Add some more functions to the RealExtras class

The new functions are `floor`, `trunc`, `modf` and `remainder`

This closes ekmett/numeric-extras/#2

CHANGELOG.markdown

@@ -1,3 +1,6 @@
+0.0.4
+-----
+* Added functions `floor`, `trunc`, `modf` and `remainder`
 0.0.3
 -----
 * Marked `Numeric.Extras` `Trustworthy`.

Numeric/Extras.hs

@@ -7,8 +7,15 @@ module Numeric.Extras
     ( RealExtras(..)
     ) where
 
+#if defined(__GLASGOW_HASKELL__) && __GLASGOW_HASKELL__ < 710
+import Control.Applicative ((<$>), (<*>))
+#endif
+import Control.Arrow ((***))
 import Foreign
 import Foreign.C.Types
+import System.IO.Unsafe (unsafeDupablePerformIO)
+
+{-# ANN module "HLint: ignore Use camelCase" #-}
 
 class (Storable (C a), RealFloat (C a), RealFloat a) => RealExtras a where
     type C a :: *
@@ -18,6 +25,10 @@ class (Storable (C a), RealFloat (C a), RealFloat a) => RealExtras a where
     hypot :: a -> a -> a
     cbrt  :: a -> a
     erf   :: a -> a
+    floor :: a -> a
+    trunc :: a -> a
+    modf  :: a -> (a, a)
+    remainder :: a -> a -> a
 
 instance RealExtras Double where
     type C Double = CDouble
@@ -27,15 +38,26 @@ instance RealExtras Double where
     hypot = lift2D c_hypot
     cbrt = lift1D c_cbrt
     erf = lift1D c_erf
+    floor = lift1D c_floor
+    trunc = lift1D c_trunc
+    modf = lift1D2 c_modf
+    remainder = lift2D c_remainder
 
 lift1D :: (CDouble -> CDouble) -> Double -> Double
 lift1D f a = realToFrac (f (realToFrac a))
 {-# INLINE lift1D #-}
 
+lift1D2 :: (CDouble -> (CDouble, CDouble)) -> Double -> (Double, Double)
+lift1D2 f a = (realToFrac *** realToFrac) (f (realToFrac a))
+{-# INLINE lift1D2 #-}
+
 lift2D :: (CDouble -> CDouble -> CDouble) -> Double -> Double -> Double
 lift2D f a b = realToFrac (f (realToFrac a) (realToFrac b))
 {-# INLINE lift2D #-}
 
+c_modf :: CDouble -> (CDouble, CDouble)
+c_modf a = unsafeDupablePerformIO $ alloca (\i -> (,) <$> c_modf_imp a i <*> peek i)
+
 instance RealExtras Float where
     type C Float = CFloat
     fmod = lift2F c_fmodf
@@ -44,15 +66,26 @@ instance RealExtras Float where
     hypot = lift2F c_hypotf
     cbrt  = lift1F c_cbrtf
     erf   = lift1F c_erff
+    floor = lift1F c_floorf
+    trunc = lift1F c_truncf
+    modf = lift1F2 c_modff
+    remainder = lift2F c_remainderf
 
 lift1F :: (CFloat -> CFloat) -> Float -> Float
 lift1F f a = realToFrac (f (realToFrac a))
 {-# INLINE lift1F #-}
 
+lift1F2 :: (CFloat -> (CFloat, CFloat)) -> Float -> (Float, Float)
+lift1F2 f a = (realToFrac *** realToFrac) (f (realToFrac a))
+{-# INLINE lift1F2 #-}
+
 lift2F :: (CFloat -> CFloat -> CFloat) -> Float -> Float -> Float
 lift2F f a b = realToFrac (f (realToFrac a) (realToFrac b))
 {-# INLINE lift2F #-}
 
+c_modff :: CFloat -> (CFloat, CFloat)
+c_modff a = unsafeDupablePerformIO $ alloca (\i -> (,) <$> c_modff_imp a i <*> peek i)
+
 foreign import ccall unsafe "math.h fmod"
     c_fmod :: CDouble -> CDouble -> CDouble
 foreign import ccall unsafe "math.h expm1"
@@ -65,6 +98,14 @@ foreign import ccall unsafe "math.h cbrt"
     c_cbrt :: CDouble -> CDouble
 foreign import ccall unsafe "math.h erf"
     c_erf :: CDouble -> CDouble
+foreign import ccall unsafe "math.h floor"
+    c_floor :: CDouble -> CDouble
+foreign import ccall unsafe "math.h trunc"
+    c_trunc :: CDouble -> CDouble
+foreign import ccall unsafe "math.h modf"
+    c_modf_imp :: CDouble -> Ptr CDouble -> IO CDouble
+foreign import ccall unsafe "math.h remainder"
+    c_remainder :: CDouble -> CDouble -> CDouble
 
 foreign import ccall unsafe "math.h fmodf"
     c_fmodf :: CFloat -> CFloat -> CFloat
@@ -78,5 +119,13 @@ foreign import ccall unsafe "math.h cbrtf"
     c_cbrtf :: CFloat -> CFloat
 foreign import ccall unsafe "math.h erff"
     c_erff :: CFloat -> CFloat
+foreign import ccall unsafe "math.h floorf"
+    c_floorf :: CFloat -> CFloat
+foreign import ccall unsafe "math.h truncf"
+    c_truncf :: CFloat -> CFloat
+foreign import ccall unsafe "math.h modff"
+    c_modff_imp :: CFloat -> Ptr CFloat -> IO CFloat
+foreign import ccall unsafe "math.h remainderf"
+    c_remainderf :: CFloat -> CFloat -> CFloat
 
 default (Double)

numeric-extras.cabal

@@ -1,5 +1,5 @@
 name:              numeric-extras
-version:           0.0.3
+version:           0.0.4
 synopsis:          Useful tools from the C standard library
 homepage:          http://github.com/ekmett/numeric-extras
 bug-reports:       http://github.com/ekmett/numeric-extras/issues