Partial work (connections working)

11 files changed, 347 insertions, 386 deletions

diff --git a/doc/cheat.texi b/doc/cheat.texi
index 4e81b92..68e4274 100644
--- a/doc/cheat.texi
+++ b/doc/cheat.texi
@@ -107,9 +107,6 @@
 @item C-c C-q
 @tab geiser-repl-exit
 @tab Kill Scheme process
-@item C-c C-k
-@tab geiser-repl-nuke
-@tab Soft restart for unresponsive REPL
 @item M-.
 @tab geiser-edit-symbol-at-point
 @tab Edit identifier at point
diff --git a/doc/repl.texi b/doc/repl.texi
index 03fb42a..aefa432 100644
--- a/doc/repl.texi
+++ b/doc/repl.texi
@@ -118,15 +118,10 @@ There are also a few commands to twiddle with the Scheme process.
 mercilessly kill the process (but not before stowing your history in the
 file system). Unless you're using a remote REPL, that is, in which case
 both commands will just sever the connection and leave the remote
-process alone. A softer nuke is performed by @kbd{C-c C-k}: some (rare,
-i promise) times, Geiser's REPL can get confused by the input
-received from then underlying Scheme (specially if you have multiple
-threads writing to the standard ports), and become irresponsive; you can
-try this command to try to revive it without killing the process or
-closing your connection. Finally, if worse comes to worst and the
-process is dead, @kbd{C-c C-z} will restart it (but the same shortcut,
-issued when the REPL is alive, will bring you back to the buffer you
-came from, as explained @ref{switching-repl-buff,,here}).
+process alone. If worse comes to worst and the process is dead, @kbd{C-c
+C-z} will restart it (but the same shortcut, issued when the REPL is
+alive, will bring you back to the buffer you came from, as explained
+@ref{switching-repl-buff,,here}).
 
 The remaining commands are meatier, and deserve sections of their own.
 
diff --git a/elisp/Makefile.am b/elisp/Makefile.am
index 1f1ca76..d98751b 100644
--- a/elisp/Makefile.am
+++ b/elisp/Makefile.am
@@ -15,6 +15,7 @@ dist_lisp_LISP = \
    geiser-eval.el \
    geiser-guile.el \
    geiser-impl.el \
+   geiser-inf.el \
    geiser-log.el \
    geiser-menu.el \
    geiser-mode.el \
diff --git a/elisp/geiser-connection.el b/elisp/geiser-connection.el
index dc669aa..d1e7d59 100644
--- a/elisp/geiser-connection.el
+++ b/elisp/geiser-connection.el
@@ -19,8 +19,7 @@
 (require 'geiser-base)
 (require 'geiser-impl)
 
-(require 'comint)
-(require 'advice)
+(require 'tq)
 
 
 ;;; Buffer connections:
@@ -71,234 +70,155 @@
 
 ;;; Connection datatype:
 
-(defsubst geiser-con--make-connection (buffer)
+(defun geiser-con--make-connection (proc prompt debug-prompt)
   (list :geiser-connection
-        (cons :requests (list))
-        (cons :current nil)
+        (cons :tq (tq-create proc))
+        (cons :eot (format "\\(%s%s\\)"
+                           prompt
+                           (if debug-prompt
+                               (format "\\|%s" debug-prompt)
+                             "")))
+        (cons :prompt prompt)
+        (cons :debug-prompt debug-prompt)
         (cons :count 0)
-        (cons :completed (make-hash-table :weakness 'value))
-        (cons :buffer buffer)
-        (cons :reply (geiser-con--make-reply-buffer buffer))))
-
-(defvar geiser-con--eot-regexp nil)
-(geiser-impl--register-local-variable
- 'geiser-con--eot-regexp 'eot-regexp nil
- "A regular expression used to detect end of transmissions.
-By default, Geiser uses the prompt regexp.")
-
-(defun geiser-con--make-reply-buffer (buffer)
-  (let ((name (concat " geiser-con-reply: " (buffer-name buffer)))
-        (eot (with-current-buffer buffer geiser-con--eot-regexp)))
-    (with-current-buffer (get-buffer-create name)
-      (setq geiser-con--eot-regexp eot)
-      (current-buffer))))
+        (cons :completed (make-hash-table :weakness 'value))))
+
+(defun geiser-con--connection-swap-proc (con proc)
+  (let* ((this-proc (geiser-con--connection-process con))
+         (this-filter (process-filter this-proc))
+         (this-buffer (process-buffer this-proc))
+         (filter (process-filter proc))
+         (buffer (process-buffer proc))
+         (tq (geiser-con--connection-tq con)))
+    (set-process-filter this-proc filter)
+    (set-process-buffer this-proc buffer)
+    (set-process-filter proc this-filter)
+    (set-process-buffer proc this-buffer)
+    (setcdr tq (cons proc (tq-buffer tq)))
+    this-proc))
 
 (defsubst geiser-con--connection-p (c)
   (and (listp c) (eq (car c) :geiser-connection)))
 
