add src/Gargantext/Data/HashMap/Strict/Utils.hs

src/Gargantext/Data/HashMap/Strict/Utils.hs

+module Gargantext.Data.HashMap.Strict.Utils where
+
+import Data.Hashable (Hashable)
+import Data.HashMap.Strict (HashMap)
+import qualified Data.HashMap.Strict as HM
+import Gargantext.Prelude
+
+unionsWith :: (Foldable f, Eq k, Hashable k) => (a->a->a) -> f (HashMap k a) -> HashMap k a
+unionsWith f = foldl' (HM.unionWith f) HM.empty