In UCBLogo, the code looks like:
if (ufun != NIL && flag__caseobj(ufun, PROC_STEPPED)) {
if (tracing) {
int i = 1;
while (i++ < trace_level) print_space(stdout);
}
print_node(stdout, this_line);
(void)reader(stdin, " >>> ");
}
This makes sense in UCBLogo because the trace output is interwoven with the single-step dialog.
However, in FMSLogo, the single-step dialog is a separate dialog box, so adding
indentation to the commander history, where the trace output goes, doesn't make sense.