Implement cider-pprint-eval-last-sexp-to-comment

This function has similar functionality to the other pprint interactions;
however this variant inserts the result of the evaluation directly in the
current buffer.

The comment prefix used in the output is user-configurable, and for consistency
we also use same prefix in cider-eval-defun-to-comment.

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### New Features
 
 * [#2082](https://github.com/clojure-emacs/cider/pull/2082), [cider-nrepl#440](https://github.com/clojure-emacs/cider-nrepl/pull/440): Add specialized stacktraces for clojure.spec assertions.
+* [#2111](https://github.com/clojure-emacs/cider/pull/2111): Add `cider-pprint-eval-last-sexp-to-comment`
 
 ### Changes
 

cider-interaction.el

@@ -244,6 +244,24 @@ namespace-qualified function of zero arity."
   "Face used to highlight compilation warnings in Clojure buffers."
   :group 'cider)
 
+(defcustom cider-pprint-comment-prefix ";; => "
+  "The prefix to insert before the first line of pprint output."
+  :type 'string
+  :group 'cider
+  :package-version '(cider . "0.16.0"))
+
+(defcustom cider-pprint-comment-continued-prefix ";;    "
+  "The prefix to use on the second and subsequent lines of pprint output."
+  :type 'string
+  :group 'cider
+  :package-version '(cider . "0.16.0"))
+
+(defcustom cider-pprint-comment-postfix ""
+  "The postfix to be appended after the final line of pprint output."
+  :type 'string
+  :group 'cider
+  :package-version '(cider . "0.16.0"))
+
 (defconst cider-clojure-artifact-id "org.clojure/clojure"
   "Artifact identifier for Clojure.")
 
@@ -795,6 +813,30 @@ COMMENT-PREFIX is the comment prefix to use."
                                  (cider-emit-interactive-eval-err-output err))
                                '()))
 
+(defun cider-eval-pprint-with-multiline-comment-handler (buffer location comment-prefix continued-prefix comment-postfix)
+  "Make a handler for evaluating and inserting results in BUFFER.
+The inserted text is pretty-printed and region will be commented.
+LOCATION is the location at which to insert.
+COMMENT-PREFIX is the comment prefix for the first line of output.
+CONTINUED-PREFIX is the comment prefix to use for the remaining lines.
+COMMENT-POSTFIX is the text to output after the last line."
+  (cl-flet ((multiline-comment-handler (buffer value)
+             (with-current-buffer buffer
+               (save-excursion
+                 (goto-char location)
+                 (let ((lines (split-string value "[\n]+" t)))
+                   ;; only the first line gets the normal comment-prefix
+                   (insert (concat comment-prefix (pop lines) "\n"))
+                   (dolist (elem lines)
+                     (insert (concat continued-prefix elem "\n")))
+                   (unless (string= comment-postfix "")
+                     (insert comment-postfix "\n")))))))
+    (nrepl-make-response-handler buffer
+                                 '()
+                                 #'multiline-comment-handler
+                                 #'multiline-comment-handler
+                               '())))
+
 (defun cider-popup-eval-out-handler (&optional buffer)
   "Make a handler for evaluating and printing stdout/stderr in popup BUFFER.
 
@@ -1167,9 +1209,28 @@ With a prefix arg, LOC, insert before the form, otherwise afterwards."
          (insertion-point (nth (if loc 0 1) bounds)))
     (cider-interactive-eval nil
                             (cider-eval-print-with-comment-handler
-                             (current-buffer) insertion-point ";; => ")
+                             (current-buffer)
+                             insertion-point
+                             cider-pprint-comment-prefix)
                             bounds)))
 
+(defun cider-pprint-eval-last-sexp-to-comment (loc)
+  "Evaluate the last sexp and insert result as comment at LOC.
+
+With a prefix arg, LOC, insert before the form, otherwise afterwards."
+  (interactive "P")
+  (let* ((bounds (cider-last-sexp 'bounds))
+         (insertion-point (nth (if loc 0 1) bounds)))
+    (cider-interactive-eval nil
+                            (cider-eval-pprint-with-multiline-comment-handler
+                             (current-buffer)
+                             insertion-point
+                             cider-pprint-comment-prefix
+                             cider-pprint-comment-continued-prefix
+                             cider-pprint-comment-postfix)
+                            bounds
+                            (cider--nrepl-pprint-request-plist (cider--pretty-print-width)))))
+
 (declare-function cider-switch-to-repl-buffer "cider-mode")
 
