*trace-print-circle*
controls how circular structures are printed during output from tracing. It allows the printing of circular structures by the tracer to be controlled independently of the usual printing mechanism, which is governed by
*print-circle*
.
*print-circle*
is bound to the value of
*trace-print-circle*
while printing tracing information.
USER 19 > (setq *trace-print-circle* t)
T
USER 20 > (defun circ (l)
(rplacd (last l) l)
l)
CIRC
USER 21 > (trace second)
SECOND
USER 22 > (second (circ '(1 2 3 4)))
0 SECOND > (#1=(1 2 3 4 . #1#))
0 SECOND < (2) 2
LispWorks User Guide and Reference Manual - 21 Dec 2011