Utils/Containers/Internal/StrictFold.hs

    {-# LANGUAGE CPP #-}
    #if !defined(TESTING) && __GLASGOW_HASKELL__ >= 703
    {-# LANGUAGE Safe #-}
    #endif

    #include "containers.h"
    {-# OPTIONS_HADDOCK hide #-}

    module Utils.Containers.Internal.StrictFold (foldlStrict) where

    -- | Same as regular 'Data.List.foldl'', but marked INLINE so that it is always
    -- inlined. This allows further optimization of the call to f, which can be
    -- optimized/specialised/inlined.

    foldlStrict :: (a -> b -> a) -> a -> [b] -> a
    foldlStrict f = go
      where
        go z []     = z
        go z (x:xs) = let z' = f z x in z' `seq` go z' xs
    {-# INLINE foldlStrict #-}