0.8.11.19:

[sbcl.git] / src / code / describe.lisp

diff --git a/src/code/describe.lisp b/src/code/describe.lisp
index cf4e87f..ca2ab73 100644 (file)
--- a/src/code/describe.lisp
+++ b/src/code/describe.lisp
@@ -1,4 +1,4 @@
-;;;; most of the DESCRIBE mechanism -- that part which isn't derived
+;;;; most of the DESCRIBE system -- that part which isn't derived

 ;;;; from PCL code
 
 ;;;; This software is part of the SBCL system. See the README file for
 ;;;; from PCL code
 
 ;;;; This software is part of the SBCL system. See the README file for

@@ -12,33 +12,45 @@
 
 (in-package "SB-IMPL") ;(SB-IMPL, not SB!IMPL, since we're built in warm load.)
 \f
 
 (in-package "SB-IMPL") ;(SB-IMPL, not SB!IMPL, since we're built in warm load.)
 \f

-(defvar *describe-indentation-step* 3
-  #+sb-doc
-  "the number of spaces that sets off each line of a recursive description")
-

 (declaim (ftype (function (t stream)) describe-object))
 (declaim (ftype (function (t stream)) describe-object))

-(defgeneric describe-object ((x t) stream))
+(defgeneric describe-object (x stream))

 
 (defun describe (x &optional (stream-designator *standard-output*))
   #+sb-doc
   "Print a description of the object X."
   (let ((stream (out-synonym-of stream-designator)))
 
 (defun describe (x &optional (stream-designator *standard-output*))
   #+sb-doc
   "Print a description of the object X."
   (let ((stream (out-synonym-of stream-designator)))

-    (pprint-logical-block (stream nil)
-      (fresh-line stream)
-      (describe-object x stream)
-      (fresh-line stream)))
+    ;; Until sbcl-0.8.0.x, we did
+    ;;   (FRESH-LINE STREAM)
+    ;;   (PPRINT-LOGICAL-BLOCK (STREAM NIL)
+    ;;     ...
+    ;; here. However, ANSI's specification of DEFUN DESCRIBE,
+    ;;   DESCRIBE exists as an interface primarily to manage argument
+    ;;   defaulting (including conversion of arguments T and NIL into
+    ;;   stream objects) and to inhibit any return values from
+    ;;   DESCRIBE-OBJECT. 
+    ;; doesn't mention either FRESH-LINEing or PPRINT-LOGICAL-BLOCKing,
+    ;; and the example of typical DESCRIBE-OBJECT behavior in ANSI's
+    ;; specification of DESCRIBE-OBJECT will work poorly if we do them
+    ;; here. (The example method for DESCRIBE-OBJECT does its own
+    ;; FRESH-LINEing, which is a physical directive which works poorly
+    ;; inside a pretty-printer logical block.)
+    (describe-object x stream)
+    ;; We don't TERPRI here either (any more since sbcl-0.8.0.x), because
+    ;; again ANSI's specification of DESCRIBE doesn't mention it and
+    ;; ANSI's example of DESCRIBE-OBJECT does its own final TERPRI.
+    )

   (values))
 \f
 ;;;; miscellaneous DESCRIBE-OBJECT methods
 
 (defmethod describe-object ((x t) s)
   (values))
 \f
 ;;;; miscellaneous DESCRIBE-OBJECT methods
 
 (defmethod describe-object ((x t) s)

-  (format s "~@<~S ~_is a ~S.~:>" x (type-of x)))
+  (format s "~&~@<~S ~_is a ~S.~:>~%" x (type-of x)))

 
 (defmethod describe-object ((x cons) s)
   (call-next-method)
 
 (defmethod describe-object ((x cons) s)
   (call-next-method)

-  (when (and (legal-function-name-p x)
+  (when (and (legal-fun-name-p x)

             (fboundp x))
             (fboundp x))

-    (%describe-function (fdefinition x) s :function x)
+    (%describe-fun (fdefinition x) s :function x)

     ;;was: (format s "~@:_Its FDEFINITION is ~S.~@:_" (fdefinition x))
     ;; TO DO: should check for SETF documentation.
     ;; TO DO: should make it clear whether the definition is a
     ;;was: (format s "~@:_Its FDEFINITION is ~S.~@:_" (fdefinition x))
     ;; TO DO: should check for SETF documentation.
     ;; TO DO: should make it clear whether the definition is a

