```
>>> mempty :: StepT Identity IntStop
```
(Arbitrary a, Monad m) => Arbitrary (StepT m a)Defined in servant-0.20.2 · Servant.Types.SourceT
Doesn't generate Error constructors.

valuefromStepT :: StepT m a -> SourceT m a

Create SourceT from Step.

Note: often enough you want to use SourceT directly.

valuesource :: Foldable f => f a -> SourceT m a

Create pure SourceT.

Example1 expression

>>> source "foo" :: SourceT Identity CharfromStepT (Effect (Identity (Yield 'f' (Yield 'o' (Yield 'o' Stop)))))

valuerunSourceT :: Monad m => SourceT m a -> ExceptT String m [a]

Get the answers.

Example1 expression

>>> runSourceT (source "foo" :: SourceT Identity Char)ExceptT (Identity (Right "foo"))

Example1 expression

>>> runSourceT (source "foo" :: SourceT [] Char)ExceptT [Right "foo"]

valuerunStepT :: Monad m => StepT m a -> ExceptT String m [a]

valuemapMaybe :: Functor m => (a -> Maybe b) -> SourceT m a -> SourceT m b

Filter values.

Example1 expression

>>> toList $ mapMaybe (\x -> if odd x then Just x else Nothing) (source [0..10]) :: [Int][1,3,5,7,9]

Example1 expression

>>> mapMaybe (\x -> if odd x then Just x else Nothing) (source [0..2]) :: SourceT Identity IntfromStepT (Effect (Identity (Skip (Yield 1 (Skip Stop)))))

Illustrates why we need Skip.

valuemapMaybeStep :: Functor m => (a -> Maybe b) -> StepT m a -> StepT m b

valueforeach

:: Monad m
=> (String -> m ())
error handler
-> (a -> m ())
-> SourceT m a
-> m ()

Run action for each value in the SourceT.

Example1 expression

>>> foreach fail print $ source ("abc" :: String)'a''b''c'

valueforeachStep

:: Monad m
=> (String -> m ())
error handler
-> (a -> m ())
-> StepT m a
-> m ()

See foreach.

valuefromAction :: Functor m => (a -> Bool) -> m a -> SourceT m a

valuefromActionStep :: Functor m => (a -> Bool) -> m a -> StepT m a

valuereadFile :: FilePath -> SourceT IO ByteString

Read file.

Example1 expression

>>> foreach fail BS.putStr (readFile "servant.cabal")cabal-version:      3.0name:               servant...

valuetransformWithAtto

:: Monad m
=> Parser a
-> SourceT m ByteString
-> SourceT m a

Transform using attoparsec parser.

Note: parser should not accept empty input!

Example1 expression

>>> let parser = A.skipWhile A8.isSpace_w8 >> A.takeWhile1 A8.isDigit_w8

Example1 expression

>>> runExcept $ runSourceT $ transformWithAtto parser (source $ [fromString "1 2 3"])Right ["1","2","3"]

Example1 expression

>>> runExcept $ runSourceT $ transformWithAtto parser (source $ map fromString ["1", "2", "3"])Right ["123"]

Example1 expression

>>> runExcept $ runSourceT $ transformWithAtto parser (source $ map fromString ["1", "2 3", "4"])Right ["12","34"]

Example1 expression

>>> runExcept $ runSourceT $ transformWithAtto parser (source [fromString "foobar"])Left "Failed reading: takeWhile1"

valuetransformStepWithAtto

:: Monad m
=> Parser a
-> StepT m ByteString
-> StepT m a