| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Chassis
Synopsis
- data Void
- absurd :: Void -> a
- data Bool
- not :: Bool -> Bool
- data Int
- type String = [Char]
- data ByteString
- data Text
- class Show a where
- class Semigroup a where
- (<>) :: a -> a -> a
- class Semigroup a => Monoid a where
- mempty :: a
- class Eq a where
- class Eq a => Ord a where
- ($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
- (&) :: a -> (a -> b) -> b
- data IO a
- data Maybe a
- maybe :: b -> (a -> b) -> Maybe a -> b
- data Either a b
- either :: (a -> c) -> (b -> c) -> Either a b -> c
- data NonEmpty a = a :| [a]
- data Map k a
- fst :: (a, b) -> a
- snd :: (a, b) -> b
- const :: a -> b -> a
- curry :: ((a, b) -> c) -> a -> b -> c
- uncurry :: (a -> b -> c) -> (a, b) -> c
- class Foldable (t :: Type -> Type) where
- class Functor (f :: Type -> Type) where
- ($>) :: Functor f => f a -> b -> f b
- (<$>) :: Functor f => (a -> b) -> f a -> f b
- void :: Functor f => f a -> f ()
- class Functor f => Applicative (f :: Type -> Type) where
- when :: Applicative f => Bool -> f () -> f ()
- unless :: Applicative f => Bool -> f () -> f ()
- whenM :: Monad m => m Bool -> m () -> m ()
- whenJust :: Applicative m => Maybe a -> (a -> m ()) -> m ()
- class (Functor t, Foldable t) => Traversable (t :: Type -> Type) where
- traverse_ :: (Foldable t, Applicative f) => (a -> f b) -> t a -> f ()
- for_ :: (Foldable t, Applicative f) => t a -> (a -> f b) -> f ()
- filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a]
- class Applicative m => Monad (m :: Type -> Type) where
- join :: Monad m => m (m a) -> m a
- forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()
- forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b)
- mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
- sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
- (=<<) :: Monad m => (a -> m b) -> m a -> m b
- (>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
- class Contravariant (f :: Type -> Type) where
- contramap :: (a -> b) -> f b -> f a
- (>$<) :: Contravariant f => (a -> b) -> f b -> f a
- data Predicate a
- data Equivalence a
- data Comparison a
- data Op a b
- class Functor g => Distributive (g :: Type -> Type) where
- distribute :: Functor f => f (g a) -> g (f a)
- class Functor w => Comonad (w :: Type -> Type) where
- (=>=) :: Comonad w => (w a -> b) -> (w b -> c) -> w a -> c
- (<<=) :: Comonad w => (w a -> b) -> w a -> w b
- class Profunctor (p :: Type -> Type -> Type) where
- class Profunctor p => Strong (p :: Type -> Type -> Type) where
- class Profunctor p => Choice (p :: Type -> Type -> Type) where
- class Category (cat :: k -> k -> Type) where
- class Category a => Arrow (a :: Type -> Type -> Type) where
- data Kleisli (m :: Type -> Type) a b
- (>>>) :: forall k cat (a :: k) (b :: k) (c :: k). Category cat => cat a b -> cat b c -> cat a c
- (<<<) :: forall k cat (b :: k) (c :: k) (a :: k). Category cat => cat b c -> cat a b -> cat a c
- type Env e = EnvT e Identity
- data EnvT e (w :: Type -> Type) a = EnvT e (w a)
- env :: e -> a -> Env e a
- runEnv :: Env e a -> (e, a)
- runEnvT :: EnvT e w a -> (e, w a)
- data Rec (a :: u -> Type) (b :: [u]) where
- class RMap (rs :: [u])
- rtraverse :: forall u h f g (rs :: [u]). Applicative h => (forall (x :: u). f x -> h (g x)) -> Rec f rs -> h (Rec g rs)