@@ -46,53 +58,59 @@
     ))
 
 (defmethod describe-object ((x array) s)
     ))
 
 (defmethod describe-object ((x array) s)

-  (let ((rank (array-rank x)))
-    (cond ((> rank 1)
-          (format s "~S ~_is " x)
-          (write-string (if (%array-displaced-p x) "a displaced" "an") s)
-          (format s " array of rank ~S." rank)
-          (format s "~@:_Its dimensions are ~S." (array-dimensions x)))
-         (t
-          (format s
-                  "~@:_~S is a ~:[~;displaced ~]vector of length ~S." x
-                  (and (array-header-p x) (%array-displaced-p x)) (length x))
-          (when (array-has-fill-pointer-p x)
-            (format s "~@:_It has a fill pointer, currently ~S."
-                    (fill-pointer x))))))
-  (let ((array-element-type (array-element-type x)))
-    (unless (eq array-element-type t)
-      (format s
-             "~@:_Its element type is specialized to ~S."
-             array-element-type))))
+  (fresh-line s)
+  (pprint-logical-block (s nil)
+    (cond
+     ((= 1 (array-rank x))
+      (format s "~S is a vector with ~D elements."
+             x (car (array-dimensions x)))
+      (when (array-has-fill-pointer-p x)
+       (format s "~@:_It has a fill pointer value of ~S."
+               (fill-pointer x))))
+     (t
+      (format s "~S is an array of dimension ~:S."
+             x (array-dimensions x))))
+    (let ((array-element-type (array-element-type x)))
+      (unless (eq array-element-type t)
+       (format s
+               "~@:_Its element type is specialized to ~S."
+               array-element-type)))
+    (if (and (array-header-p x) (%array-displaced-p x))
+       (format s "~@:_The array is displaced with offset ~S."
+               (%array-displacement x))))
+  (terpri s))

 
 (defmethod describe-object ((x hash-table) s)
   (declare (type stream s))
 
 (defmethod describe-object ((x hash-table) s)
   (declare (type stream s))

-  (format s "~@<~S ~_is an ~S hash table.~:>" x (hash-table-test x))
-  (format s "~_Its SIZE is ~S." (hash-table-size x))
+  (format s "~&~@<~S ~_is an ~S hash table.~:>" x (hash-table-test x))
+  (format s "~&Its SIZE is ~S." (hash-table-size x))

   (format s
   (format s

-         "~@:_~@<Its REHASH-SIZE is ~S. ~_Its REHASH-THRESHOLD is ~S.~:>"
+         "~&~@<Its REHASH-SIZE is ~S. ~_Its REHASH-THRESHOLD is ~S.~:>"

          (hash-table-rehash-size x)
          (hash-table-rehash-threshold x))
          (hash-table-rehash-size x)
          (hash-table-rehash-threshold x))

-  (let ((count (hash-table-count x)))
-    (format s "~@:_It holds ~S key/value pair~:P~:[: ~2I~_~;.~]"
-           count (zerop count))
-    (let ((n 0))
-      (declare (type index n))
-      (dohash (k v x)
-       (unless (zerop n)
-         (write-char #\space s))
-       (incf n)
-       (when (and *print-length* (> n *print-length*))
-         (format s "~:_...")
-         (return))
-       (format s "~:_(~@<~S ~:_~S~:>)" k v)))))
+  (fresh-line s)
+  (pprint-logical-block (s nil)
+    (let ((count (hash-table-count x)))
+      (format s "It holds ~S key/value pair~:P~:[: ~2I~_~;.~]"
+             count (zerop count))
+      (let ((n 0))
+       (declare (type index n))
+       (dohash (k v x)
+         (unless (zerop n)
+           (write-char #\space s))
+         (incf n)
+         (when (and *print-length* (> n *print-length*))
+           (format s "~:_...")
+           (return))
+         (format s "~:_(~@<~S ~:_~S~:>)" k v)))))
+  (terpri s))

 
 (defmethod describe-object ((condition condition) s)
   (sb-kernel:describe-condition condition s))
 \f
 ;;;; DESCRIBE-OBJECT methods for symbols and functions, including all
 ;;;; sorts of messy stuff about documentation, type information,
 
 (defmethod describe-object ((condition condition) s)
   (sb-kernel:describe-condition condition s))
 \f
 ;;;; DESCRIBE-OBJECT methods for symbols and functions, including all
 ;;;; sorts of messy stuff about documentation, type information,

-;;;; packaging, function implementation, etc..
+;;;; packaging, function implementation, etc...

