\ rot13 in forth w/bitwise rot13'ing
\ by Teknovore/1999

: rot13 dup 32 and invert dup rot and dup 65 >= swap dup 90 <= rot -1 = if -1
= if 65 - 13 + 26 mod 65 + then then swap invert or ;

variable foo

: dorot begin key dup foo ! dup 4 = 0= if rot13 then foo @ 4 = until ;

dorot
cr
bye