-(defsubst geiser-con--connection-buffer (c)
-  (cdr (assoc :buffer c)))
-
 (defsubst geiser-con--connection-process (c)
-  (get-buffer-process (geiser-con--connection-buffer c)))
+  (tq-process (cdr (assoc :tq c))))
+
+(defsubst geiser-con--connection-tq (c)
+  (cdr (assoc :tq c)))
 
-(defsubst geiser-con--connection-requests (c)
-  (cdr (assoc :requests c)))
+(defsubst geiser-con--connection-eot (c)
+  (cdr (assoc :eot c)))
 
-(defsubst geiser-con--connection-current-request (c)
-  (cdr (assoc :current c)))
+(defsubst geiser-con--connection-prompt (c)
+  (cdr (assoc :prompt c)))
 
-(defsubst geiser-con--connection-reply-buffer (c)
-  (cdr (assoc :reply c)))
+(defsubst geiser-con--connection-debug-prompt (c)
+  (cdr (assoc :debug-prompt c)))
 
 (defsubst geiser-con--connection-completed (c r)
   (geiser-con--request-deactivate r)
   (puthash (geiser-con--request-id r) r (cdr (assoc :completed c))))
 
-(defun geiser-con--connection-clean-current-request (c)
-  (let* ((cell (assoc :current c))
-         (req (cdr cell)))
-    (when req
-      (geiser-con--connection-completed c req)
-      (setcdr cell nil))))
-
-(defun geiser-con--connection-add-request (c r)
-  (let ((reqs (assoc :requests c)))
-    (setcdr reqs (append (cdr reqs) (list r)))))
-
 (defsubst geiser-con--connection-completed-p (c id)
   (gethash id (cdr (assoc :completed c))))
 
-(defun geiser-con--connection-pop-request (c)
-  (let* ((reqs (assoc :requests c))
-         (current (assoc :current c))
-         (old-current (cdr current))
-         (new-current (cadr reqs))
-         (new-reqs (cddr reqs)))
-    (when old-current (geiser-con--connection-completed c old-current))
-    (setcdr reqs new-reqs)
-    (if (and new-current
-             (geiser-con--request-deactivated-p new-current))
-        (geiser-con--connection-pop-request c)
-      (setcdr current new-current))))
-
 (defun geiser-con--connection-inc-count (c)
   (let* ((cnt (assoc :count c))
          (new (1+ (cdr cnt))))
     (setcdr cnt new)
     new))
 
-
-;;; Connection setup:
-(make-variable-buffer-local
- (defvar geiser-con--debugging-prompt-regexp nil))
-
-(make-variable-buffer-local
- (defvar geiser-con--debugging-inhibits-eval t))
-
-(make-variable-buffer-local
- (defvar geiser-con--debugging-preamble-regexp nil))
-
-(defun geiser-con--is-debugging (&optional con)
-  (with-current-buffer (or (and con (geiser-con--connection-buffer con))
-                           (current-buffer))
-    (and geiser-con--debugging-prompt-regexp
-         geiser-con--debugging-inhibits-eval
-         comint-last-prompt-overlay
-         (string-match-p geiser-con--debugging-prompt-regexp
-                         (buffer-substring (overlay-start
-                                            comint-last-prompt-overlay)
-                                           (overlay-end
-                                            comint-last-prompt-overlay))))))
-
-(defsubst geiser-con--has-entered-debugger (con)
-  (with-current-buffer (geiser-con--connection-buffer con)
-    (and geiser-con--debugging-prompt-regexp
-         (re-search-backward geiser-con--debugging-prompt-regexp nil t)
-         (or (null geiser-con--debugging-preamble-regexp)
-             (save-excursion
-               (re-search-backward geiser-con--debugging-preamble-regexp
-                                   nil t))))))
-
-(defun geiser-con--connection-teardown ()
-  (when geiser-con--connection
-    (kill-buffer
-     (geiser-con--connection-reply-buffer geiser-con--connection))))
-
-(defun geiser-con--setup-connection (buffer
-                                     prompt-regexp
-                                     &optional debug-prompt-regexp
-                                     debug-preamble-regexp)
-  (with-current-buffer buffer
-    (geiser-con--connection-teardown)
-    (setq geiser-con--debugging-prompt-regexp debug-prompt-regexp)
-    (setq geiser-con--debugging-preamble-regexp debug-preamble-regexp)
-    (setq geiser-con--connection (geiser-con--make-connection buffer))
-    (set (make-local-variable 'comint-redirect-insert-matching-regexp) t)
-    (setq comint-prompt-regexp
-	  (if debug-prompt-regexp
-	      (format "\\(%s\\)\\|\\(%s\\)" prompt-regexp debug-prompt-regexp)
-	    prompt-regexp))
-    (add-hook 'comint-redirect-hook 'geiser-con--comint-redirect-hook nil t)))
+(defun geiser-con--has-entered-debugger (con answer)
+  (let ((dp (geiser-con--connection-debug-prompt con)))
+    (and (stringp dp) (string-match dp answer))))
+
+(defun geiser-con--connection-close (con)
+  (let ((tq (geiser-con--connection-tq con)))
+    (and tq (tq-close tq))))
+
+(defvar geiser-con--connection-sentinel nil)
+(defun geiser-con--connection-sentinel (p s)
+  (setq geiser-con--connection-sentinel
+        (concat geiser-con--connection-sentinel s)))
+
+(defun geiser-con--open-connection (host port prompt debug-prompt)
+  (setq geiser-con--connection-sentinel "")
+  (let ((proc (make-network-process :name "geiser-con"
+                                    :host host
+                                    :service port
+                                    :filter 'geiser-con--connection-sentinel
+                                    :noquery t)))
+    (with-timeout (10
+                   (error (format "Timeout connecting to %s:%s" host port)))
+      (while (not (string-match prompt geiser-con--connection-sentinel))
+        (accept-process-output proc 1)))
+    (geiser-con--make-connection proc prompt debug-prompt)))
 
