All breakpoints in a definition are forgotten each time you
reinstrument it. If you wish to make a breakpoint that won’t be
forgotten, you can write a source breakpoint, which is simply a
call to the function edebug in your source code. You can, of
course, make such a call conditional. For example, in the fac
function, you can insert the first line as shown below, to stop when the
argument reaches zero:
(defun fac (n)
(if (= n 0) (edebug))
(if (< 0 n)
(* n (fac (1- n)))
1))
When the fac definition is instrumented and the function is
called, the call to edebug acts as a breakpoint. Depending on
the execution mode, Edebug stops or pauses there.
If no instrumented code is being executed when edebug is called,
that function calls debug.