transpose Function

transpose takes a map of lists of strings and swaps the keys and values to produce a new map of lists of strings.

Examples​

> transpose({"a" = ["1", "2"], "b" = ["2", "3"]})
{
  "1" = [
    "a",
  ],
  "2" = [
    "a",
    "b",
  ],
  "3" = [
    "b",
  ],
}