Implementing `split`

I implemented the split function in Haskell:

split :: (Eq a) => a -> [a] -> [[a]]
split _ [] = []
split x ys = f : split x rest 
  where (f, rest) = break (== x) (dropWhile (== x) ys)

Note that I'm calling dropWhile (== x) since break's second-tuple value will include the "broken on" value.

example:

*Main> break (== 'a') "dogacactus"
("dog","acactus")

Testing

*Main> split2 '3' "123aaaBBB3"
["12","aaaBBB",""]

Generally it looks good, at least to an Haskell beginner like me.
I find the use of dropWhile to be a bit confusing. I admit I had to read your comment to understand why you used it.

I think it could also have introduced a bug. What is the expected behaviour for split ',' ",,"?
Your code returns [""] but I would expect ["","",""]. Was your behaviour intended?

This solution fixed the issue.

split :: (Eq a) => a -> [a] -> [[a]]
split _ [] = []
split separator ys = f : (split separator (dropSeparator separator rest))
  where (f, rest) = break (== separator) ys

dropSeparator :: Eq a => a ->  [a] -> [a]
dropSeparator _ [] = []
dropSeparator separator (x:xs) = if x == separator then xs else x:xs

I prefer using meaningful variable names, such as separator, even if I'm not sure if it is idiomatic Haskell. Ditto for the parentheses and the introduction of the helper function.

StackExchange Code Review Q#62917, answer score: 6