graphql-engine/server/src-lib/Data/HashMap/Strict/InsOrd/Extended.hs
Tom Harding e22eb1afea Weeding (2/?)
## Description

Following on from #4572, this removes more dead code as identified by Weeder. Comments and thoughts similarly welcome!

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4587
GitOrigin-RevId: 73aa6a5a2833ee41d29b71fcd0a72ed19822ca73
2022-06-09 16:40:49 +00:00

39 lines
1.1 KiB
Haskell

module Data.HashMap.Strict.InsOrd.Extended
( module OMap,
catMaybes,
partition,
alterF,
)
where
import Data.HashMap.Strict.InsOrd as OMap
import Data.Hashable (Hashable)
import Prelude
catMaybes :: InsOrdHashMap k (Maybe v) -> InsOrdHashMap k v
catMaybes = OMap.mapMaybe id
partition :: (Eq k, Hashable k) => (v -> Bool) -> OMap.InsOrdHashMap k v -> (OMap.InsOrdHashMap k v, OMap.InsOrdHashMap k v)
partition predicate =
OMap.foldlWithKey'
( \(left, right) key val ->
if (predicate val)
then (OMap.insert key val left, right)
else (left, OMap.insert key val right)
)
(mempty, mempty)
-- | Alter a hashmap using a function that can fail, in which case the entire operation fails.
-- (Maybe a version with the key also being passed to the function could be useful.)
alterF ::
(Functor f, Eq k, Hashable k) =>
(Maybe v -> f (Maybe v)) ->
k ->
InsOrdHashMap k v ->
f (InsOrdHashMap k v)
alterF f k m = alter' <$> f (OMap.lookup k m)
where
alter' = \case
Nothing -> OMap.delete k m
Just v -> OMap.insert k v m