Compiling REx `\n \s* x '
  size 7 Got 60 bytes for offset annotations.
  first at 1
  rarest char x at 0
  rarest char
   at 0
     1: EXACT <\n>(3)
     3: STAR(5)
     4:   SPACE(0)
     5: EXACT <x>(7)
     7: END(0)