New flag to automatically start REPLs when geiser-mode is activated

When no live REPL is found, of course.  The flag's imaginatively
called geiser-mode-start-repl-p.

2 files changed, 20 insertions, 6 deletions

diff --git a/elisp/geiser-mode.el b/elisp/geiser-mode.el
index 77feeec..b6d083a 100644
--- a/elisp/geiser-mode.el
+++ b/elisp/geiser-mode.el
@@ -41,6 +41,12 @@ scheme buffers."
   :group 'geiser-mode
   :type 'boolean)
 
+(geiser-custom--defcustom geiser-mode-start-repl-p nil
+  "Whether a REPL should be automatically started if one is not
+active when `geiser-mode' is activated in a buffer."
+  :group 'geiser-mode
+  :type 'boolean)
+
 (geiser-custom--defcustom geiser-mode-autodoc-p t
   "Whether `geiser-autodoc-mode' gets enabled by default in Scheme buffers."
   :group 'geiser-mode
@@ -258,7 +264,11 @@ interacting with the Geiser REPL is at your disposal.
     (geiser-autodoc-mode (if geiser-mode 1 -1)))
   (when geiser-mode-smart-tab-p
     (geiser-smart-tab-mode (if geiser-mode 1 -1)))
-  (geiser-syntax--add-kws))
+  (geiser-syntax--add-kws)
+  (when (and geiser-mode
+             geiser-mode-start-repl-p
+             (not (geiser-repl--connection*)))
+    (save-current-buffer (switch-to-geiser))))
 
 (defun turn-on-geiser-mode ()
   "Enable `geiser-mode' (in a Scheme buffer)."
diff --git a/elisp/geiser-repl.el b/elisp/geiser-repl.el
index 0b4fe54..1d1b317 100644
--- a/elisp/geiser-repl.el
+++ b/elisp/geiser-repl.el
@@ -376,12 +376,15 @@ module command as a string")
                               (overlay-end comint-last-prompt-overlay)
                               t)))))
 
-(defun geiser-repl--connection ()
+(defun geiser-repl--connection* ()
   (let ((buffer (geiser-repl--set-up-repl geiser-impl--implementation)))
-    (or (and (buffer-live-p buffer)
-             (get-buffer-process buffer)
-             (with-current-buffer buffer geiser-repl--connection))
-        (error "No Geiser REPL for this buffer (try M-x run-geiser)"))))
+   (and (buffer-live-p buffer)
+        (get-buffer-process buffer)
+        (with-current-buffer buffer geiser-repl--connection))))
+
+(defun geiser-repl--connection ()
+  (or (geiser-repl--connection*)
+      (error "No Geiser REPL for this buffer (try M-x run-geiser)")))
 
 (setq geiser-eval--default-connection-function 'geiser-repl--connection)
 
@@ -677,6 +680,7 @@ buffer."
 
 (defun switch-to-geiser (&optional ask impl buffer)
   "Switch to running Geiser REPL.
+
 With prefix argument, ask for which one if more than one is running.
 If no REPL is running, execute `run-geiser' to start a fresh one."
   (interactive "P")