BasicPrelude

BasicPrelude mostly re-exports several key libraries in their entirety. The exception is Data.List, where various functions are replaced by similar versions that are either generalized, operate on Text, or are implemented strictly.

Module exports

module CorePrelude

module Data.List

module Control.Monad

Folds and traversals

class Foldable t where

Data structures that can be folded.

For example, given a data type

data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)

a suitable instance would be

instance Foldable Tree where
   foldMap f Empty = mempty
   foldMap f (Leaf x) = f x
   foldMap f (Node l k r) = foldMap f l `mappend` f k `mappend` foldMap f r

This is suitable even for abstract types, as the monoid is assumed to satisfy the monoid laws. Alternatively, one could define foldr:

instance Foldable Tree where
   foldr f z Empty = z
   foldr f z (Leaf x) = f x z
   foldr f z (Node l k r) = foldr f (f k (foldr f z r)) l

Foldable instances are expected to satisfy the following laws:

foldr f z t = appEndo (foldMap (Endo . f) t ) z

foldl f z t = appEndo (getDual (foldMap (Dual . Endo . flip f) t)) z

fold = foldMap id

sum, product, maximum, and minimum should all be essentially equivalent to foldMap forms, such as

sum = getSum . foldMap Sum

but may be less defined.

If the type is also a Functor instance, it should satisfy

foldMap f = fold . fmap f

which implies that

foldMap f . fmap g = foldMap (f . g)

Minimal complete definition

foldMap | foldr

Methods

foldMap :: Monoid m => (a -> m) -> t a -> m

Map each element of the structure to a monoid, and combine the results.

foldr :: (a -> b -> b) -> b -> t a -> b

Right-associative fold of a structure.

In the case of lists, foldr, when applied to a binary operator, a starting value (typically the right-identity of the operator), and a list, reduces the list using the binary operator, from right to left:

foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)

Note that, since the head of the resulting expression is produced by an application of the operator to the first element of the list, foldr can produce a terminating expression from an infinite list.

For a general Foldable structure this should be semantically identical to,

foldr f z = foldr f z . toList

foldr' :: (a -> b -> b) -> b -> t a -> b

Right-associative fold of a structure, but with strict application of the operator.

foldl :: (b -> a -> b) -> b -> t a -> b

Left-associative fold of a structure.

In the case of lists, foldl, when applied to a binary operator, a starting value (typically the left-identity of the operator), and a list, reduces the list using the binary operator, from left to right:

foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn

Note that to produce the outermost application of the operator the entire input list must be traversed. This means that foldl' will diverge if given an infinite list.

Also note that if you want an efficient left-fold, you probably want to use foldl' instead of foldl. The reason for this is that latter does not force the "inner" results (e.g. z f x1 in the above example) before applying them to the operator (e.g. to (f x2)). This results in a thunk chain O(n) elements long, which then must be evaluated from the outside-in.

For a general Foldable structure this should be semantically identical to,

foldl f z = foldl f z . toList

foldl' :: (b -> a -> b) -> b -> t a -> b

Left-associative fold of a structure but with strict application of the operator.

This ensures that each step of the fold is forced to weak head normal form before being applied, avoiding the collection of thunks that would otherwise occur. This is often what you want to strictly reduce a finite list to a single, monolithic result (e.g. length).

For a general Foldable structure this should be semantically identical to,

foldl f z = foldl' f z . toList

foldr1 :: (a -> a -> a) -> t a -> a

A variant of foldr that has no base case, and thus may only be applied to non-empty structures.

foldr1 f = foldr1 f . toList

foldl1 :: (a -> a -> a) -> t a -> a

A variant of foldl that has no base case, and thus may only be applied to non-empty structures.

foldl1 f = foldl1 f . toList

null :: t a -> Bool

Test whether the structure is empty. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.

length :: t a -> Int

Returns the size/length of a finite structure as an Int. The default implementation is optimized for structures that are similar to cons-lists, because there is no general way to do better.

elem :: Eq a => a -> t a -> Bool infix 4

Does the element occur in the structure?

maximum :: Ord a => t a -> a

The largest element of a non-empty structure.

minimum :: Ord a => t a -> a

The least element of a non-empty structure.

Instances

Foldable []

Methods

fold :: Monoid m => [m] -> m

foldMap :: Monoid m => (a -> m) -> [a] -> m

foldr :: (a -> b -> b) -> b -> [a] -> b

foldr' :: (a -> b -> b) -> b -> [a] -> b

foldl :: (b -> a -> b) -> b -> [a] -> b

foldl' :: (b -> a -> b) -> b -> [a] -> b

foldr1 :: (a -> a -> a) -> [a] -> a

foldl1 :: (a -> a -> a) -> [a] -> a

toList :: [a] -> [a]

null :: [a] -> Bool

length :: [a] -> Int

elem :: Eq a => a -> [a] -> Bool

maximum :: Ord a => [a] -> a

minimum :: Ord a => [a] -> a

sum :: Num a => [a] -> a

product :: Num a => [a] -> a

Foldable Maybe

Methods

fold :: Monoid m => Maybe m -> m

foldMap :: Monoid m => (a -> m) -> Maybe a -> m

foldr :: (a -> b -> b) -> b -> Maybe a -> b

foldr' :: (a -> b -> b) -> b -> Maybe a -> b

foldl :: (b -> a -> b) -> b -> Maybe a -> b

foldl' :: (b -> a -> b) -> b -> Maybe a -> b

foldr1 :: (a -> a -> a) -> Maybe a -> a

foldl1 :: (a -> a -> a) -> Maybe a -> a

toList :: Maybe a -> [a]

null :: Maybe a -> Bool

length :: Maybe a -> Int

elem :: Eq a => a -> Maybe a -> Bool

maximum :: Ord a => Maybe a -> a

minimum :: Ord a => Maybe a -> a

sum :: Num a => Maybe a -> a

product :: Num a => Maybe a -> a

Foldable V1

Methods

fold :: Monoid m => V1 m -> m

foldMap :: Monoid m => (a -> m) -> V1 a -> m

foldr :: (a -> b -> b) -> b -> V1 a -> b

foldr' :: (a -> b -> b) -> b -> V1 a -> b

foldl :: (b -> a -> b) -> b -> V1 a -> b

foldl' :: (b -> a -> b) -> b -> V1 a -> b

foldr1 :: (a -> a -> a) -> V1 a -> a

foldl1 :: (a -> a -> a) -> V1 a -> a

toList :: V1 a -> [a]

null :: V1 a -> Bool

length :: V1 a -> Int

elem :: Eq a => a -> V1 a -> Bool

maximum :: Ord a => V1 a -> a

minimum :: Ord a => V1 a -> a

sum :: Num a => V1 a -> a

product :: Num a => V1 a -> a

Foldable U1

Methods

fold :: Monoid m => U1 m -> m

foldMap :: Monoid m => (a -> m) -> U1 a -> m

foldr :: (a -> b -> b) -> b -> U1 a -> b

foldr' :: (a -> b -> b) -> b -> U1 a -> b

foldl :: (b -> a -> b) -> b -> U1 a -> b

foldl' :: (b -> a -> b) -> b -> U1 a -> b

foldr1 :: (a -> a -> a) -> U1 a -> a

foldl1 :: (a -> a -> a) -> U1 a -> a

toList :: U1 a -> [a]

null :: U1 a -> Bool

length :: U1 a -> Int

elem :: Eq a => a -> U1 a -> Bool

maximum :: Ord a => U1 a -> a

minimum :: Ord a => U1 a -> a

sum :: Num a => U1 a -> a

product :: Num a => U1 a -> a

Foldable Par1

Methods

fold :: Monoid m => Par1 m -> m

foldMap :: Monoid m => (a -> m) -> Par1 a -> m

foldr :: (a -> b -> b) -> b -> Par1 a -> b

foldr' :: (a -> b -> b) -> b -> Par1 a -> b

foldl :: (b -> a -> b) -> b -> Par1 a -> b

foldl' :: (b -> a -> b) -> b -> Par1 a -> b

foldr1 :: (a -> a -> a) -> Par1 a -> a

foldl1 :: (a -> a -> a) -> Par1 a -> a

toList :: Par1 a -> [a]

null :: Par1 a -> Bool

length :: Par1 a -> Int

elem :: Eq a => a -> Par1 a -> Bool

maximum :: Ord a => Par1 a -> a

minimum :: Ord a => Par1 a -> a

sum :: Num a => Par1 a -> a

product :: Num a => Par1 a -> a

Foldable Identity

Methods

fold :: Monoid m => Identity m -> m

foldMap :: Monoid m => (a -> m) -> Identity a -> m

foldr :: (a -> b -> b) -> b -> Identity a -> b

foldr' :: (a -> b -> b) -> b -> Identity a -> b

foldl :: (b -> a -> b) -> b -> Identity a -> b

foldl' :: (b -> a -> b) -> b -> Identity a -> b

foldr1 :: (a -> a -> a) -> Identity a -> a

foldl1 :: (a -> a -> a) -> Identity a -> a

toList :: Identity a -> [a]

null :: Identity a -> Bool

length :: Identity a -> Int

elem :: Eq a => a -> Identity a -> Bool

maximum :: Ord a => Identity a -> a

minimum :: Ord a => Identity a -> a

sum :: Num a => Identity a -> a

product :: Num a => Identity a -> a

Foldable Min

Methods

fold :: Monoid m => Min m -> m

foldMap :: Monoid m => (a -> m) -> Min a -> m

foldr :: (a -> b -> b) -> b -> Min a -> b

foldr' :: (a -> b -> b) -> b -> Min a -> b

foldl :: (b -> a -> b) -> b -> Min a -> b

foldl' :: (b -> a -> b) -> b -> Min a -> b

foldr1 :: (a -> a -> a) -> Min a -> a

foldl1 :: (a -> a -> a) -> Min a -> a

toList :: Min a -> [a]

null :: Min a -> Bool

length :: Min a -> Int

elem :: Eq a => a -> Min a -> Bool

maximum :: Ord a => Min a -> a

minimum :: Ord a => Min a -> a

sum :: Num a => Min a -> a

product :: Num a => Min a -> a

Foldable Max

Methods

fold :: Monoid m => Max m -> m

foldMap :: Monoid m => (a -> m) -> Max a -> m

foldr :: (a -> b -> b) -> b -> Max a -> b

foldr' :: (a -> b -> b) -> b -> Max a -> b

foldl :: (b -> a -> b) -> b -> Max a -> b

foldl' :: (b -> a -> b) -> b -> Max a -> b

foldr1 :: (a -> a -> a) -> Max a -> a

foldl1 :: (a -> a -> a) -> Max a -> a

toList :: Max a -> [a]

null :: Max a -> Bool

length :: Max a -> Int

elem :: Eq a => a -> Max a -> Bool

maximum :: Ord a => Max a -> a

minimum :: Ord a => Max a -> a

sum :: Num a => Max a -> a

product :: Num a => Max a -> a

Foldable First

Methods

fold :: Monoid m => First m -> m

foldMap :: Monoid m => (a -> m) -> First a -> m

foldr :: (a -> b -> b) -> b -> First a -> b

foldr' :: (a -> b -> b) -> b -> First a -> b

foldl :: (b -> a -> b) -> b -> First a -> b

foldl' :: (b -> a -> b) -> b -> First a -> b

foldr1 :: (a -> a -> a) -> First a -> a

foldl1 :: (a -> a -> a) -> First a -> a

toList :: First a -> [a]

null :: First a -> Bool

length :: First a -> Int

elem :: Eq a => a -> First a -> Bool

maximum :: Ord a => First a -> a

minimum :: Ord a => First a -> a

sum :: Num a => First a -> a

product :: Num a => First a -> a

Foldable Last

Methods

fold :: Monoid m => Last m -> m

foldMap :: Monoid m => (a -> m) -> Last a -> m

foldr :: (a -> b -> b) -> b -> Last a -> b

foldr' :: (a -> b -> b) -> b -> Last a -> b

foldl :: (b -> a -> b) -> b -> Last a -> b

foldl' :: (b -> a -> b) -> b -> Last a -> b

foldr1 :: (a -> a -> a) -> Last a -> a

foldl1 :: (a -> a -> a) -> Last a -> a

toList :: Last a -> [a]

null :: Last a -> Bool

length :: Last a -> Int

elem :: Eq a => a -> Last a -> Bool

maximum :: Ord a => Last a -> a

minimum :: Ord a => Last a -> a

sum :: Num a => Last a -> a

product :: Num a => Last a -> a

Foldable Option

Methods

fold :: Monoid m => Option m -> m

foldMap :: Monoid m => (a -> m) -> Option a -> m

foldr :: (a -> b -> b) -> b -> Option a -> b

foldr' :: (a -> b -> b) -> b -> Option a -> b

foldl :: (b -> a -> b) -> b -> Option a -> b

foldl' :: (b -> a -> b) -> b -> Option a -> b

foldr1 :: (a -> a -> a) -> Option a -> a

foldl1 :: (a -> a -> a) -> Option a -> a

toList :: Option a -> [a]

null :: Option a -> Bool

length :: Option a -> Int

elem :: Eq a => a -> Option a -> Bool

maximum :: Ord a => Option a -> a

minimum :: Ord a => Option a -> a

sum :: Num a => Option a -> a

product :: Num a => Option a -> a

Foldable NonEmpty

Methods

fold :: Monoid m => NonEmpty m -> m

foldMap :: Monoid m => (a -> m) -> NonEmpty a -> m

foldr :: (a -> b -> b) -> b -> NonEmpty a -> b

foldr' :: (a -> b -> b) -> b -> NonEmpty a -> b

foldl :: (b -> a -> b) -> b -> NonEmpty a -> b

foldl' :: (b -> a -> b) -> b -> NonEmpty a -> b

foldr1 :: (a -> a -> a) -> NonEmpty a -> a

foldl1 :: (a -> a -> a) -> NonEmpty a -> a

toList :: NonEmpty a -> [a]

null :: NonEmpty a -> Bool

length :: NonEmpty a -> Int

elem :: Eq a => a -> NonEmpty a -> Bool

maximum :: Ord a => NonEmpty a -> a

minimum :: Ord a => NonEmpty a -> a

sum :: Num a => NonEmpty a -> a

product :: Num a => NonEmpty a -> a

Foldable Complex

Methods

fold :: Monoid m => Complex m -> m

foldMap :: Monoid m => (a -> m) -> Complex a -> m

foldr :: (a -> b -> b) -> b -> Complex a -> b

foldr' :: (a -> b -> b) -> b -> Complex a -> b

foldl :: (b -> a -> b) -> b -> Complex a -> b

foldl' :: (b -> a -> b) -> b -> Complex a -> b

foldr1 :: (a -> a -> a) -> Complex a -> a

foldl1 :: (a -> a -> a) -> Complex a -> a

toList :: Complex a -> [a]

null :: Complex a -> Bool

length :: Complex a -> Int

elem :: Eq a => a -> Complex a -> Bool

maximum :: Ord a => Complex a -> a

minimum :: Ord a => Complex a -> a

sum :: Num a => Complex a -> a

product :: Num a => Complex a -> a

Foldable ZipList

Methods

fold :: Monoid m => ZipList m -> 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