 
 ;;; Requests handling:
 
-(defun geiser-con--comint-buffer-form (con)
-  (with-current-buffer (geiser-con--connection-reply-buffer con)
-    (goto-char (point-max))
-    (if (geiser-con--has-entered-debugger con)
+(defun geiser-con--req-form (req answer)
+  (let ((con (geiser-con--request-connection req)))
+    (if (geiser-con--has-entered-debugger con answer)
         `((error (key . geiser-debugger))
-          (output . ,(buffer-substring (point-min) (point))))
-      (condition-case nil
-          (progn
-            (goto-char (point-min))
-            (re-search-forward "((\\(result\\|error\\)\\>")
-            (goto-char (match-beginning 0))
-            (let ((form (read (current-buffer))))
-              (if (listp form) form (error ""))))
+          (output . ,answer))
+      (condition-case err
+          (car (read-from-string answer))
         (error `((error (key . geiser-con-error))
-                 (output . ,(buffer-string))))))))
-
-(defun geiser-con--process-next (con)
-  (when (not (geiser-con--connection-current-request con))
-    (let* ((buffer (geiser-con--connection-buffer con))
-           (req (geiser-con--connection-pop-request con))
-           (str (and req (geiser-con--request-string req)))
-           (rbuffer (geiser-con--connection-reply-buffer con)))
-      (when (and buffer (buffer-live-p buffer) req str)
-        (with-current-buffer rbuffer
-          (delete-region (point-min) (point-max)))
-        (set-buffer buffer)
-        (if (geiser-con--is-debugging)
-            (geiser-con--connection-completed con req)
-          (geiser-log--info "<%s>: %s" (geiser-con--request-id req) str)
-          (comint-redirect-send-command (format "%s" str) rbuffer nil t))))))
-
-(defun geiser-con--process-completed-request (req)
-  (let* ((cont (geiser-con--request-continuation req))
-         (id (geiser-con--request-id req))
-         (rstr (geiser-con--request-string req))
-         (buffer (geiser-con--request-buffer req))
-         (con (geiser-con--request-connection req))
-         (form (geiser-con--comint-buffer-form con)))
+                 (output . ,(format "%s\n(%s)"
+                                    answer
+                                    (error-message-string err)))))))))
+
+(defun geiser-con--process-completed-request (req answer)
+  (let ((cont (geiser-con--request-continuation req))
+        (id (geiser-con--request-id req))
+        (rstr (geiser-con--request-string req))
+        (form (geiser-con--req-form req answer))
+        (buffer (or (geiser-con--request-buffer req) (current-buffer)))
+        (con (geiser-con--request-connection req)))
     (if (not cont)
         (geiser-log--warn "<%s> Droping result for request %S: %s"
                           id rstr form)
       (condition-case cerr
-          (with-current-buffer (or buffer (current-buffer))
+          (with-current-buffer buffer
             (funcall cont form)
-            (geiser-con--request-deactivate req)
             (geiser-log--info "<%s>: processed" id))
         (error (geiser-log--error
                 "<%s>: continuation failed %S \n\t%s" id rstr cerr))))
-    (geiser-con--connection-clean-current-request con)))
-
-(defun geiser-con--comint-redirect-hook ()
-  (if (not geiser-con--connection)
-      (geiser-log--error "No connection in buffer")
-    (let ((req (geiser-con--connection-current-request
-                geiser-con--connection)))
-      (if (not req)
-          (geiser-log--error "No current request")
-        (geiser-con--process-completed-request req)))))
-
-(defadvice comint-redirect-setup
-  (after geiser-con--advice
-         (output-buffer comint-buffer finished-regexp &optional echo))
-  (with-current-buffer comint-buffer
-    (when geiser-con--eot-regexp
-      (setq comint-redirect-finished-regexp geiser-con--eot-regexp))
-    (when geiser-con--connection (setq mode-line-process nil))))
-(ad-activate 'comint-redirect-setup)
+    (geiser-con--connection-completed con req)))
+
+(defun geiser-con--connection-add-request (c r)
+  (tq-enqueue (geiser-con--connection-tq c)
+              (geiser-con--request-string r)
+              (geiser-con--connection-eot c)
+              r
+              'geiser-con--process-completed-request
+              t))
 
