(text as text, optional char_to_trim as text) =>
let
char = if char_to_trim = null then " " else char_to_trim,
split = Text.Split(text, char),
removeblanks = List.Select(split, each _ <> ""),
result=Text.Combine(removeblanks, char)
in
result
非原創,在國外網站找到的。不過還沒找到實際應用場景。