Foldable Dual

Methods

fold :: Monoid m => Dual m -> m

foldMap :: Monoid m => (a -> m) -> Dual a -> m

foldr :: (a -> b -> b) -> b -> Dual a -> b

foldr' :: (a -> b -> b) -> b -> Dual a -> b

foldl :: (b -> a -> b) -> b -> Dual a -> b

foldl' :: (b -> a -> b) -> b -> Dual a -> b

foldr1 :: (a -> a -> a) -> Dual a -> a

foldl1 :: (a -> a -> a) -> Dual a -> a

toList :: Dual a -> [a]

null :: Dual a -> Bool

length :: Dual a -> Int

elem :: Eq a => a -> Dual a -> Bool

maximum :: Ord a => Dual a -> a

minimum :: Ord a => Dual a -> a

sum :: Num a => Dual a -> a

product :: Num a => Dual a -> a

Foldable Sum

Methods

fold :: Monoid m => Sum m -> m

foldMap :: Monoid m => (a -> m) -> Sum a -> m

foldr :: (a -> b -> b) -> b -> Sum a -> b

foldr' :: (a -> b -> b) -> b -> Sum a -> b

foldl :: (b -> a -> b) -> b -> Sum a -> b

foldl' :: (b -> a -> b) -> b -> Sum a -> b

foldr1 :: (a -> a -> a) -> Sum a -> a

foldl1 :: (a -> a -> a) -> Sum a -> a

toList :: Sum a -> [a]

null :: Sum a -> Bool

length :: Sum a -> Int

elem :: Eq a => a -> Sum a -> Bool

maximum :: Ord a => Sum a -> a

minimum :: Ord a => Sum a -> a

sum :: Num a => Sum a -> a

product :: Num a => Sum a -> a

Foldable Product

Methods

fold :: Monoid m => Product m -> m

foldMap :: Monoid m => (a -> m) -> Product a -> m

foldr :: (a -> b -> b) -> b -> Product a -> b

foldr' :: (a -> b -> b) -> b -> Product a -> b

foldl :: (b -> a -> b) -> b -> Product a -> b

foldl' :: (b -> a -> b) -> b -> Product a -> b

foldr1 :: (a -> a -> a) -> Product a -> a

foldl1 :: (a -> a -> a) -> Product a -> a

toList :: Product a -> [a]

null :: Product a -> Bool

length :: Product a -> Int

elem :: Eq a => a -> Product a -> Bool

maximum :: Ord a => Product a -> a

minimum :: Ord a => Product a -> a

sum :: Num a => Product a -> a

product :: Num a => Product a -> a

Foldable First

Methods

fold :: Monoid m => First m -> m

foldMap :: Monoid m => (a -> m) -> First a -> m

foldr :: (a -> b -> b) -> b -> First a -> b

foldr' :: (a -> b -> b) -> b -> First a -> b

foldl :: (b -> a -> b) -> b -> First a -> b

foldl' :: (b -> a -> b) -> b -> First a -> b

foldr1 :: (a -> a -> a) -> First a -> a

foldl1 :: (a -> a -> a) -> First a -> a

toList :: First a -> [a]

null :: First a -> Bool

length :: First a -> Int

elem :: Eq a => a -> First a -> Bool

maximum :: Ord a => First a -> a

minimum :: Ord a => First a -> a

sum :: Num a => First a -> a

product :: Num a => First a -> a

Foldable Last

Methods

fold :: Monoid m => Last m -> m

foldMap :: Monoid m => (a -> m) -> Last a -> m

foldr :: (a -> b -> b) -> b -> Last a -> b

foldr' :: (a -> b -> b) -> b -> Last a -> b

foldl :: (b -> a -> b) -> b -> Last a -> b

foldl' :: (b -> a -> b) -> b -> Last a -> b

foldr1 :: (a -> a -> a) -> Last a -> a

foldl1 :: (a -> a -> a) -> Last a -> a

toList :: Last a -> [a]

null :: Last a -> Bool

length :: Last a -> Int

elem :: Eq a => a -> Last a -> Bool

maximum :: Ord a => Last a -> a

minimum :: Ord a => Last a -> a

sum :: Num a => Last a -> a

product :: Num a => Last a -> a

Foldable Digit

Methods

fold :: Monoid m => Digit m -> m

foldMap :: Monoid m => (a -> m) -> Digit a -> m

foldr :: (a -> b -> b) -> b -> Digit a -> b

foldr' :: (a -> b -> b) -> b -> Digit a -> b

foldl :: (b -> a -> b) -> b -> Digit a -> b

foldl' :: (b -> a -> b) -> b -> Digit a -> b

foldr1 :: (a -> a -> a) -> Digit a -> a

foldl1 :: (a -> a -> a) -> Digit a -> a

toList :: Digit a -> [a]

null :: Digit a -> Bool

length :: Digit a -> Int

elem :: Eq a => a -> Digit a -> Bool

maximum :: Ord a => Digit a -> a

minimum :: Ord a => Digit a -> a

sum :: Num a => Digit a -> a

product :: Num a => Digit a -> a

Foldable Node

Methods

fold :: Monoid m => Node m -> m

foldMap :: Monoid m => (a -> m) -> Node a -> m

foldr :: (a -> b -> b) -> b -> Node a -> b

foldr' :: (a -> b -> b) -> b -> Node a -> b

foldl :: (b -> a -> b) -> b -> Node a -> b

foldl' :: (b -> a -> b) -> b -> Node a -> b

foldr1 :: (a -> a -> a) -> Node a -> a

foldl1 :: (a -> a -> a) -> Node a -> a

toList :: Node a -> [a]

null :: Node a -> Bool

length :: Node a -> Int

elem :: Eq a => a -> Node a -> Bool

maximum :: Ord a => Node a -> a

minimum :: Ord a => Node a -> a

sum :: Num a => Node a -> a

product :: Num a => Node a -> a

Foldable Elem

Methods

fold :: Monoid m => Elem m -> m

foldMap :: Monoid m => (a -> m) -> Elem a -> m

foldr :: (a -> b -> b) -> b -> Elem a -> b

foldr' :: (a -> b -> b) -> b -> Elem a -> b

foldl :: (b -> a -> b) -> b -> Elem a -> b

foldl' :: (b -> a -> b) -> b -> Elem a -> b

foldr1 :: (a -> a -> a) -> Elem a -> a

foldl1 :: (a -> a -> a) -> Elem a -> a

toList :: Elem a -> [a]

null :: Elem a -> Bool

length :: Elem a -> Int

elem :: Eq a => a -> Elem a -> Bool

maximum :: Ord a => Elem a -> a

minimum :: Ord a => Elem a -> a

sum :: Num a => Elem a -> a

product :: Num a => Elem a -> a

Foldable FingerTree

Methods

fold :: Monoid m => FingerTree m -> m

foldMap :: Monoid m => (a -> m) -> FingerTree a -> m

foldr :: (a -> b -> b) -> b -> FingerTree a -> b

foldr' :: (a -> b -> b) -> b -> FingerTree a -> b

foldl :: (b -> a -> b) -> b -> FingerTree a -> b

foldl' :: (b -> a -> b) -> b -> FingerTree a -> b

foldr1 :: (a -> a -> a) -> FingerTree a -> a

foldl1 :: (a -> a -> a) -> FingerTree a -> a

toList :: FingerTree a -> [a]

null :: FingerTree a -> Bool

length :: FingerTree a -> Int

elem :: Eq a => a -> FingerTree a -> Bool

maximum :: Ord a => FingerTree a -> a

minimum :: Ord a => FingerTree a -> a

sum :: Num a => FingerTree a -> a

product :: Num a => FingerTree a -> a

Foldable IntMap

Methods

fold :: Monoid m => IntMap m -> m

foldMap :: Monoid m => (a -> m) -> IntMap a -> m

foldr :: (a -> b -> b) -> b -> IntMap a -> b

foldr' :: (a -> b -> b) -> b -> IntMap a -> b

foldl :: (b -> a -> b) -> b -> IntMap a -> b

foldl' :: (b -> a -> b) -> b -> IntMap a -> b

foldr1 :: (a -> a -> a) -> IntMap a -> a

foldl1 :: (a -> a -> a) -> IntMap a -> a

toList :: IntMap a -> [a]

null :: IntMap a -> Bool

length :: IntMap a -> Int

elem :: Eq a => a -> IntMap a -> Bool

maximum :: Ord a => IntMap a -> a

minimum :: Ord a => IntMap a -> a

sum :: Num a => IntMap a -> a

product :: Num a => IntMap a -> a

Foldable Seq

Methods

fold :: Monoid m => Seq m -> m

foldMap :: Monoid m => (a -> m) -> Seq a -> m

foldr :: (a -> b -> b) -> b -> Seq a -> b

foldr' :: (a -> b -> b) -> b -> Seq a -> b

foldl :: (b -> a -> b) -> b -> Seq a -> b

foldl' :: (b -> a -> b) -> b -> Seq a -> b

foldr1 :: (a -> a -> a) -> Seq a -> a

foldl1 :: (a -> a -> a) -> Seq a -> a

toList :: Seq a -> [a]

null :: Seq a -> Bool

length :: Seq a -> Int

elem :: Eq a => a -> Seq a -> Bool

maximum :: Ord a => Seq a -> a

minimum :: Ord a => Seq a -> a

sum :: Num a => Seq a -> a

product :: Num a => Seq a -> a

Foldable ViewL

Methods

fold :: Monoid m => ViewL m -> m

foldMap :: Monoid m => (a -> m) -> ViewL a -> m

foldr :: (a -> b -> b) -> b -> ViewL a -> b

foldr' :: (a -> b -> b) -> b -> ViewL a -> b

foldl :: (b -> a -> b) -> b -> ViewL a -> b

foldl' :: (b -> a -> b) -> b -> ViewL a -> b

foldr1 :: (a -> a -> a) -> ViewL a -> a

foldl1 :: (a -> a -> a) -> ViewL a -> a

toList :: ViewL a -> [a]

null :: ViewL a -> Bool

length :: ViewL a -> Int

elem :: Eq a => a -> ViewL a -> Bool

maximum :: Ord a => ViewL a -> a

minimum :: Ord a => ViewL a -> a

sum :: Num a => ViewL a -> a

product :: Num a => ViewL a -> a

Foldable ViewR

Methods

fold :: Monoid m => ViewR m -> m

foldMap :: Monoid m => (a -> m) -> ViewR a -> m

foldr :: (a -> b -> b) -> b -> ViewR a -> b

foldr' :: (a -> b -> b) -> b -> ViewR a -> b

foldl :: (b -> a -> b) -> b -> ViewR a -> b

foldl' :: (b -> a -> b) -> b -> ViewR a -> b

foldr1 :: (a -> a -> a) -> ViewR a -> a

foldl1 :: (a -> a -> a) -> ViewR a -> a

toList :: ViewR a -> [a]

null :: ViewR a -> Bool

length :: ViewR a -> Int

elem :: Eq a => a -> ViewR a -> Bool

maximum :: Ord a => ViewR a -> a

minimum :: Ord a => ViewR a -> a

sum :: Num a => ViewR a -> a

product :: Num a => ViewR a -> a

Foldable Set

Methods

fold :: Monoid m => Set m -> m

foldMap :: Monoid m => (a -> m) -> Set a -> m

foldr :: (a -> b -> b) -> b -> Set a -> b

foldr' :: (a -> b -> b) -> b -> Set a -> b

foldl :: (b -> a -> b) -> b -> Set a -> b

foldl' :: (b -> a -> b) -> b -> Set a -> b

foldr1 :: (a -> a -> a) -> Set a -> a

foldl1 :: (a -> a -> a) -> Set a -> a

toList :: Set a -> [a]

null :: Set a -> Bool

length :: Set a -> Int

elem :: Eq a => a -> Set a -> Bool

maximum :: Ord a => Set a -> a

minimum :: Ord a => Set a -> a

sum :: Num a => Set a -> a

product :: Num a => Set a -> a

Foldable Hashed

Methods

fold :: Monoid m => Hashed m -> m

foldMap :: Monoid m => (a -> m) -> Hashed a -> m

foldr :: (a -> b -> b) -> b -> Hashed a -> b

foldr' :: (a -> b -> b) -> b -> Hashed a -> b

foldl :: (b -> a -> b) -> b -> Hashed a -> b

foldl' :: (b -> a -> b) -> b -> Hashed a -> b

foldr1 :: (a -> a -> a) -> Hashed a -> a

foldl1 :: (a -> a -> a) -> Hashed a -> a

toList :: Hashed a -> [a]

null :: Hashed a -> Bool

length :: Hashed a -> Int

elem :: Eq a => a -> Hashed a -> Bool

maximum :: Ord a => Hashed a -> a

minimum :: Ord a => Hashed a -> a

sum :: Num a => Hashed a -> a

product :: Num a => Hashed a -> a

Foldable Array

Methods

fold :: Monoid m => Array m -> m

foldMap :: Monoid m => (a -> m) -> Array a -> m

foldr :: (a -> b -> b) -> b -> Array a -> b

foldr' :: (a -> b -> b) -> b -> Array a -> b

foldl :: (b -> a -> b) -> b -> Array a -> b

foldl' :: (b -> a -> b) -> b -> Array a -> b

foldr1 :: (a -> a -> a) -> Array a -> a

foldl1 :: (a -> a -> a) -> Array a -> a

toList :: Array a -> [a]

