tools/eval: add +overlay feature

Now, inline evaluation will display results in an overlay next to the
cursor, rather than in the minibuffer (unless it gets too big, in which
case it'll use a popup buffer).

init.example.el

@@ -76,7 +76,7 @@
        ;;docker
        ;;editorconfig      ; let someone else argue about tabs vs spaces
        ;;ein               ; tame Jupyter notebooks with emacs
-       eval              ; run code, run (also, repls)
+       (eval +overlay)     ; run code, run (also, repls)
        flycheck          ; tasing you for every semicolon you forget
        ;;flyspell          ; tasing you for misspelling mispelling
        ;;gist              ; interacting with github gists

modules/README.org

@@ -84,7 +84,7 @@ Small modules that give Emacs access to external tools & services.
 + [[file:tools/direnv/README.org][direnv]]:
 + [[file:tools/editorconfig/README.org][editorconfig]]:
 + [[file:tools/ein/README.org][ein]]:
-+ [[file:tools/eval/README.org][eval]]: REPL & code evaluation support for a variety of languages
++ [[file:tools/eval/README.org][eval]] =+overlay=: REPL & code evaluation support for a variety of languages
 + flycheck: Live error/warning highlights
 + flyspell: Spell checking
 + gist:

modules/lang/emacs-lisp/autoload.el

@@ -7,19 +7,23 @@
 (defun +emacs-lisp-eval (beg end)
   "Evaluate a region and print it to the echo area (if one line long), otherwise
 to a pop up buffer."
-  (require 'pp)
-  (let ((debug-on-error t)
-        (buffer-file-name (buffer-file-name (buffer-base-buffer)))
-        (doom--current-module (ignore-errors (doom-module-from-path buffer-file-name)))
-        (temp-buffer-show-hook
-         (cons (if (fboundp '+word-wrap-mode)
-                   '+word-wrap-mode
-                 'visual-line-mode)
-               temp-buffer-show-hook)))
-    (pp-eval-expression
-     (read (buffer-substring-no-properties beg end)))
-    (when-let (win (get-buffer-window "*Pp Eval Output*"))
-      (fit-window-to-buffer win))))
+  (+eval-display-results
+   (let* ((buffer-file-name (buffer-file-name (buffer-base-buffer))))
+     (string-trim-right
+      (condition-case-unless-debug e
+          (let ((result
+                 (let ((debug-on-error t))
+                   (eval (read (buffer-substring-no-properties beg end))
+                         `((buffer-file-name . ,buffer-file-name)
+                           (doom--current-module
+                            . ,(ignore-errors
+                                 (doom-module-from-path buffer-file-name))))))))
+            (if (stringp result)
+                result
+              (require 'pp)
+              (pp-to-string result)))
+        (error (error-message-string e)))))
+   (current-buffer)))
 
 (defvar +emacs-lisp--face nil)
 ;;;###autoload

modules/tools/eval/README.org

@@ -18,11 +18,13 @@
 - [[Troubleshooting][Troubleshooting]]
 
 * Description
-This modules adds inline code evaluation support to Emacs, and supplies a
-universal interface for opening and interacting with REPLs.
+This modules adds inline code evaluation support to Emacs and a universal
+interface for opening and interacting with REPLs.
 
 ** Module Flags
-This module has no flags.
++ =+overlay= Enables the use of overlays (near the cursor) to display the result
+  of inline code evaluation (rather than the minibuffer). That is, unless the
+  results are too big, in which case it will still fall back to popup buffers.
 
 ** Plugins
 + [[https://github.com/syohex/emacs-quickrun][quickrun]]

modules/tools/eval/autoload/eval.el

@@ -1,5 +1,51 @@
 ;;; tools/eval/autoload/eval.el -*- lexical-binding: t; -*-
 
+;;;###autoload
+(defun +eval-display-results-in-popup (output &optional source-buffer)
+  "Display OUTPUT in a popup buffer."
+  (let ((output-buffer (get-buffer-create "*doom eval*"))
+        (origin (selected-window)))
+    (with-current-buffer output-buffer
+      (setq-local scroll-margin 0)
+      (erase-buffer)
+      (insert output)
+      (goto-char (point-min))
+      (if (fboundp '+word-wrap-mode)
+          (+word-wrap-mode +1)
+        (visual-line-mode +1)))
+    (when-let (win (display-buffer output-buffer))
+      (fit-window-to-buffer win))
+    (select-window origin)
+    output-buffer))
+
+;;;###autoload
+(defun +eval-display-results-in-overlay (output &optional source-buffer)
+  "Display OUTPUT in a floating overlay next to the cursor."
+  (let ((this-command #'+eval/buffer-or-region)
+        eros-overlays-use-font-lock)
+    (with-current-buffer (or source-buffer (current-buffer))
+      (eros--make-result-overlay output
+        :where (line-end-position)
+        :duration eros-eval-result-duration))))
+
+;;;###autoload
+(defun +eval-display-results (output &optional source-buffer)
+  "Display OUTPUT in an overlay or a popup buffer."
+  (funcall (if (and (or current-prefix-arg
+                        (with-temp-buffer
+                          (insert output)
+                          (>= (count-lines (point-min) (point-max))
+                              +eval-overlay-max-lines)))
+                    (require 'eros nil t))
+               #'+eval-display-results-in-popup
+             #'+eval-display-results-in-overlay)
+           output source-buffer)
+  output)
+
+
+;;
+;;; Commands
+
 ;;;###autoload
 (defun +eval/buffer ()
   "Evaluate the whole buffer."

