DsMonad

Documentation

type DsM = TcRnIf DsGblEnv DsLclEnv

mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)

Map each element of a structure to a monadic action, evaluate these actions from left to right, and collect the results. For a version that ignores the results see mapM_.

mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])

The mapAndUnzipM function maps its first argument over a list, returning the result as a pair of lists. This function is mainly used with complicated data structures or a state monad.

initDs :: HscEnv -> TcGblEnv -> DsM a -> IO (Messages, Maybe a)

Run a DsM action inside the IO monad.

initDsTc :: DsM a -> TcM a

Run a DsM action inside the TcM monad.

initTcDsForSolver :: TcM a -> DsM (Messages, Maybe a)

initDsWithModGuts :: HscEnv -> ModGuts -> DsM a -> IO (Messages, Maybe a)

Run a DsM action in the context of an existing ModGuts

fixDs :: (a -> DsM a) -> DsM a

foldlM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b

Monadic fold over the elements of a structure, associating to the left, i.e. from left to right.

foldrM :: (Foldable t, Monad m) => (a -> b -> m b) -> b -> t a -> m b

Monadic fold over the elements of a structure, associating to the right, i.e. from right to left.

whenGOptM :: GeneralFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()

unsetGOptM :: GeneralFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a

unsetWOptM :: WarningFlag -> TcRnIf gbl lcl a -> TcRnIf gbl lcl a

xoptM :: Extension -> TcRnIf gbl lcl Bool

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

Applicative []

