Constrictor

This library provides strict versions of many functions in base, as well as a few functions that do not have lazy versions that exist in base (see the section on Folds).

Many functions in this library have an increased constraint from Functor/Applicative to Monad in order to achieve strictness in their arguments and/or result.

Strict 'lift-like' functions

(<$!>) :: Monad m => (a -> b) -> m a -> m b infixl 4

This is <$>, but strict in its argument and result.

This is re-defined in this module, and not just re-exported from Monad. The reason for this is that there is no way to hide the docs for re-exports with Haddocks.

In the common case that one might import Monad, we recommend structuring imports like so:

import Control.Monad hiding (($!))
import Constrictor

or

import Control.Monad
import Constrictor hiding (($!))

There should be no side effects (i.e. naming/scoping conflicts) introduced as a result of structuring one's imports in this way.

fmap' :: Monad m => (a -> b) -> m a -> m b infixl 4

This is fmap, but strict in its argument and result.

Note this is equivalent to <$!>, and is provided for convenience.

liftM' :: Monad m => (a -> b) -> m a -> m b infixl 4

This is liftM, but strict in its argument and result.

Note this is equivalent to <$!>, and is provided for convenience.

liftM2' :: Monad m => (a -> b -> c) -> m a -> m b -> m c

This is liftM2, but strict in its arguments and result.

liftM3' :: Monad m => (a -> b -> c -> d) -> m a -> m b -> m c -> m d

This is liftM3, but strict in its arguments and result.

liftM4' :: Monad m => (a -> b -> c -> d -> e) -> m a -> m b -> m c -> m d -> m e

This is liftM4, but strict in its arguments and result.

liftM5' :: Monad m => (a -> b -> c -> d -> e -> f) -> m a -> m b -> m c -> m d -> m e -> m f

This is liftM5, but strict in its arguments and result.

ap' :: Monad m => m (a -> b) -> m a -> m b

This is ap, but strict in its arguments and result.

traverse' :: (Traversable t, Applicative f) => (a -> f b) -> t a -> f (t b)

Strict version of traverse.

traverse'' :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)

Stricter version of traverse.

mapM' :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)

Strict version of mapM.

This is just traverse' specialised to Monad.

Folds

Lazy monoidal folds

foldrMap :: (Monoid m, Foldable t) => (a -> m) -> t a -> m

Map each element of a foldable structure to a monoid, and combine the results. This function is right-associative.

Note that this is equivalent to foldMap.

foldlMap :: (Monoid m, Foldable t) => (a -> m) -> t a -> m

Map each element of a foldable structure to a monoid, and combine the results. This function is left-associative.

The operator is applied lazily. For a strict version, see foldlMap'.

Strict monoidal folds

foldrMap' :: (Monoid m, Foldable t) => (a -> m) -> t a -> m

Map each element of a foldable structure to a monoid, and combine the results. This function is right-associative.

Note that this is equivalent to foldMap, but is strict.

foldlMap' :: (Monoid m, Foldable t) => (a -> m) -> t a -> m

Map each element of a foldable structure to a monoid, and combine the results. This function is left-associative.

The operator is applied strictly. For a lazy version, see foldlMap.

Lazy applicative folds

foldlMapA :: forall t b a f. (Foldable t, Monoid b, Applicative f) => (a -> f b) -> t a -> f b

Lazy in the monoidal accumulator. Monoidal accumulation happens from left to right.

foldrMapA :: forall t b a f. (Foldable t, Monoid b, Applicative f) => (a -> f b) -> t a -> f b

Lazy in the monoidal accumulator. Monoidal accumulation happens from left to right.

Strict monadic folds

foldlMapM' :: forall t b a m. (Foldable t, Monoid b, Monad m) => (a -> m b) -> t a -> m b

Strict in the monoidal accumulator. For monads strict in the left argument of bind, this will run in constant space. Monoidal accumulation happens from left to right.

foldrMapM' :: forall t b a m. (Foldable t, Monoid b, Monad m) => (a -> m b) -> t a -> m b

Types

Wrapped applicative functor

newtype Ap f a

A wrapped applicative functor. Please note that base 4.12.0.0 will include this type, and it will be removed from this library at that point.

Constructors

Ap

Fields

• getAp :: f a

Instances

Monad f => Monad (Ap f)

Methods

(>>=) :: Ap f a -> (a -> Ap f b) -> Ap f b

(>>) :: Ap f a -> Ap f b -> Ap f b

return :: a -> Ap f a

fail :: String -> Ap f a

Functor f => Functor (Ap f)

Methods

fmap :: (a -> b) -> Ap f a -> Ap f b

(<$) :: a -> Ap f b -> Ap f a

MonadFix f => MonadFix (Ap f)

Methods

mfix :: (a -> Ap f a) -> Ap f a

MonadFail f => MonadFail (Ap f)

Methods

fail :: String -> Ap f a

Applicative f => Applicative (Ap f)

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

Foldable f => Foldable (Ap f)

Methods

fold :: Monoid m => Ap f m -> m

foldMap :: Monoid m => (a -> m) -> Ap f a -> m

foldr :: (a -> b -> b) -> b -> Ap f a -> b

foldr' :: (a -> b -> b) -> b -> Ap f a -> b

foldl :: (b -> a -> b) -> b -> Ap f a -> b

foldl' :: (b -> a -> b) -> b -> Ap f a -> b

foldr1 :: (a -> a -> a) -> Ap f a -> a

foldl1 :: (a -> a -> a) -> Ap f a -> a

toList :: Ap f a -> [a]

null :: Ap f a -> Bool

length :: Ap f a -> Int

elem :: Eq a => a -> Ap f a -> Bool

maximum :: Ord a => Ap f a -> a

minimum :: Ord a => Ap f a -> a

sum :: Num a => Ap f a -> a

product :: Num a => Ap f a -> a

Traversable f => Traversable (Ap f)

Methods

traverse :: Applicative f => (a -> f b) -> Ap f a -> f (Ap f b)

sequenceA :: Applicative f => Ap f (f a) -> f (Ap f a)

mapM :: Monad m => (a -> m b) -> Ap f a -> m (Ap f b)

sequence :: Monad m => Ap f (m a) -> m (Ap f a)

Alternative f => Alternative (Ap f)

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]

MonadPlus f => MonadPlus (Ap f)

Methods

mzero :: Ap f a

mplus :: Ap f a -> Ap f a -> Ap f a

Generic1 * (Ap f)

Associated Types

type Rep1 (Ap f) (f :: Ap f -> *) :: k -> *

Methods

from1 :: f a -> Rep1 (Ap f) f a

to1 :: Rep1 (Ap f) f a -> f a

Enum (f a) => Enum (Ap f a)

Methods

succ :: Ap f a -> Ap f a

pred :: Ap f a -> Ap f a

toEnum :: Int -> Ap f a

fromEnum :: Ap f a -> Int

enumFrom :: Ap f a -> [Ap f a]

enumFromThen :: Ap f a -> Ap f a -> [Ap f a]

enumFromTo :: Ap f a -> Ap f a -> [Ap f a]

enumFromThenTo :: Ap f a -> Ap f a -> Ap f a -> [Ap f a]

Eq (f a) => Eq (Ap f a)

Methods

(==) :: Ap f a -> Ap f a -> Bool

(/=) :: Ap f a -> Ap f a -> Bool

Num (f a) => Num (Ap f a)

Methods

(+) :: Ap f a -> Ap f a -> Ap f a

(-) :: Ap f a -> Ap f a -> Ap f a

(*) :: Ap f a -> Ap f a -> Ap f a

negate :: Ap f a -> Ap f a

abs :: Ap f a -> Ap f a

signum :: Ap f a -> Ap f a

fromInteger :: Integer -> Ap f a

Ord (f a) => Ord (Ap f a)

Methods

compare :: Ap f a -> Ap f a -> Ordering

(<) :: Ap f a -> Ap f a -> Bool

(<=) :: Ap f a -> Ap f a -> Bool

(>) :: Ap f a -> Ap f a -> Bool

(>=) :: Ap f a -> Ap f a -> Bool

max :: Ap f a -> Ap f a -> Ap f a

min :: Ap f a -> Ap f a -> Ap f a

Read (f a) => Read (Ap f a)

Methods

readsPrec :: Int -> ReadS (Ap f a)

readList :: ReadS [Ap f a]

readPrec :: ReadPrec (Ap f a)

readListPrec :: ReadPrec [Ap f a]

Show (f a) => Show (Ap f a)

Methods

showsPrec :: Int -> Ap f a -> ShowS

show :: Ap f a -> String

showList :: [Ap f a] -> ShowS

Generic (Ap f a)

Associated Types

type Rep (Ap f a) :: * -> *

Methods

from :: Ap f a -> Rep (Ap f a) x

to :: Rep (Ap f a) x -> Ap f a

(Applicative f, Semigroup a) => Semigroup (Ap f a)

Methods

(<>) :: Ap f a -> Ap f a -> Ap f a

sconcat :: NonEmpty (Ap f a) -> Ap f a

stimes :: Integral b => b -> Ap f a -> Ap f a

(Applicative f, Monoid a) => Monoid (Ap f a)

Methods

mempty :: Ap f a

mappend :: Ap f a -> Ap f a -> Ap f a

mconcat :: [Ap f a] -> Ap f a

type Rep1 * (Ap f)

type Rep1 * (Ap f) = D1 * (MetaData "Ap" "Constrictor" "constrictor-0.1.1.2-LdLdFPskOMzKsgPFY9bfKb" True) (C1 * (MetaCons "Ap" PrefixI True) (S1 * (MetaSel (Just Symbol "getAp") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec1 * f)))

type Rep (Ap f a)

type Rep (Ap f a) = D1 * (MetaData "Ap" "Constrictor" "constrictor-0.1.1.2-LdLdFPskOMzKsgPFY9bfKb" True) (C1 * (MetaCons "Ap" PrefixI True) (S1 * (MetaSel (Just Symbol "getAp") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 * (f a))))