Re: [Sbcl-help] How do I do trace ?

[Nikodemus S. <nik...@ra...>]

2009/2/9 David Creelman <cre...@gm...>:

> I want to see where my code is going wrong and I've tried doing trace, but it
> doesn't seem to want to work.
>
> Is there something else that I need to do to get trace working?

Here's a trivial example:

* (defun fib (n) (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2)))))

FIB
* (trace fib)

(FIB)
* (fib 4)
  0: (FIB 4)
    1: (FIB 3)
      2: (FIB 2)
        3: (FIB 1)
        3: FIB returned 1
        3: (FIB 0)
        3: FIB returned 0
      2: FIB returned 1
      2: (FIB 1)
      2: FIB returned 1
    1: FIB returned 2
    1: (FIB 2)
      2: (FIB 1)
      2: FIB returned 1
      2: (FIB 0)
      2: FIB returned 0
    1: FIB returned 1
  0: FIB returned 3
3

If you're still having trouble, please send more details.

Cheers,

 -- Nikodemus