chore: impl foldl through foldr
chore: impl foldl through foldr

rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming,rockdragon/julia-programming