- rcast :: forall k1 k2 (rs :: [k1]) (ss :: [k1]) (f :: k2 -> Type) record (is :: [Nat]). (RecSubset record rs ss is, RecSubsetFCtx record f) => record f ss -> record f rs
- data CoRec (a :: u -> Type) (b :: [u]) where
- type (∈) (r :: k) (rs :: [k]) = RElem r rs (RIndex r rs)
- type (:.) (f :: l -> Type) (g :: k -> l) = Compose f g
- data Compose (f :: l -> Type) (g :: k -> l) (x :: k)
- onCompose :: forall l1 k1 l2 f (g :: k1 -> l1) (a :: k1) h (k2 :: k1 -> l2). (f (g a) -> h (k2 a)) -> (f :. g) a -> (h :. k2) a
- class Generic a
- data UTCTime
- data Path b t
- data Rel
- data Abs
- data File
- data Dir
- mkRelDir :: FilePath -> Q Exp
- mkRelFile :: FilePath -> Q Exp
- mkAbsDir :: FilePath -> Q Exp
- mkAbsFile :: FilePath -> Q Exp
- (</>) :: Path b Dir -> Path Rel t -> Path b t
- flip :: (a -> b -> c) -> b -> a -> c
- rights :: [Either a b] -> [b]
- type Type = Type
- data Constraint
- type Exp a = a -> Type
- type family Eval (e :: Exp a) :: a
- type FMap = Map :: (a -> Exp b) -> f a -> f b -> Type
- class (Typeable e, Show e) => Exception e where
- displayException :: e -> String
- data SomeException
Void
Uninhabited data type
Since: base-4.8.0.0
Instances
| Eq Void | Since: base-4.8.0.0 |
| Data Void | Since: base-4.8.0.0 |
Defined in Data.Void Methods gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Void -> c Void # gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c Void # dataTypeOf :: Void -> DataType # dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c Void) # dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c Void) # gmapT :: (forall b. Data b => b -> b) -> Void -> Void # gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Void -> r # gmapQ :: (forall d. Data d => d -> u) -> Void -> [u] # gmapQi :: Int -> (forall d. Data d => d -> u) -> Void -> u # gmapM :: Monad m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Void -> m Void # | |
| Ord Void | Since: base-4.8.0.0 |
| Read Void | Reading a Since: base-4.8.0.0 |
| Show Void | Since: base-4.8.0.0 |
| Ix Void | Since: base-4.8.0.0 |
| Generic Void | Since: base-4.8.0.0 |
| Semigroup Void | Since: base-4.9.0.0 |
| Hashable Void | |
Defined in Data.Hashable.Class | |
| Exception Void | Since: base-4.8.0.0 |
Defined in Data.Void Methods toException :: Void -> SomeException # fromException :: SomeException -> Maybe Void # displayException :: Void -> String # | |
| Lift Void | Since: template-haskell-2.15.0.0 |
| type Rep Void | |
Since Void values logically don't exist, this witnesses the
logical reasoning tool of "ex falso quodlibet".
>>>let x :: Either Void Int; x = Right 5>>>:{case x of Right r -> r Left l -> absurd l :} 5
Since: base-4.8.0.0
Bool
Instances
Numbers
A fixed-precision integer type with at least the range [-2^29 .. 2^29-1].
The exact range for a given implementation can be determined by using
minBound and maxBound from the Bounded class.
Instances
StringTextByteString
data ByteString #
A space-efficient representation of a Word8 vector, supporting many
efficient operations.
A ByteString contains 8-bit bytes, or by using the operations from
Data.ByteString.Char8 it can be interpreted as containing 8-bit
characters.
Instances
A space efficient, packed, unboxed Unicode text type.
