"lib/merge-sort.4th" INCLUDED
ALSO MERGE-SORT

STRUCT
CELL% FIELD NODE>LINK
CELL% FIELD NODE>DATA
ENDSTRUCT NODE%

: COMPARE-NODES ( node1 node2 -- -1 | 0 | 1 )
   >R NODE>DATA @ R> NODE>DATA @ - SIGNUM ;

: MAKE-LIST ( xu ... x1 u -- head )
   0 >R RSP@ SWAP BEGIN ?DUP WHILE
      1- -ROT NODE% %ALLOCATE DUP ROT ! DUP NODE>LINK -ROT NODE>DATA ! SWAP
   REPEAT DROP R> ;

: SHOW-LIST ( head -- )
   BEGIN ?DUP WHILE
      DUP NODE>LINK @ SWAP NODE>DATA @ . SPACE
   REPEAT EOL ;

7 5 3 6 8 9 4 2 4 9 MAKE-LIST
"Before: " TYPE DUP SHOW-LIST
' NODE>LINK ' COMPARE-NODES MERGE-SORT>
"After:  " TYPE SHOW-LIST