{-# LANGUAGE Trustworthy #-}{-# LANGUAGE CPP, NoImplicitPrelude, MagicHash, UnboxedTuples #-}{-# OPTIONS_HADDOCK not-home #-}------------------------------------------------------------------------------- |-- Module : GHC.Internal.Num-- Copyright : (c) The University of Glasgow 1994-2002-- License : see libraries/base/LICENSE---- Maintainer : ghc-devs@haskell.org-- Stability : internal-- Portability : non-portable (GHC Extensions)---- The 'Num' class and the 'Integer' type.-------------------------------------------------------------------------------moduleGHC.Internal.Num (Num (..),subtract ,quotRemInteger ,moduleGHC.Num.Integer ,moduleGHC.Num.Natural -- reexported for backward compatibility,moduleGHC.Internal.Natural ,moduleGHC.Internal.Integer )where #include "MachDeps.h" importqualifiedGHC.Internal.Natural importqualifiedGHC.Internal.Integer importGHC.Internal.Base importGHC.Num.Integer importGHC.Num.Natural infixl7* infixl6+ ,- default()-- Double isn't available yet,-- and we shouldn't be using defaults anyway-- | Basic numeric class.---- The Haskell Report defines no laws for 'Num'. However, @('+')@ and @('*')@ are-- customarily expected to define a ring and have the following properties:---- [__Associativity of @('+')@__]: @(x + y) + z@ = @x + (y + z)@-- [__Commutativity of @('+')@__]: @x + y@ = @y + x@-- [__@'fromInteger' 0@ is the additive identity__]: @x + fromInteger 0@ = @x@-- [__'negate' gives the additive inverse__]: @x + negate x@ = @fromInteger 0@-- [__Associativity of @('*')@__]: @(x * y) * z@ = @x * (y * z)@-- [__@'fromInteger' 1@ is the multiplicative identity__]:-- @x * fromInteger 1@ = @x@ and @fromInteger 1 * x@ = @x@-- [__Distributivity of @('*')@ with respect to @('+')@__]:-- @a * (b + c)@ = @(a * b) + (a * c)@ and @(b + c) * a@ = @(b * a) + (c * a)@-- [__Coherence with 'toInteger'__]: if the type also implements 'GHC.Real.Integral', then-- 'fromInteger' is a left inverse for 'GHC.Internal.Real.toInteger', i.e. @fromInteger (toInteger i) == i@---- Note that it /isn't/ customarily expected that a type instance of both 'Num'-- and 'Ord' implement an ordered ring. Indeed, in @base@ only 'Integer' and-- 'Data.Ratio.Rational' do.classNum a where{-# MINIMAL(+),(*),abs ,signum ,fromInteger ,(negate |(-))#-}(+) ,(-),(*) ::a ->a ->a -- | Unary negation.negate ::a ->a -- | Absolute value.abs ::a ->a -- | Sign of a number.-- The functions 'abs' and 'signum' should satisfy the law:---- > abs x * signum x == x---- For real numbers, the 'signum' is either @-1@ (negative), @0@ (zero)-- or @1@ (positive).signum ::a ->a -- | Conversion from an 'Integer'.-- An integer literal represents the application of the function-- 'fromInteger' to the appropriate value of type 'Integer',-- so such literals have type @('Num' a) => a@.fromInteger ::Integer ->a {-# INLINE(-)#-}{-# INLINEnegate #-}a x - a y =a x a -> a -> a forall a. Num a => a -> a -> a + a -> a forall a. Num a => a -> a negate a y negate a x =a 0a -> a -> a forall a. Num a => a -> a -> a - a x -- | the same as @'flip' ('-')@.---- Because @-@ is treated specially in the Haskell grammar,-- @(-@ /e/@)@ is not a section, but an application of prefix negation.-- However, @('subtract'@ /exp/@)@ is equivalent to the disallowed section.