VARIABLE STATEBLK
VARIABLE LIFEBLK
VARIABLE STATEP

\ : -ROT       ROT ROT ;

: WRAPY        DUP 0< IF DROP 15 THEN DUP 15 > IF DROP 0 THEN ;
: WRAPX        DUP 0< IF DROP 63 THEN DUP 63 > IF DROP 0 THEN ;
: WRAP WRAPY SWAP WRAPX SWAP ;
: DECEASED?    WRAP 64 * + LIFEBLK @ BLOCK + C@ BL = ;
: LIVING?      DECEASED? 0= ;
: (-1,-1)      2DUP 1- SWAP 1- SWAP LIVING? 1 AND ;
: (0,-1)       >R 2DUP 1- LIVING? 1 AND R> + ;
: (1,-1)       >R 2DUP 1- SWAP 1+ SWAP LIVING? 1 AND R> + ;
: (-1,0)       >R 2DUP SWAP 1- SWAP LIVING? 1 AND R> + ;
: (1,0)        >R 2DUP SWAP 1+ SWAP LIVING? 1 AND R> + ;
: (-1,1)       >R 2DUP 1+ SWAP 1- SWAP LIVING? 1 AND R> + ;
: (0,1)        >R 2DUP 1+ LIVING? 1 AND R> + ;
: (1,1)        >R 1+ SWAP 1+ SWAP LIVING? 1 AND R> + ;
: NEIGHBORS    (-1,-1) (0,-1) (1,-1) (-1,0) (1,0) (-1,1) (0,1) (1,1) ;
: BORN?        NEIGHBORS 3 = ;
: SURVIVES?    2DUP LIVING? -ROT NEIGHBORS 2 = AND ;
: LIVES?       2DUP BORN? -ROT SURVIVES? OR ;
: NEWSTATE     STATEBLK @ BLOCK UPDATE STATEP ! ;
: STATE!       STATEP @ C! 1 STATEP +! ;
: ALIVE        [CHAR] * STATE! ;
: DEAD BL STATE! ;
: ITERATE-CELL 2DUP SWAP LIVES? IF ALIVE ELSE DEAD THEN ;
: ITERATE-ROW  0 BEGIN DUP 64 < WHILE ITERATE-CELL 1+ REPEAT DROP ;
: ITERATE-BLOCK        0 BEGIN DUP 16 < WHILE ITERATE-ROW 1+ REPEAT DROP ;
: GENERATION   LIFEBLK @ STATEBLK @ LIFEBLK ! STATEBLK ! ;
: ITERATE      NEWSTATE ITERATE-BLOCK GENERATION ;
: DONE?        KEY [CHAR] Q = ;
: PROMPT       CR ." PRESS Q TO EXIT; OTHER KEY TO CONTINUE" ;
: VIEW PAGE LIFEBLK @ LIST PROMPT ;
: LIFE BEGIN VIEW ITERATE DONE? UNTIL ;