null :: Array a -> Bool

length :: Array a -> Int

elem :: Eq a => a -> Array a -> Bool

maximum :: Ord a => Array a -> a

minimum :: Ord a => Array a -> a

sum :: Num a => Array a -> a

product :: Num a => Array a -> a

Foldable HashSet

Methods

fold :: Monoid m => HashSet m -> m

foldMap :: Monoid m => (a -> m) -> HashSet a -> m

foldr :: (a -> b -> b) -> b -> HashSet a -> b

foldr' :: (a -> b -> b) -> b -> HashSet a -> b

foldl :: (b -> a -> b) -> b -> HashSet a -> b

foldl' :: (b -> a -> b) -> b -> HashSet a -> b

foldr1 :: (a -> a -> a) -> HashSet a -> a

foldl1 :: (a -> a -> a) -> HashSet a -> a

toList :: HashSet a -> [a]

null :: HashSet a -> Bool

length :: HashSet a -> Int

elem :: Eq a => a -> HashSet a -> Bool

maximum :: Ord a => HashSet a -> a

minimum :: Ord a => HashSet a -> a

sum :: Num a => HashSet a -> a

product :: Num a => HashSet a -> a

Foldable Vector

Methods

fold :: Monoid m => Vector m -> m

foldMap :: Monoid m => (a -> m) -> Vector a -> m

foldr :: (a -> b -> b) -> b -> Vector a -> b

foldr' :: (a -> b -> b) -> b -> Vector a -> b

foldl :: (b -> a -> b) -> b -> Vector a -> b

foldl' :: (b -> a -> b) -> b -> Vector a -> b

foldr1 :: (a -> a -> a) -> Vector a -> a

foldl1 :: (a -> a -> a) -> Vector a -> a

toList :: Vector a -> [a]

null :: Vector a -> Bool

length :: Vector a -> Int

elem :: Eq a => a -> Vector a -> Bool

maximum :: Ord a => Vector a -> a

minimum :: Ord a => Vector a -> a

sum :: Num a => Vector a -> a

product :: Num a => Vector a -> a

Foldable (Either a)

Methods

fold :: Monoid m => Either a m -> m

foldMap :: Monoid m => (a -> m) -> Either a a -> m

foldr :: (a -> b -> b) -> b -> Either a a -> b

foldr' :: (a -> b -> b) -> b -> Either a a -> b

foldl :: (b -> a -> b) -> b -> Either a a -> b

foldl' :: (b -> a -> b) -> b -> Either a a -> b

foldr1 :: (a -> a -> a) -> Either a a -> a

foldl1 :: (a -> a -> a) -> Either a a -> a

toList :: Either a a -> [a]

null :: Either a a -> Bool

length :: Either a a -> Int

elem :: Eq a => a -> Either a a -> Bool

maximum :: Ord a => Either a a -> a

minimum :: Ord a => Either a a -> a

sum :: Num a => Either a a -> a

product :: Num a => Either a a -> a

Foldable f => Foldable (Rec1 f)

Methods

fold :: Monoid m => Rec1 f m -> m

foldMap :: Monoid m => (a -> m) -> Rec1 f a -> m

foldr :: (a -> b -> b) -> b -> Rec1 f a -> b

foldr' :: (a -> b -> b) -> b -> Rec1 f a -> b

foldl :: (b -> a -> b) -> b -> Rec1 f a -> b

foldl' :: (b -> a -> b) -> b -> Rec1 f a -> b

foldr1 :: (a -> a -> a) -> Rec1 f a -> a

foldl1 :: (a -> a -> a) -> Rec1 f a -> a

toList :: Rec1 f a -> [a]

null :: Rec1 f a -> Bool

length :: Rec1 f a -> Int

elem :: Eq a => a -> Rec1 f a -> Bool

maximum :: Ord a => Rec1 f a -> a

minimum :: Ord a => Rec1 f a -> a

sum :: Num a => Rec1 f a -> a

product :: Num a => Rec1 f a -> a

Foldable (URec Char)

Methods

fold :: Monoid m => URec Char m -> m

foldMap :: Monoid m => (a -> m) -> URec Char a -> m

foldr :: (a -> b -> b) -> b -> URec Char a -> b

foldr' :: (a -> b -> b) -> b -> URec Char a -> b

foldl :: (b -> a -> b) -> b -> URec Char a -> b

foldl' :: (b -> a -> b) -> b -> URec Char a -> b

foldr1 :: (a -> a -> a) -> URec Char a -> a

foldl1 :: (a -> a -> a) -> URec Char a -> a

toList :: URec Char a -> [a]

null :: URec Char a -> Bool

length :: URec Char a -> Int

elem :: Eq a => a -> URec Char a -> Bool

maximum :: Ord a => URec Char a -> a

minimum :: Ord a => URec Char a -> a

sum :: Num a => URec Char a -> a

product :: Num a => URec Char a -> a

Foldable (URec Double)

Methods

fold :: Monoid m => URec Double m -> m

foldMap :: Monoid m => (a -> m) -> URec Double a -> m

foldr :: (a -> b -> b) -> b -> URec Double a -> b

foldr' :: (a -> b -> b) -> b -> URec Double a -> b

foldl :: (b -> a -> b) -> b -> URec Double a -> b

foldl' :: (b -> a -> b) -> b -> URec Double a -> b

foldr1 :: (a -> a -> a) -> URec Double a -> a

foldl1 :: (a -> a -> a) -> URec Double a -> a

toList :: URec Double a -> [a]

null :: URec Double a -> Bool

length :: URec Double a -> Int

elem :: Eq a => a -> URec Double a -> Bool

maximum :: Ord a => URec Double a -> a

minimum :: Ord a => URec Double a -> a

sum :: Num a => URec Double a -> a

product :: Num a => URec Double a -> a

Foldable (URec Float)

Methods

fold :: Monoid m => URec Float m -> m

foldMap :: Monoid m => (a -> m) -> URec Float a -> m

foldr :: (a -> b -> b) -> b -> URec Float a -> b

foldr' :: (a -> b -> b) -> b -> URec Float a -> b

foldl :: (b -> a -> b) -> b -> URec Float a -> b

foldl' :: (b -> a -> b) -> b -> URec Float a -> b

foldr1 :: (a -> a -> a) -> URec Float a -> a

foldl1 :: (a -> a -> a) -> URec Float a -> a

toList :: URec Float a -> [a]

null :: URec Float a -> Bool

length :: URec Float a -> Int

elem :: Eq a => a -> URec Float a -> Bool

maximum :: Ord a => URec Float a -> a

minimum :: Ord a => URec Float a -> a

sum :: Num a => URec Float a -> a

product :: Num a => URec Float a -> a

Foldable (URec Int)

Methods

fold :: Monoid m => URec Int m -> m

foldMap :: Monoid m => (a -> m) -> URec Int a -> m

foldr :: (a -> b -> b) -> b -> URec Int a -> b

foldr' :: (a -> b -> b) -> b -> URec Int a -> b

foldl :: (b -> a -> b) -> b -> URec Int a -> b

foldl' :: (b -> a -> b) -> b -> URec Int a -> b

foldr1 :: (a -> a -> a) -> URec Int a -> a

foldl1 :: (a -> a -> a) -> URec Int a -> a

toList :: URec Int a -> [a]

null :: URec Int a -> Bool

length :: URec Int a -> Int

elem :: Eq a => a -> URec Int a -> Bool

maximum :: Ord a => URec Int a -> a

minimum :: Ord a => URec Int a -> a

sum :: Num a => URec Int a -> a

product :: Num a => URec Int a -> a

Foldable (URec Word)

Methods

fold :: Monoid m => URec Word m -> m

foldMap :: Monoid m => (a -> m) -> URec Word a -> m

foldr :: (a -> b -> b) -> b -> URec Word a -> b

foldr' :: (a -> b -> b) -> b -> URec Word a -> b

foldl :: (b -> a -> b) -> b -> URec Word a -> b

foldl' :: (b -> a -> b) -> b -> URec Word a -> b

foldr1 :: (a -> a -> a) -> URec Word a -> a

foldl1 :: (a -> a -> a) -> URec Word a -> a

toList :: URec Word a -> [a]

null :: URec Word a -> Bool

length :: URec Word a -> Int

elem :: Eq a => a -> URec Word a -> Bool

maximum :: Ord a => URec Word a -> a

minimum :: Ord a => URec Word a -> a

sum :: Num a => URec Word a -> a

product :: Num a => URec Word a -> a

Foldable (URec (Ptr ()))

Methods

fold :: Monoid m => URec (Ptr ()) m -> m

foldMap :: Monoid m => (a -> m) -> URec (Ptr ()) a -> m

foldr :: (a -> b -> b) -> b -> URec (Ptr ()) a -> b

foldr' :: (a -> b -> b) -> b -> URec (Ptr ()) a -> b

foldl :: (b -> a -> b) -> b -> URec (Ptr ()) a -> b

foldl' :: (b -> a -> b) -> b -> URec (Ptr ()) a -> b

foldr1 :: (a -> a -> a) -> URec (Ptr ()) a -> a

foldl1 :: (a -> a -> a) -> URec (Ptr ()) a -> a

toList :: URec (Ptr ()) a -> [a]

null :: URec (Ptr ()) a -> Bool

length :: URec (Ptr ()) a -> Int

elem :: Eq a => a -> URec (Ptr ()) a -> Bool

maximum :: Ord a => URec (Ptr ()) a -> a

minimum :: Ord a => URec (Ptr ()) a -> a

sum :: Num a => URec (Ptr ()) a -> a

product :: Num a => URec (Ptr ()) a -> a

Foldable ((,) a)

Methods

fold :: Monoid m => (a, m) -> m

foldMap :: Monoid m => (a -> m) -> (a, a) -> m

foldr :: (a -> b -> b) -> b -> (a, a) -> b

foldr' :: (a -> b -> b) -> b -> (a, a) -> b

foldl :: (b -> a -> b) -> b -> (a, a) -> b

foldl' :: (b -> a -> b) -> b -> (a, a) -> b

foldr1 :: (a -> a -> a) -> (a, a) -> a

foldl1 :: (a -> a -> a) -> (a, a) -> a

toList :: (a, a) -> [a]

null :: (a, a) -> Bool

length :: (a, a) -> Int

elem :: Eq a => a -> (a, a) -> Bool

maximum :: Ord a => (a, a) -> a

minimum :: Ord a => (a, a) -> a

sum :: Num a => (a, a) -> a

product :: Num a => (a, a) -> a

Foldable (Array i)

Methods

fold :: Monoid m => Array i m -> m

foldMap :: Monoid m => (a -> m) -> Array i a -> m

foldr :: (a -> b -> b) -> b -> Array i a -> b

foldr' :: (a -> b -> b) -> b -> Array i a -> b

foldl :: (b -> a -> b) -> b -> Array i a -> b

foldl' :: (b -> a -> b) -> b -> Array i a -> b

foldr1 :: (a -> a -> a) -> Array i a -> a

foldl1 :: (a -> a -> a) -> Array i a -> a

toList :: Array i a -> [a]

null :: Array i a -> Bool

length :: Array i a -> Int

elem :: Eq a => a -> Array i a -> Bool

maximum :: Ord a => Array i a -> a

minimum :: Ord a => Array i a -> a

sum :: Num a => Array i a -> a

product :: Num a => Array i a -> a

Foldable (Arg a)

Methods

fold :: Monoid m => Arg a m -> m

foldMap :: Monoid m => (a -> m) -> Arg a a -> m

foldr :: (a -> b -> b) -> b -> Arg a a -> b

foldr' :: (a -> b -> b) -> b -> Arg a a -> b

foldl :: (b -> a -> b) -> b -> Arg a a -> b

foldl' :: (b -> a -> b) -> b -> Arg a a -> b

foldr1 :: (a -> a -> a) -> Arg a a -> a

foldl1 :: (a -> a -> a) -> Arg a a -> a

toList :: Arg a a -> [a]

null :: Arg a a -> Bool

length :: Arg a a -> Int

elem :: Eq a => a -> Arg a a -> Bool

maximum :: Ord a => Arg a a -> a

minimum :: Ord a => Arg a a -> a

sum :: Num a => Arg a a -> a

product :: Num a => Arg a a -> a

Foldable (Proxy *)

Methods

fold :: Monoid m => Proxy * m -> m

foldMap :: Monoid m => (a -> m) -> Proxy * a -> m

foldr :: (a -> b -> b) -> b -> Proxy * a -> b

foldr' :: (a -> b -> b) -> b -> Proxy * a -> b

foldl :: (b -> a -> b) -> b -> Proxy * a -> b

foldl' :: (b -> a -> b) -> b -> Proxy * a -> b

foldr1 :: (a -> a -> a) -> Proxy * a -> a

foldl1 :: (a -> a -> a) -> Proxy * a -> a

toList :: Proxy * a -> [a]

null :: Proxy * a -> Bool

length :: Proxy * a -> Int

elem :: Eq a => a -> Proxy * a -> Bool

maximum :: Ord a => Proxy * a -> a

minimum :: Ord a => Proxy * a -> a

sum :: Num a => Proxy * a -> a

product :: Num a => Proxy * a -> a

Foldable (Map k)

Methods

fold :: Monoid m => Map k m -> m

foldMap :: Monoid m => (a -> m) -> Map k a -> m

foldr :: (a -> b -> b) -> b -> Map k a -> b

foldr' :: (a -> b -> b) -> b -> Map k a -> b

foldl :: (b -> a -> b) -> b -> Map k a -> b

foldl' :: (b -> a -> b) -> b -> Map k a -> b

foldr1 :: (a -> a -> a) -> Map k a -> a

foldl1 :: (a -> a -> a) -> Map k a -> a

toList :: Map k a -> [a]

null :: Map k a -> Bool

length :: Map k a -> Int

elem :: Eq a => a -> Map k a -> Bool

maximum :: Ord a => Map k a -> a

minimum :: Ord a => Map k a -> a

sum :: Num a => Map k a -> a

product :: Num a => Map k a -> a

Foldable f => Foldable (MaybeT f)

