anchor.diff:  (defconst +golden-packed-file-name+
     "google-protobuf/src/google/protobuf/testdata/golden_packed_fields_message")
   
  -(defconst +optional-field-info+
  -  '((optional-int32 . 101) (optional-int64 . 102)
  -    (optional-uint32 . 103) (optional-uint64 . 104)
  -    (optional-sint32 . 105) (optional-sint64 . 106)
  -    (optional-fixed32 . 107) (optional-fixed64 . 108)
  -    (optional-sfixed32 . 109) (optional-sfixed64 . 110)
  -    (optional-float . 111s0) (optional-double . 112d0)
  -    (optional-bool . t)
  -    (optional-string . "115") (optional-bytes . "116")
  -    (optional-nested-enum . #.pb:+testalltypes-nestedenum-baz+)
  -    (optional-foreign-enum . #.pb:+foreignenum-foreign-baz+)
  -    (optional-import-enum . #.pb:+importenum-import-baz+)
  +(defparameter *optional-field-info*
  +  ;; field name, default value, value set by tests
  +  '((optional-int32 0 101) (optional-int64 0 102)
  +    (optional-uint32 0 103) (optional-uint64 0 104)
  +    (optional-sint32 0 105) (optional-sint64 0 106)
  +    (optional-fixed32 0 107) (optional-fixed64 0 108)
  +    (optional-sfixed32 0 109) (optional-sfixed64 0 110)
  +    (optional-float 0s0 111s0) (optional-double 0d0 112d0)
  +    (optional-bool nil t)
  +    (optional-string "" "115") (optional-bytes "" "116")
  +    (optional-nested-enum
  +     #.pb:+testalltypes-nestedenum-foo+ #.pb:+testalltypes-nestedenum-baz+)
  +    (optional-foreign-enum
  +     #.pb:+foreignenum-foreign-foo+ #.pb:+foreignenum-foreign-baz+)
  +    (optional-import-enum
  +     #.pb:+importenum-import-foo+ #.pb:+importenum-import-baz+)
       ;; XXXX: C++ test does not verify these fields.
  -    (optional-string-piece . "124") (optional-cord . "125")
  +    (optional-string-piece "" "124") (optional-cord "" "125")
       ))
   
  -(defconst +default-field-info+
  -  '((default-int32 . 401) (default-int64 . 402)
  -    (default-uint32 . 403) (default-uint64 . 404)
  -    (default-sint32 . 405) (default-sint64 . 406)
  -    (default-fixed32 . 407) (default-fixed64 . 408)
  -    (default-sfixed32 . 409) (default-sfixed64 . 410)
  -    (default-float . 411s0) (default-double . 412d0)
  -    (default-bool . nil)
  -    (default-string . "415") (default-bytes . "416")
  -    (default-nested-enum . #.pb:+testalltypes-nestedenum-foo+)
  -    (default-foreign-enum . #.pb:+foreignenum-foreign-foo+)
  -    (default-import-enum . #.pb:+importenum-import-foo+)
  +(defparameter *default-field-info*
  +  ;; field name, default value, value set by tests
  +  '((default-int32 41 401) (default-int64 42 402)
  +    (default-uint32 43 403) (default-uint64 44 404)
  +    (default-sint32 -45 405) (default-sint64 46 406)
  +    (default-fixed32 47 407) (default-fixed64 48 408)
  +    (default-sfixed32 49 409) (default-sfixed64 -50 410)
  +    (default-float 51.5s0 411s0) (default-double 52d3 412d0)
  +    (default-bool t nil)
  +    (default-string "hello" "415") (default-bytes "world" "416")
  +    (default-nested-enum
  +     #.pb:+testalltypes-nestedenum-bar+ #.pb:+testalltypes-nestedenum-foo+)
  +    (default-foreign-enum
  +     #.pb:+foreignenum-foreign-bar+ #.pb:+foreignenum-foreign-foo+)
  +    (default-import-enum
  +     #.pb:+importenum-import-bar+ #.pb:+importenum-import-foo+)
       ;; XXXX: C++ test does not verify these fields.
  -    (default-string-piece . "424") (default-cord . "425")
  +    (default-string-piece "abc" "424") (default-cord "123" "425")
       ))
   
