为什么REPL没有显示函数调用的完整跟踪？

您可以调用trace多个函数，并且需要调用trace要查看其跟踪信息的每个函数。所以，你可以这样做：

CL-USER> (trace find-first-odd oddp)
(FIND-FIRST-ODD ODDP)
CL-USER> (find-first-odd '(2 4 6 7 8))
0: (FIND-FIRST-ODD (2 4 6 7 8))
0: FIND-FIRST-ODD returned 7
7


但是，内置函数可能不会产生任何跟踪信息，并且oddp在 SBCL 中看起来是不可跟踪的。这可能是因为oddp在 SBCL 中内联了。您可以尝试使用notinline声明：

(defun find-first-odd (x)
(declare (notinline oddp))
(find-if #'oddp x))


CL-USER> (trace find-first-odd oddp)
(FIND-FIRST-ODD ODDP)
CL-USER> (find-first-odd '(2 4 6 7 8))
0: (FIND-FIRST-ODD (2 4 6 7 8))
1: (ODDP 2)
1: ODDP returned NIL
1: (ODDP 4)
1: ODDP returned NIL
1: (ODDP 6)
1: ODDP returned NIL
1: (ODDP 7)
1: ODDP returned T
0: FIND-FIRST-ODD returned 7
7


如果失败，您可以将内置函数包装在另一个可以跟踪的函数定义中：

(defun my-oddp (&rest args)
(apply #'oddp args))
(defun find-first-odd-trace (x)
(find-if #'my-oddp x))


CL-USER> (untrace)
T
CL-USER> (trace find-first-odd-trace my-oddp)
(FIND-FIRST-ODD-TRACE MY-ODDP)
CL-USER> (find-first-odd-trace '(2 4 6 7 8))
0: (FIND-FIRST-ODD-TRACE (2 4 6 7 8))
1: (MY-ODDP 2)
1: MY-ODDP returned NIL
1: (MY-ODDP 4)
1: MY-ODDP returned NIL
1: (MY-ODDP 6)
1: MY-ODDP returned NIL
1: (MY-ODDP 7)
1: MY-ODDP returned T
0: FIND-FIRST-ODD-TRACE returned 7
7


您可能还想查看对 的调用find-if。在这里你可以看到，虽然find-if是一个内置函数，但在 SBCL 中它是可追溯的：

CL-USER> (trace find-if)
(FIND-IF)
CL-USER> (find-first-odd-trace '(2 4 6 7 8))
0: (FIND-FIRST-ODD-TRACE (2 4 6 7 8))
1: (FIND-IF # (2 4 6 7 8))
2: (MY-ODDP 2)
2: MY-ODDP returned NIL
2: (MY-ODDP 4)
2: MY-ODDP returned NIL
2: (MY-ODDP 6)
2: MY-ODDP returned NIL
2: (MY-ODDP 7)
2: MY-ODDP returned T
1: FIND-IF returned 7
0: FIND-FIRST-ODD-TRACE returned 7
7