Methods

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

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

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

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

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

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

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

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

toList :: MaybeT f a -> [a]

null :: MaybeT f a -> Bool

length :: MaybeT f a -> Int

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

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

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

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

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

Foldable f => Foldable (ListT f)

Methods

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

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

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

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

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

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

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

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

toList :: ListT f a -> [a]

null :: ListT f a -> Bool

length :: ListT f a -> Int

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

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

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

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

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

Foldable (HashMap k)

Methods

fold :: Monoid m => HashMap k m -> m

foldMap :: Monoid m => (a -> m) -> HashMap k a -> m

foldr :: (a -> b -> b) -> b -> HashMap k a -> b

foldr' :: (a -> b -> b) -> b -> HashMap k a -> b

foldl :: (b -> a -> b) -> b -> HashMap k a -> b

foldl' :: (b -> a -> b) -> b -> HashMap k a -> b

foldr1 :: (a -> a -> a) -> HashMap k a -> a

foldl1 :: (a -> a -> a) -> HashMap k a -> a

toList :: HashMap k a -> [a]

null :: HashMap k a -> Bool

length :: HashMap k a -> Int

elem :: Eq a => a -> HashMap k a -> Bool

maximum :: Ord a => HashMap k a -> a

minimum :: Ord a => HashMap k a -> a

sum :: Num a => HashMap k a -> a

product :: Num a => HashMap k a -> a

Foldable (K1 i c)

Methods

fold :: Monoid m => K1 i c m -> m

foldMap :: Monoid m => (a -> m) -> K1 i c a -> m

foldr :: (a -> b -> b) -> b -> K1 i c a -> b

foldr' :: (a -> b -> b) -> b -> K1 i c a -> b

foldl :: (b -> a -> b) -> b -> K1 i c a -> b

foldl' :: (b -> a -> b) -> b -> K1 i c a -> b

foldr1 :: (a -> a -> a) -> K1 i c a -> a

foldl1 :: (a -> a -> a) -> K1 i c a -> a

toList :: K1 i c a -> [a]

null :: K1 i c a -> Bool

length :: K1 i c a -> Int

elem :: Eq a => a -> K1 i c a -> Bool

maximum :: Ord a => K1 i c a -> a

minimum :: Ord a => K1 i c a -> a

sum :: Num a => K1 i c a -> a

product :: Num a => K1 i c a -> a

(Foldable f, Foldable g) => Foldable ((:+:) f g)

Methods

fold :: Monoid m => (f :+: g) m -> m

foldMap :: Monoid m => (a -> m) -> (f :+: g) a -> m

foldr :: (a -> b -> b) -> b -> (f :+: g) a -> b

foldr' :: (a -> b -> b) -> b -> (f :+: g) a -> b

foldl :: (b -> a -> b) -> b -> (f :+: g) a -> b

foldl' :: (b -> a -> b) -> b -> (f :+: g) a -> b

foldr1 :: (a -> a -> a) -> (f :+: g) a -> a

foldl1 :: (a -> a -> a) -> (f :+: g) a -> a

toList :: (f :+: g) a -> [a]

null :: (f :+: g) a -> Bool

length :: (f :+: g) a -> Int

elem :: Eq a => a -> (f :+: g) a -> Bool

maximum :: Ord a => (f :+: g) a -> a

minimum :: Ord a => (f :+: g) a -> a

sum :: Num a => (f :+: g) a -> a

product :: Num a => (f :+: g) a -> a

(Foldable f, Foldable g) => Foldable ((:*:) f g)

Methods

fold :: Monoid m => (f :*: g) m -> m

foldMap :: Monoid m => (a -> m) -> (f :*: g) a -> m

foldr :: (a -> b -> b) -> b -> (f :*: g) a -> b

foldr' :: (a -> b -> b) -> b -> (f :*: g) a -> b

foldl :: (b -> a -> b) -> b -> (f :*: g) a -> b

foldl' :: (b -> a -> b) -> b -> (f :*: g) a -> b

foldr1 :: (a -> a -> a) -> (f :*: g) a -> a

foldl1 :: (a -> a -> a) -> (f :*: g) a -> a

toList :: (f :*: g) a -> [a]

null :: (f :*: g) a -> Bool

length :: (f :*: g) a -> Int

elem :: Eq a => a -> (f :*: g) a -> Bool

maximum :: Ord a => (f :*: g) a -> a

minimum :: Ord a => (f :*: g) a -> a

sum :: Num a => (f :*: g) a -> a

product :: Num a => (f :*: g) a -> a

(Foldable f, Foldable g) => Foldable ((:.:) f g)

Methods

fold :: Monoid m => (f :.: g) m -> m

foldMap :: Monoid m => (a -> m) -> (f :.: g) a -> m

foldr :: (a -> b -> b) -> b -> (f :.: g) a -> b

foldr' :: (a -> b -> b) -> b -> (f :.: g) a -> b

foldl :: (b -> a -> b) -> b -> (f :.: g) a -> b

foldl' :: (b -> a -> b) -> b -> (f :.: g) a -> b

foldr1 :: (a -> a -> a) -> (f :.: g) a -> a

foldl1 :: (a -> a -> a) -> (f :.: g) a -> a

toList :: (f :.: g) a -> [a]

null :: (f :.: g) a -> Bool

length :: (f :.: g) a -> Int

elem :: Eq a => a -> (f :.: g) a -> Bool

maximum :: Ord a => (f :.: g) a -> a

minimum :: Ord a => (f :.: g) a -> a

sum :: Num a => (f :.: g) a -> a

product :: Num a => (f :.: g) a -> a

Foldable (Const * m)

Methods

fold :: Monoid m => Const * m m -> m

foldMap :: Monoid m => (a -> m) -> Const * m a -> m

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

Foldable f => Foldable (WriterT w f)

Methods

fold :: Monoid m => WriterT w f m -> m

foldMap :: Monoid m => (a -> m) -> WriterT w f a -> m

foldr :: (a -> b -> b) -> b -> WriterT w f a -> b

foldr' :: (a -> b -> b) -> b -> WriterT w f a -> b

foldl :: (b -> a -> b) -> b -> WriterT w f a -> b

foldl' :: (b -> a -> b) -> b -> WriterT w f a -> b

foldr1 :: (a -> a -> a) -> WriterT w f a -> a

foldl1 :: (a -> a -> a) -> WriterT w f a -> a

toList :: WriterT w f a -> [a]

null :: WriterT w f a -> Bool

length :: WriterT w f a -> Int

elem :: Eq a => a -> WriterT w f a -> Bool

maximum :: Ord a => WriterT w f a -> a

minimum :: Ord a => WriterT w f a -> a

sum :: Num a => WriterT w f a -> a

product :: Num a => WriterT w f a -> a

Foldable f => Foldable (WriterT w f)

Methods

fold :: Monoid m => WriterT w f m -> m

foldMap :: Monoid m => (a -> m) -> WriterT w f a -> m

foldr :: (a -> b -> b) -> b -> WriterT w f a -> b

foldr' :: (a -> b -> b) -> b -> WriterT w f a -> b

foldl :: (b -> a -> b) -> b -> WriterT w f a -> b

foldl' :: (b -> a -> b) -> b -> WriterT w f a -> b

foldr1 :: (a -> a -> a) -> WriterT w f a -> a

foldl1 :: (a -> a -> a) -> WriterT w f a -> a

toList :: WriterT w f a -> [a]

null :: WriterT w f a -> Bool

length :: WriterT w f a -> Int

elem :: Eq a => a -> WriterT w f a -> Bool

maximum :: Ord a => WriterT w f a -> a

minimum :: Ord a => WriterT w f a -> a

sum :: Num a => WriterT w f a -> a

product :: Num a => WriterT w f a -> a

Foldable f => Foldable (IdentityT * f)

Methods

fold :: Monoid m => IdentityT * f m -> m

foldMap :: Monoid m => (a -> m) -> IdentityT * f a -> m

foldr :: (a -> b -> b) -> b -> IdentityT * f a -> b

foldr' :: (a -> b -> b) -> b -> IdentityT * f a -> b

foldl :: (b -> a -> b) -> b -> IdentityT * f a -> b

foldl' :: (b -> a -> b) -> b -> IdentityT * f a -> b

foldr1 :: (a -> a -> a) -> IdentityT * f a -> a

foldl1 :: (a -> a -> a) -> IdentityT * f a -> a

toList :: IdentityT * f a -> [a]

null :: IdentityT * f a -> Bool

length :: IdentityT * f a -> Int

elem :: Eq a => a -> IdentityT * f a -> Bool

maximum :: Ord a => IdentityT * f a -> a

minimum :: Ord a => IdentityT * f a -> a

sum :: Num a => IdentityT * f a -> a

product :: Num a => IdentityT * f a -> a

Foldable f => Foldable (ExceptT e f)

Methods

fold :: Monoid m => ExceptT e f m -> m

foldMap :: Monoid m => (a -> m) -> ExceptT e f a -> m

foldr :: (a -> b -> b) -> b -> ExceptT e f a -> b

foldr' :: (a -> b -> b) -> b -> ExceptT e f a -> b

foldl :: (b -> a -> b) -> b -> ExceptT e f a -> b

foldl' :: (b -> a -> b) -> b -> ExceptT e f a -> b

foldr1 :: (a -> a -> a) -> ExceptT e f a -> a

foldl1 :: (a -> a -> a) -> ExceptT e f a -> a

toList :: ExceptT e f a -> [a]

null :: ExceptT e f a -> Bool

length :: ExceptT e f a -> Int

elem :: Eq a => a -> ExceptT e f a -> Bool

maximum :: Ord a => ExceptT e f a -> a

minimum :: Ord a => ExceptT e f a -> a

sum :: Num a => ExceptT e f a -> a

product :: Num a => ExceptT e f a -> a

Foldable f => Foldable (ErrorT e f)

Methods

fold :: Monoid m => ErrorT e f m -> m

foldMap :: Monoid m => (a -> m) -> ErrorT e f a -> m

foldr :: (a -> b -> b) -> b -> ErrorT e f a -> b

foldr' :: (a -> b -> b) -> b -> ErrorT e f a -> b

foldl :: (b -> a -> b) -> b -> ErrorT e f a -> b

foldl' :: (b -> a -> b) -> b -> ErrorT e f a -> b

foldr1 :: (a -> a -> a) -> ErrorT e f a -> a

foldl1 :: (a -> a -> a) -> ErrorT e f a -> a

toList :: ErrorT e f a -> [a]

null :: ErrorT e f a -> Bool

length :: ErrorT e f a -> Int

elem :: Eq a => a -> ErrorT e f a -> Bool

maximum :: Ord a => ErrorT e f a -> a

minimum :: Ord a => ErrorT e f a -> a

sum :: Num a => ErrorT e f a -> a

product :: Num a => ErrorT e f a -> a

Foldable f => Foldable (M1 i c f)

Methods

fold :: Monoid m => M1 i c f m -> m

foldMap :: Monoid m => (a -> m) -> M1 i c f a -> m

foldr :: (a -> b -> b) -> b -> M1 i c f a -> b

foldr' :: (a -> b -> b) -> b -> M1 i c f a -> b

foldl :: (b -> a -> b) -> b -> M1 i c f a -> b

foldl' :: (b -> a -> b) -> b -> M1 i c f a -> b

foldr1 :: (a -> a -> a) -> M1 i c f a -> a

foldl1 :: (a -> a -> a) -> M1 i c f a -> a

toList :: M1 i c f a -> [a]

null :: M1 i c f a -> Bool

length :: M1 i c f a -> Int

elem :: Eq a => a -> M1 i c f a -> Bool

maximum :: Ord a => M1 i c f a -> a

minimum :: Ord a => M1 i c f a -> a

sum :: Num a => M1 i c f a -> a

product :: Num a => M1 i c f a -> a

(Foldable f, Foldable g) => Foldable (Sum * f g)

Methods

fold :: Monoid m => Sum * f g m -> m

foldMap :: Monoid m => (a -> m) -> Sum * f g a -> m

foldr :: (a -> b -> b) -> b -> Sum * f g a -> b

foldr' :: (a -> b -> b) -> b -> Sum * f g a -> b

foldl :: (b -> a -> b) -> b -> Sum * f g a -> b

foldl' :: (b -> a -> b) -> b -> Sum * f g a -> b

foldr1 :: (a -> a -> a) -> Sum * f g a -> a

foldl1 :: (a -> a -> a) -> Sum * f g a -> a

toList :: Sum * f g a -> [a]

null :: Sum * f g a -> Bool

length :: Sum * f g a -> Int

elem :: Eq a => a -> Sum * f g a -> Bool

maximum :: Ord a => Sum * f g a -> a

minimum :: Ord a => Sum * f g a -> a

sum :: Num a => Sum * f g a -> a

product :: Num a => Sum * f g a -> a

(Foldable f, Foldable g) => Foldable (Product * f g)

Methods

fold :: Monoid m => Product * f g m -> m

foldMap :: Monoid m => (a -> m) -> Product * f g a -> m

foldr :: (a -> b -> b) -> b -> Product * f g a -> b

foldr' :: (a -> b -> b) -> b -> Product * f g a -> b

foldl :: (b -> a -> b) -> b -> Product * f g a -> b

foldl' :: (b -> a -> b) -> b -> Product * f g a -> b

foldr1 :: (a -> a -> a) -> Product * f g a -> a

foldl1 :: (a -> a -> a) -> Product * f g a -> a

toList :: Product * f g a -> [a]

null :: Product * f g a -> Bool

length :: Product * f g a -> Int

elem :: Eq a => a -> Product * f g a -> Bool

maximum :: Ord a => Product * f g a -> a

minimum :: Ord a => Product * f g a -> a

sum :: Num a => Product * f g a -> a

product :: Num a => Product * f g a -> a

(Foldable f, Foldable g) => Foldable (Compose * * f g)

Methods

fold :: Monoid m => Compose * * f g m -> m

foldMap :: Monoid m => (a -> m) -> Compose * * f g a -> m

foldr :: (a -> b -> b) -> b -> Compose * * f g a -> b

foldr' :: (a -> b -> b) -> b -> Compose * * f g a -> b

foldl :: (b -> a -> b) -> b -> Compose * * f g a -> b

foldl' :: (b -> a -> b) -> b -> Compose * * f g a -> b

foldr1 :: (a -> a -> a) -> Compose * * f g a -> a

foldl1 :: (a -> a -> a) -> Compose * * f g a -> a

toList :: Compose * * f g a -> [a]

null :: Compose * * f g a -> Bool

length :: Compose * * f g a -> Int

elem :: Eq a => a -> Compose * * f g a -> Bool

maximum :: Ord a => Compose * * f g a -> a

minimum :: Ord a => Compose * * f g a -> a

sum :: Num a => Compose * * f g a -> a

product :: Num a => Compose * * f g a -> a

elem :: Foldable t => forall a. Eq a => a -> t a -> Bool

Does the element occur in the structure?

maximum :: Foldable t => forall a. Ord a => t a -> a

The largest element of a non-empty structure.

minimum :: Foldable t => forall a. Ord a => t a -> a

The least element of a non-empty structure.

traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f ()

Map each element of a structure to an action, evaluate these actions from left to right, and ignore the results. For a version that doesn't ignore the results see traverse.

sequenceA_ :: (Foldable t, Applicative f) => t (f a) -> f ()

Evaluate each action in the structure from left to right, and ignore the results. For a version that doesn't ignore the results see sequenceA.

for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f ()

for_ is traverse_ with its arguments flipped. For a version that doesn't ignore the results see for.