 
 ;;; Message sending interface:
 
-(defconst geiser-con--error-message "Geiser connection not active")
+(defun geiser-con--send-string (con str cont &optional sbuf)
+  (let ((req (geiser-con--make-request con str cont sbuf)))
+    (geiser-con--connection-add-request con req)
+    req))
 
 (defvar geiser-connection-timeout 30000
   "Time limit, in msecs, blocking on synchronous evaluation requests")
 
-(defun geiser-con--send-string/wait (b/p str cont &optional timeout sbuf)
+(defun geiser-con--send-string/wait (con str cont &optional timeout sbuf)
   (save-current-buffer
-    (let* ((con (geiser-con--get-connection b/p))
-           (proc (and con (geiser-con--connection-process con))))
-      (unless proc (error geiser-con--error-message))
-      (when (geiser-con--is-debugging con) (error "REPL is in debug mode"))
-      (let* ((req (geiser-con--make-request con str cont sbuf))
+    (let ((proc (and con (geiser-con--connection-process con))))
+      (unless proc (error "Geiser connection not active"))
+      (let* ((req (geiser-con--send-string con str cont sbuf))
              (id (geiser-con--request-id req))
-             (timeout (/ (or timeout geiser-connection-timeout) 1000.0))
-             (waitsecs 0.1))
-        (geiser-con--connection-add-request con req)
+             (timeout (/ (or timeout geiser-connection-timeout) 1000.0)))
         (with-timeout (timeout (geiser-con--request-deactivate req))
           (condition-case nil
               (while (and (geiser-con--connection-process con)
                           (not (geiser-con--connection-completed-p con id)))
-                (geiser-con--process-next con)
-                (accept-process-output proc waitsecs nil t))
+                (accept-process-output proc (/ timeout 10)))
             (error (geiser-con--request-deactivate req))))))))
 
 
 (provide 'geiser-connection)
-;;; geiser-connection.el ends here
diff --git a/elisp/geiser-eval.el b/elisp/geiser-eval.el
index 3534312..72093cc 100644
--- a/elisp/geiser-eval.el
+++ b/elisp/geiser-eval.el
@@ -119,11 +119,11 @@ module-exports, autodoc, callers, callees and generic-methods.")
 
 ;;; Code sending:
 
-(defvar geiser-eval--default-proc-function nil)
+(defvar geiser-eval--default-connection-function nil)
 
-(defsubst geiser-eval--proc ()
-  (and geiser-eval--default-proc-function
-       (funcall geiser-eval--default-proc-function)))
+(defsubst geiser-eval--connection ()
+  (and geiser-eval--default-connection-function
+       (funcall geiser-eval--default-connection-function)))
 
 (defsubst geiser-eval--log (s)
   (geiser-log--info "RETORT: %S" s)
@@ -138,7 +138,7 @@ module-exports, autodoc, callers, callees and generic-methods.")
 
