Commit before changing thingsHit to use stream

src/FoldableHelp.hs

@@ -7,6 +7,7 @@ module FoldableHelp
     , safeMinMaybeL
     , filter3
     , takeUntil
+    , ssfold
     , module Data.Foldable
     )
     where
@@ -91,3 +92,11 @@ filter3 t1 t2 t3 = L.fold $ (,,)
  -}
 takeUntil :: Foldable t => (a -> Bool) -> t a -> [a]
 takeUntil p = foldr (\x xs -> x : if p x then [] else xs) []
+
+-- from haskell-cafe
+-- short circuit a fold when a given property is satisfied
+-- the fold builds a function that is then called on a0
+ssfold :: Foldable t => (a -> Bool) -> (a -> b -> a) -> a -> t b -> a
+{-# INLINABLE ssfold #-}
+ssfold p f a0 xs = foldr (\x g a -> if p a then a else g (f a x)) id xs a0
+