Since: base-2.1

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

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

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

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

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 Complex

Since: base-4.9.0.0

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

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

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 First

Since: base-4.9.0.0

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

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 Option

Since: base-4.9.0.0

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

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 Identity

Since: base-4.8.0.0

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 STM

Since: base-4.8.0.0

Defined in GHC.Conc.Sync

Methods

pure :: a -> STM a

(<*>) :: STM (a -> b) -> STM a -> STM b

liftA2 :: (a -> b -> c) -> STM a -> STM b -> STM c

(*>) :: STM a -> STM b -> STM b

(<*) :: STM a -> STM b -> STM a

Applicative First

Since: base-4.8.0.0

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

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

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

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

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

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

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

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 NonEmpty

Since: base-4.9.0.0

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 PutM

Defined in Data.Binary.Put

Methods

pure :: a -> PutM a

(<*>) :: PutM (a -> b) -> PutM a -> PutM b

liftA2 :: (a -> b -> c) -> PutM a -> PutM b -> PutM c

(*>) :: PutM a -> PutM b -> PutM b

(<*) :: PutM a -> PutM b -> PutM a

Applicative Get

Defined in Data.Binary.Get.Internal

Methods

pure :: a -> Get a

(<*>) :: Get (a -> b) -> Get a -> Get b

liftA2 :: (a -> b -> c) -> Get a -> Get b -> Get c

(*>) :: Get a -> Get b -> Get b

(<*) :: Get a -> Get b -> Get a

Applicative Put

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

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

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 Capability

Defined in System.Console.Terminfo.Base

Methods

pure :: a -> Capability a

(<*>) :: Capability (a -> b) -> Capability a -> Capability b

liftA2 :: (a -> b -> c) -> Capability a -> Capability b -> Capability c

(*>) :: Capability a -> Capability b -> Capability b

(<*) :: Capability a -> Capability b -> Capability a

Applicative P

Since: base-4.5.0.0

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 Pair

Defined in Pair

Methods

pure :: a -> Pair a

(<*>) :: Pair (a -> b) -> Pair a -> Pair b

liftA2 :: (a -> b -> c) -> Pair a -> Pair b -> Pair c

(*>) :: Pair a -> Pair b -> Pair b

(<*) :: Pair a -> Pair b -> Pair a

Applicative UniqSM

Defined in UniqSupply

Methods

pure :: a -> UniqSM a

(<*>) :: UniqSM (a -> b) -> UniqSM a -> UniqSM b

liftA2 :: (a -> b -> c) -> UniqSM a -> UniqSM b -> UniqSM c

(*>) :: UniqSM a -> UniqSM b -> UniqSM b

(<*) :: UniqSM a -> UniqSM b -> UniqSM a

Applicative CoreM

Defined in CoreMonad

Methods

pure :: a -> CoreM a

(<*>) :: CoreM (a -> b) -> CoreM a -> CoreM b

liftA2 :: (a -> b -> c) -> CoreM a -> CoreM b -> CoreM c

(*>) :: CoreM a -> CoreM b -> CoreM b

(<*) :: CoreM a -> CoreM b -> CoreM a

Applicative P

Defined in Lexer

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 PD

Defined in CmmMonad

Methods

pure :: a -> PD a

(<*>) :: PD (a -> b) -> PD a -> PD b

liftA2 :: (a -> b -> c) -> PD a -> PD b -> PD c

(*>) :: PD a -> PD b -> PD b

(<*) :: PD a -> PD b -> PD a

Applicative UnifyResultM

Defined in Unify

Methods

pure :: a -> UnifyResultM a

(<*>) :: UnifyResultM (a -> b) -> UnifyResultM a -> UnifyResultM b

liftA2 :: (a -> b -> c) -> UnifyResultM a -> UnifyResultM b -> UnifyResultM c

(*>) :: UnifyResultM a -> UnifyResultM b -> UnifyResultM b

(<*) :: UnifyResultM a -> UnifyResultM b -> UnifyResultM a

Applicative LiftM

Defined in StgLiftLams.LiftM

Methods

pure :: a -> LiftM a

(<*>) :: LiftM (a -> b) -> LiftM a -> LiftM b

liftA2 :: (a -> b -> c) -> LiftM a -> LiftM b -> LiftM c

(*>) :: LiftM a -> LiftM b -> LiftM b

(<*) :: LiftM a -> LiftM b -> LiftM a

Applicative LlvmM

Defined in LlvmCodeGen.Base

Methods

pure :: a -> LlvmM a

(<*>) :: LlvmM (a -> b) -> LlvmM a -> LlvmM b

liftA2 :: (a -> b -> c) -> LlvmM a -> LlvmM b -> LlvmM c

(*>) :: LlvmM a -> LlvmM b -> LlvmM b

(<*) :: LlvmM a -> LlvmM b -> LlvmM a

Applicative FCode

Defined in GHC.StgToCmm.Monad

Methods

pure :: a -> FCode a

(<*>) :: FCode (a -> b) -> FCode a -> FCode b

liftA2 :: (a -> b -> c) -> FCode a -> FCode b -> FCode c

(*>) :: FCode a -> FCode b -> FCode b

(<*) :: FCode a -> FCode b -> FCode a

Applicative CmmParse

Defined in GHC.StgToCmm.ExtCode

Methods

pure :: a -> CmmParse a

(<*>) :: CmmParse (a -> b) -> CmmParse a -> CmmParse b

liftA2 :: (a -> b -> c) -> CmmParse a -> CmmParse b -> CmmParse c

(*>) :: CmmParse a -> CmmParse b -> CmmParse b