  -(defconst +repeated-field-info+
  -  '((repeated-int32 201 301) (repeated-int64 202 302)
  -    (repeated-uint32 203 303) (repeated-uint64 204 304)
  -    (repeated-sint32 205 305) (repeated-sint64 206 306)
  -    (repeated-fixed32 207 307) (repeated-fixed64 208 308)
  -    (repeated-sfixed32 209 309) (repeated-sfixed64 210 310)
  -    (repeated-float 211s0 311s0) (repeated-double 212d0 312d0)
  -    (repeated-bool t nil)
  +(defparameter *repeated-field-info*
  +  ;; field name, default value, value set by tests, modification value
  +  '((repeated-int32 201 301 501) (repeated-int64 202 302 502)
  +    (repeated-uint32 203 303 503) (repeated-uint64 204 304 504)
  +    (repeated-sint32 205 305 505) (repeated-sint64 206 306 506)
  +    (repeated-fixed32 207 307 507) (repeated-fixed64 208 308 508)
  +    (repeated-sfixed32 209 309 509) (repeated-sfixed64 210 310 510)
  +    (repeated-float 211s0 311s0 511s0) (repeated-double 212d0 312d0 512d0)
  +    (repeated-bool t nil t)
       (repeated-string
        #.(base:string-to-utf8-octets "215")
  -     #.(base:string-to-utf8-octets "315"))
  +     #.(base:string-to-utf8-octets "315")
  +     #.(base:string-to-utf8-octets "515"))
       (repeated-bytes
        #.(base:string-to-utf8-octets "216")
  -     #.(base:string-to-utf8-octets "316"))
  +     #.(base:string-to-utf8-octets "316")
  +     #.(base:string-to-utf8-octets "516"))
       (repeated-nested-enum
  -     #.pb:+testalltypes-nestedenum-bar+ #.pb:+testalltypes-nestedenum-baz+)
  +     #.pb:+testalltypes-nestedenum-bar+
  +     #.pb:+testalltypes-nestedenum-baz+
  +     #.pb:+testalltypes-nestedenum-foo+)
       (repeated-foreign-enum
  -     #.pb:+foreignenum-foreign-bar+ #.pb:+foreignenum-foreign-baz+)
  +     #.pb:+foreignenum-foreign-bar+
  +     #.pb:+foreignenum-foreign-baz+
  +     #.pb:+foreignenum-foreign-foo+)
       (repeated-import-enum
  -     #.pb:+importenum-import-bar+ #.pb:+importenum-import-baz+)
  +     #.pb:+importenum-import-bar+
  +     #.pb:+importenum-import-baz+
  +     #.pb:+importenum-import-foo+)
       ;; XXXX: C++ test does not verify these fields.
       (repeated-string-piece
        #.(base:string-to-utf8-octets "224")
  -     #.(base:string-to-utf8-octets "324"))
  +     #.(base:string-to-utf8-octets "324")
  +     #.(base:string-to-utf8-octets "524"))
       (repeated-cord
        #.(base:string-to-utf8-octets "225")
  -     #.(base:string-to-utf8-octets "325"))
  +     #.(base:string-to-utf8-octets "325")
  +     #.(base:string-to-utf8-octets "525"))
       ))
   
   (defun field-equal (x y)
  
positive.code:   (setf (pb:d (pb:optional-import-message m)) 120)
  
    ;; repeated fields
    (let ((field-info +repeated-field-info+))
      (loop for (field . values) in field-info do
            (let ((accessor (field-function "" field))
                  (v0 (first values))
  
negative.code: 
  (defun set-all-fields (m)
    ;; optional and default fields
    (let ((field-info (append *optional-field-info* *default-field-info*)))
      (loop for (field . values) in field-info do
            (let ((setter (field-setter field))
                  (value (second values)))
              (funcall setter value m))))
    (setf (pb:a (pb:optionalgroup m)) 117)
    (setf (pb:bb (pb:optional-nested-message m)) 118)
  