{-# LANGUAGE NoImplicitPrelude, UnicodeSyntax #-} module Utils where -------------------------------------------------------------------------------- -- Imports -------------------------------------------------------------------------------- -- from base: import Prelude ( (+), (-), (^) , Enum, toEnum, fromEnum , fromInteger , Integral, fromIntegral ) import Control.Monad ( Monad, (>>=), fail, mapM ) import Foreign.Ptr ( Ptr ) import Foreign.Storable ( Storable, ) import Foreign.Marshal.Array ( peekArray ) import Data.Bool ( Bool ) import Data.Ord ( Ord ) import Data.Bits ( Bits, shiftR, (.&.) ) import Data.Int ( Int ) import Data.Functor ( Functor, (<\$)) import System.IO ( IO ) -- from base-unicode-symbols: import Data.Function.Unicode ( (∘) ) import Data.Ord.Unicode ( (≥), (≤) ) import Data.Bool.Unicode ( (∧) ) -------------------------------------------------------------------------------- -- Utils -------------------------------------------------------------------------------- -- | @bits s e b@ extract bit @s@ to @e@ (including) from @b@. bits ∷ Bits α ⇒ Int → Int → α → α bits s e b = (2 ^ (e - s + 1) - 1) .&. (b `shiftR` s) -- | @between n b e@ tests if @n@ is between the given bounds @b@ and @e@ -- (including). between ∷ Ord α ⇒ α → α → α → Bool between n b e = n ≥ b ∧ n ≤ e -- | Execute the given action but ignore the result. void ∷ Functor m ⇒ m α → m () void = (() <\$) -- | A generalized 'toEnum' that works on any 'Integral' type. genToEnum ∷ (Integral i, Enum e) ⇒ i → e genToEnum = toEnum ∘ fromIntegral -- | A generalized 'fromEnum' that returns any 'Integral' type. genFromEnum ∷ (Integral i, Enum e) ⇒ e → i genFromEnum = fromIntegral ∘ fromEnum -- | @mapPeekArray f n a@ applies the monadic function @f@ to each of the @n@ -- elements of the array @a@ and returns the results in a list. mapPeekArray ∷ Storable α ⇒ (α → IO β) → Int → Ptr α → IO [β] mapPeekArray f n a = peekArray n a >>= mapM f -- | Monadic if...then...else... ifM ∷ Monad m ⇒ m Bool → m α → m α → m α ifM cM tM eM = do c ← cM if c then tM else eM -- The End ---------------------------------------------------------------------