 
 ;;; Print the specified kind of documentation about the given NAME. If
 ;;; NAME is null, or not a valid name, then don't print anything.
 
 ;;; Print the specified kind of documentation about the given NAME. If
 ;;; NAME is null, or not a valid name, then don't print anything.

@@ -101,7 +119,7 @@
   (when (and name (typep name '(or symbol cons)))
     (let ((doc (fdocumentation name kind)))
       (when doc
   (when (and name (typep name '(or symbol cons)))
     (let ((doc (fdocumentation name kind)))
       (when doc

-       (format s "~_~@(~A documentation:~)~@:_  ~A"
+       (format s "~&~@(~A documentation:~)~%  ~A"

                (or kind-doc kind) doc))))
   (values))
 
                (or kind-doc kind) doc))))
   (values))
 

@@ -110,24 +128,24 @@
 ;;; up as a name. (In the case of anonymous closures and other
 ;;; things, it might not be.) TYPE-SPEC is the function type specifier
 ;;; extracted from the definition, or NIL if none.
 ;;; up as a name. (In the case of anonymous closures and other
 ;;; things, it might not be.) TYPE-SPEC is the function type specifier
 ;;; extracted from the definition, or NIL if none.

-(declaim (ftype (function (t stream t)) %describe-function-name))
-(defun %describe-function-name (name s type-spec) 
+(declaim (ftype (function (t stream t)) %describe-fun-name))
+(defun %describe-fun-name (name s type-spec) 

   (when (and name (typep name '(or symbol cons)))
     (multiple-value-bind (type where)
   (when (and name (typep name '(or symbol cons)))
     (multiple-value-bind (type where)

-       (if (or (symbolp name) (and (listp name) (eq (car name) 'setf)))
+       (if (legal-fun-name-p name)

            (values (type-specifier (info :function :type name))
                    (info :function :where-from name))
            (values type-spec :defined))
       (when (consp type)
            (values (type-specifier (info :function :type name))
                    (info :function :where-from name))
            (values type-spec :defined))
       (when (consp type)

-       (format s "~@:_Its ~(~A~) argument types are:~@:_  ~S"
+       (format s "~&Its ~(~A~) argument types are:~%  ~S"

                where (second type))
                where (second type))

-       (format s "~@:_Its result type is:~@:_  ~S" (third type))))
+       (format s "~&Its result type is:~%  ~S" (third type))))

     (let ((inlinep (info :function :inlinep name)))
       (when inlinep
        (format s
     (let ((inlinep (info :function :inlinep name)))
       (when inlinep
        (format s

-               "~@:_It is currently declared ~(~A~);~
+               "~&It is currently declared ~(~A~);~

                 ~:[no~;~] expansion is available."
                 ~:[no~;~] expansion is available."

-               inlinep (info :function :inline-expansion name))))))
+               inlinep (info :function :inline-expansion-designator name))))))

 
 ;;; Print information from the debug-info about where CODE-OBJ was
 ;;; compiled from.
 
 ;;; Print information from the debug-info about where CODE-OBJ was
 ;;; compiled from.

@@ -137,7 +155,7 @@
     (when info
       (let ((sources (sb-c::debug-info-source info)))
        (when sources
     (when info
       (let ((sources (sb-c::debug-info-source info)))
        (when sources

-         (format s "~@:_On ~A it was compiled from:"
+         (format s "~&On ~A it was compiled from:"

                  ;; FIXME: The FORMAT-UNIVERSAL-TIME calls in the system
                  ;; should become more consistent, probably not using
                  ;; any nondefault options.
                  ;; FIXME: The FORMAT-UNIVERSAL-TIME calls in the system
                  ;; should become more consistent, probably not using
                  ;; any nondefault options.

@@ -149,75 +167,83 @@
            (let ((name (sb-c::debug-source-name source)))
              (ecase (sb-c::debug-source-from source)
                (:file
            (let ((name (sb-c::debug-source-name source)))
              (ecase (sb-c::debug-source-from source)
                (:file

-                (format s "~@:_~A~@:_  Created: " (namestring name))
+                (format s "~&~A~@:_  Created: " (namestring name))

                 (format-universal-time s (sb-c::debug-source-created
                                           source)))
                 (format-universal-time s (sb-c::debug-source-created
                                           source)))

-               (:lisp (format s "~@:_~S" name))))))))))
+               (:lisp (format s "~&~S" name))))))))))

 
 ;;; Describe a compiled function. The closure case calls us to print
 ;;; the guts.
 