 (defun geiser-eval--send/wait (code &optional timeout buffer)
   (setq geiser-eval--sync-retort nil)
-  (geiser-con--send-string/wait (geiser-eval--proc)
+  (geiser-con--send-string/wait (geiser-eval--connection)
                                 (geiser-eval--code-str code)
                                 'geiser-eval--set-sync-retort
                                 timeout
diff --git a/elisp/geiser-inf.el b/elisp/geiser-inf.el
new file mode 100644
index 0000000..4b7020e
--- /dev/null
+++ b/elisp/geiser-inf.el
@@ -0,0 +1,83 @@
+;;; geiser-inf.el -- inferior scheme processes
+
+;; Copyright (c) 2010 Jose Antonio Ortega Ruiz
+
+;; This program is free software; you can redistribute it and/or
+;; modify it under the terms of the Modified BSD License. You should
+;; have received a copy of the license along with this program. If
+;; not, see <http://www.xfree86.org/3.3.6/COPYRIGHT2.html#5>.
+
+;; Start date: Thu Nov 11, 2010 01:04
+
+
+(require 'geiser-impl)
+(require 'geiser-base)
+
+(require 'cmuscheme)
+
+
+;; Implementation-dependent parameters
+
+(geiser-impl--define-caller geiser-inf--binary binary ()
+  "A variable or function returning the path to the scheme binary
+for this implementation.")
+
+(geiser-impl--define-caller geiser-inf--arglist arglist ()
+  "A function taking no arguments and returning a list of
+arguments to be used when invoking the scheme binary.")
+
+(geiser-impl--define-caller geiser-inf--prompt-regexp prompt-regexp ()
+  "A variable (or thunk returning a value) giving the regular
+expression for this implementation's scheme prompt.")
+
+(geiser-impl--define-caller geiser-inf--init-server-cmd init-server-cmd ()
+  "A variable (or thunk returning a value) giving the REPL server
+initialization command for local processes. The command must return a
+list of the form (server PORT).")
+
+
+;; Auxiliary functions
+
+(defun geiser-inf--wait-for-prompt (timeout)
+  (let ((p (point)) (seen) (buffer (current-buffer)))
+    (while (and (not seen)
+                (> timeout 0)
+                (get-buffer-process buffer))
+      (sleep-for 0.1)
+      (setq timeout (- timeout 100))
+      (goto-char p)
+      (setq seen (re-search-forward comint-prompt-regexp nil t)))
+    (goto-char (point-max))
+    (unless seen (error "%s" "No prompt found!"))))
+
+(defun geiser-inf--make-buffer (impl)
+  (with-current-buffer (generate-new-buffer (format "* inferior %s *" impl))
+    (inferior-scheme-mode)
+    (current-buffer)))
+
+
+;; Starting an inferior REPL
+
+(defun geiser-inf--run-scheme (impl)
+  (let ((bin (geiser-inf--binary impl))
+        (args (geiser-inf--arglist impl))
+        (prompt-rx (geiser-inf--prompt-regexp impl)))
+    (unless (and bin args prompt-rx)
+      (error "Sorry, I don't know how to start %s" impl))
+    (with-current-buffer (geiser-inf--make-buffer impl)
+      (setq comint-prompt-regexp prompt-rx)
+      (condition-case err
+          (apply 'make-comint-in-buffer
+             `(,(buffer-name) ,(current-buffer) ,bin nil ,@args))
+        (error (error "Unable to start REPL: %s" (error-message-string err))))
+      (geiser-inf--wait-for-prompt 10000)
+      (cons (current-buffer)
+            (comint-redirect-results-list (geiser-inf--server-init-cmd impl)
+                                          "(server-port \\([0-9]\\)+)"
+                                          1)))))
+
+
+
+
+(provide 'geiser-inf)
+
diff --git a/elisp/geiser-log.el b/elisp/geiser-log.el
index d078b19..49b067d 100644
--- a/elisp/geiser-log.el
+++ b/elisp/geiser-log.el
@@ -44,7 +44,6 @@
   "Simple mode for Geiser log messages buffer."
   (kill-all-local-variables)
   (buffer-disable-undo)
-  (set (make-local-variable 'comint-redirect-subvert-readonly) t)
   (add-hook 'after-change-functions
             '(lambda (b e len)
                (let ((inhibit-read-only t))
diff --git a/elisp/geiser-racket.el b/elisp/geiser-racket.el
index 8c66e67..c680907 100644
--- a/elisp/geiser-racket.el
+++ b/elisp/geiser-racket.el
@@ -242,7 +242,6 @@ using start-geiser, a procedure in the geiser/server module."
   (binary geiser-racket--binary)
   (arglist geiser-racket--parameters)
   (startup)
-  (eot-regexp "\0")
   (prompt-regexp geiser-racket--prompt-regexp)
   (marshall-procedure geiser-racket--geiser-procedure)
   (find-module geiser-racket--get-module)
diff --git a/elisp/geiser-reload.el b/elisp/geiser-reload.el
index a5c0125..ca3eb1c 100644
--- a/elisp/geiser-reload.el
+++ b/elisp/geiser-reload.el
@@ -38,6 +38,7 @@
            geiser-connection
            geiser-syntax
            geiser-menu
+           geiser-inf
            geiser-impl
            geiser-custom
            geiser-log
diff --git a/elisp/geiser-repl.el b/elisp/geiser-repl.el
index a05346c..fcf7278 100644
--- a/elisp/geiser-repl.el
+++ b/elisp/geiser-repl.el
@@ -13,6 +13,7 @@
 (require 'geiser-autodoc)
 (require 'geiser-edit)
 (require 'geiser-completion)
+(require 'geiser-inf)
 (require 'geiser-impl)
 (require 'geiser-eval)
 (require 'geiser-connection)
@@ -106,6 +107,30 @@ expression, if any."
   :group 'geiser-repl)
 
 
+;;; Implementation-dependent parameters
+
+(geiser-impl--define-caller
+    geiser-repl--debugger-prompt-regexp debugger-prompt-regexp ()
+  "A variable (or thunk returning a value) giving the regular
+expression for this implementation's debugging prompt.")
+
+(geiser-impl--define-caller geiser-repl--startup startup ()
+  "Function taking no parameters that is called after the REPL
+has been initialised. All Geiser functionality is available to
+you at that point.")
+
+(geiser-impl--define-caller geiser-repl--enter-cmd enter-command (module)
+  "Function taking a module designator and returning a REPL enter
+module command as a string")
+
+(geiser-impl--define-caller geiser-repl--import-cmd import-command (module)
+  "Function taking a module designator and returning a REPL import
+module command as a string")
+
+(geiser-impl--define-caller geiser-repl--exit-cmd exit-command ()
+  "Function returning the REPL exit command as a string")
+
+
 ;;; Geiser REPL buffers and processes:
 
