CREATE bintree.txt  \ Leo Wong 26 March 02003 fyj +
\ >data bintree bintree.txt link xbintree xnode

\ See: twigs.txt

from tools.txt

: bintree  \ Define a binary tree
   CREATE  0 , ;

: link  ( node -- )  \ Add a link to a binary tree  
   ALIGN HERE SWAP !  0 , 0 , ;  \ left  right

: >data  ( node -- a )  \ Address of a node's data
   2 CELLS + ;

DEFER xnode  ( node -- )  \ Execute node
   ' ? is xnode

: xbintree  ( bintree -- )  \ Execute nodes in a binary tree
   @ ?DUP 0= ?? EXIT DUP RECURSE DUP xnode CELL+ RECURSE ;