Contributed by John A. Peters - 11/19/2001
Here is the F83 code 0 ( FIND WHERE A WORD IS REFERENCED. WWB 06APR86AEC) 1 NEED EVERYWORD 2 HIDDEN DEFINITIONS NEED PAIRED NEED REFERENCE-CLASS 3 : (REFERENCE) ( nfa cfa cfa' -- cfa ) >BODY 4 BEGIN ( nfa cfa pfa+) 2DUP @ = 5 IF 2 PICK NAME.ID THEN 6 DUP @ REFERENCE-CLASS REFERENCE-CLASS+ ?DUP 0= 7 UNTIL NIP ; 8 : REFERENCE ( cfa nfa -- cfa ) 9 TUCK NAME> DUP @ ['] QUIT @ = IF (REFERENCE) EXIT THEN 0 DUP @ C@ DOES-OP = DUP IF DROP DUP DUP @ U< THEN 1 IF @ DOES-SIZE + 2- (REFERENCE) EXIT THEN 2 DROP NIP ; FORTH DEFINITIONS 3 : (REF) ( cfa -- ) [ HIDDEN ] CR 4 ['] REFERENCE IS EACH EVERYWORD DROP ; 5 : REF ' (REF) ;