>>> for_ [1..4] print
1
2
3
4

maximumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a

minimumBy :: Foldable t => (a -> a -> Ordering) -> t a -> a

class (Functor t, Foldable t) => Traversable t where

Functors representing data structures that can be traversed from left to right.

A definition of traverse must satisfy the following laws:

naturality

t . traverse f = traverse (t . f) for every applicative transformation t

identity

traverse Identity = Identity

composition

traverse (Compose . fmap g . f) = Compose . fmap (traverse g) . traverse f

A definition of sequenceA must satisfy the following laws:

naturality

t . sequenceA = sequenceA . fmap t for every applicative transformation t

identity

sequenceA . fmap Identity = Identity

composition

sequenceA . fmap Compose = Compose . fmap sequenceA . sequenceA

where an applicative transformation is a function

t :: (Applicative f, Applicative g) => f a -> g a

preserving the Applicative operations, i.e.

• t (pure x) = pure x

• t (x <*> y) = t x <*> t y

and the identity functor Identity and composition of functors Compose are defined as

  newtype Identity a = Identity a

  instance Functor Identity where
    fmap f (Identity x) = Identity (f x)

  instance Applicative Identity where
    pure x = Identity x
    Identity f <*> Identity x = Identity (f x)

  newtype Compose f g a = Compose (f (g a))

  instance (Functor f, Functor g) => Functor (Compose f g) where
    fmap f (Compose x) = Compose (fmap (fmap f) x)

  instance (Applicative f, Applicative g) => Applicative (Compose f g) where
    pure x = Compose (pure (pure x))
    Compose f <*> Compose x = Compose ((<*>) <$> f <*> x)

(The naturality law is implied by parametricity.)

Instances are similar to Functor, e.g. given a data type

data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)

a suitable instance would be

instance Traversable Tree where
   traverse f Empty = pure Empty
   traverse f (Leaf x) = Leaf <$> f x
   traverse f (Node l k r) = Node <$> traverse f l <*> f k <*> traverse f r

This is suitable even for abstract types, as the laws for <*> imply a form of associativity.

The superclass instances should satisfy the following:

• In the Functor instance, fmap should be equivalent to traversal with the identity applicative functor (fmapDefault).
• In the Foldable instance, foldMap should be equivalent to traversal with a constant applicative functor (foldMapDefault).

Minimal complete definition

traverse | sequenceA

Methods

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

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

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

Evaluate each action in the structure from left to right, and and collect the results. For a version that ignores the results see sequenceA_.

mapM :: 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_.

sequence :: Monad m => t (m a) -> m (t a)

Evaluate each monadic action in the structure from left to right, and collect the results. For a version that ignores the results see sequence_.

Instances

Traversable []

Methods

traverse :: Applicative f => (a -> f b) -> [a] -> f [b]

sequenceA :: Applicative f => [f a] -> f [a]

mapM :: Monad m => (a -> m b) -> [a] -> m [b]

sequence :: Monad m => [m a] -> m [a]

Traversable Maybe

Methods

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

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

mapM :: Monad m => (a -> m b) -> Maybe a -> m (Maybe b)

sequence :: Monad m => Maybe (m a) -> m (Maybe a)

Traversable V1

Methods

traverse :: Applicative f => (a -> f b) -> V1 a -> f (V1 b)

sequenceA :: Applicative f => V1 (f a) -> f (V1 a)

mapM :: Monad m => (a -> m b) -> V1 a -> m (V1 b)

sequence :: Monad m => V1 (m a) -> m (V1 a)

Traversable U1

Methods

traverse :: Applicative f => (a -> f b) -> U1 a -> f (U1 b)

sequenceA :: Applicative f => U1 (f a) -> f (U1 a)

mapM :: Monad m => (a -> m b) -> U1 a -> m (U1 b)

sequence :: Monad m => U1 (m a) -> m (U1 a)

Traversable Par1

Methods

traverse :: Applicative f => (a -> f b) -> Par1 a -> f (Par1 b)

sequenceA :: Applicative f => Par1 (f a) -> f (Par1 a)

mapM :: Monad m => (a -> m b) -> Par1 a -> m (Par1 b)

sequence :: Monad m => Par1 (m a) -> m (Par1 a)

Traversable Identity

Methods

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

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

mapM :: Monad m => (a -> m b) -> Identity a -> m (Identity b)

sequence :: Monad m => Identity (m a) -> m (Identity a)

Traversable Min

Methods

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

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

mapM :: Monad m => (a -> m b) -> Min a -> m (Min b)

sequence :: Monad m => Min (m a) -> m (Min a)

Traversable Max

Methods

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

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

mapM :: Monad m => (a -> m b) -> Max a -> m (Max b)

sequence :: Monad m => Max (m a) -> m (Max a)

Traversable First

Methods

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

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

mapM :: Monad m => (a -> m b) -> First a -> m (First b)

sequence :: Monad m => First (m a) -> m (First a)

Traversable Last

Methods

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

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

mapM :: Monad m => (a -> m b) -> Last a -> m (Last b)

sequence :: Monad m => Last (m a) -> m (Last a)

Traversable Option

Methods

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

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

mapM :: Monad m => (a -> m b) -> Option a -> m (Option b)

sequence :: Monad m => Option (m a) -> m (Option a)

Traversable NonEmpty

Methods

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

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

mapM :: Monad m => (a -> m b) -> NonEmpty a -> m (NonEmpty b)

sequence :: Monad m => NonEmpty (m a) -> m (NonEmpty a)

Traversable Complex

Methods

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

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

mapM :: Monad m => (a -> m b) -> Complex a -> m (Complex b)

sequence :: Monad m => Complex (m a) -> m (Complex a)

Traversable ZipList

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)

Traversable Dual

Methods

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

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

mapM :: Monad m => (a -> m b) -> Dual a -> m (Dual b)

sequence :: Monad m => Dual (m a) -> m (Dual a)

Traversable Sum

Methods

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

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

mapM :: Monad m => (a -> m b) -> Sum a -> m (Sum b)

sequence :: Monad m => Sum (m a) -> m (Sum a)

Traversable Product

Methods

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

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

mapM :: Monad m => (a -> m b) -> Product a -> m (Product b)

sequence :: Monad m => Product (m a) -> m (Product a)

Traversable First

Methods

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

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

mapM :: Monad m => (a -> m b) -> First a -> m (First b)

sequence :: Monad m => First (m a) -> m (First a)

Traversable Last

Methods

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

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

mapM :: Monad m => (a -> m b) -> Last a -> m (Last b)

sequence :: Monad m => Last (m a) -> m (Last a)

Traversable Digit

Methods

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

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

mapM :: Monad m => (a -> m b) -> Digit a -> m (Digit b)

sequence :: Monad m => Digit (m a) -> m (Digit a)

Traversable Node

Methods

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

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

mapM :: Monad m => (a -> m b) -> Node a -> m (Node b)

sequence :: Monad m => Node (m a) -> m (Node a)

Traversable Elem

Methods

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

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

mapM :: Monad m => (a -> m b) -> Elem a -> m (Elem b)

sequence :: Monad m => Elem (m a) -> m (Elem a)

Traversable FingerTree

Methods

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

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

mapM :: Monad m => (a -> m b) -> FingerTree a -> m (FingerTree b)

sequence :: Monad m => FingerTree (m a) -> m (FingerTree a)

Traversable IntMap

Methods

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

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

mapM :: Monad m => (a -> m b) -> IntMap a -> m (IntMap b)

sequence :: Monad m => IntMap (m a) -> m (IntMap a)

Traversable Seq

Methods

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

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

mapM :: Monad m => (a -> m b) -> Seq a -> m (Seq b)

sequence :: Monad m => Seq (m a) -> m (Seq a)

Traversable ViewL

Methods

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

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

mapM :: Monad m => (a -> m b) -> ViewL a -> m (ViewL b)

sequence :: Monad m => ViewL (m a) -> m (ViewL a)

Traversable ViewR

Methods

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

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

mapM :: Monad m => (a -> m b) -> ViewR a -> m (ViewR b)

sequence :: Monad m => ViewR (m a) -> m (ViewR a)

Traversable Array

Methods

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

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

mapM :: Monad m => (a -> m b) -> Array a -> m (Array b)

sequence :: Monad m => Array (m a) -> m (Array a)

Traversable Vector

Methods

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

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

mapM :: Monad m => (a -> m b) -> Vector a -> m (Vector b)

sequence :: Monad m => Vector (m a) -> m (Vector a)

Traversable (Either a)

Methods

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

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

mapM :: Monad m => (a -> m b) -> Either a a -> m (Either a b)

sequence :: Monad m => Either a (m a) -> m (Either a a)

Traversable f => Traversable (Rec1 f)

Methods

traverse :: Applicative f => (a -> f b) -> Rec1 f a -> f (Rec1 f b)

sequenceA :: Applicative f => Rec1 f (f a) -> f (Rec1 f a)

mapM :: Monad m => (a -> m b) -> Rec1 f a -> m (Rec1 f b)

sequence :: Monad m => Rec1 f (m a) -> m (Rec1 f a)

Traversable (URec Char)

Methods

traverse :: Applicative f => (a -> f b) -> URec Char a -> f (URec Char b)

sequenceA :: Applicative f => URec Char (f a) -> f (URec Char a)

mapM :: Monad m => (a -> m b) -> URec Char a -> m (URec Char b)

sequence :: Monad m => URec Char (m a) -> m (URec Char a)

Traversable (URec Double)

Methods

traverse :: Applicative f => (a -> f b) -> URec Double a -> f (URec Double b)

sequenceA :: Applicative f => URec Double (f a) -> f (URec Double a)

mapM :: Monad m => (a -> m b) -> URec Double a -> m (URec Double b)

sequence :: Monad m => URec Double (m a) -> m (URec Double a)

Traversable (URec Float)

Methods

traverse :: Applicative f => (a -> f b) -> URec Float a -> f (URec Float b)

sequenceA :: Applicative f => URec Float (f a) -> f (URec Float a)

mapM :: Monad m => (a -> m b) -> URec Float a -> m (URec Float b)

sequence :: Monad m => URec Float (m a) -> m (URec Float a)

Traversable (URec Int)

Methods

traverse :: Applicative f => (a -> f b) -> URec Int a -> f (URec Int b)

sequenceA :: Applicative f => URec Int (f a) -> f (URec Int a)

mapM :: Monad m => (a -> m b) -> URec Int a -> m (URec Int b)

sequence :: Monad m => URec Int (m a) -> m (URec Int a)

Traversable (URec Word)

Methods

traverse :: Applicative f => (a -> f b) -> URec Word a -> f (URec Word b)

sequenceA :: Applicative f => URec Word (f a) -> f (URec Word a)

mapM :: Monad m => (a -> m b) -> URec Word a -> m (URec Word b)

sequence :: Monad m => URec Word (m a) -> m (URec Word a)

Traversable (URec (Ptr ()))

Methods

traverse :: Applicative f => (a -> f b) -> URec (Ptr ()) a -> f (URec (Ptr ()) b)

sequenceA :: Applicative f => URec (Ptr ()) (f a) -> f (URec (Ptr ()) a)

mapM :: Monad m => (a -> m b) -> URec (Ptr ()) a -> m (URec (Ptr ()) b)

sequence :: Monad m => URec (Ptr ()) (m a) -> m (URec (Ptr ()) a)

Traversable ((,) a)

Methods

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

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

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

sequence :: Monad m => (a, m a) -> m (a, a)

Ix i => Traversable (Array i)

Methods

traverse :: Applicative f => (a -> f b) -> Array i a -> f (Array i b)

sequenceA :: Applicative f => Array i (f a) -> f (Array i a)

mapM :: Monad m => (a -> m b) -> Array i a -> m (Array i b)

sequence :: Monad m => Array i (m a) -> m (Array i a)

Traversable (Arg a)

Methods

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

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

mapM :: Monad m => (a -> m b) -> Arg a a -> m (Arg a b)

sequence :: Monad m => Arg a (m a) -> m (Arg a a)

Traversable (Proxy *)

Methods

traverse :: Applicative f => (a -> f b) -> Proxy * a -> f (Proxy * b)

sequenceA :: Applicative f => Proxy * (f a) -> f (Proxy * a)

mapM :: Monad m => (a -> m b) -> Proxy * a -> m (Proxy * b)

sequence :: Monad m => Proxy * (m a) -> m (Proxy * a)

Traversable (Map k)

Methods

traverse :: Applicative f => (a -> f b) -> Map k a -> f (Map k b)

sequenceA :: Applicative f => Map k (f a) -> f (Map k a)

mapM :: Monad m => (a -> m b) -> Map k a -> m (Map k b)

sequence :: Monad m => Map k (m a) -> m (Map k a)

Traversable f => Traversable (MaybeT f)

Methods

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

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

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

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

Traversable f => Traversable (ListT f)

Methods

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

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

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

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

Traversable (HashMap k)

