I recently had to reinvent this, but I'm sure I've seen a version of it
on cll decades ago. Anyone remember which poster or post? I'm
interested to see how it was described.

```
(defmacro debug (&rest syms)
(let ((leader (if (stringp (car syms)) (pop syms) "DEBUG")))
(let ((format-string (format nil "~A: ~{~A=~~S~^, ~}~~&" leader syms)))
`(format t ,format-string ,@syms))))
```

The best docstring I could come up with is:

"\(DEBUG [\"DEBUG-MSG\"] [ITEMS...] \) prints DEBUG-MSG: [ITEM=VAL ...]
on standard output"

A slight advantage may be gleaned if the string and arguments to DEBUG
are treated as such:

```
(defmacro debug (&rest syms-and-strings)
(let* ((args nil)
(fmt-string
(with-output-to-string (stream)
(loop for (c . rest) on syms-and-strings do
(typecase c
(string (princ c stream))
((or (and symbol (not keyword)) (not atom))
(push c args)
(princ c stream)
(princ "=~S" stream))
(otherwise (prin1 c stream)))
(princ (if (endp rest) #\Newline #\Space) stream)))))
`(format t ,fmt-string ,@(nreverse args))))
```

But then it loses some of the declarative conciseness

* In <m335512mos.fsf@leonis4.robolove.meer.net> :
I Wrote on Sat, 15 Apr 2023 20:54:19 +0530:

> I recently had to reinvent this, but I'm sure I've seen a version of it
> on cll decades ago. Anyone remember which poster or post? I'm
> interested to see how it was described.

I found this one now, https://github.com/danlentz/printv

>
> ```
> (defmacro debug (&rest syms)
> (let ((leader (if (stringp (car syms)) (pop syms) "DEBUG")))
> (let ((format-string (format nil "~A: ~{~A=~~S~^, ~}~~&" leader syms)))
> `(format t ,format-string ,@syms))))
> ```
>
>
> The best docstring I could come up with is:
>
> "\(DEBUG [\"DEBUG-MSG\"] [ITEMS...] \) prints DEBUG-MSG: [ITEM=VAL ...]
> on standard output"
>
>
> A slight advantage may be gleaned if the string and arguments to DEBUG
> are treated as such:
>
> ```
> (defmacro debug (&rest syms-and-strings)
> (let* ((args nil)
> (fmt-string
> (with-output-to-string (stream)
> (loop for (c . rest) on syms-and-strings do
> (typecase c
> (string (princ c stream))
> ((or (and symbol (not keyword)) (not atom))
> (push c args)
> (princ c stream)
> (princ "=~S" stream))
> (otherwise (prin1 c stream)))
> (princ (if (endp rest) #\Newline #\Space) stream)))))
> `(format t ,fmt-string ,@(nreverse args))))
> ```
>
> But then it loses some of the declarative conciseness