text: flatten: function [
      "Flatten the block"
      block [any-block!]
  ][
      load form block
  ]
  
  red>> flatten [[1] 2 [[3 4] 5] [[[]]] [[[6]]] 7 8 []]
  == [1 2 3 4 5 6 7 8]
  
  ;flatten a list to a string
  >> blk: [1 2 ["test"] "a" [["bb"]] 3 4 [[[99]]]]
  >> form blk
  == "1 2 test a bb 3 4 99"
  