autodoc fails to get slot writers

[ethanxxxl]

This seems to happen in class-readers-and-accessors during the for writers = ... portion of the code. When there is a writer defined with :writer in defclass, closer-mop:slot-definition-writers returns a single symbole, not a list.

(defun class-readers-and-accessors (class-name &key (ignore-symbol-p 'starts-with-percent-p))
  (let* ((class (find-class class-name))
         (slots (class-direct-slots class)))
    (loop for slot in slots
          for readers = (remove-if ignore-symbol-p
                                   (slot-definition-readers slot))
          for writers = (remove-if ignore-symbol-p
                                   (mapcar #'second
                                           (slot-definition-writers slot)))
          append readers into all-readers
          append writers into all-writers
          finally (return (values (sort all-readers
                                        #'string<)
                                  (sort all-writers
                                        #'string<))))))

steps to reproduce... load this code:

(ql:quickload :40ants-doc)
(ql:quickload :40ants-doc-full)
(ql:quickload :40ants-doc/autodoc)

(asdf:defsystem "foobar-manual"
  :class :package-inferred-system
  :components ((:file autodoc-test)))

(defpackage #:foobar-manual
  (:use #:common-lisp
        #:40ants-doc)
  (:export foobar))

(in-package foobar-manual)

(defclass foobar ()
  ((slot1 :initarg :slot1
          :accessor slot1)
   (slot2 :initarg :slot2
          :writer set-slot2)))

(defmethod slot1 ((f foobar))
  "slot 1 getter"
  (slot-value f 'slot1))

(defmethod (setf slot1) ((f foobar) obj)
  "slot 1 setter"
  (setf (slot-value f 'slot1) obj))

(defmethod set-slot2 ((f foobar) obj)
  "slot 2 setter"
  (setf (slot-value f 'slot2) obj))

(defun test-foobar ()
  (let ((f (make-instance 'foobar :slot1 10 :slot2 20)))
    (format t "~%slot1: ~S  |  slot2: ~S" (slot1 f) (slot-value f 'slot2))
    (setf (slot1 f) 100)
    (set-slot2 200 f)
    (format t "~%slot1: ~S  |  slot2: ~S" (slot1 f) (slot-value f 'slot2))))

(40ants-doc/autodoc:defautodoc @foobar-docs-auto (:system :foobar-manual))
(40ants-doc-full/builder:render-to-files 
 @foobar-docs-auto
 :format :html)