I am new here and a Lisp beginner at his first significant development.
I am having problem to use the :step option of the (trace) form as documented here:
I am using the ECL 12.2.1 REPL on Linux i686.
CL-USER> (defun factorial (n)
(if (plusp n)
(* n (factorial (1- n)))
CL-USER> (trace (factorial :step t))
Condition of type: SIMPLE-ERROR
Not a valid argument to TRACE: (FACTORIAL :STEP T)
1. (RESTART-TOPLEVEL) Go back to Top-Level REPL.
Broken at SI:BYTECODES. [Evaluation of: (TRACE (FACTORIAL :STEP T))] In: #<process TOP-LEVEL>.
** BREAK [LEVEL 2]>
What am I doing wrong? Does the (trace) macro accept lists, doesn't it?
BTW the equivalent and very similar option in another Lisp (GNU CLISP) works:
(trace (factorial :step-if t))