Methods

traverse :: Applicative f => (a -> f b) -> HashMap k a -> f (HashMap k b)

sequenceA :: Applicative f => HashMap k (f a) -> f (HashMap k a)

mapM :: Monad m => (a -> m b) -> HashMap k a -> m (HashMap k b)

sequence :: Monad m => HashMap k (m a) -> m (HashMap k a)

Traversable (K1 i c)

Methods

traverse :: Applicative f => (a -> f b) -> K1 i c a -> f (K1 i c b)

sequenceA :: Applicative f => K1 i c (f a) -> f (K1 i c a)

mapM :: Monad m => (a -> m b) -> K1 i c a -> m (K1 i c b)

sequence :: Monad m => K1 i c (m a) -> m (K1 i c a)

(Traversable f, Traversable g) => Traversable ((:+:) f g)

Methods

traverse :: Applicative f => (a -> f b) -> (f :+: g) a -> f ((f :+: g) b)

sequenceA :: Applicative f => (f :+: g) (f a) -> f ((f :+: g) a)

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

sequence :: Monad m => (f :+: g) (m a) -> m ((f :+: g) a)

(Traversable f, Traversable g) => Traversable ((:*:) f g)

Methods

traverse :: Applicative f => (a -> f b) -> (f :*: g) a -> f ((f :*: g) b)

sequenceA :: Applicative f => (f :*: g) (f a) -> f ((f :*: g) a)

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

sequence :: Monad m => (f :*: g) (m a) -> m ((f :*: g) a)

(Traversable f, Traversable g) => Traversable ((:.:) f g)

Methods

traverse :: Applicative f => (a -> f b) -> (f :.: g) a -> f ((f :.: g) b)

sequenceA :: Applicative f => (f :.: g) (f a) -> f ((f :.: g) a)

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

sequence :: Monad m => (f :.: g) (m a) -> m ((f :.: g) a)

Traversable (Const * m)

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 m => (a -> m b) -> Const * m a -> m (Const * m b)

sequence :: Monad m => Const * m (m a) -> m (Const * m a)

Traversable f => Traversable (WriterT w f)

Methods

traverse :: Applicative f => (a -> f b) -> WriterT w f a -> f (WriterT w f b)

sequenceA :: Applicative f => WriterT w f (f a) -> f (WriterT w f a)

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

sequence :: Monad m => WriterT w f (m a) -> m (WriterT w f a)

Traversable f => Traversable (WriterT w f)

Methods

traverse :: Applicative f => (a -> f b) -> WriterT w f a -> f (WriterT w f b)

sequenceA :: Applicative f => WriterT w f (f a) -> f (WriterT w f a)

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

sequence :: Monad m => WriterT w f (m a) -> m (WriterT w f a)

Traversable f => Traversable (IdentityT * f)

Methods

traverse :: Applicative f => (a -> f b) -> IdentityT * f a -> f (IdentityT * f b)

sequenceA :: Applicative f => IdentityT * f (f a) -> f (IdentityT * f a)

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

sequence :: Monad m => IdentityT * f (m a) -> m (IdentityT * f a)

Traversable f => Traversable (ExceptT e f)

Methods

traverse :: Applicative f => (a -> f b) -> ExceptT e f a -> f (ExceptT e f b)

sequenceA :: Applicative f => ExceptT e f (f a) -> f (ExceptT e f a)

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

sequence :: Monad m => ExceptT e f (m a) -> m (ExceptT e f a)

Traversable f => Traversable (ErrorT e f)

Methods

traverse :: Applicative f => (a -> f b) -> ErrorT e f a -> f (ErrorT e f b)

sequenceA :: Applicative f => ErrorT e f (f a) -> f (ErrorT e f a)

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

sequence :: Monad m => ErrorT e f (m a) -> m (ErrorT e f a)

Traversable f => Traversable (M1 i c f)

Methods

traverse :: Applicative f => (a -> f b) -> M1 i c f a -> f (M1 i c f b)

sequenceA :: Applicative f => M1 i c f (f a) -> f (M1 i c f a)

mapM :: Monad m => (a -> m b) -> M1 i c f a -> m (M1 i c f b)

sequence :: Monad m => M1 i c f (m a) -> m (M1 i c f a)

(Traversable f, Traversable g) => Traversable (Sum * f g)

Methods

traverse :: Applicative f => (a -> f b) -> Sum * f g a -> f (Sum * f g b)

sequenceA :: Applicative f => Sum * f g (f a) -> f (Sum * f g a)

mapM :: Monad m => (a -> m b) -> Sum * f g a -> m (Sum * f g b)

sequence :: Monad m => Sum * f g (m a) -> m (Sum * f g a)

(Traversable f, Traversable g) => Traversable (Product * f g)

Methods

traverse :: Applicative f => (a -> f b) -> Product * f g a -> f (Product * f g b)

sequenceA :: Applicative f => Product * f g (f a) -> f (Product * f g a)

mapM :: Monad m => (a -> m b) -> Product * f g a -> m (Product * f g b)

sequence :: Monad m => Product * f g (m a) -> m (Product * f g a)

(Traversable f, Traversable g) => Traversable (Compose * * f g)

Methods

traverse :: Applicative f => (a -> f b) -> Compose * * f g a -> f (Compose * * f g b)

sequenceA :: Applicative f => Compose * * f g (f a) -> f (Compose * * f g a)

mapM :: Monad m => (a -> m b) -> Compose * * f g a -> m (Compose * * f g b)

sequence :: Monad m => Compose * * f g (m a) -> m (Compose * * f g a)

for :: (Traversable t, Applicative f) => t a -> (a -> f b) -> f (t b)

for is traverse with its arguments flipped. For a version that ignores the results see for_.

Enhanced exports

Simpler name for a typeclassed operation

map :: Functor f => (a -> b) -> f a -> f b

map = fmap

empty :: Monoid w => w

Deprecated: Use mempty

empty = mempty

(++) :: Monoid w => w -> w -> w infixr 5

(++) = mappend

concat :: Monoid w => [w] -> w

concat = mconcat

intercalate :: Monoid w => w -> [w] -> w

intercalate = mconcat .: intersperse

Strict implementation

sum :: (Foldable f, Num a) => f a -> a

Compute the sum of a finite list of numbers.

product :: (Foldable f, Num a) => f a -> a

Compute the product of a finite list of numbers.

Text for Read and Show operations

tshow :: Show a => a -> Text

Convert a value to readable Text

Since: 0.6.0

fromShow :: (Show a, IsString b) => a -> b

Convert a value to readable IsString

Since 0.3.12

read :: Read a => Text -> a

Parse Text to a value

readIO :: (MonadIO m, Read a) => Text -> m a

The readIO function is similar to read except that it signals parse failure to the IO monad instead of terminating the program.

Since: 0.7.0

FilePath for file operations

readFile :: MonadIO m => FilePath -> m Text

Read a file and return the contents of the file as Text. The entire file is read strictly.

Since: 0.7.0

writeFile :: MonadIO m => FilePath -> Text -> m ()

Write Text to a file. The file is truncated to zero length before writing begins.

Since: 0.7.0

appendFile :: MonadIO m => FilePath -> Text -> m ()

Write Text to the end of a file.

Since: 0.7.0

Text exports

Text operations (Pure)

lines :: Text -> [Text]

O(n) Breaks a Text up into a list of Texts at newline Chars. The resulting strings do not contain newlines.

words :: Text -> [Text]

O(n) Breaks a Text up into a list of words, delimited by Chars representing white space.

unlines :: [Text] -> Text

O(n) Joins lines, after appending a terminating newline to each.

unwords :: [Text] -> Text

O(n) Joins words using single space characters.

textToString :: Text -> String

ltextToString :: LText -> String

fpToText :: FilePath -> Text

Deprecated: Use Data.Text.pack

This function assumes file paths are encoded in UTF8. If it cannot decode the FilePath, the result is just an approximation.

Since 0.3.13

fpFromText :: Text -> FilePath

Deprecated: Use Data.Text.unpack

Since 0.3.13

fpToString :: FilePath -> String

Deprecated: Use id

Since 0.3.13

encodeUtf8 :: Text -> ByteString

Encode text using UTF-8 encoding.

decodeUtf8 :: ByteString -> Text

Note that this is not the standard Data.Text.Encoding.decodeUtf8. That function will throw impure exceptions on any decoding errors. This function instead uses decodeLenient.

Text operations (IO)

getLine :: MonadIO m => m Text

Since: 0.7.0

getContents :: MonadIO m => m LText

Since: 0.7.0

interact :: MonadIO m => (LText -> LText) -> m ()

Since: 0.7.0

Miscellaneous prelude re-exports

Math

gcd :: Integral a => a -> a -> a

gcd x y is the non-negative factor of both x and y of which every common factor of x and y is also a factor; for example gcd 4 2 = 2, gcd (-4) 6 = 2, gcd 0 4 = 4. gcd 0 0 = 0. (That is, the common divisor that is "greatest" in the divisibility preordering.)

Note: Since for signed fixed-width integer types, abs minBound < 0, the result may be negative if one of the arguments is minBound (and necessarily is if the other is 0 or minBound) for such types.

lcm :: Integral a => a -> a -> a

lcm x y is the smallest positive integer that both x and y divide.

Show and Read

class Show a where

Conversion of values to readable Strings.

Derived instances of Show have the following properties, which are compatible with derived instances of Read:

• The result of show is a syntactically correct Haskell expression containing only constants, given the fixity declarations in force at the point where the type is declared. It contains only the constructor names defined in the data type, parentheses, and spaces. When labelled constructor fields are used, braces, commas, field names, and equal signs are also used.
• If the constructor is defined to be an infix operator, then showsPrec will produce infix applications of the constructor.
• the representation will be enclosed in parentheses if the precedence of the top-level constructor in x is less than d (associativity is ignored). Thus, if d is 0 then the result is never surrounded in parentheses; if d is 11 it is always surrounded in parentheses, unless it is an atomic expression.
• If the constructor is defined using record syntax, then show will produce the record-syntax form, with the fields given in the same order as the original declaration.

For example, given the declarations

infixr 5 :^:
data Tree a =  Leaf a  |  Tree a :^: Tree a

the derived instance of Show is equivalent to

instance (Show a) => Show (Tree a) where

       showsPrec d (Leaf m) = showParen (d > app_prec) $
            showString "Leaf " . showsPrec (app_prec+1) m
         where app_prec = 10

       showsPrec d (u :^: v) = showParen (d > up_prec) $
            showsPrec (up_prec+1) u .
            showString " :^: "      .
            showsPrec (up_prec+1) v
         where up_prec = 5

Note that right-associativity of :^: is ignored. For example,

• show (Leaf 1 :^: Leaf 2 :^: Leaf 3) produces the string "Leaf 1 :^: (Leaf 2 :^: Leaf 3)".

Minimal complete definition

showsPrec | show

Methods

showsPrec :: Int -> a -> ShowS

Convert a value to a readable String.

showsPrec should satisfy the law

showsPrec d x r ++ s  ==  showsPrec d x (r ++ s)

Derived instances of Read and Show satisfy the following:

• (x,"") is an element of (readsPrec d (showsPrec d x "")).

That is, readsPrec parses the string produced by showsPrec, and delivers the value that showsPrec started with.

show :: a -> String

A specialised variant of showsPrec, using precedence context zero, and returning an ordinary String.

showList :: [a] -> ShowS

The method showList is provided to allow the programmer to give a specialised way of showing lists of values. For example, this is used by the predefined Show instance of the Char type, where values of type String should be shown in double quotes, rather than between square brackets.

Instances

Show Bool

Methods

showsPrec :: Int -> Bool -> ShowS

show :: Bool -> String

showList :: [Bool] -> ShowS

Show Char

Methods

showsPrec :: Int -> Char -> ShowS

show :: Char -> String

showList :: [Char] -> ShowS

Show Int

Methods

showsPrec :: Int -> Int -> ShowS

show :: Int -> String

showList :: [Int] -> ShowS

Show Int8

Methods

showsPrec :: Int -> Int8 -> ShowS

show :: Int8 -> String

showList :: [Int8] -> ShowS

Show Int16

Methods

showsPrec :: Int -> Int16 -> ShowS

show :: Int16 -> String

showList :: [Int16] -> ShowS

Show Int32

Methods

showsPrec :: Int -> Int32 -> ShowS

show :: Int32 -> String

showList :: [Int32] -> ShowS

Show Int64

Methods

showsPrec :: Int -> Int64 -> ShowS

show :: Int64 -> String

showList :: [Int64] -> ShowS

Show Integer

Methods

showsPrec :: Int -> Integer -> ShowS

show :: Integer -> String

showList :: [Integer] -> ShowS

Show Ordering

Methods

showsPrec :: Int -> Ordering -> ShowS

show :: Ordering -> String

showList :: [Ordering] -> ShowS

Show Word

Methods

showsPrec :: Int -> Word -> ShowS

show :: Word -> String

showList :: [Word] -> ShowS

Show Word8

Methods

showsPrec :: Int -> Word8 -> ShowS

show :: Word8 -> String

showList :: [Word8] -> ShowS

Show Word16

Methods

showsPrec :: Int -> Word16 -> ShowS

show :: Word16 -> String

showList :: [Word16] -> ShowS

Show Word32

Methods

showsPrec :: Int -> Word32 -> ShowS

show :: Word32 -> String

showList :: [Word32] -> ShowS

Show Word64

Methods

showsPrec :: Int -> Word64 -> ShowS

show :: Word64 -> String

showList :: [Word64] -> ShowS

Show CallStack

Methods

showsPrec :: Int -> CallStack -> ShowS

show :: CallStack -> String

showList :: [CallStack] -> ShowS

Show TypeRep

Methods

showsPrec :: Int -> TypeRep -> ShowS

show :: TypeRep -> String

showList :: [TypeRep] -> ShowS

Show ()