 ;;; Describe a compiled function. The closure case calls us to print
 ;;; the guts.

-(defun %describe-function-compiled (x s kind name)
+(defun %describe-fun-compiled (x s kind name)

   (declare (type stream s))
   (declare (type stream s))

-  ;; FIXME: The lowercaseness of %SIMPLE-FUN-ARGLIST results, and the
-  ;; non-sentenceness of the "Arguments" label, makes awkward output.
-  ;; Better would be "Its arguments are: ~S" (with uppercase argument
-  ;; names) when arguments are known, and otherwise "There is no
-  ;; information available about its arguments." or "It has no
-  ;; arguments." (And why is %SIMPLE-FUN-ARGLIST a string instead of a
-  ;; list of symbols anyway?)

   (let ((args (%simple-fun-arglist x)))
   (let ((args (%simple-fun-arglist x)))

-    (format s "~@:_~@(~@[~A ~]arguments:~@:_~)" kind)

     (cond ((not args)
     (cond ((not args)

-          (format s "  There is no argument information available."))
-         ((string= args "()")

           (write-string "  There are no arguments." s))
          (t
           (write-string "  There are no arguments." s))
          (t

+           (format s "~&~@(The ~@[~A's ~]arguments are:~@:_~)" kind)

           (write-string "  " s)
           (write-string "  " s)

-          (pprint-logical-block (s nil)
-            (pprint-indent :current 2)
-            (write-string args s)))))
+            (let ((*print-pretty* t)
+                  (*print-escape* t)
+                  (*print-base* 10)
+                  (*print-radix* nil))
+              (pprint-logical-block (s nil)
+                 (pprint-indent :current 2)
+                 (format s "~A" args))))))

   (let ((name (or name (%simple-fun-name x))))
     (%describe-doc name s 'function kind)
     (unless (eq kind :macro)
   (let ((name (or name (%simple-fun-name x))))
     (%describe-doc name s 'function kind)
     (unless (eq kind :macro)

-      (%describe-function-name name s (%simple-fun-type x))))
+      (%describe-fun-name name s (%simple-fun-type x))))

   (%describe-compiled-from (sb-kernel:fun-code-header x) s))
 
   (%describe-compiled-from (sb-kernel:fun-code-header x) s))
 

-;;; Describe a function with the specified kind and name. The latter
-;;; arguments provide some information about where the function came
-;;; from. KIND=NIL means not from a name.
-(defun %describe-function (x s &optional (kind nil) name)
+;;; Describe a function object. KIND and NAME provide some information
+;;; about where the function came from.
+(defun %describe-fun (x s &optional (kind :function) (name nil))

   (declare (type function x))
   (declare (type stream s))
   (declare (type function x))
   (declare (type stream s))

-  (declare (type (member :macro :function nil) kind))
+  (declare (type (member :macro :function) kind))

   (fresh-line s)
   (fresh-line s)

-  (ecase kind
-    (:macro (format s "Macro-function: ~S" x))
-    (:function (format s "Function: ~S" x))
-    ((nil) (format s "~S is a function." x)))
-  (case (get-type x)
-    (#.sb-vm:closure-header-widetag
-     (%describe-function-compiled (%closure-fun x) s kind name)
-     (format s "~@:_Its closure environment is:")
-     (pprint-logical-block (s nil)
-       (pprint-indent :current 8)
-       (dotimes (i (- (get-closure-length x) (1- sb-vm:closure-info-offset)))
-        (format s "~@:_~S: ~S" i (%closure-index-ref x i)))))
-    ((#.sb-vm:simple-fun-header-widetag #.sb-vm:closure-fun-header-widetag)
-     (%describe-function-compiled x s kind name))
-    (#.sb-vm:funcallable-instance-header-widetag
-     (typecase x
-       (standard-generic-function
-       ;; There should be a special method for this case; we'll
-       ;; delegate to that.
-       (describe-object x s))
-       (t
-       (format s "~@:_It is an unknown type of funcallable instance."))))
-    (t
-     (format s "~@:_It is an unknown type of function."))))
+  (pprint-logical-block (s nil)
+    (ecase kind
+      (:macro (format s "Macro-function: ~S" x))
+      (:function (if name
+                    (format s "Function: ~S" x)
+                    (format s "~S is a function." x))))
+    (format s "~@:_~@<Its associated name (as in ~S) is ~2I~_~S.~:>"
+           'function-lambda-expression
+           (%fun-name x))
+    (case (widetag-of x)
+      (#.sb-vm:closure-header-widetag
+       (%describe-fun-compiled (%closure-fun x) s kind name)
+       (format s "~@:_Its closure environment is:")
+       (pprint-logical-block (s nil)
+        (pprint-indent :current 8)
+        (dotimes (i (- (get-closure-length x) (1- sb-vm:closure-info-offset)))
+          (format s "~@:_~S: ~S" i (%closure-index-ref x i)))))
+      (#.sb-vm:simple-fun-header-widetag
+       (%describe-fun-compiled x s kind name))
+      (#.sb-vm:funcallable-instance-header-widetag
+       ;; Only STANDARD-GENERIC-FUNCTION would be handled here, but
+       ;; since it has its own DESCRIBE-OBJECT method, it should've been
+       ;; picked off before getting here. So hopefully we never get here.
+       (format s "~@:_It is an unknown type of funcallable instance."))
+      (t
+       (format s "~@:_It is an unknown type of function."))))
+  (terpri s))