 (defun cider-eval-last-sexp-to-repl (&optional prefix)
@@ -1186,11 +1247,10 @@ If invoked with a PREFIX argument, switch to the REPL buffer."
   "Evaluate expr before point and insert its pretty-printed result in the REPL.
 If invoked with a PREFIX argument, switch to the REPL buffer."
   (interactive "P")
-  (let* ((conn-buffer (cider-current-connection)))
-    (cider-interactive-eval nil
-                            (cider-insert-eval-handler conn-buffer)
-                            (cider-last-sexp 'bounds)
-                            (cider--nrepl-pprint-request-plist (cider--pretty-print-width))))
+  (cider-interactive-eval nil
+                          (cider-insert-eval-handler (cider-current-connection))
+                          (cider-last-sexp 'bounds)
+                          (cider--nrepl-pprint-request-plist (cider--pretty-print-width)))
   (when prefix
     (cider-switch-to-repl-buffer)))
 
@@ -1211,10 +1271,13 @@ Print its value into the current buffer."
                             (when (consp form) form)
                             (cider--nrepl-pprint-request-plist (cider--pretty-print-width)))))
 
-(defun cider-pprint-eval-last-sexp ()
-  "Evaluate the sexp preceding point and pprint its value in a popup buffer."
-  (interactive)
-  (cider--pprint-eval-form (cider-last-sexp 'bounds)))
+(defun cider-pprint-eval-last-sexp (&optional prefix)
+  "Evaluate the sexp preceding point and pprint its value in a popup buffer.
+If invoked with a PREFIX argument, insert as comment in the current buffer."
+  (interactive "P")
+  (if prefix
+      (cider-pprint-eval-last-sexp-to-comment nil)
+    (cider--pprint-eval-form (cider-last-sexp 'bounds))))
 
 (defun cider--prompt-and-insert-inline-dbg ()
   "Insert a #dbg button at the current sexp."

cider-mode.el

@@ -235,6 +235,7 @@ Configure `cider-cljs-*-repl' to change the ClojureScript REPL to use for your b
     ["Eval last sexp and replace" cider-eval-last-sexp-and-replace]
     ["Eval last sexp to REPL" cider-eval-last-sexp-to-repl]
     ["Eval last sexp and pretty-print to REPL" cider-pprint-eval-last-sexp-to-repl]
+    ["Eval last sexp and pretty-print to comment" cider-pprint-eval-last-sexp-to-comment]
     ["Insert last sexp in REPL" cider-insert-last-sexp-in-repl]
     ["Eval top-level sexp to comment" cider-eval-defun-to-comment]
     "--"

doc/interactive_programming.md

@@ -22,7 +22,7 @@ Here's a list of `cider-mode`'s keybindings:
 `cider-eval-last-sexp-and-replace`            |<kbd>C-c C-v w</kbd>                 | Evaluate the form preceding point and replace it with its result.
 `cider-eval-last-sexp-to-repl`                |<kbd>C-c M-e</kbd>                   | Evaluate the form preceding point and output it result to the REPL buffer.  If invoked with a prefix argument, takes you to the REPL buffer after being invoked.
 `cider-insert-last-sexp-in-repl`              |<kbd>C-c M-p</kbd>                   | Load the form preceding point in the REPL buffer.
-`cider-pprint-eval-last-sexp`                 |<kbd>C-c C-p</kbd>                   | Evaluate the form preceding point and pretty-print the result in a popup buffer.
+`cider-pprint-eval-last-sexp`                 |<kbd>C-c C-p</kbd>                   | Evaluate the form preceding point and pretty-print the result in a popup buffer. If invoked with a prefix argument, insert the result into the current buffer as a comment.
 `cider-pprint-eval-defun-at-point`            |<kbd>C-c C-f</kbd>                   | Evaluate the top level form under point and pretty-print the result in a popup buffer.
 `cider-eval-defun-at-point`                   |<kbd>C-M-x</kbd> <br/> <kbd>C-c C-c</kbd>  | Evaluate the top level form under point and display the result in the echo area.
 `cider-eval-sexp-at-point`                    |<kbd>C-c C-v v</kbd>                 | Evaluate the form around point.