diff options
author | Griffin Smith <grfn@gws.fyi> | 2021-04-11T21·53-0400 |
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committer | glittershark <grfn@gws.fyi> | 2021-04-12T14·45+0000 |
commit | 6266c5d32f9ff651fcfc3a4cc0c68e89da56ca65 (patch) | |
tree | 5be3967585787c4456e17cb29423770217fdcede /users/glittershark/xanthous/src/Xanthous/Random.hs | |
parent | 968effb5dc1a4617a0dceaffc70e986abe300c6e (diff) |
refactor(users/glittershark): Rename to grfn r/2485
Rename my //users directory and all places that refer to glittershark to grfn, including nix references and documentation. This may require some extra attention inside of gerrit's database after it lands to allow me to actually push things. Change-Id: I4728b7ec2c60024392c1c1fa6e0d4a59b3e266fa Reviewed-on: https://cl.tvl.fyi/c/depot/+/2933 Tested-by: BuildkiteCI Reviewed-by: tazjin <mail@tazj.in> Reviewed-by: lukegb <lukegb@tvl.fyi> Reviewed-by: glittershark <grfn@gws.fyi>
Diffstat (limited to 'users/glittershark/xanthous/src/Xanthous/Random.hs')
-rw-r--r-- | users/glittershark/xanthous/src/Xanthous/Random.hs | 118 |
1 files changed, 0 insertions, 118 deletions
diff --git a/users/glittershark/xanthous/src/Xanthous/Random.hs b/users/glittershark/xanthous/src/Xanthous/Random.hs deleted file mode 100644 index 6d34109df7f8..000000000000 --- a/users/glittershark/xanthous/src/Xanthous/Random.hs +++ /dev/null @@ -1,118 +0,0 @@ --------------------------------------------------------------------------------- -{-# LANGUAGE UndecidableInstances #-} -{-# OPTIONS_GHC -fno-warn-orphans #-} --------------------------------------------------------------------------------- -module Xanthous.Random - ( Choose(..) - , ChooseElement(..) - , Weighted(..) - , evenlyWeighted - , weightedBy - , subRand - , chance - , chooseSubset - ) where --------------------------------------------------------------------------------- -import Xanthous.Prelude --------------------------------------------------------------------------------- -import Data.List.NonEmpty (NonEmpty(..)) -import Control.Monad.Random.Class (MonadRandom(getRandomR, getRandom)) -import Control.Monad.Random (Rand, evalRand, mkStdGen, StdGen) -import Data.Functor.Compose -import Data.Random.Shuffle.Weighted -import Data.Random.Distribution -import Data.Random.Distribution.Uniform -import Data.Random.Distribution.Uniform.Exclusive -import Data.Random.Sample -import qualified Data.Random.Source as DRS --------------------------------------------------------------------------------- - -instance {-# INCOHERENT #-} (Monad m, MonadRandom m) => DRS.MonadRandom m where - getRandomWord8 = getRandom - getRandomWord16 = getRandom - getRandomWord32 = getRandom - getRandomWord64 = getRandom - getRandomDouble = getRandom - getRandomNByteInteger n = getRandomR (0, 256 ^ n) - -class Choose a where - type RandomResult a - choose :: MonadRandom m => a -> m (RandomResult a) - -newtype ChooseElement a = ChooseElement a - -instance MonoFoldable a => Choose (ChooseElement a) where - type RandomResult (ChooseElement a) = Maybe (Element a) - choose (ChooseElement xs) = do - chosenIdx <- getRandomR (0, olength xs - 1) - let pick _ (Just x) = Just x - pick (x, i) Nothing - | i == chosenIdx = Just x - | otherwise = Nothing - pure $ ofoldr pick Nothing $ zip (toList xs) [0..] - -instance MonoFoldable a => Choose (NonNull a) where - type RandomResult (NonNull a) = Element a - choose - = fmap (fromMaybe (error "unreachable")) -- why not lol - . choose - . ChooseElement - . toNullable - -instance Choose (NonEmpty a) where - type RandomResult (NonEmpty a) = a - choose = choose . fromNonEmpty @[_] - -instance Choose (a, a) where - type RandomResult (a, a) = a - choose (x, y) = choose (x :| [y]) - -newtype Weighted w t a = Weighted (t (w, a)) - deriving (Functor, Foldable) via (t `Compose` (,) w) - -instance Traversable t => Traversable (Weighted w t) where - traverse f (Weighted twa) = Weighted <$> (traverse . traverse) f twa - -evenlyWeighted :: [a] -> Weighted Int [] a -evenlyWeighted = Weighted . itoList - --- | Weight the elements of some functor by a function. Larger values of 'w' per --- its 'Ord' instance will be more likely to be generated -weightedBy :: Functor t => (a -> w) -> t a -> Weighted w t a -weightedBy weighting xs = Weighted $ (weighting &&& id) <$> xs - -instance (Num w, Ord w, Distribution Uniform w, Excludable w) => Choose (Weighted w [] a) where - type RandomResult (Weighted w [] a) = Maybe a - choose (Weighted ws) = sample $ headMay <$> weightedSample 1 ws - -instance (Num w, Ord w, Distribution Uniform w, Excludable w) => Choose (Weighted w NonEmpty a) where - type RandomResult (Weighted w NonEmpty a) = a - choose (Weighted ws) = - sample - $ fromMaybe (error "unreachable") . headMay - <$> weightedSample 1 (toList ws) - -subRand :: MonadRandom m => Rand StdGen a -> m a -subRand sub = evalRand sub . mkStdGen <$> getRandom - --- | Has a @n@ chance of returning 'True' --- --- eg, chance 0.5 will return 'True' half the time -chance - :: (Num w, Ord w, Distribution Uniform w, Excludable w, MonadRandom m) - => w - -> m Bool -chance n = choose $ weightedBy (bool 1 (n * 2)) bools - --- | Choose a random subset of *about* @w@ of the elements of the given --- 'Witherable' structure -chooseSubset :: ( Num w, Ord w, Distribution Uniform w, Excludable w - , Witherable t - , MonadRandom m - ) => w -> t a -> m (t a) -chooseSubset = filterA . const . chance - --------------------------------------------------------------------------------- - -bools :: NonEmpty Bool -bools = True :| [False] |