| base-4.1.0.0: Basic libraries | Source code | Contents | Index

Data.Ord

Portability | portable
Stability | stable
Maintainer | libraries@haskell.org

Description
Orderings
Synopsis

class Eq a => Ord a where

compare :: a -> a -> Ordering
(<) :: a -> a -> Bool
(>=) :: a -> a -> Bool
(>) :: a -> a -> Bool
(<=) :: a -> a -> Bool
max :: a -> a -> a
min :: a -> a -> a

Ordering (LT, EQ, GT)
comparing :: Ord a => (b -> a) -> b -> b -> Ordering

Documentation

class Eq a => Ord a where | Source

The `Ord` class is used for totally ordered datatypes.

Instances of `Ord` can be derived for any user-defined datatype whose constituent types are in `Ord`. The declared order of the constructors in the data declaration determines the ordering in derived `Ord` instances. The `Ordering` datatype allows a single comparison to determine the precise ordering of two objects.

Minimal complete definition: either `compare` or `<=`. Using `compare` can be more efficient for complex types.

Methods

compare :: a -> a -> Ordering | Source

(<) :: a -> a -> Bool | Source

(>=) :: a -> a -> Bool | Source

(>) :: a -> a -> Bool | Source

(<=) :: a -> a -> Bool | Source

max :: a -> a -> a | Source

min :: a -> a -> a | Source

Instances

Ord Bool
Ord Char
Ord Double
Ord Float
Ord Int
Ord Int8
Ord Int16
Ord Int32
Ord Int64
Ord Integer
Ord Ordering
Ord Word
Ord Word8
Ord Word16
Ord Word32
Ord Word64
Ord ()
Ord ArithException
Ord CUIntMax
Ord CIntMax
Ord CUIntPtr
Ord CIntPtr
Ord CTime
Ord CClock
Ord CSigAtomic
Ord CWchar
Ord CSize
Ord CPtrdiff
Ord CLDouble
Ord CDouble
Ord CFloat
Ord CULLong
Ord CLLong
Ord CULong
Ord CLong
Ord CUInt
Ord CInt
Ord CUShort
Ord CShort
Ord CUChar
Ord CSChar
Ord CChar
Ord IOMode
Ord ExitCode
Ord ArrayException
Ord AsyncException
Ord BufferMode
Ord GeneralCategory
Ord IntPtr
Ord WordPtr
Ord Fd
Ord CRLim
Ord CTcflag
Ord CSpeed
Ord CCc
Ord CUid
Ord CNlink
Ord CGid
Ord CSsize
Ord CPid
Ord COff
Ord CMode
Ord CIno
Ord CDev
Ord ThreadStatus
Ord BlockReason
Ord ThreadId
Ord SeekMode
Ord Any
Ord All
Ord Unique
Ord Version
Ord a => Ord ([] a)
Integral a => Ord (Ratio a)
Ord (Ptr a)
Ord (FunPtr a)
Ord a => Ord ([::] a)
Ord a => Ord (Maybe a)
Ord (ForeignPtr a)
Ord a => Ord (Down a)
Ord (Fixed a)
Ord a => Ord (Last a)
Ord a => Ord (First a)
Ord a => Ord (Product a)
Ord a => Ord (Sum a)
Ord a => Ord (Dual a)
(Ord a, Ord b) => Ord (Either a b)
(Ord a, Ord b) => Ord ((,) a b)
(Ix i, Ord e) => Ord (Array i e)
(Ord a, Ord b, Ord c) => Ord ((,,) a b c)
(Ord a, Ord b, Ord c, Ord d) => Ord ((,,,) a b c d)
(Ord a, Ord b, Ord c, Ord d, Ord e) => Ord ((,,,,) a b c d e)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f) => Ord ((,,,,,) a b c d e f)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g) => Ord ((,,,,,,) a b c d e f g)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h) => Ord ((,,,,,,,) a b c d e f g h)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i) => Ord ((,,,,,,,,) a b c d e f g h i)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j) => Ord ((,,,,,,,,,) a b c d e f g h i j)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k) => Ord ((,,,,,,,,,,) a b c d e f g h i j k)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l) => Ord ((,,,,,,,,,,,) a b c d e f g h i j k l)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m) => Ord ((,,,,,,,,,,,,) a b c d e f g h i j k l m)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n) => Ord ((,,,,,,,,,,,,,) a b c d e f g h i j k l m n)
(Ord a, Ord b, Ord c, Ord d, Ord e, Ord f, Ord g, Ord h, Ord i, Ord j, Ord k, Ord l, Ord m, Ord n, Ord o) => Ord ((,,,,,,,,,,,,,,) a b c d e f g h i j k l m n o)

Ordering (LT, EQ, GT)

comparing :: Ord a => (b -> a) -> b -> b -> Ordering | Source

     comparing p x y = compare (p x) (p y)

Useful combinator for use in conjunction with the `xxxBy` family of functions from Data.List, for example:

       ... sortBy (comparing fst) ...

Produced by Haddock version 2.4.2