{-# LANGUAGE DeriveAnyClass #-} {-# LANGUAGE DeriveGeneric #-} {-# LANGUAGE LambdaCase #-} {-# OPTIONS_GHC -Wno-orphans #-} module Data.Function.FastMemo.Integer () where import Data.Function.FastMemo.Class (Memoizable (..)) import Data.Function.FastMemo.Natural () import GHC.Generics (Generic) import Numeric.Natural (Natural) instance Memoizable Integer where memoize :: forall b. (Integer -> b) -> Integer -> b memoize Integer -> b f = forall a b. Memoizable a => (a -> b) -> a -> b memoize (Integer -> b f forall b c a. (b -> c) -> (a -> b) -> a -> c . (Sign, Natural) -> Integer signedNatToInteger) forall b c a. (b -> c) -> (a -> b) -> a -> c . Integer -> (Sign, Natural) integerToSignedNat data Sign = NegativePlus1 | NonNegative deriving (forall x. Rep Sign x -> Sign forall x. Sign -> Rep Sign x forall a. (forall x. a -> Rep a x) -> (forall x. Rep a x -> a) -> Generic a $cto :: forall x. Rep Sign x -> Sign $cfrom :: forall x. Sign -> Rep Sign x Generic, forall b. (Sign -> b) -> Sign -> b forall a. (forall b. (a -> b) -> a -> b) -> Memoizable a memoize :: forall b. (Sign -> b) -> Sign -> b $cmemoize :: forall b. (Sign -> b) -> Sign -> b Memoizable) integerToSignedNat :: Integer -> (Sign, Natural) integerToSignedNat :: Integer -> (Sign, Natural) integerToSignedNat Integer i | Integer i forall a. Ord a => a -> a -> Bool < Integer 0 = (Sign NegativePlus1, forall a. Num a => Integer -> a fromInteger (- (Integer i forall a. Num a => a -> a -> a + Integer 1))) | Bool otherwise = (Sign NonNegative, forall a. Num a => Integer -> a fromInteger Integer i) signedNatToInteger :: (Sign, Natural) -> Integer signedNatToInteger :: (Sign, Natural) -> Integer signedNatToInteger = \case (Sign NegativePlus1, Natural n) -> - (forall a. Integral a => a -> Integer toInteger Natural n forall a. Num a => a -> a -> a + Integer 1) (Sign NonNegative, Natural n) -> forall a. Integral a => a -> Integer toInteger Natural n