Instances
| Hashable Text | |
Defined in Data.Hashable.Class | |
| Chunk Text | |
Defined in Data.Attoparsec.Internal.Types | |
| Ixed Text | |
Defined in Control.Lens.At | |
| type State Text | |
Defined in Data.Attoparsec.Internal.Types | |
| type ChunkElem Text | |
Defined in Data.Attoparsec.Internal.Types | |
| type Item Text | |
| type Index Text | |
Defined in Control.Lens.At | |
| type IxValue Text | |
Defined in Control.Lens.At | |
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
showis 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
showsPrecwill produce infix applications of the constructor. - the representation will be enclosed in parentheses if the
precedence of the top-level constructor in
xis less thand(associativity is ignored). Thus, ifdis0then the result is never surrounded in parentheses; ifdis11it is always surrounded in parentheses, unless it is an atomic expression. - If the constructor is defined using record syntax, then
showwill 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 = 5Note that right-associativity of :^: is ignored. For example,
show(Leaf 1 :^: Leaf 2 :^: Leaf 3)"Leaf 1 :^: (Leaf 2 :^: Leaf 3)".
Methods
Instances
Classic Algebra
The class of semigroups (types with an associative binary operation).
Instances should satisfy the following:
Since: base-4.9.0.0
Instances
class Semigroup a => Monoid a where #
The class of monoids (types with an associative binary operation that has an identity). Instances should satisfy the following:
- Right identity
x<>mempty= x- Left identity
mempty<>x = x- Associativity
x(<>(y<>z) = (x<>y)<>zSemigrouplaw)- Concatenation
mconcat=foldr(<>)mempty
The method names refer to the monoid of lists under concatenation, but there are many other instances.
Some types can be viewed as a monoid in more than one way,
e.g. both addition and multiplication on numbers.
In such cases we often define newtypes and make those instances
of Monoid, e.g. Sum and Product.
NOTE: Semigroup is a superclass of Monoid since base-4.11.0.0.
Instances
| Monoid Ordering | Since: base-2.1 |
| Monoid () | Since: base-2.1 |
| Monoid ByteString | |
Defined in Data.ByteString.Internal Methods mempty :: ByteString # mappend :: ByteString -> ByteString -> ByteString # mconcat :: [ByteString] -> ByteString # | |
| Monoid More | |
| Monoid IntSet | |
| Monoid Doc | |
| Monoid ByteArray | |
| Monoid [a] | Since: base-2.1 |
| Semigroup a => Monoid (Maybe a) | Lift a semigroup into Since 4.11.0: constraint on inner Since: base-2.1 |
| Monoid a => Monoid (IO a) | Since: base-4.9.0.0 |
| Monoid p => Monoid (Par1 p) | Since: base-4.12.0.0 |
| Monoid (IResult a) | |
| Monoid (Result a) | |
| Monoid (Parser a) | |
| Monoid (Predicate a) | |
| Monoid (Comparison a) | |
Defined in Data.Functor.Contravariant Methods mempty :: Comparison a # mappend :: Comparison a -> Comparison a -> Comparison a # mconcat :: [Comparison a] -> Comparison a # | |
| Monoid (Equivalence a) | |
Defined in Data.Functor.Contravariant Methods mempty :: Equivalence a # mappend :: Equivalence a -> Equivalence a -> Equivalence a # mconcat :: [Equivalence a] -> Equivalence a # | |
| (Ord a, Bounded a) => Monoid (Min a) | Since: base-4.9.0.0 |
| (Ord a, Bounded a) => Monoid (Max a) | Since: base-4.9.0.0 |
| Monoid m => Monoid (WrappedMonoid m) | Since: base-4.9.0.0 |
Defined in Data.Semigroup Methods mempty :: WrappedMonoid m # mappend :: WrappedMonoid m -> WrappedMonoid m -> WrappedMonoid m # mconcat :: [WrappedMonoid m] -> WrappedMonoid m # | |
| Semigroup a => Monoid (Option a) | Since: base-4.9.0.0 |
| Monoid (IntMap a) | |
