( Forth testing harness
  "#" means "assert". We stop at first failure, indicating
  the failure through IO on port 1 )

: fail SPC ." failed" LF 1 1 PC! BYE ;

: # IF SPC ." pass" LF ELSE fail THEN ;

: #eq 2DUP SWAP . SPC '=' EMIT SPC . '?' EMIT = # ;