Add bqn-comint-use-overlay

Show inline results using overlays, instead of just the minibuffer.

bqn-mode.el

@@ -6,7 +6,7 @@
 
 ;; Author: Marshall Lochbaum <[email protected]>
 ;; Version: 0.1.0
-;; Package-Requires: ((emacs "26.1"))
+;; Package-Requires: ((emacs "26.1") (eros "0.1.0"))
 ;; URL: https://github.com/museoa/bqn-mode
 ;; SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -304,6 +304,15 @@ BQN buffers (or recreate them)."
   :type 'boolean
   :group 'bqn)
 
+(defcustom bqn-comint-use-overlay nil
+  "Should BQN use overlays for all `bqn-comint-eval-*' style functions?
+If this is nil, print the result in the minibuffer instead."
+  :type 'boolean
+  :group 'bqn
+  :set (lambda (sym val)
+         (when val (require 'eros))
+         (set-default-toplevel-value sym val)))
+
 ;;;###autoload
 (defun bqn-comint-buffer ()
   "Run an inferior BQN process inside Emacs and return its buffer."
@@ -413,9 +422,14 @@ bqn-comint-process-session and echoes the result."
     (error "Attempt to evaluate empty region to %s" bqn-comint--process-name))
   (when (and bqn-comint-flash-on-send (pulse-available-p))
     (pulse-momentary-highlight-region start end))
-  (let ((region (buffer-substring-no-properties start end))
-        (process (get-buffer-process (bqn-comint-buffer))))
-    (message "%s" (bqn--comint-call-process-silently process region))))
+  (let* ((region (buffer-substring-no-properties start end))
+         (process (get-buffer-process (bqn-comint-buffer)))
+         (response (bqn--comint-call-process-silently process region)))
+    (if bqn-comint-use-overlay
+        (eros--make-result-overlay response
+          :where end
+          :duration eros-eval-result-duration)
+      (message "%s" response))))
 
 (defun bqn-comint-eval-dwim ()
   "Evaluate the active region or the current line, displaying the result."