| Monoid (Seq a) | |
| Ord a => Monoid (Set a) | |
| Monoid (DList a) | |
| Prim a => Monoid (Vector a) | |
| Storable a => Monoid (Vector a) | |
| (Hashable a, Eq a) => Monoid (HashSet a) | O(n+m) To obtain good performance, the smaller set must be presented as the first argument. Examples
|
| Monoid (Vector a) | |
| Monoid (Doc a) | |
| Monoid (PrimArray a) | Since: primitive-0.6.4.0 |
| Monoid (SmallArray a) | |
Defined in Data.Primitive.SmallArray Methods mempty :: SmallArray a # mappend :: SmallArray a -> SmallArray a -> SmallArray a # mconcat :: [SmallArray a] -> SmallArray a # | |
| Monoid (Array a) | |
| Semigroup a => Monoid (Maybe a) | |
| (KnownSymbol s, Monoid t) => Monoid (ElField '(s, t)) | |
| Monoid (MergeSet a) | |
| Monoid b => Monoid (a -> b) | Since: base-2.1 |
| Monoid (U1 p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b) => Monoid (a, b) | Since: base-2.1 |
| Monoid a => Monoid (Op a b) | |
| (Eq k, Hashable k) => Monoid (HashMap k v) | If a key occurs in both maps, the mapping from the first will be the mapping in the result. Examples
|
| Ord k => Monoid (Map k v) | |
| Monoid (Parser i a) | |
| Monoid a => Monoid (s :-> a) | |
| Monoid (ReifiedFold s a) | |
Defined in Control.Lens.Reified Methods mempty :: ReifiedFold s a # mappend :: ReifiedFold s a -> ReifiedFold s a -> ReifiedFold s a # mconcat :: [ReifiedFold s a] -> ReifiedFold s a # | |
| Monoid (f a) => Monoid (Indexing f a) |
|
| (Monoid a, Monoid b) => Monoid (Pair a b) | |
| Monoid (f p) => Monoid (Rec1 f p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b, Monoid c) => Monoid (a, b, c) | Since: base-2.1 |
| Monoid (Rec f ('[] :: [u])) | |
| (Monoid (f r), Monoid (Rec f rs)) => Monoid (Rec f (r ': rs)) | |
| (Semigroup a, Monoid a) => Monoid (Tagged s a) | |
| Monoid (ReifiedIndexedFold i s a) | |
Defined in Control.Lens.Reified Methods mempty :: ReifiedIndexedFold i s a # mappend :: ReifiedIndexedFold i s a -> ReifiedIndexedFold i s a -> ReifiedIndexedFold i s a # mconcat :: [ReifiedIndexedFold i s a] -> ReifiedIndexedFold i s a # | |
| ArrowPlus p => Monoid (Tambara p a b) | |
| Reifies s (ReifiedMonoid a) => Monoid (ReflectedMonoid a s) | |
Defined in Data.Reflection Methods mempty :: ReflectedMonoid a s # mappend :: ReflectedMonoid a s -> ReflectedMonoid a s -> ReflectedMonoid a s # mconcat :: [ReflectedMonoid a s] -> ReflectedMonoid a s # | |
| Monoid c => Monoid (K1 i c p) | Since: base-4.12.0.0 |
| (Monoid (f p), Monoid (g p)) => Monoid ((f :*: g) p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b, Monoid c, Monoid d) => Monoid (a, b, c, d) | Since: base-2.1 |
| Monoid (f p) => Monoid (M1 i c f p) | Since: base-4.12.0.0 |
| Monoid (f (g p)) => Monoid ((f :.: g) p) | Since: base-4.12.0.0 |
| (Monoid a, Monoid b, Monoid c, Monoid d, Monoid e) => Monoid (a, b, c, d, e) | Since: base-2.1 |
| Monoid (f (g a)) => Monoid (Compose f g a) | |
The Eq class defines equality (==) and inequality (/=).
All the basic datatypes exported by the Prelude are instances of Eq,
and Eq may be derived for any datatype whose constituents are also
instances of Eq.
The Haskell Report defines no laws for Eq. However, == is customarily
expected to implement an equivalence relationship where two values comparing
equal are indistinguishable by "public" functions, with a "public" function
being one not allowing to see implementation details. For example, for a
type representing non-normalised natural numbers modulo 100, a "public"
function doesn't make the difference between 1 and 201. It is expected to
have the following properties: