Common Lisp での power-assert （30分で作った適当実装）

power-assert.lisp

(in-package :cl-user)

(defmacro power-assert (form)
  (assert (listp form))
  (let ((op (first form))
	(result (gensym))
	binding
	eval-form)
    (assert (fboundp op) ()
	    "Operator must be fbound. (op is ~A)" op)
    (assert (not (special-operator-p op)) ()
	    "Operator must not a special-operator (op is ~A)" op)
    (assert (not (macro-function op)) ()
	    "Operator must not a macro (currently) (op is ~A)." op)
    (loop for arg in (rest form)
       as gsym = (gensym)
       do (push `(,gsym ,arg) binding)
       collect gsym into eval-form-args
       finally
	 (setf binding (nreverse binding)
	       eval-form (list* op eval-form-args)))
    `(let (,@binding (,result nil))
       (handler-bind
	   ((error (lambda (e)
		     (format *debug-io* "~&Result: ~A~%" ,result)
		     ,@(loop for i from 1
			  for (gsym original) in binding
			  collect `(format *debug-io* "~&~:R form: ~A => ~A~%"
					   ,i ',original ,gsym))
		     ;; decline
		     )))
	 (setf ,result
	       (assert ,eval-form ()
		       "Assertion ~A failed" ',form))))))


#|
(power-assert (eq (+ 1 2) (- 5 2)))

CL-USER> (power-assert (eq (+ 1 2) (- 5 1)))

Result: NIL
first form: (+ 1 2) => 3
second form: (- 5 1) => 4

Assertion (EQ (+ 1 2) (- 5 1)) failed
   [Condition of type SIMPLE-ERROR]
|#