在SBCL中使用步進器的一個簡單例子

Question

使用LispWorks步進器進行計算相當直觀，但我無法在SBCL中找到它。有人請給我一個關於如何在REPL中使用SBCL步進器的一些簡單功能的分步示例？謝謝。

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 

命令：

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. 

參見SBCL手冊：single stepping。