 (defvar geiser-repl--repls nil)
@@ -161,50 +186,27 @@ expression, if any."
         (geiser-repl-mode)
         (geiser-impl--set-buffer-implementation impl)))))
 
-(geiser-impl--define-caller geiser-repl--binary binary ()
-  "A variable or function returning the path to the scheme binary
-for this implementation.")
-
-(geiser-impl--define-caller geiser-repl--arglist arglist ()
-  "A function taking no arguments and returning a list of
-arguments to be used when invoking the scheme binary.")
-
-(geiser-impl--define-caller geiser-repl--prompt-regexp prompt-regexp ()
-  "A variable (or thunk returning a value) giving the regular
-expression for this implementation's scheme prompt.")
-
-(geiser-impl--define-caller
-    geiser-repl--debugger-prompt-regexp debugger-prompt-regexp ()
-  "A variable (or thunk returning a value) giving the regular
-expression for this implementation's debugging prompt.")
-
-(geiser-impl--define-caller
-    geiser-repl--debugger-preamble-regexp debugger-preamble-regexp ()
-  "A variable (or thunk returning a value) used to determine whether
-the REPL has entered debugging mode.")
+(defun geiser-repl--read-impl (prompt &optional active)
+  (geiser-impl--read-impl prompt (and active (geiser-repl--active-impls))))
 
-(geiser-impl--define-caller geiser-repl--startup startup ()
-  "Function taking no parameters that is called after the REPL
-has been initialised. All Geiser functionality is available to
-you at that point.")
+(defsubst geiser-repl--only-impl-p ()
+  (and (null (cdr geiser-active-implementations))
+       (car geiser-active-implementations)))
 
-(geiser-impl--define-caller geiser-repl--enter-cmd enter-command (module)
-  "Function taking a module designator and returning a REPL enter
-module command as a string")
+
+;;; REPL connections
 
-(geiser-impl--define-caller geiser-repl--import-cmd import-command (module)
-  "Function taking a module designator and returning a REPL import
-module command as a string")
+(make-variable-buffer-local
+ (defvar geiser-repl--address nil))
 
-(geiser-impl--define-caller geiser-repl--exit-cmd exit-command ()
-  "Function returning the REPL exit command as a string")
+(make-variable-buffer-local
+ (defvar geiser-repl--connection nil))
 
 (make-variable-buffer-local
- (defvar geiser-repl--address nil))
+ (defvar geiser-remote-p nil))
 
 (defsubst geiser-repl--host () (car geiser-repl--address))
 (defsubst geiser-repl--port () (cdr geiser-repl--address))
-(defsubst geiser-repl--remote-p () geiser-repl--address)
 
 (defun geiser-repl--get-address (&optional host port)
   (let ((defhost (or (geiser-repl--host) geiser-repl-default-host))
@@ -214,124 +216,52 @@ module command as a string")
                            nil nil defhost))
           (or port (read-number "Port: " defport)))))
 
-(defun geiser-repl--save-remote-data (remote address)
-  (setq geiser-repl--address (and remote address))
+(defun geiser-repl--save-remote-data (address remote)
+  (setq geiser-repl--address address)
+  (setq geiser-remote-p remote)
   (setq header-line-format (and remote
                                 (format "Host: %s   Port: %s"
                                         (geiser-repl--host)
                                         (geiser-repl--port)))))
 
-(defun geiser-repl--start-repl (impl &optional remote host port)
+(defun geiser-repl--start-repl (impl host port remote)
   (message "Starting Geiser REPL for %s ..." impl)
   (geiser-repl--to-repl-buffer impl)
-  (let ((program (if remote (geiser-repl--get-address host port)
-                   (geiser-repl--binary impl)))
-        (args (geiser-repl--arglist impl))
-        (prompt-rx (geiser-repl--prompt-regexp impl))
+  (let ((address (geiser-repl--get-address host port))
+        (prompt-rx (geiser-inf--prompt-regexp impl))
         (deb-prompt-rx (geiser-repl--debugger-prompt-regexp impl))
-        (deb-preamble-rx (geiser-repl--debugger-preamble-regexp impl))
         (cname (geiser-repl--repl-name impl)))
-    (unless (and program prompt-rx)
+    (unless prompt-rx
       (error "Sorry, I don't know how to start a REPL for %s" impl))
-    (set (make-local-variable 'comint-prompt-regexp) prompt-rx)
-    (geiser-repl--save-remote-data remote program)
+    (geiser-repl--save-remote-data address remote)
     (condition-case err
-        (apply 'make-comint-in-buffer
-               `(,cname ,(current-buffer) ,program nil ,@args))
+        (progn
+          (setq geiser-repl--connection
+                (geiser-con--open-connection (car address)
+                                             (cdr address)
+                                             prompt-rx
+                                             deb-prompt-rx))
+          (set (make-local-variable 'comint-prompt-regexp)
+               (geiser-con--connection-eot geiser-repl--connection))
+          (apply 'make-comint-in-buffer `(,cname ,(current-buffer) ,address)))
       (error (insert "Unable to start REPL:\n\n"
                      (error-message-string err) "\n")
              (error "Couldn't start Geiser")))
-    (geiser-repl--wait-for-prompt 10000)
+    (geiser-inf--wait-for-prompt 10000)
     (geiser-repl--history-setup)
-    (geiser-con--setup-connection (current-buffer)
-                                  prompt-rx
-                                  deb-prompt-rx
-                                  deb-preamble-rx)
     (add-to-list 'geiser-repl--repls (current-buffer))
     (geiser-repl--set-this-buffer-repl (current-buffer))
     (geiser-repl--startup impl)
     (message "Geiser REPL up and running!")))
 
