( Case Words )

: <OF> OVER = IF DROP R> 2 + >R ELSE R> DUP @ + >R THEN ;

: CASE ?COMP CSP @ !CSP 4 ;  IMMEDIATE

: OF 4 ?PAIRS COMPILE <OF> HERE 0 , 5 ; IMMEDIATE

: ENDOF 5 ?PAIRS COMPILE BRANCH HERE 0 , SWAP 2 [COMPILE]
  THEN 4 ; IMMEDIATE

: ENDCASE 4 ?PAIRS COMPILE DROP BEGIN SP@ CSP @ <> WHILE 2
  [COMPILE] THEN REPEAT CSP ! ; IMMEDIATE

( CASE   1 OF do something ENDOF {repeat as necessary} )
( may do something if no case match ENDCASE )