(<*) :: CmmParse a -> CmmParse b -> CmmParse a

Applicative PV

Defined in RdrHsSyn

Methods

pure :: a -> PV a

(<*>) :: PV (a -> b) -> PV a -> PV b

liftA2 :: (a -> b -> c) -> PV a -> PV b -> PV c

(*>) :: PV a -> PV b -> PV b

(<*) :: PV a -> PV b -> PV a

Applicative Hsc

Defined in HscTypes

Methods

pure :: a -> Hsc a

(<*>) :: Hsc (a -> b) -> Hsc a -> Hsc b

liftA2 :: (a -> b -> c) -> Hsc a -> Hsc b -> Hsc c

(*>) :: Hsc a -> Hsc b -> Hsc b

(<*) :: Hsc a -> Hsc b -> Hsc a

Applicative CompPipeline

Defined in PipelineMonad

Methods

pure :: a -> CompPipeline a

(<*>) :: CompPipeline (a -> b) -> CompPipeline a -> CompPipeline b

liftA2 :: (a -> b -> c) -> CompPipeline a -> CompPipeline b -> CompPipeline c

(*>) :: CompPipeline a -> CompPipeline b -> CompPipeline b

(<*) :: CompPipeline a -> CompPipeline b -> CompPipeline a

Applicative Ghc

Defined in GhcMonad

Methods

pure :: a -> Ghc a

(<*>) :: Ghc (a -> b) -> Ghc a -> Ghc b

liftA2 :: (a -> b -> c) -> Ghc a -> Ghc b -> Ghc c

(*>) :: Ghc a -> Ghc b -> Ghc b

(<*) :: Ghc a -> Ghc b -> Ghc a

Applicative SimplM

Defined in SimplMonad

Methods

pure :: a -> SimplM a

(<*>) :: SimplM (a -> b) -> SimplM a -> SimplM b

liftA2 :: (a -> b -> c) -> SimplM a -> SimplM b -> SimplM c

(*>) :: SimplM a -> SimplM b -> SimplM b

(<*) :: SimplM a -> SimplM b -> SimplM a

Applicative TcPluginM

Defined in TcRnTypes

Methods

pure :: a -> TcPluginM a

(<*>) :: TcPluginM (a -> b) -> TcPluginM a -> TcPluginM b

liftA2 :: (a -> b -> c) -> TcPluginM a -> TcPluginM b -> TcPluginM c

(*>) :: TcPluginM a -> TcPluginM b -> TcPluginM b

(<*) :: TcPluginM a -> TcPluginM b -> TcPluginM a

Applicative CpsRn

Defined in RnPat

Methods

pure :: a -> CpsRn a

(<*>) :: CpsRn (a -> b) -> CpsRn a -> CpsRn b

liftA2 :: (a -> b -> c) -> CpsRn a -> CpsRn b -> CpsRn c

(*>) :: CpsRn a -> CpsRn b -> CpsRn b

(<*) :: CpsRn a -> CpsRn b -> CpsRn a

Applicative MetaTyVarUpdateResult

Defined in TcUnify

Methods

pure :: a -> MetaTyVarUpdateResult a

(<*>) :: MetaTyVarUpdateResult (a -> b) -> MetaTyVarUpdateResult a -> MetaTyVarUpdateResult b

liftA2 :: (a -> b -> c) -> MetaTyVarUpdateResult a -> MetaTyVarUpdateResult b -> MetaTyVarUpdateResult c

(*>) :: MetaTyVarUpdateResult a -> MetaTyVarUpdateResult b -> MetaTyVarUpdateResult b

(<*) :: MetaTyVarUpdateResult a -> MetaTyVarUpdateResult b -> MetaTyVarUpdateResult a

Applicative TcS

Defined in TcSMonad

Methods

pure :: a -> TcS a

(<*>) :: TcS (a -> b) -> TcS a -> TcS b

liftA2 :: (a -> b -> c) -> TcS a -> TcS b -> TcS c

(*>) :: TcS a -> TcS b -> TcS b

(<*) :: TcS a -> TcS b -> TcS a

Applicative NatM

Defined in NCGMonad

Methods

pure :: a -> NatM a

(<*>) :: NatM (a -> b) -> NatM a -> NatM b

liftA2 :: (a -> b -> c) -> NatM a -> NatM b -> NatM c

(*>) :: NatM a -> NatM b -> NatM b

(<*) :: NatM a -> NatM b -> NatM a

Applicative (Either e)

Since: base-3.0

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

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, Strings concatenate:

("hello ", (+15)) <*> ("world!", 2002)
("hello world!",2017)

Since: base-2.1

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 (ST s)

Since: base-4.4.0.0

Defined in GHC.ST

Methods

pure :: a -> ST s a

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

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

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

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

Monad m => Applicative (WrappedMonad m)

Since: base-2.1

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

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

Applicative (Proxy :: Type -> Type)

Since: base-4.7.0.0

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

(Functor m, Monad m) => Applicative (MaybeT m)

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

Applicative (State s)

Defined in State

Methods

pure :: a -> State s a

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

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

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

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

Applicative (MaybeErr err)

Defined in Maybes

Methods

pure :: a -> MaybeErr err a

(<*>) :: MaybeErr err (a -> b) -> MaybeErr err a -> MaybeErr err b

liftA2 :: (a -> b -> c) -> MaybeErr err a -> MaybeErr err b -> MaybeErr err c

(*>) :: MaybeErr err a -> MaybeErr err b -> MaybeErr err b

(<*) :: MaybeErr err a -> MaybeErr err b -> MaybeErr err a

Applicative (SetM s)

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 (CmdLineP s)

Defined in CmdLineParser

Methods

pure :: a -> CmdLineP s a

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

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

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

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

Monad m => Applicative (EwM m)

Defined in CmdLineParser

Methods

pure :: a -> EwM m a

(<*>) :: EwM m (a -> b) -> EwM m a -> EwM m b

liftA2 :: (a -> b -> c) -> EwM m a -> EwM m b -> EwM m c

(*>) :: EwM m a -> EwM m b -> EwM m b

(<*) :: EwM m a -> EwM m b -> EwM m a

Applicative (IOEnv m)