Methods

showsPrec :: Int -> () -> ShowS

show :: () -> String

showList :: [()] -> ShowS

Show TyCon

Methods

showsPrec :: Int -> TyCon -> ShowS

show :: TyCon -> String

showList :: [TyCon] -> ShowS

Show Module

Methods

showsPrec :: Int -> Module -> ShowS

show :: Module -> String

showList :: [Module] -> ShowS

Show TrName

Methods

showsPrec :: Int -> TrName -> ShowS

show :: TrName -> String

showList :: [TrName] -> ShowS

Show Handle

Methods

showsPrec :: Int -> Handle -> ShowS

show :: Handle -> String

showList :: [Handle] -> ShowS

Show HandleType

Methods

showsPrec :: Int -> HandleType -> ShowS

show :: HandleType -> String

showList :: [HandleType] -> ShowS

Show Void

Methods

showsPrec :: Int -> Void -> ShowS

show :: Void -> String

showList :: [Void] -> ShowS

Show Version

Methods

showsPrec :: Int -> Version -> ShowS

show :: Version -> String

showList :: [Version] -> ShowS

Show PatternMatchFail

Methods

showsPrec :: Int -> PatternMatchFail -> ShowS

show :: PatternMatchFail -> String

showList :: [PatternMatchFail] -> ShowS

Show RecSelError

Methods

showsPrec :: Int -> RecSelError -> ShowS

show :: RecSelError -> String

showList :: [RecSelError] -> ShowS

Show RecConError

Methods

showsPrec :: Int -> RecConError -> ShowS

show :: RecConError -> String

showList :: [RecConError] -> ShowS

Show RecUpdError

Methods

showsPrec :: Int -> RecUpdError -> ShowS

show :: RecUpdError -> String

showList :: [RecUpdError] -> ShowS

Show NoMethodError

Methods

showsPrec :: Int -> NoMethodError -> ShowS

show :: NoMethodError -> String

showList :: [NoMethodError] -> ShowS

Show TypeError

Methods

showsPrec :: Int -> TypeError -> ShowS

show :: TypeError -> String

showList :: [TypeError] -> ShowS

Show NonTermination

Methods

showsPrec :: Int -> NonTermination -> ShowS

show :: NonTermination -> String

showList :: [NonTermination] -> ShowS

Show NestedAtomically

Methods

showsPrec :: Int -> NestedAtomically -> ShowS

show :: NestedAtomically -> String

showList :: [NestedAtomically] -> ShowS

Show BlockedIndefinitelyOnMVar

Methods

showsPrec :: Int -> BlockedIndefinitelyOnMVar -> ShowS

show :: BlockedIndefinitelyOnMVar -> String

showList :: [BlockedIndefinitelyOnMVar] -> ShowS

Show BlockedIndefinitelyOnSTM

Methods

showsPrec :: Int -> BlockedIndefinitelyOnSTM -> ShowS

show :: BlockedIndefinitelyOnSTM -> String

showList :: [BlockedIndefinitelyOnSTM] -> ShowS

Show Deadlock

Methods

showsPrec :: Int -> Deadlock -> ShowS

show :: Deadlock -> String

showList :: [Deadlock] -> ShowS

Show AllocationLimitExceeded

Methods

showsPrec :: Int -> AllocationLimitExceeded -> ShowS

show :: AllocationLimitExceeded -> String

showList :: [AllocationLimitExceeded] -> ShowS

Show AssertionFailed

Methods

showsPrec :: Int -> AssertionFailed -> ShowS

show :: AssertionFailed -> String

showList :: [AssertionFailed] -> ShowS

Show SomeAsyncException

Methods

showsPrec :: Int -> SomeAsyncException -> ShowS

show :: SomeAsyncException -> String

showList :: [SomeAsyncException] -> ShowS

Show AsyncException

Methods

showsPrec :: Int -> AsyncException -> ShowS

show :: AsyncException -> String

showList :: [AsyncException] -> ShowS

Show ArrayException

Methods

showsPrec :: Int -> ArrayException -> ShowS

show :: ArrayException -> String

showList :: [ArrayException] -> ShowS

Show ExitCode

Methods

showsPrec :: Int -> ExitCode -> ShowS

show :: ExitCode -> String

showList :: [ExitCode] -> ShowS

Show IOErrorType

Methods

showsPrec :: Int -> IOErrorType -> ShowS

show :: IOErrorType -> String

showList :: [IOErrorType] -> ShowS

Show BufferMode

Methods

showsPrec :: Int -> BufferMode -> ShowS

show :: BufferMode -> String

showList :: [BufferMode] -> ShowS

Show Newline

Methods

showsPrec :: Int -> Newline -> ShowS

show :: Newline -> String

showList :: [Newline] -> ShowS

Show NewlineMode

Methods

showsPrec :: Int -> NewlineMode -> ShowS

show :: NewlineMode -> String

showList :: [NewlineMode] -> ShowS

Show CChar

Methods

showsPrec :: Int -> CChar -> ShowS

show :: CChar -> String

showList :: [CChar] -> ShowS

Show CSChar

Methods

showsPrec :: Int -> CSChar -> ShowS

show :: CSChar -> String

showList :: [CSChar] -> ShowS

Show CUChar

Methods

showsPrec :: Int -> CUChar -> ShowS

show :: CUChar -> String

showList :: [CUChar] -> ShowS

Show CShort

Methods

showsPrec :: Int -> CShort -> ShowS

show :: CShort -> String

showList :: [CShort] -> ShowS

Show CUShort

Methods

showsPrec :: Int -> CUShort -> ShowS

show :: CUShort -> String

showList :: [CUShort] -> ShowS

Show CInt

Methods

showsPrec :: Int -> CInt -> ShowS

show :: CInt -> String

showList :: [CInt] -> ShowS

Show CUInt

Methods

showsPrec :: Int -> CUInt -> ShowS

show :: CUInt -> String

showList :: [CUInt] -> ShowS

Show CLong

Methods

showsPrec :: Int -> CLong -> ShowS

show :: CLong -> String

showList :: [CLong] -> ShowS

Show CULong

Methods

showsPrec :: Int -> CULong -> ShowS

show :: CULong -> String

showList :: [CULong] -> ShowS

Show CLLong

Methods

showsPrec :: Int -> CLLong -> ShowS

show :: CLLong -> String

showList :: [CLLong] -> ShowS

Show CULLong

Methods

showsPrec :: Int -> CULLong -> ShowS

show :: CULLong -> String

showList :: [CULLong] -> ShowS

Show CFloat

Methods

showsPrec :: Int -> CFloat -> ShowS

show :: CFloat -> String

showList :: [CFloat] -> ShowS

Show CDouble

Methods

showsPrec :: Int -> CDouble -> ShowS

show :: CDouble -> String

showList :: [CDouble] -> ShowS

Show CPtrdiff

Methods

showsPrec :: Int -> CPtrdiff -> ShowS

show :: CPtrdiff -> String

showList :: [CPtrdiff] -> ShowS

Show CSize

Methods

showsPrec :: Int -> CSize -> ShowS

show :: CSize -> String

showList :: [CSize] -> ShowS

Show CWchar

Methods

showsPrec :: Int -> CWchar -> ShowS

show :: CWchar -> String

showList :: [CWchar] -> ShowS

Show CSigAtomic

Methods

showsPrec :: Int -> CSigAtomic -> ShowS

show :: CSigAtomic -> String

showList :: [CSigAtomic] -> ShowS

Show CClock

Methods

showsPrec :: Int -> CClock -> ShowS

show :: CClock -> String

showList :: [CClock] -> ShowS

Show CTime

Methods

showsPrec :: Int -> CTime -> ShowS

show :: CTime -> String

showList :: [CTime] -> ShowS

Show CUSeconds

Methods

showsPrec :: Int -> CUSeconds -> ShowS

show :: CUSeconds -> String

showList :: [CUSeconds] -> ShowS

Show CSUSeconds

Methods

showsPrec :: Int -> CSUSeconds -> ShowS

show :: CSUSeconds -> String

showList :: [CSUSeconds] -> ShowS

Show CIntPtr

Methods

showsPrec :: Int -> CIntPtr -> ShowS

show :: CIntPtr -> String

showList :: [CIntPtr] -> ShowS

Show CUIntPtr

Methods

showsPrec :: Int -> CUIntPtr -> ShowS

show :: CUIntPtr -> String

showList :: [CUIntPtr] -> ShowS

Show CIntMax

Methods

showsPrec :: Int -> CIntMax -> ShowS

show :: CIntMax -> String

showList :: [CIntMax] -> ShowS

Show CUIntMax

Methods

showsPrec :: Int -> CUIntMax -> ShowS

show :: CUIntMax -> String

showList :: [CUIntMax] -> ShowS

Show All

Methods

showsPrec :: Int -> All -> ShowS

show :: All -> String

showList :: [All] -> ShowS

Show Any

Methods

showsPrec :: Int -> Any -> ShowS

show :: Any -> String

showList :: [Any] -> ShowS

Show Fixity

Methods

showsPrec :: Int -> Fixity -> ShowS

show :: Fixity -> String

showList :: [Fixity] -> ShowS

Show Associativity

Methods

showsPrec :: Int -> Associativity -> ShowS

show :: Associativity -> String

showList :: [Associativity] -> ShowS

Show SourceUnpackedness

Methods

showsPrec :: Int -> SourceUnpackedness -> ShowS

show :: SourceUnpackedness -> String

showList :: [SourceUnpackedness] -> ShowS

Show SourceStrictness

Methods

showsPrec :: Int -> SourceStrictness -> ShowS

show :: SourceStrictness -> String

showList :: [SourceStrictness] -> ShowS

Show DecidedStrictness

Methods

showsPrec :: Int -> DecidedStrictness -> ShowS

show :: DecidedStrictness -> String

showList :: [DecidedStrictness] -> ShowS

Show MaskingState

Methods

showsPrec :: Int -> MaskingState -> ShowS

show :: MaskingState -> String

showList :: [MaskingState] -> ShowS

Show IOException

Methods

showsPrec :: Int -> IOException -> ShowS

show :: IOException -> String

showList :: [IOException] -> ShowS

Show ErrorCall

Methods

showsPrec :: Int -> ErrorCall -> ShowS

show :: ErrorCall -> String

showList :: [ErrorCall] -> ShowS

Show ArithException

Methods

showsPrec :: Int -> ArithException -> ShowS

show :: ArithException -> String

showList :: [ArithException] -> ShowS

Show SomeNat

Methods

showsPrec :: Int -> SomeNat -> ShowS

show :: SomeNat -> String

showList :: [SomeNat] -> ShowS

Show SomeSymbol

Methods

showsPrec :: Int -> SomeSymbol -> ShowS

show :: SomeSymbol -> String

showList :: [SomeSymbol] -> ShowS

Show SomeException

Methods

showsPrec :: Int -> SomeException -> ShowS

show :: SomeException -> String

showList :: [SomeException] -> ShowS

Show SrcLoc

Methods

showsPrec :: Int -> SrcLoc -> ShowS

show :: SrcLoc -> String

showList :: [SrcLoc] -> ShowS

Show ByteString

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

Show ByteString

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

Show IntSet

Methods

showsPrec :: Int -> IntSet -> ShowS

show :: IntSet -> String

showList :: [IntSet] -> ShowS

Show CodePoint

Methods

showsPrec :: Int -> CodePoint -> ShowS

show :: CodePoint -> String

showList :: [CodePoint] -> ShowS

Show DecoderState

Methods

showsPrec :: Int -> DecoderState -> ShowS

show :: DecoderState -> String

showList :: [DecoderState] -> ShowS

Show Decoding

Methods

showsPrec :: Int -> Decoding -> ShowS

show :: Decoding -> String

showList :: [Decoding] -> ShowS

Show UnicodeException

Methods

showsPrec :: Int -> UnicodeException -> ShowS

show :: UnicodeException -> String

showList :: [UnicodeException] -> ShowS

Show a => Show [a]

Methods

showsPrec :: Int -> [a] -> ShowS

show :: [a] -> String

showList :: [[a]] -> ShowS

Show a => Show (Maybe a)

Methods

showsPrec :: Int -> Maybe a -> ShowS

show :: Maybe a -> String

showList :: [Maybe a] -> ShowS

Show a => Show (Ratio a)

Methods

showsPrec :: Int -> Ratio a -> ShowS

show :: Ratio a -> String

showList :: [Ratio a] -> ShowS

Show (Ptr a)

Methods

showsPrec :: Int -> Ptr a -> ShowS

show :: Ptr a -> String

showList :: [Ptr a] -> ShowS

Show (FunPtr a)

Methods

showsPrec :: Int -> FunPtr a -> ShowS

show :: FunPtr a -> String

showList :: [FunPtr a] -> ShowS

Show (V1 p)

Methods

showsPrec :: Int -> V1 p -> ShowS

show :: V1 p -> String

showList :: [V1 p] -> ShowS

Show (U1 p)

Methods

showsPrec :: Int -> U1 p -> ShowS

show :: U1 p -> String

showList :: [U1 p] -> ShowS

Show p => Show (Par1 p)

Methods

showsPrec :: Int -> Par1 p -> ShowS

show :: Par1 p -> String

showList :: [Par1 p] -> ShowS

Show (ForeignPtr a)

Methods

showsPrec :: Int -> ForeignPtr a -> ShowS

show :: ForeignPtr a -> String

showList :: [ForeignPtr a] -> ShowS

Show a => Show (Identity a)

This instance would be equivalent to the derived instances of the Identity newtype if the runIdentity field were removed

Methods

showsPrec :: Int -> Identity a -> ShowS

show :: Identity a -> String

showList :: [Identity a] -> ShowS

Show a => Show (Min a)

Methods

showsPrec :: Int -> Min a -> ShowS

show :: Min a -> String

showList :: [Min a] -> ShowS

Show a => Show (Max a)

Methods

showsPrec :: Int -> Max a -> ShowS

show :: Max a -> String

showList :: [Max a] -> ShowS

Show a => Show (First a)

Methods

showsPrec :: Int -> First a -> ShowS

show :: First a -> String

showList :: [First a] -> ShowS

Show a => Show (Last a)

Methods

showsPrec :: Int -> Last a -> ShowS

show :: Last a -> String

showList :: [Last a] -> ShowS

Show m => Show (WrappedMonoid m)

Methods

showsPrec :: Int -> WrappedMonoid m -> ShowS

show :: WrappedMonoid m -> String

showList :: [WrappedMonoid m] -> ShowS

Show a => Show (Option a)

Methods

showsPrec :: Int -> Option a -> ShowS

show :: Option a -> String

showList :: [Option a] -> ShowS

Show a => Show (NonEmpty a)

