haskell - Intercalate function giving Non-exhaustive patterns -


i'm trying intercalate 2 lists this:

intercalate [0, 2, 4] [1, 3, 5] [0, 1, 2, 3, 4, 5]

so created function:

intercalate (x:xs) (y:ys) = x:(y:(intercalate xs ys)) intercalate [] [] = []

however error:

 exception: <interactive>:3:5-57: non-exhaustive patterns in function intercalate

i can't understand why!

a hint should enough here:

you handle case in both lists empty.

you handle case in both lists nonempty.

can think 2 more cases?


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