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\ 8-6.FORTH -------------------------------------------------------------
\ -----------------------------------------------------------------------
\ Code from Starting Forth Chapter 8
\ ANSized by Benjamin Hoyt in 1997

( problem 8-6 )

CREATE BOARD  9 ALLOT

: SQUARE  ( square# -- addr )  BOARD + ;
: CLEAR   BOARD  9 ERASE ;  CLEAR
: BAR   ." | " ;
: DASHES   CR  9 0 DO  [CHAR] - EMIT  LOOP CR ;

: .BOX  ( square# -- )  
	SQUARE C@  DUP 0= IF  2 SPACES  
			ELSE  DUP 1 = IF ." X "  
				    ELSE ." O "  
				    THEN 
	 	        THEN  
	DROP ;

: DISPLAY  ( -- )
	CR  9 0 DO  I IF  I 3 MOD  0= IF DASHES  
				    ELSE BAR  
				    THEN 
		    THEN  
		    I .BOX  
	      LOOP  CR QUIT ;

: PLAY  ( player square# -- )
   1-  0 MAX  8 MIN  SQUARE C! ;

: X!  ( square# -- )   1 SWAP  PLAY  DISPLAY ;
: O!  ( square# -- )  -1 SWAP  PLAY  DISPLAY ;