| Copyright | (c) The University of Glasgow 1992-2002 |
|---|---|
| License | see libraries/base/LICENSE |
| Maintainer | cvs-ghc@haskell.org |
| Stability | internal |
| Portability | non-portable (GHC extensions) |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
GHC.Enum
Synopsis
- class Bounded a where
- class Enum a where
- succ :: a -> a
- pred :: a -> a
- toEnum :: Int -> a
- fromEnum :: a -> Int
- enumFrom :: a -> [a]
- enumFromThen :: a -> a -> [a]
- enumFromTo :: a -> a -> [a]
- enumFromThenTo :: a -> a -> a -> [a]
- boundedEnumFrom :: (Enum a, Bounded a) => a -> [a]
- boundedEnumFromThen :: (Enum a, Bounded a) => a -> a -> [a]
- toEnumError :: Show a => String -> Int -> (a, a) -> b
- fromEnumError :: Show a => String -> a -> b
- succError :: String -> a
- predError :: String -> a
Documentation
class Bounded a where Source #
The Bounded class is used to name the upper and lower limits of a
type. Ord is not a superclass of Bounded since types that are not
totally ordered may also have upper and lower bounds.
The Bounded class may be derived for any enumeration type;
minBound is the first constructor listed in the data declaration
and maxBound is the last.
Bounded may also be derived for single-constructor datatypes whose
constituent types are in Bounded.
Instances
| Bounded Bool # | Since: base-2.1 |
| Bounded Char # | Since: base-2.1 |
| Bounded Int # | Since: base-2.1 |
| Bounded Int8 # | Since: base-2.1 |
| Bounded Int16 # | Since: base-2.1 |
| Bounded Int32 # | Since: base-2.1 |
| Bounded Int64 # | Since: base-2.1 |
| Bounded Ordering # | Since: base-2.1 |
| Bounded Word # | Since: base-2.1 |
| Bounded Word8 # | Since: base-2.1 |
| Bounded Word16 # | Since: base-2.1 |
| Bounded Word32 # | Since: base-2.1 |
| Bounded Word64 # | Since: base-2.1 |
| Bounded VecCount # | Since: base-4.10.0.0 |
| Bounded VecElem # | Since: base-4.10.0.0 |
| Bounded () # | Since: base-2.1 |
| Bounded GeneralCategory # | Since: base-2.1 |
Defined in GHC.Unicode | |
| Bounded IntPtr # | |
| Bounded WordPtr # | |
| Bounded CUIntMax # | |
| Bounded CIntMax # | |
| Bounded CUIntPtr # | |
| Bounded CIntPtr # | |
| Bounded CSigAtomic # | |
Defined in Foreign.C.Types | |
| Bounded CWchar # | |
| Bounded CSize # | |
| Bounded CPtrdiff # | |
| Bounded CBool # | |
| Bounded CULLong # | |
| Bounded CLLong # | |
| Bounded CULong # | |
| Bounded CLong # | |
| Bounded CUInt # | |
| Bounded CInt # | |
| Bounded CUShort # | |
| Bounded CShort # | |
| Bounded CUChar # | |
| Bounded CSChar # | |
| Bounded CChar # | |
| Bounded DecidedStrictness # | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded SourceStrictness # | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded SourceUnpackedness # | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded Associativity # | Since: base-4.9.0.0 |
Defined in GHC.Generics | |
| Bounded Any # | Since: base-2.1 |
| Bounded All # | Since: base-2.1 |
| Bounded Fd # | |
| Bounded CKey # | |
| Bounded CId # | |
| Bounded CFsFilCnt # | |
| Bounded CFsBlkCnt # | |
| Bounded CClockId # | |
| Bounded CBlkCnt # | |
| Bounded CBlkSize # | |
| Bounded CRLim # | |
| Bounded CTcflag # | |
| Bounded CUid # | |
| Bounded CNlink # | |
| Bounded CGid # | |
| Bounded CSsize # | |
| Bounded CPid # | |
| Bounded COff # | |
| Bounded CMode # | |
| Bounded CIno # | |
| Bounded CDev # | |
| Bounded ByteOrder # | Since: base-4.11.0.0 |
| Bounded a => Bounded (Product a) # | Since: base-2.1 |
| Bounded a => Bounded (Sum a) # | Since: base-2.1 |
| Bounded a => Bounded (Dual a) # | Since: base-2.1 |
| Bounded a => Bounded (Identity a) # | Since: base-4.9.0.0 |
| Bounded m => Bounded (WrappedMonoid m) # | Since: base-4.9.0.0 |
Defined in Data.Semigroup | |
| Bounded a => Bounded (Last a) # | Since: base-4.9.0.0 |
| Bounded a => Bounded (First a) # | Since: base-4.9.0.0 |
| Bounded a => Bounded (Max a) # | Since: base-4.9.0.0 |
| Bounded a => Bounded (Min a) # | Since: base-4.9.0.0 |
| (Bounded a, Bounded b) => Bounded (a, b) # | Since: base-2.1 |
| Bounded (Proxy t) # | Since: base-4.7.0.0 |
| (Bounded a, Bounded b, Bounded c) => Bounded (a, b, c) # | Since: base-2.1 |
| a ~ b => Bounded (a :~: b) # | Since: base-4.7.0.0 |