Defined in IOEnv

Methods

pure :: a -> IOEnv m a

(<*>) :: IOEnv m (a -> b) -> IOEnv m a -> IOEnv m b

liftA2 :: (a -> b -> c) -> IOEnv m a -> IOEnv m b -> IOEnv m c

(*>) :: IOEnv m a -> IOEnv m b -> IOEnv m b

(<*) :: IOEnv m a -> IOEnv m b -> IOEnv m a

Applicative (RegM freeRegs)

Defined in RegAlloc.Linear.State

Methods

pure :: a -> RegM freeRegs a

(<*>) :: RegM freeRegs (a -> b) -> RegM freeRegs a -> RegM freeRegs b

liftA2 :: (a -> b -> c) -> RegM freeRegs a -> RegM freeRegs b -> RegM freeRegs c

(*>) :: RegM freeRegs a -> RegM freeRegs b -> RegM freeRegs b

(<*) :: RegM freeRegs a -> RegM freeRegs b -> RegM freeRegs a

Applicative m => Applicative (GhcT m)

Defined in GhcMonad

Methods

pure :: a -> GhcT m a

(<*>) :: GhcT m (a -> b) -> GhcT m a -> GhcT m b

liftA2 :: (a -> b -> c) -> GhcT m a -> GhcT m b -> GhcT m c

(*>) :: GhcT m a -> GhcT m b -> GhcT m b

(<*) :: GhcT m a -> GhcT m b -> GhcT m a

Applicative f => Applicative (Rec1 f)

Since: base-4.9.0.0

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

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

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

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

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

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

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

(Applicative f, Monad f) => Applicative (WhenMissing f x)

Equivalent to ReaderT k (ReaderT x (MaybeT f)).

Since: containers-0.5.9

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

(Monoid w, Applicative m) => Applicative (WriterT w m)

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)

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)

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)

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)

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 (Stream m a)

Defined in Stream

Methods

pure :: a0 -> Stream m a a0

(<*>) :: Stream m a (a0 -> b) -> Stream m a a0 -> Stream m a b

liftA2 :: (a0 -> b -> c) -> Stream m a a0 -> Stream m a b -> Stream m a c

(*>) :: Stream m a a0 -> Stream m a b -> Stream m a b

(<*) :: Stream m a a0 -> Stream m a b -> Stream m a a0

Applicative ((->) r :: Type -> Type)

Since: base-2.1

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

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

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

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

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

(Monad f, Applicative f) => Applicative (WhenMatched f x y)

Equivalent to ReaderT Key (ReaderT x (ReaderT y (MaybeT f)))

Since: containers-0.5.9

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

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)

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 (M1 i c f)

Since: base-4.9.0.0

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

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

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

(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

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

(Monoid w, Functor m, Monad m) => Applicative (RWST r w s m)

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

(Functor m, Monad m) => Applicative (RWST r w s m)

Defined in Control.Monad.Trans.RWS.CPS

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

(<$>) :: 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

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)

duplicateLocalDs :: Id -> DsM Id

newSysLocalDsNoLP :: Type -> DsM Id

newSysLocalDs :: Type -> DsM Id

newSysLocalsDsNoLP :: [Type] -> DsM [Id]

newSysLocalsDs :: [Type] -> DsM [Id]

newUniqueId :: Id -> Type -> DsM Id

newFailLocalDs :: Type -> DsM Id

newPredVarDs :: PredType -> DsM Var

getSrcSpanDs :: DsM SrcSpan

putSrcSpanDs :: SrcSpan -> DsM a -> DsM a

mkPrintUnqualifiedDs :: DsM PrintUnqualified

newUnique :: TcRnIf gbl lcl Unique

data UniqSupply

Unique Supply

A value of type UniqSupply is unique, and it can supply one distinct Unique. Also, from the supply, one can also manufacture an arbitrary number of further UniqueSupply values, which will be distinct from the first and from all others.

newUniqueSupply :: TcRnIf gbl lcl UniqSupply

getGhcModeDs :: DsM GhcMode

dsGetFamInstEnvs :: DsM FamInstEnvs

dsLookupGlobal :: Name -> DsM TyThing

dsLookupGlobalId :: Name -> DsM Id

dsLookupTyCon :: Name -> DsM TyCon

dsLookupDataCon :: Name -> DsM DataCon

dsLookupConLike :: Name -> DsM ConLike

type DsMetaEnv = NameEnv DsMetaVal

data DsMetaVal

Constructors

DsBound Id

DsSplice (HsExpr GhcTc)

dsGetMetaEnv :: DsM (NameEnv DsMetaVal)

dsLookupMetaEnv :: Name -> DsM (Maybe DsMetaVal)

dsExtendMetaEnv :: DsMetaEnv -> DsM a -> DsM a

getPmDelta :: DsM Delta

Get the current pattern match oracle state. See dsl_delta.

updPmDelta :: Delta -> DsM a -> DsM a

Set the pattern match oracle state within the scope of the given action. See dsl_delta.

dsGetCompleteMatches :: TyCon -> DsM [CompleteMatch]

The COMPLETE pragmas provided by the user for a given TyCon.

type DsWarning = (SrcSpan, SDoc)

warnDs :: WarnReason -> SDoc -> DsM ()

Emit a warning for the current source location NB: Warns whether or not -Wxyz is set

warnIfSetDs :: WarningFlag -> SDoc -> DsM ()

Emit a warning only if the correct WarnReason is set in the DynFlags

errDs :: SDoc -> DsM ()

errDsCoreExpr :: SDoc -> DsM CoreExpr

Issue an error, but return the expression for (), so that we can continue reporting errors.

failWithDs :: SDoc -> DsM a

failDs :: DsM a

discardWarningsDs :: DsM a -> DsM a

askNoErrsDs :: DsM a -> DsM (a, Bool)

data DsMatchContext

Constructors

DsMatchContext (HsMatchContext Name) SrcSpan

Instances

Outputable DsMatchContext

Defined in DsMonad

Methods

ppr :: DsMatchContext -> SDoc

pprPrec :: Rational -> DsMatchContext -> SDoc

data EquationInfo

Constructors

EqnInfo

Fields

• eqn_pats :: [Pat GhcTc]

  The patterns for an equation

  NB: We have already applied decideBangHood to these patterns. See Note [decideBangHood] in DsUtils

• eqn_orig :: Origin

  Was this equation present in the user source?

  This helps us avoid warnings on patterns that GHC elaborated.

  For instance, the pattern -1 :: Word gets desugared into W# :: Word, but we shouldn't warn about an overflowed literal for both of these cases.

• eqn_rhs :: MatchResult

  What to do after match

Instances

Outputable EquationInfo

Defined in DsMonad

Methods

ppr :: EquationInfo -> SDoc

pprPrec :: Rational -> EquationInfo -> SDoc

data MatchResult

Constructors

MatchResult CanItFail (CoreExpr -> DsM CoreExpr)

type DsWrapper = CoreExpr -> CoreExpr

idDsWrapper :: DsWrapper

data CanItFail

Constructors

CanFail

CantFail

orFail :: CanItFail -> CanItFail -> CanItFail

dsNoLevPoly :: Type -> SDoc -> DsM ()

Fail with an error message if the type is levity polymorphic.

dsNoLevPolyExpr :: CoreExpr -> SDoc -> DsM ()

Check an expression for levity polymorphism, failing if it is levity polymorphic.

dsWhenNoErrs :: DsM a -> (a -> CoreExpr) -> DsM CoreExpr

Runs the thing_inside. If there are no errors, then returns the expr given. Otherwise, returns unitExpr. This is useful for doing a bunch of levity polymorphism checks and then avoiding making a core App. (If we make a core App on a levity polymorphic argument, detecting how to handle the let/app invariant might call isUnliftedType, which panics on a levity polymorphic type.) See #12709 for an example of why this machinery is necessary.

pprRuntimeTrace

Arguments

:: String

header

-> SDoc

information to output

-> CoreExpr

expression

-> DsM CoreExpr

Inject a trace message into the compiled program. Whereas pprTrace prints out information *while compiling*, pprRuntimeTrace captures that information and causes it to be printed *at runtime* using Debug.Trace.trace.

pprRuntimeTrace hdr doc expr

will produce an expression that looks like

trace (hdr + doc) expr

When using this to debug a module that Debug.Trace depends on, it is necessary to import {--} Debug.Trace () in that module. We could avoid this inconvenience by wiring in Debug.Trace.trace, but that doesn't seem worth the effort and maintenance cost.

Orphan instances

MonadThings (IOEnv (Env DsGblEnv DsLclEnv))

Methods

lookupThing :: Name -> IOEnv (Env DsGblEnv DsLclEnv) TyThing

lookupId :: Name -> IOEnv (Env DsGblEnv DsLclEnv) Id

lookupDataCon :: Name -> IOEnv (Env DsGblEnv DsLclEnv) DataCon

lookupTyCon :: Name -> IOEnv (Env DsGblEnv DsLclEnv) TyCon