-(defun geiser-repl--process ()
+(defun geiser-repl--connection ()
   (let ((buffer (geiser-repl--set-up-repl geiser-impl--implementation)))
-    (or (and (buffer-live-p buffer) (get-buffer-process buffer))
+    (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)"))))
 
-(setq geiser-eval--default-proc-function 'geiser-repl--process)
-
-(defun geiser-repl--wait-for-prompt (timeout)
-  (let ((p (point)) (seen) (buffer (current-buffer)))
-    (while (and (not seen)
-                (> timeout 0)
-                (get-buffer-process buffer))
-      (sleep-for 0.1)
-      (setq timeout (- timeout 100))
-      (goto-char p)
-      (setq seen (re-search-forward comint-prompt-regexp nil t)))
-    (goto-char (point-max))
-    (unless seen (error "No prompt found!"))))
-
-
-;;; Interface: starting and interacting with geiser REPL:
-
-(defun geiser-repl--read-impl (prompt &optional active)
-  (geiser-impl--read-impl prompt (and active (geiser-repl--active-impls))))
-
-(defsubst geiser-repl--only-impl-p ()
-  (and (null (cdr geiser-active-implementations))
-       (car geiser-active-implementations)))
-
-(defun run-geiser (impl)
-  "Start a new Geiser REPL."
-  (interactive
-   (list (or (geiser-repl--only-impl-p)
-             (and (eq major-mode 'geiser-repl-mode)
-                  geiser-impl--implementation)
-             (geiser-repl--read-impl
-              "Start Geiser for scheme implementation: "))))
-   (geiser-repl--start-repl impl))
-
-(defun geiser-connect (impl &optional host port)
-  "Start a new Geiser REPL connected to a remote Scheme process."
-  (interactive
-   (list (or (geiser-repl--only-impl-p)
-             (and (eq major-mode 'geiser-repl-mode)
-                  geiser-impl--implementation)
-             (geiser-repl--read-impl
-              "Scheme implementation: "))))
-  (geiser-repl--start-repl impl t host port))
-
-(make-variable-buffer-local
- (defvar geiser-repl--last-scm-buffer nil))
-
-(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")
-  (let* ((impl (or impl geiser-impl--implementation))
-         (in-repl (eq major-mode 'geiser-repl-mode))
-         (in-live-repl (and in-repl (get-buffer-process (current-buffer))))
-         (repl (cond ((and (not ask)
-                           (not impl)
-                           (not in-repl)
-                           (or geiser-repl--repl (car geiser-repl--repls))))
-                     ((and (not ask)
-                           (not in-repl)
-                           impl
-                           (geiser-repl--repl/impl impl)))))
-         (pop-up-windows geiser-repl-window-allow-split))
-    (cond ((or in-live-repl
-               (and (eq (current-buffer) repl) (not (eq repl buffer))))
-           (when (buffer-live-p geiser-repl--last-scm-buffer)
-             (pop-to-buffer geiser-repl--last-scm-buffer)))
-          (repl (pop-to-buffer repl))
-          ((geiser-repl--remote-p) (geiser-connect impl))
-          (t (run-geiser impl)))
-    (when (and buffer (eq major-mode 'geiser-repl-mode))
-      (setq geiser-repl--last-scm-buffer buffer))))
-
-(defalias 'geiser 'switch-to-geiser)
+(setq geiser-eval--default-connection-function 'geiser-repl--connection)
 
 (defun geiser-repl--send (cmd)
   (when (and cmd (eq major-mode 'geiser-repl-mode))
@@ -341,53 +271,6 @@ If no REPL is running, execute `run-geiser' to start a fresh one."
     (let ((comint-input-filter (lambda (x) nil)))
       (comint-send-input nil t))))
 
