Un semplice esempio di utilizzo dello stepper in SBCL

Question

Passare attraverso il calcolo con lo stepper LispWorks è piuttosto intuitivo, ma non riesco a capirlo in SBCL. Qualcuno può darmi un esempio dettagliato di come utilizzare lo stepper SBCL nel REPL su alcune semplici funzioni? Grazie.

Answer 1

* (proclaim '(optimize (debug 3))) 

* (defun foo (a b) (* (+ a b) b)) 

FOO 
* (step (foo 1 2)) 
; Evaluating call: 
; (FOO 1 2) 
; With arguments: 
; 1 
; 2 

1] step 
; Evaluating call: 
; (+ A B) 
; With unknown arguments 

0] step 
; Evaluating call: 
; (* (+ A B) B) 
; With unknown arguments 

0] step 
; (FOO 1 2) => 6 

Comandi:

Stepping: 
    START Selects the CONTINUE restart if one exists and starts 
     single-stepping. Single stepping affects only code 
     compiled with under high DEBUG optimization quality. 
     See User Manual for details. 
    STEP Steps into the current form. 
    NEXT Steps over the current form. 
    OUT Stops stepping temporarily, but resumes it when the topmost 
     frame that was stepped into returns. 
    STOP Stops single-stepping. 

consultare il manuale SBCL: single stepping.