Re: Behavior of Scheme REPL

On Tue, 18 Aug 2026 12:40:47 +0100
Sean Whitton <[email protected]> wrote:

> Jakub T. Jankiewicz [17/Aug  8:34pm +02] wrote:
> > I've noticed that that cmuscheme that is shipped with Emacs prints
> > multiple prompts when you evaluate Scheme code with C-x C-e
> >
> > ...
> >
> > IMHO it would be better if the code is echoed back into the scheme shell,
> > or at least a newline is added between the prompts. so the output from the
> > process appear between the prompts like it appear when running it from
> > normal terminal emulator.  
> 
> I think if someone wants to fix this we would take the patch.
> 

Here is the patch:

diff --git i/lisp/cmuscheme.el w/lisp/cmuscheme.el
index 6c714f2f80a..be0a4c50c5f 100644
--- i/lisp/cmuscheme.el
+++ w/lisp/cmuscheme.el
@@ -256,8 +256,15 @@ scheme-start-file
 (defun scheme-send-region (start end)
   "Send the current region to the inferior Scheme process."
   (interactive "r")
-  (comint-send-region (scheme-proc) start end)
-  (comint-send-string (scheme-proc) "\n"))
+  (let ((proc (scheme-proc)))
+    (with-current-buffer (process-buffer proc)
+      (save-excursion
+        (goto-char (process-mark proc))
+        (unless (bolp)
+          (let ((inhibit-read-only t))
+            (insert-before-markers "\n")))))
+    (comint-send-region proc start end)
+    (comint-send-string proc "\n")))
 
 (defun scheme-send-definition ()
   "Send the current definition to the inferior Scheme process."


-- 
Jakub T. Jankiewicz, Open-source Developer & Wikipedia Editor
Official Website: https://jakub.jankiewicz.org
Educational Project:  https://wikizeit.edu.pl