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@emasaka
Created August 24, 2010 10:39
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(define (traverse-tree tree func)
(define (spin cns prev)
(let ((next (car cns)))
(set-car! cns (cdr cns))
(set-cdr! cns prev)
next ))
(let ((marker (gensym)))
(let loop ((cns tree) (prev marker))
(let ((next (spin cns prev)))
(cond ((pair? next)
(loop next cns) )
((not (eq? next marker))
(or (null? next) (func next))
(loop cns next) ))))) )
(define sample-list '((3 (5 (7)) 11)))
(let ((tree (list-copy sample-list)))
(traverse-tree tree print)
(print tree) )
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