gui-utils:read-snips/chars-from-buffer

• (gui-utils:read-snips/chars-from-buffer edit start end) -> (-> (union char snip% eof-object))
      edit : (instance text%)
      start = 0 : integer
      end = (send edit last-position) : integer

  This function returns a thunk, which when called returns all of the characaters and non-text-snips from the edit, one by one.