 
 (defmethod describe-object ((x function) s)
 
 (defmethod describe-object ((x function) s)

-  (%describe-function x s))
-  
+  (%describe-fun x s :function))
+
+(defgeneric describe-symbol-fdefinition (function stream &key name))
+
+(defmethod describe-symbol-fdefinition ((fun function) stream &key name)
+  (%describe-fun fun stream :function name))
+
+(defmethod describe-symbol-fdefinition ((fun standard-generic-function) stream
+                                        &key name)
+  (declare (ignore name))
+  ;; Just delegate.
+  (describe-object fun stream))
+

 (defmethod describe-object ((x symbol) s)
   (declare (type stream s))
 
 (defmethod describe-object ((x symbol) s)
   (declare (type stream s))
 

@@ -227,9 +253,9 @@
        (multiple-value-bind (symbol status)
            (find-symbol (symbol-name x) package)
          (declare (ignore symbol))
        (multiple-value-bind (symbol status)
            (find-symbol (symbol-name x) package)
          (declare (ignore symbol))

-         (format s "~S is ~_an ~(~A~) symbol ~_in ~S."
+         (format s "~&~@<~S is ~_an ~(~A~) symbol ~_in ~S.~:>"

                  x status (symbol-package x)))
                  x status (symbol-package x)))

-       (format s "~S is ~_an uninterned symbol." x)))
+       (format s "~&~@<~S is ~_an uninterned symbol.~:>" x)))

   ;; TO DO: We could grovel over all packages looking for and
   ;; reporting other phenomena, e.g. IMPORT and SHADOW, or
   ;; availability in some package even after (SYMBOL-PACKAGE X) has
   ;; TO DO: We could grovel over all packages looking for and
   ;; reporting other phenomena, e.g. IMPORT and SHADOW, or
   ;; availability in some package even after (SYMBOL-PACKAGE X) has

@@ -239,59 +265,70 @@
   (let* ((kind (info :variable :kind x))
         (wot (ecase kind
                (:special "special variable")
   (let* ((kind (info :variable :kind x))
         (wot (ecase kind
                (:special "special variable")

+               (:macro "symbol macro")

                (:constant "constant")
                (:global "undefined variable")
                (:alien nil))))
                (:constant "constant")
                (:global "undefined variable")
                (:alien nil))))

-    (cond
-     ((eq kind :alien)
-      (let ((info (info :variable :alien-info x)))
-       (format s "~@:_~@<It is an alien at #X~8,'0X of type ~3I~:_~S.~:>~@:_"
-               (sap-int (eval (sb-alien::heap-alien-info-sap-form info)))
-               (sb-alien-internals:unparse-alien-type
-                (sb-alien::heap-alien-info-type info)))
-       (format s "~@<Its current value is ~3I~:_~S.~:>"
-               (eval x))))
-     ((boundp x)
-      (format s "~@:_It is a ~A; its ~_value is ~S." wot (symbol-value x)))
-     ((not (eq kind :global))
-      (format s "~@:_It is a ~A; no current value." wot)))
+    (pprint-logical-block (s nil)
+      (cond
+       ((eq kind :alien)
+       (let ((info (info :variable :alien-info x)))
+         (format s "~&~@<It is an alien at #X~8,'0X of type ~3I~:_~S.~:>"
+                 (sap-int (eval (sb-alien::heap-alien-info-sap-form info)))
+                 (sb-alien-internals:unparse-alien-type
+                  (sb-alien::heap-alien-info-type info)))
+         (format s "~&~@<Its current value is ~3I~:_~S.~:>"
+                 (eval x))))
+       ((eq kind :macro)
+       (let ((expansion (info :variable :macro-expansion x)))
+         (format s "~&It is a ~A with expansion ~S." wot expansion)))
+       ((boundp x)
+       (format s "~&~@<It is a ~A; its ~_value is ~S.~:>"
+               wot (symbol-value x)))
+       ((not (eq kind :global))
+       (format s "~&~@<It is a ~A; no current value.~:>" wot)))

