Rework the mechanism for legacy compatibility

slime.el

@@ -4058,30 +4058,39 @@ inserted in the current buffer."
      (run-hooks 'slime-transcript-stop-hook)
      (message "Evaluation aborted on %s." condition))))
 
-(defun slime-eval-print (string)
-  "Eval STRING in Lisp; insert any output and the result at point."
-  (slime-eval-async `(swank:eval-and-grab-output ,string)
-    (lambda (result)
-      (cl-destructuring-bind (standard-output
-                              value
-                              error-output trace-output)
-          result
-        (push-mark)
-        (insert error-output trace-output standard-output
-                value)))))
-
-(defun slime-eval-save (string)
-  "Evaluate STRING in Lisp and save the result in the kill ring."
-  (slime-eval-async `(swank:eval-and-grab-output ,string)
-    (lambda (result)
-      (cl-destructuring-bind (standard-output
-                              value
-                              error-output trace-output)
-          result
-        (let ((string (concat error-output trace-output standard-output
-                              value)))
-          (kill-new string)
-          (message "Evaluation finished; pushed result to kill ring."))))))
+(defconst slime-output-targets
+  '(common-lisp:values
+    common-lisp:*standard-output*
+    common-lisp:*trace-output*
+    common-lisp:*error-output*)
+  "Possible keys in the alist returned by Common Lisp function `swank:eval-and-grab-output'.")
+
+(cl-defun slime-eval-print
+    (string &optional (targets-to-print '(common-lisp:*standard-output*
+                                          common-lisp:values)))
+  "Eval STRING in Lisp; insert standard output and the result at point.
+
+Contents to be inserted may be specified via optional parameter `targets-to-print' which should be a (multi)subset of list `slime-output-targets'."
+  (cl-assert (null (cl-set-difference targets-to-print slime-output-targets)))
+  (slime-eval-async `(swank:eval-and-grab-output ,string ',targets-to-print)
+    (lambda (results-alist)
+      (push-mark)
+      (dolist (target targets-to-print)
+        (insert (cdr (assoc target results-alist)))))))
+
+(cl-defun slime-eval-save
+    (string &optional (targets-to-save '(common-lisp:*standard-output*
+                                         common-lisp:values)))
+  "Evaluate STRING in Lisp and save the result in the kill ring.
+
+Contents to be saved may be specified via optional parameter `targets-to-save' which should be a (multi)subset of list `slime-output-targets'."
+  (cl-assert (null (cl-set-difference targets-to-save slime-output-targets)))
+  (slime-eval-async `(swank:eval-and-grab-output ,string ',targets-to-save)
+    (lambda (results-alist)
+      (kill-new
+       (mapconcat (lambda (target) (cdr (assoc target results-alist)))
+                  targets-to-save ""))
+      (message "Evaluation finished; pushed result to kill ring."))))
 
 (defun slime-eval-describe (form)
   "Evaluate FORM in Lisp and display the result in a new buffer."

swank.lisp

@@ -1761,20 +1761,40 @@ Errors are trapped and invoke our debugger."
         (finish-output)
         (format-values-for-echo-area values)))))
 
-(defslimefun eval-and-grab-output (string)
+(defslimefun eval-and-grab-output
+    (string &optional (targets-to-capture '(*standard-output* values)))
+  "Evaluate contents of STRING, return alist of results including various output streams. Possible keys in the returned alist should be listed in the value of `slime-output-targets' variable in `slime.el'."
   (with-buffer-syntax ()
     (with-retry-restart (:msg "Retry SLIME evaluation request.")
-      (let* ((trace-output-stream (make-string-output-stream))
-             (*trace-output* trace-output-stream)
-             (error-output-stream (make-string-output-stream))
-             (*error-output* error-output-stream)
-             (standard-output-stream (make-string-output-stream))
-             (*standard-output* standard-output-stream)
-             (values (multiple-value-list (eval (from-string string)))))
-        (list (get-output-stream-string standard-output-stream) 
-              (format nil "~{~S~^~%~}" values)
-              (get-output-stream-string error-output-stream)
-              (get-output-stream-string trace-output-stream))))))
+      (macrolet ((maybe-value-string (form)
+                   `(if (member 'values targets-to-capture)
+                        ,form
+                        ""))
+                 (maybe-output-stream-string (stream-symbol)
+                   `(if (member ',stream-symbol targets-to-capture)
+                        (get-output-stream-string ,stream-symbol)
+                        ""))
+                 (maybe-make-string-output-stream (stream-symbol)
+                   `(if (member ',stream-symbol targets-to-capture)
+                        (make-string-output-stream)
+                        ,stream-symbol)))
+        (let* ((*trace-output*
+                 (maybe-make-string-output-stream *trace-output*))
+               (*error-output*
+                 (maybe-make-string-output-stream *error-output*))
+               (*standard-output*
+                 (maybe-make-string-output-stream *standard-output*))
+               (values (multiple-value-list (eval (from-string string)))))
+          ;; It is not clear what would be the most natural order here.
+          ;; We picked the reversed binding order.
+          (list (cons 'values
+                      (maybe-value-string (format nil "~{~S~^~%~}" values))) 
+                (cons '*standard-output*
+                      (maybe-output-stream-string *standard-output*))
+                (cons '*error-output*
+                      (maybe-output-stream-string *error-output*))
+                (cons '*trace-output*
+                      (maybe-output-stream-string *trace-output*))))))))
 
 (defun eval-region (string)
   "Evaluate STRING.