modules/tools/eval/config.el

@@ -1,12 +1,16 @@
 ;;; tools/eval/config.el -*- lexical-binding: t; -*-
 
+(defvar +eval-overlay-max-lines 4
+  "The output height threshold (inclusive) before output is displayed in a popup
+buffer rather than an overlay on the line at point.")
+
 ;; remove ellipsis when printing sexps in message buffer
 (setq eval-expression-print-length nil
       eval-expression-print-level  nil)
 
 
 ;;
-;; Packages
+;;; Packages
 
 (set-popup-rule!
   (lambda (bufname _)
@@ -26,15 +30,6 @@
 
   (set-popup-rule! "^\\*quickrun" :size 0.3 :ttl 0)
 
-  (defadvice! +eval--quickrun-auto-close-a (&rest _)
-    "Allows us to silently re-run quickrun from within the quickrun buffer."
-    :before '(quickrun quickrun-region)
-    (when-let (win (get-buffer-window quickrun--buffer-name))
-      (let ((inhibit-message t))
-        (quickrun--kill-running-process)
-        (message ""))
-      (delete-window win)))
-
   (defadvice! +eval--quickrun-fix-evil-visual-region-a ()
     "Make `quickrun-replace-region' recognize evil visual selections."
     :override #'quickrun--outputter-replace-region
@@ -51,17 +46,47 @@
           (insert output))
         (setq quickrun-option-outputter quickrun--original-outputter))))
 
+  (defadvice! +eval--quickrun-auto-close-a (&rest _)
+    "Silently re-create the quickrun popup when re-evaluating."
+    :before '(quickrun quickrun-region)
+    (when-let (win (get-buffer-window quickrun--buffer-name))
+      (let ((inhibit-message t))
+        (quickrun--kill-running-process)
+        (message ""))
+      (delete-window win)))
+
   (add-hook! 'quickrun-after-run-hook
     (defun +eval-quickrun-shrink-window-h ()
       "Shrink the quickrun output window once code evaluation is complete."
       (when-let (win (get-buffer-window quickrun--buffer-name))
         (with-selected-window (get-buffer-window quickrun--buffer-name)
           (let ((ignore-window-parameters t))
-            (shrink-window-if-larger-than-buffer))))))
-
-  (add-hook! 'quickrun-after-run-hook
+            (shrink-window-if-larger-than-buffer)))))
     (defun +eval-quickrun-scroll-to-bof-h ()
       "Ensures window is scrolled to BOF on invocation."
       (when-let (win (get-buffer-window quickrun--buffer-name))
         (with-selected-window win
-          (goto-char (point-min)))))))
+          (goto-char (point-min))))))
+
+  ;; Display evaluation results in an overlay next to the cursor. If the output
+  ;; is more than 4 lines long, it is displayed in a popup.
+  (when (featurep! +overlay)
+    (defadvice! +eval--inhibit-quickrun-popup-a (buf cb)
+      :override #'quickrun--pop-to-buffer
+      (setq quickrun--original-buffer (current-buffer))
+      (with-current-buffer buf
+        (setq quickrun-option-outputter #'ignore)
+        (funcall cb)))
+
+    (advice-add #'quickrun--recenter :override #'ignore)
+    (add-hook! 'quickrun-after-run-hook
+      (defun +eval-display-in-popup-overlay-h ()
+        (+eval-display-results
+         (with-current-buffer quickrun--buffer-name
+           (string-trim (buffer-string)))
+         quickrun--original-buffer)))))
+
+
+(use-package! eros
+  :when (featurep! +overlay)
+  :hook (emacs-lisp-mode . eros-mode))

modules/tools/eval/packages.el

@@ -2,4 +2,5 @@
 ;;; tools/eval/packages.el
 
 (package! quickrun)
-
+(when (featurep! +overlay)
+  (package! eros))