{-# INLINEsubtract #-}subtract ::(Num a )=>a ->a ->a subtract :: forall a. Num a => a -> a -> a subtract a x a y =a y a -> a -> a forall a. Num a => a -> a -> a - a x -- | @since base-2.01instanceNum Int whereI# Int# x + :: Int -> Int -> Int + I# Int# y =Int# -> Int I# (Int# x Int# -> Int# -> Int# +# Int# y )I# Int# x - :: Int -> Int -> Int - I# Int# y =Int# -> Int I# (Int# x Int# -> Int# -> Int# -# Int# y )negate :: Int -> Int negate (I# Int# x )=Int# -> Int I# (Int# -> Int# negateInt# Int# x )I# Int# x * :: Int -> Int -> Int * I# Int# y =Int# -> Int I# (Int# x Int# -> Int# -> Int# *# Int# y )abs :: Int -> Int abs Int n =ifInt n Int -> Int -> Bool `geInt` Int 0thenInt n elseInt -> Int forall a. Num a => a -> a negate Int n signum :: Int -> Int signum Int n |Int n Int -> Int -> Bool `ltInt` Int 0=Int -> Int forall a. Num a => a -> a negate Int 1|Int n Int -> Int -> Bool `eqInt` Int 0=Int 0|Bool otherwise =Int 1fromInteger :: Integer -> Int fromInteger Integer i =Int# -> Int I# (Integer -> Int# integerToInt# Integer i )-- | @since base-2.01instanceNum Word where(W# Word# x# )+ :: Word -> Word -> Word + (W# Word# y# )=Word# -> Word W# (Word# x# Word# -> Word# -> Word# `plusWord#` Word# y# )(W# Word# x# )- :: Word -> Word -> Word - (W# Word# y# )=Word# -> Word W# (Word# x# Word# -> Word# -> Word# `minusWord#` Word# y# )(W# Word# x# )* :: Word -> Word -> Word * (W# Word# y# )=Word# -> Word W# (Word# x# Word# -> Word# -> Word# `timesWord#` Word# y# )negate :: Word -> Word negate (W# Word# x# )=Word# -> Word W# (Int# -> Word# int2Word# (Int# -> Int# negateInt# (Word# -> Int# word2Int# Word# x# )))abs :: Word -> Word abs Word x =Word x signum :: Word -> Word signum Word 0=Word 0signum Word _=Word 1fromInteger :: Integer -> Word fromInteger Integer i =Word# -> Word W# (Integer -> Word# integerToWord# Integer i )-- | @since base-2.01instanceNum Integer where+ :: Integer -> Integer -> Integer (+) =Integer -> Integer -> Integer integerAdd (-)=Integer -> Integer -> Integer integerSub * :: Integer -> Integer -> Integer (*) =Integer -> Integer -> Integer integerMul negate :: Integer -> Integer negate =Integer -> Integer integerNegate fromInteger :: Integer -> Integer fromInteger Integer i =Integer i abs :: Integer -> Integer abs =Integer -> Integer integerAbs signum :: Integer -> Integer signum =Integer -> Integer integerSignum -- | Note that `Natural`'s 'Num' instance isn't a ring: no element but 0 has an-- additive inverse. It is a semiring though.---- @since base-4.8.0.0instanceNum Natural where+ :: Natural -> Natural -> Natural (+) =Natural -> Natural -> Natural naturalAdd (-)=Natural -> Natural -> Natural naturalSubThrow * :: Natural -> Natural -> Natural (*) =Natural -> Natural -> Natural naturalMul negate :: Natural -> Natural negate =Natural -> Natural naturalNegate fromInteger :: Integer -> Natural fromInteger Integer i =Integer -> Natural integerToNaturalThrow Integer i abs :: Natural -> Natural abs =Natural -> Natural forall a. a -> a id signum :: Natural -> Natural signum =Natural -> Natural naturalSignum {-# DEPRECATEDquotRemInteger"Use integerQuotRem# instead"#-}quotRemInteger ::Integer ->Integer ->(#Integer ,Integer #)quotRemInteger :: Integer -> Integer -> (# Integer, Integer #) quotRemInteger =Integer -> Integer -> (# Integer, Integer #) integerQuotRem#