Haskell Help

Okay, major help needed if someone out there has the time, this has been killing my brain for ages.

-- e.g., insertions 'c' "ab" = ["cab", "acb", "abc"]
-- It may help to define two functions which call each other.

Thus far I have.

insertions :: x -> [x] -> [[x]]
insertions x [] = [[]]
insertions x (y:ys) = ??

insertions :: x -> [x] -> [[x]]
insertions x [] = [[]]
insertions x (y:ys) = (y:ys).map(function(s:String, i:int, array:Array) {
  return x + s;
})