try haskell

try-haskell.hs

join :: Char -> [String] -> String
join _ [] = []
join _ [s] = s
join gl arr = 
    head arr ++ gl : joingl (tail arr)
    where
        joingl = join gl

putStrLn (join ':' ["str1", "str2", "str3"])


-- (List, Last, Tail)
type HlprSplTp = ([String], String, String)

splitHlpr :: Char -> HlprSplTp -> HlprSplTp
splitHlpr c (arr, [], []) = (
        arr ++ [[]],
        [],
        []
    )
splitHlpr c (arr, lst, []) = (
        arr ++ [lst],
        [],
        []
    )
splitHlpr c (arr, lst, tl) = 
    if head tl == c 
        then splitHlpr c (
            arr ++ [lst],
            [],
            tail tl
        )
        else splitHlpr c (
            arr,
            lst ++ [head tl],
            tail tl
        )

split :: Char -> String -> [String]
split _ [] = []
split s [c] = if s == c then [[],[]] else [[c]]
split c str =
    let 
        (arr, _, _) = splitHlpr c ([],[], str)
    in
        arr

print (split ':' "str1:str2:str3")