| Coercible a b => Bounded (Coercion a b) # | Since: base-4.7.0.0 |
| (Applicative f, Bounded a) => Bounded (Ap f a) # | Since: base-4.12.0.0 |
| Bounded a => Bounded (Const a b) # | Since: base-4.9.0.0 |
| (Bounded a, Bounded b, Bounded c, Bounded d) => Bounded (a, b, c, d) # | Since: base-2.1 |
| a ~~ b => Bounded (a :~~: b) # | Since: base-4.10.0.0 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e) => Bounded (a, b, c, d, e) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f) => Bounded (a, b, c, d, e, f) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g) => Bounded (a, b, c, d, e, f, g) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h) => Bounded (a, b, c, d, e, f, g, h) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i) => Bounded (a, b, c, d, e, f, g, h, i) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j) => Bounded (a, b, c, d, e, f, g, h, i, j) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k) => Bounded (a, b, c, d, e, f, g, h, i, j, k) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n) # | Since: base-2.1 |
| (Bounded a, Bounded b, Bounded c, Bounded d, Bounded e, Bounded f, Bounded g, Bounded h, Bounded i, Bounded j, Bounded k, Bounded l, Bounded m, Bounded n, Bounded o) => Bounded (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) # | Since: base-2.1 |
Class Enum defines operations on sequentially ordered types.
The enumFrom... methods are used in Haskell's translation of
arithmetic sequences.
Instances of Enum may be derived for any enumeration type (types
whose constructors have no fields). The nullary constructors are
assumed to be numbered left-to-right by fromEnum from 0 through n-1.
See Chapter 10 of the Haskell Report for more details.
For any type that is an instance of class Bounded as well as Enum,
the following should hold:
- The calls
succmaxBoundpredminBound fromEnumandtoEnumshould give a runtime error if the result value is not representable in the result type. For example,toEnum7 ::BoolenumFromandenumFromThenshould be defined with an implicit bound, thus:
enumFrom x = enumFromTo x maxBound
enumFromThen x y = enumFromThenTo x y bound
where
bound | fromEnum y >= fromEnum x = maxBound
| otherwise = minBoundMethods
the successor of a value. For numeric types, succ adds 1.
the predecessor of a value. For numeric types, pred subtracts 1.
Convert from an Int.
Convert to an Int.
It is implementation-dependent what fromEnum returns when
applied to a value that is too large to fit in an Int.
Used in Haskell's translation of [n..] with [n..] = enumFrom n,
a possible implementation being enumFrom n = n : enumFrom (succ n).
For example:
enumFrom 4 :: [Integer] = [4,5,6,7,...]
enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound :: Int]
enumFromThen :: a -> a -> [a] Source #
Used in Haskell's translation of [n,n'..]
with [n,n'..] = enumFromThen n n', a possible implementation being
enumFromThen n n' = n : n' : worker (f x) (f x n'),
worker s v = v : worker s (s v), x = fromEnum n' - fromEnum n and
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y
For example:
enumFromThen 4 6 :: [Integer] = [4,6,8,10...]
enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound :: Int]
enumFromTo :: a -> a -> [a] Source #
Used in Haskell's translation of [n..m] with
[n..m] = enumFromTo n m, a possible implementation being
enumFromTo n m
| n <= m = n : enumFromTo (succ n) m
| otherwise = [].
For example:
enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
enumFromTo 42 1 :: [Integer] = []
enumFromThenTo :: a -> a -> a -> [a] Source #
Used in Haskell's translation of [n,n'..m] with
[n,n'..m] = enumFromThenTo n n' m, a possible implementation
being enumFromThenTo n n' m = worker (f x) (c x) n m,
x = fromEnum n' - fromEnum n, c x = bool (>=) ((x 0)
f n y
| n > 0 = f (n - 1) (succ y)
| n < 0 = f (n + 1) (pred y)
| otherwise = y and
worker s c v m
| c v m = v : worker s c (s v) m
| otherwise = []
For example:
enumFromThenTo 4 2 -6 :: [Integer] = [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
Instances
boundedEnumFrom :: (Enum a, Bounded a) => a -> [a] Source #
boundedEnumFromThen :: (Enum a, Bounded a) => a -> a -> [a] Source #
fromEnumError :: Show a => String -> a -> b Source #