Methods

showsPrec :: Int -> NonEmpty a -> ShowS

show :: NonEmpty a -> String

showList :: [NonEmpty a] -> ShowS

Show a => Show (Complex a)

Methods

showsPrec :: Int -> Complex a -> ShowS

show :: Complex a -> String

showList :: [Complex a] -> ShowS

Show a => Show (ZipList a)

Methods

showsPrec :: Int -> ZipList a -> ShowS

show :: ZipList a -> String

showList :: [ZipList a] -> ShowS

Show a => Show (Dual a)

Methods

showsPrec :: Int -> Dual a -> ShowS

show :: Dual a -> String

showList :: [Dual a] -> ShowS

Show a => Show (Sum a)

Methods

showsPrec :: Int -> Sum a -> ShowS

show :: Sum a -> String

showList :: [Sum a] -> ShowS

Show a => Show (Product a)

Methods

showsPrec :: Int -> Product a -> ShowS

show :: Product a -> String

showList :: [Product a] -> ShowS

Show a => Show (First a)

Methods

showsPrec :: Int -> First a -> ShowS

show :: First a -> String

showList :: [First a] -> ShowS

Show a => Show (Last a)

Methods

showsPrec :: Int -> Last a -> ShowS

show :: Last a -> String

showList :: [Last a] -> ShowS

Show a => Show (Down a)

Methods

showsPrec :: Int -> Down a -> ShowS

show :: Down a -> String

showList :: [Down a] -> ShowS

Show a => Show (IntMap a)

Methods

showsPrec :: Int -> IntMap a -> ShowS

show :: IntMap a -> String

showList :: [IntMap a] -> ShowS

Show a => Show (Seq a)

Methods

showsPrec :: Int -> Seq a -> ShowS

show :: Seq a -> String

showList :: [Seq a] -> ShowS

Show a => Show (ViewL a)

Methods

showsPrec :: Int -> ViewL a -> ShowS

show :: ViewL a -> String

showList :: [ViewL a] -> ShowS

Show a => Show (ViewR a)

Methods

showsPrec :: Int -> ViewR a -> ShowS

show :: ViewR a -> String

showList :: [ViewR a] -> ShowS

Show a => Show (Set a)

Methods

showsPrec :: Int -> Set a -> ShowS

show :: Set a -> String

showList :: [Set a] -> ShowS

Show a => Show (Hashed a)

Methods

showsPrec :: Int -> Hashed a -> ShowS

show :: Hashed a -> String

showList :: [Hashed a] -> ShowS

Show a => Show (Array a)

Methods

showsPrec :: Int -> Array a -> ShowS

show :: Array a -> String

showList :: [Array a] -> ShowS

Show a => Show (Array a)

Methods

showsPrec :: Int -> Array a -> ShowS

show :: Array a -> String

showList :: [Array a] -> ShowS

Show a => Show (HashSet a)

Methods

showsPrec :: Int -> HashSet a -> ShowS

show :: HashSet a -> String

showList :: [HashSet a] -> ShowS

Show a => Show (Vector a)

Methods

showsPrec :: Int -> Vector a -> ShowS

show :: Vector a -> String

showList :: [Vector a] -> ShowS

(Show a, Storable a) => Show (Vector a)

Methods

showsPrec :: Int -> Vector a -> ShowS

show :: Vector a -> String

showList :: [Vector a] -> ShowS

(Show a, Prim a) => Show (Vector a)

Methods

showsPrec :: Int -> Vector a -> ShowS

show :: Vector a -> String

showList :: [Vector a] -> ShowS

(Show b, Show a) => Show (Either a b)

Methods

showsPrec :: Int -> Either a b -> ShowS

show :: Either a b -> String

showList :: [Either a b] -> ShowS

Show (f p) => Show (Rec1 f p)

Methods

showsPrec :: Int -> Rec1 f p -> ShowS

show :: Rec1 f p -> String

showList :: [Rec1 f p] -> ShowS

Show (URec Char p)

Methods

showsPrec :: Int -> URec Char p -> ShowS

show :: URec Char p -> String

showList :: [URec Char p] -> ShowS

Show (URec Double p)

Methods

showsPrec :: Int -> URec Double p -> ShowS

show :: URec Double p -> String

showList :: [URec Double p] -> ShowS

Show (URec Float p)

Methods

showsPrec :: Int -> URec Float p -> ShowS

show :: URec Float p -> String

showList :: [URec Float p] -> ShowS

Show (URec Int p)

Methods

showsPrec :: Int -> URec Int p -> ShowS

show :: URec Int p -> String

showList :: [URec Int p] -> ShowS

Show (URec Word p)

Methods

showsPrec :: Int -> URec Word p -> ShowS

show :: URec Word p -> String

showList :: [URec Word p] -> ShowS

(Show a, Show b) => Show (a, b)

Methods

showsPrec :: Int -> (a, b) -> ShowS

show :: (a, b) -> String

showList :: [(a, b)] -> ShowS

Show (ST s a)

Methods

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

show :: ST s a -> String

showList :: [ST s a] -> ShowS

(Show b, Show a) => Show (Arg a b)

Methods

showsPrec :: Int -> Arg a b -> ShowS

show :: Arg a b -> String

showList :: [Arg a b] -> ShowS

Show (Proxy k s)

Methods

showsPrec :: Int -> Proxy k s -> ShowS

show :: Proxy k s -> String

showList :: [Proxy k s] -> ShowS

(Show k, Show a) => Show (Map k a)

Methods

showsPrec :: Int -> Map k a -> ShowS

show :: Map k a -> String

showList :: [Map k a] -> ShowS

(Show1 m, Show a) => Show (MaybeT m a)

Methods

showsPrec :: Int -> MaybeT m a -> ShowS

show :: MaybeT m a -> String

showList :: [MaybeT m a] -> ShowS

(Show1 m, Show a) => Show (ListT m a)

Methods

showsPrec :: Int -> ListT m a -> ShowS

show :: ListT m a -> String

showList :: [ListT m a] -> ShowS

(Show k, Show v) => Show (HashMap k v)

Methods

showsPrec :: Int -> HashMap k v -> ShowS

show :: HashMap k v -> String

showList :: [HashMap k v] -> ShowS

Show c => Show (K1 i c p)

Methods

showsPrec :: Int -> K1 i c p -> ShowS

show :: K1 i c p -> String

showList :: [K1 i c p] -> ShowS

(Show (g p), Show (f p)) => Show ((:+:) f g p)

Methods

showsPrec :: Int -> (f :+: g) p -> ShowS

show :: (f :+: g) p -> String

showList :: [(f :+: g) p] -> ShowS

(Show (g p), Show (f p)) => Show ((:*:) f g p)

Methods

showsPrec :: Int -> (f :*: g) p -> ShowS

show :: (f :*: g) p -> String

showList :: [(f :*: g) p] -> ShowS

Show (f (g p)) => Show ((:.:) f g p)

Methods

showsPrec :: Int -> (f :.: g) p -> ShowS

show :: (f :.: g) p -> String

showList :: [(f :.: g) p] -> ShowS

(Show a, Show b, Show c) => Show (a, b, c)

Methods

showsPrec :: Int -> (a, b, c) -> ShowS

show :: (a, b, c) -> String

showList :: [(a, b, c)] -> ShowS

Show a => Show (Const k a b)

This instance would be equivalent to the derived instances of the Const newtype if the runConst field were removed

Methods

showsPrec :: Int -> Const k a b -> ShowS

show :: Const k a b -> String

showList :: [Const k a b] -> ShowS

Show (f a) => Show (Alt k f a)

Methods

showsPrec :: Int -> Alt k f a -> ShowS

show :: Alt k f a -> String

showList :: [Alt k f a] -> ShowS

Show ((:~:) k a b)

Methods

showsPrec :: Int -> (k :~: a) b -> ShowS

show :: (k :~: a) b -> String

showList :: [(k :~: a) b] -> ShowS

(Show w, Show1 m, Show a) => Show (WriterT w m a)

Methods

showsPrec :: Int -> WriterT w m a -> ShowS

show :: WriterT w m a -> String

showList :: [WriterT w m a] -> ShowS

(Show w, Show1 m, Show a) => Show (WriterT w m a)

Methods

showsPrec :: Int -> WriterT w m a -> ShowS

show :: WriterT w m a -> String

showList :: [WriterT w m a] -> ShowS

(Show1 f, Show a) => Show (IdentityT * f a)

Methods

showsPrec :: Int -> IdentityT * f a -> ShowS

show :: IdentityT * f a -> String

showList :: [IdentityT * f a] -> ShowS

(Show e, Show1 m, Show a) => Show (ExceptT e m a)

Methods

showsPrec :: Int -> ExceptT e m a -> ShowS

show :: ExceptT e m a -> String

showList :: [ExceptT e m a] -> ShowS

(Show e, Show1 m, Show a) => Show (ErrorT e m a)

Methods

showsPrec :: Int -> ErrorT e m a -> ShowS

show :: ErrorT e m a -> String

showList :: [ErrorT e m a] -> ShowS

Show (f p) => Show (M1 i c f p)

Methods

showsPrec :: Int -> M1 i c f p -> ShowS

show :: M1 i c f p -> String

showList :: [M1 i c f p] -> ShowS

(Show a, Show b, Show c, Show d) => Show (a, b, c, d)

Methods

showsPrec :: Int -> (a, b, c, d) -> ShowS

show :: (a, b, c, d) -> String

showList :: [(a, b, c, d)] -> ShowS

(Show1 f, Show1 g, Show a) => Show (Sum * f g a)

Methods

showsPrec :: Int -> Sum * f g a -> ShowS

show :: Sum * f g a -> String

showList :: [Sum * f g a] -> ShowS

(Show1 f, Show1 g, Show a) => Show (Product * f g a)

Methods

showsPrec :: Int -> Product * f g a -> ShowS

show :: Product * f g a -> String

showList :: [Product * f g a] -> ShowS

(Show a, Show b, Show c, Show d, Show e) => Show (a, b, c, d, e)

Methods

showsPrec :: Int -> (a, b, c, d, e) -> ShowS

show :: (a, b, c, d, e) -> String

showList :: [(a, b, c, d, e)] -> ShowS

(Show1 f, Show1 g, Show a) => Show (Compose * * f g a)

Methods

showsPrec :: Int -> Compose * * f g a -> ShowS

show :: Compose * * f g a -> String

showList :: [Compose * * f g a] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f) => Show (a, b, c, d, e, f)

Methods

showsPrec :: Int -> (a, b, c, d, e, f) -> ShowS

show :: (a, b, c, d, e, f) -> String

showList :: [(a, b, c, d, e, f)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g) => Show (a, b, c, d, e, f, g)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g) -> ShowS

show :: (a, b, c, d, e, f, g) -> String

showList :: [(a, b, c, d, e, f, g)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h) => Show (a, b, c, d, e, f, g, h)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h) -> ShowS

show :: (a, b, c, d, e, f, g, h) -> String

showList :: [(a, b, c, d, e, f, g, h)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i) => Show (a, b, c, d, e, f, g, h, i)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i) -> ShowS

show :: (a, b, c, d, e, f, g, h, i) -> String

showList :: [(a, b, c, d, e, f, g, h, i)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j) => Show (a, b, c, d, e, f, g, h, i, j)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k) => Show (a, b, c, d, e, f, g, h, i, j, k)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l) => Show (a, b, c, d, e, f, g, h, i, j, k, l)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l, m) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n)] -> ShowS

(Show a, Show b, Show c, Show d, Show e, Show f, Show g, Show h, Show i, Show j, Show k, Show l, Show m, Show n, Show o) => Show (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)

Methods

showsPrec :: Int -> (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> ShowS

show :: (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) -> String

showList :: [(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o)] -> ShowS

type ShowS = String -> String

The shows functions return a function that prepends the output String to an existing String. This allows constant-time concatenation of results using function composition.

shows :: Show a => a -> ShowS

equivalent to showsPrec with a precedence of 0.

showChar :: Char -> ShowS

utility function converting a Char to a show function that simply prepends the character unchanged.

showString :: String -> ShowS

utility function converting a String to a show function that simply prepends the string unchanged.

showParen :: Bool -> ShowS -> ShowS

utility function that surrounds the inner show function with parentheses when the Bool parameter is True.

type ReadS a = String -> [(a, String)]

A parser for a type a, represented as a function that takes a String and returns a list of possible parses as (a,String) pairs.

Note that this kind of backtracking parser is very inefficient; reading a large structure may be quite slow (cf ReadP).

readsPrec :: Read a => Int -> ReadS a

attempts to parse a value from the front of the string, returning a list of (parsed value, remaining string) pairs. If there is no successful parse, the returned list is empty.

Derived instances of Read and Show satisfy the following:

• (x,"") is an element of (readsPrec d (showsPrec d x "")).

That is, readsPrec parses the string produced by showsPrec, and delivers the value that showsPrec started with.

readList :: Read a => ReadS [a]

The method readList is provided to allow the programmer to give a specialised way of parsing lists of values. For example, this is used by the predefined Read instance of the Char type, where values of type String should be are expected to use double quotes, rather than square brackets.

reads :: Read a => ReadS a

equivalent to readsPrec with a precedence of 0.

readParen :: Bool -> ReadS a -> ReadS a

readParen True p parses what p parses, but surrounded with parentheses.

readParen False p parses what p parses, but optionally surrounded with parentheses.

lex :: ReadS String

The lex function reads a single lexeme from the input, discarding initial white space, and returning the characters that constitute the lexeme. If the input string contains only white space, lex returns a single successful `lexeme' consisting of the empty string. (Thus lex "" = [("","")].) If there is no legal lexeme at the beginning of the input string, lex fails (i.e. returns []).

This lexer is not completely faithful to the Haskell lexical syntax in the following respects:

• Qualified names are not handled properly
• Octal and hexadecimal numerics are not recognized as a single token
• Comments are not treated properly

readMay :: Read a => Text -> Maybe a

IO operations

getChar :: MonadIO m => m Char

Since: 0.7.0

putChar :: MonadIO m => Char -> m ()

Since: 0.7.0

readLn :: (MonadIO m, Read a) => m a

The readLn function combines getLine and readIO.

Since: 0.7.0