 
 

-    (when (eq (info :variable :where-from x) :declared)
-      (format s "~@:_Its declared type ~_is ~S."
-             (type-specifier (info :variable :type x))))
+      (when (eq (info :variable :where-from x) :declared)
+       (format s "~&~@<Its declared type ~_is ~S.~:>"
+               (type-specifier (info :variable :type x)))))

 
     (%describe-doc x s 'variable kind))
 
   ;; Print out properties.
 
     (%describe-doc x s 'variable kind))
 
   ;; Print out properties.

-  (format s "~@[~@:_Its SYMBOL-PLIST is ~@<~2I~_~S~:>.~]" (symbol-plist x))
+  (format s "~@[~&Its SYMBOL-PLIST is ~@<~2I~_~S~:>.~]" (symbol-plist x))

 
   ;; Describe the function cell.
   (cond ((macro-function x)
 
   ;; Describe the function cell.
   (cond ((macro-function x)

-        (%describe-function (macro-function x) s :macro x))
+        (%describe-fun (macro-function x) s :macro x))

        ((special-operator-p x)
        ((special-operator-p x)

-        (%describe-doc x s 'function "Special form"))
+        (%describe-doc x s :function "Special form"))

        ((fboundp x)
        ((fboundp x)

-        (%describe-function (fdefinition x) s :function x)))
-
-  ;; FIXME: Print out other stuff from the INFO database:
-  ;;   * Does it name a type?
-  ;;   * Is it a structure accessor? (This is important since those are 
-  ;;     magical in some ways, e.g. blasting the structure if you 
-  ;;     redefine them.)
+        (describe-symbol-fdefinition (fdefinition x) s :name x)))

 
   ;; Print other documentation.
   (%describe-doc x s 'structure "Structure")
   (%describe-doc x s 'type "Type")
   (%describe-doc x s 'setf "Setf macro")
 
   ;; Print other documentation.
   (%describe-doc x s 'structure "Structure")
   (%describe-doc x s 'type "Type")
   (%describe-doc x s 'setf "Setf macro")

-

   (dolist (assoc (info :random-documentation :stuff x))
     (format s
   (dolist (assoc (info :random-documentation :stuff x))
     (format s

-           "~@:_Documentation on the ~(~A~):~@:_~A"
+           "~&~@<Documentation on the ~(~A~):~@:_~A~:>"

            (car assoc)
            (cdr assoc)))
   
            (car assoc)
            (cdr assoc)))
   

-  ;; Describe the associated class, if any.
-  (let ((symbol-named-class (cl:find-class x nil)))
+  ;; Mention the associated type information, if any.
+  ;;
+  ;; As of sbcl-0.7.2, (INFO :TYPE :KIND X) might be
+  ;;   * :PRIMITIVE, which is handled by the FIND-CLASS case.
+  ;;   * :DEFINED, which is handled specially.
+  ;;   * :INSTANCE, which is handled by the FIND-CLASS case.
+  ;;   * :FORTHCOMING-DEFCLASS-TYPE, which is an internal-to-the-compiler
+  ;;     note that we don't try to report.
+  ;;   * NIL, in which case there's nothing to see here, move along.
+  (when (eq (info :type :kind x) :defined)
+    (format s "~&It names a type specifier."))
+  (let ((symbol-named-class (find-class x nil)))

     (when symbol-named-class
     (when symbol-named-class

-      (format t "~&It names a class ~A." symbol-named-class)
-      (describe symbol-named-class))))
+      (format s "~&It names a class ~A." symbol-named-class)
+      (describe symbol-named-class s)))
+
+  (terpri s))