Data.Registry.Lift

This code is taken from https://stackoverflow.com/questions/28003135/is-it-possible-to-encode-a-generic-lift-function-in-haskell

to allow a generic lift operation over an Applicative context So if you have a function: Int -> Text -> IO Int, it can be lifted to have all of its parameters in IO:

 f :: Int -> Text -> IO Int

 lifted :: IO Int -> IO Text -> IO Int
 lifted = to @IO f

Documentation

class Applicative f => ApplyVariadic f a b where

Typeclass for lifting pure functions to effectful arguments and results

Methods

applyVariadic :: f a -> b

Instances

(Applicative f, b ~ f a) => ApplyVariadic f a b

Defined in Data.Registry.Lift

Methods

applyVariadic :: f a -> b

(Monad f, b ~ f a) => ApplyVariadic f (f a) b

Defined in Data.Registry.Lift

Methods

applyVariadic :: f (f a) -> b

(Applicative f, ApplyVariadic f a' b', b ~ (f a -> b')) => ApplyVariadic f (a -> a') b

Defined in Data.Registry.Lift

Methods

applyVariadic :: f (a -> a') -> b

allTo :: forall f a b. ApplyVariadic f a b => a -> b

Lift a pure function to effectful arguments and results

class Monad f => ApplyVariadic1 f a b where

Typeclass for lifting impure functions to effectful arguments and results

Methods

applyVariadic1 :: f a -> b

Instances

(Monad f, b ~ f a) => ApplyVariadic1 f (f a) b

Defined in Data.Registry.Lift

Methods

applyVariadic1 :: f (f a) -> b

(Monad f, ApplyVariadic1 f a' b', b ~ (f a -> b')) => ApplyVariadic1 f (a -> a') b

Defined in Data.Registry.Lift

Methods

applyVariadic1 :: f (a -> a') -> b

argsTo :: forall f a b. ApplyVariadic1 f a b => a -> b

Lift an effectful function to effectful arguments and results

class ApplyVariadic2 f g a b where

Typeclass for lifting a function with a result of type m b into a function with a result of type n b

Methods

applyVariadic2 :: (forall x. f x -> g x) -> a -> b

Instances

b ~ g a => ApplyVariadic2 f g (f a) b

Defined in Data.Registry.Lift

Methods

applyVariadic2 :: (forall x. f x -> g x) -> f a -> b

(ApplyVariadic2 f g a' b', b ~ (a -> b')) => ApplyVariadic2 f g (a -> a') b

Defined in Data.Registry.Lift

Methods

applyVariadic2 :: (forall x. f x -> g x) -> (a -> a') -> b

outTo :: forall g f a b. ApplyVariadic2 f g a b => (forall x. f x -> g x) -> a -> b

Lift a function returning an effectful result to a function returning another effectful result

Tagging

newtype Tag (s :: Symbol) a

The output of some constructors can be "tagged" with a string to indicate how a given value was built.

Constructors

Tag

Fields

• unTag :: a

Instances

Functor (Tag s)

Defined in Data.Registry.Lift

Methods

fmap :: (a -> b) -> Tag s a -> Tag s b

(<$) :: a -> Tag s b -> Tag s a

Applicative (Tag s)

Defined in Data.Registry.Lift

Methods

pure :: a -> Tag s a

(<*>) :: Tag s (a -> b) -> Tag s a -> Tag s b

liftA2 :: (a -> b -> c) -> Tag s a -> Tag s b -> Tag s c

(*>) :: Tag s a -> Tag s b -> Tag s b

(<*) :: Tag s a -> Tag s b -> Tag s a

Eq a => Eq (Tag s a)

Defined in Data.Registry.Lift

Methods

(==) :: Tag s a -> Tag s a -> Bool

(/=) :: Tag s a -> Tag s a -> Bool

Show a => Show (Tag s a)

Defined in Data.Registry.Lift

Methods

showsPrec :: Int -> Tag s a -> ShowS

show :: Tag s a -> String

showList :: [Tag s a] -> ShowS

tag :: forall (s :: Symbol) fun. CNumArgs (CountArgs fun) fun => fun -> Apply (Tag s) (CountArgs fun) fun

Tag a given constructor f with a string s. The applyLast function only applies the tag to the output type of the constructor. For example data Salary = Fixed Int | Variable Int Double tag @Variable Variable :: Int -> Double -> Tag Variable Salary

data Nat

ApplyLast typeclass provided by @neongreen It uses an auxiliary typeclass to count the arguments of a function

Constructors

Z

S Nat

data NumArgs :: Nat -> Type -> Type where

Constructors

NAZ :: NumArgs Z a

NAS :: NumArgs n b -> NumArgs (S n) (a -> b)

type family CountArgs (f :: Type) :: Nat where ...

Equations

CountArgs (a -> b) = S (CountArgs b)

CountArgs result = Z

class CNumArgs (numArgs :: Nat) (arrows :: Type) where

Methods

getNA :: NumArgs numArgs arrows

Instances

CNumArgs 'Z a

Defined in Data.Registry.Lift

Methods

getNA :: NumArgs 'Z a

CNumArgs n b => CNumArgs ('S n) (a -> b)

Defined in Data.Registry.Lift

Methods

getNA :: NumArgs ('S n) (a -> b)

type family Apply (f :: Type -> Type) (n :: Nat) (arrows :: Type) :: Type where ...

Equations

Apply f (S n) (a -> b) = a -> Apply f n b

Apply f Z a = f a

applyLast :: forall f fun. (Applicative f, CNumArgs (CountArgs fun) fun) => fun -> Apply f (CountArgs fun) fun

applyLast' :: forall f n fun. Applicative f => NumArgs n fun -> fun -> Apply f n fun