-(defun switch-to-geiser-module (&optional module buffer)
-  "Switch to running Geiser REPL and try to enter a given module."
-  (interactive)
-  (let* ((module (or module
-                     (geiser-completion--read-module
-                      "Switch to module (default top-level): ")))
-         (cmd (and module
-                   (geiser-repl--enter-cmd geiser-impl--implementation
-                                           module))))
-    (unless (eq major-mode 'geiser-repl-mode)
-      (switch-to-geiser nil nil (or buffer (current-buffer))))
-    (geiser-repl--send cmd)))
-
-(defun geiser-repl-import-module (&optional module)
-  "Import a given module in the current namespace of the REPL."
-  (interactive)
-  (let* ((module (or module
-                     (geiser-completion--read-module "Import module: ")))
-         (cmd (and module
-                   (geiser-repl--import-cmd geiser-impl--implementation
-                                            module))))
-    (switch-to-geiser nil nil (current-buffer))
-    (geiser-repl--send cmd)))
-
-(defun geiser-repl-exit (&optional arg)
-  "Exit the current REPL.
-With a prefix argument, force exit by killing the scheme process."
-  (interactive "P")
-  (when (or (not geiser-repl-query-on-exit-p)
-            (y-or-n-p "Really quit this REPL? "))
-    (let ((cmd (and (not arg)
-                    (geiser-repl--exit-cmd geiser-impl--implementation))))
-      (if cmd
-          (when (stringp cmd) (geiser-repl--send cmd))
-        (comint-kill-subjob)))))
-
-(defun geiser-repl-nuke ()
-  "Try this command if the REPL becomes unresponsive."
-  (interactive)
-  (goto-char (point-max))
-  (comint-kill-region comint-last-input-start (point))
-  (comint-redirect-cleanup)
-  (geiser-con--setup-connection (current-buffer)
-                                comint-prompt-regexp
-                                geiser-con--debugging-prompt-regexp
-                                geiser-con--debugging-preamble-regexp))
-
 
 ;;; REPL history and clean-up:
 
@@ -399,6 +282,7 @@ With a prefix argument, force exit by killing the scheme process."
   (let ((cb (current-buffer))
         (impl geiser-impl--implementation)
         (comint-prompt-read-only nil))
+    (ignore-errors (geiser-con--connection-close geiser-repl--connection))
     (setq geiser-repl--repls (remove cb geiser-repl--repls))
     (dolist (buffer (buffer-list))
       (when (buffer-live-p buffer)
@@ -426,7 +310,7 @@ With a prefix argument, force exit by killing the scheme process."
         (remove (current-buffer) geiser-repl--closed-repls)))
 
 (defun geiser-repl--input-filter (str)
-  (not (or (geiser-con--is-debugging)
+  (not (or ;; (geiser-con--is-debugging)
            (string-match "^\\s *$" str)
            (string-match "^,quit *$" str))))
 
@@ -497,7 +381,8 @@ With a prefix argument, force exit by killing the scheme process."
          (intxt (and pmark (buffer-substring pmark (point)))))
     (when intxt
       (when (and geiser-repl-forget-old-errors-p
-                 (not (geiser-con--is-debugging)))
+;;;                 (not (geiser-con--is-debugging)))
+                 )
         (compilation-forget-errors))
       (comint-send-input)
       (when (string-match "^\\s-*$" intxt)
@@ -545,7 +430,6 @@ buffer."
   (setq geiser-eval--get-module-function 'geiser-repl--module-function)
   (when geiser-repl-autodoc-p
     (geiser--save-msg (geiser-autodoc-mode 1)))
-  (setq geiser-autodoc--inhibit-function 'geiser-con--is-debugging)
   (geiser-company--setup geiser-repl-company-p)
   ;; enabling compilation-shell-minor-mode without the annoying highlighter
   (compilation-setup t))
@@ -588,15 +472,103 @@ buffer."
   ("Kill Scheme interpreter" "\C-c\C-q" geiser-repl-exit
    :enable (geiser-repl--live-p))
   ("Restart" "\C-c\C-z" switch-to-geiser :enable (not (geiser-repl--live-p)))
-  ("Revive REPL" "\C-c\C-k" geiser-repl-nuke
-   "Use this command if the REPL becomes irresponsive"
-   :enable (geiser-repl--live-p))
   --
   (custom "REPL options" geiser-repl))
 
 (define-key geiser-repl-mode-map [menu-bar completion] 'undefined)
 
 
+;;; User commands
+
+(defun run-geiser (impl)
+  "Start a new Geiser REPL."
+  (interactive
+   (list (or (geiser-repl--only-impl-p)
+             (and (eq major-mode 'geiser-repl-mode)
+                  geiser-impl--implementation)
+             (geiser-repl--read-impl
+              "Start Geiser for scheme implementation: "))))
+  (geiser-repl--start-repl impl nil nil nil))
+
+(defalias 'geiser 'run-geiser)
+
+(defun geiser-connect (impl &optional host port)
+  "Start a new Geiser REPL connected to a remote Scheme process."
+  (interactive
+   (list (or (geiser-repl--only-impl-p)
+             (and (eq major-mode 'geiser-repl-mode)
+                  geiser-impl--implementation)
+             (geiser-repl--read-impl
+              "Scheme implementation: "))))
+  (geiser-repl--start-repl impl t host port t))
+
+(make-variable-buffer-local
+ (defvar geiser-repl--last-scm-buffer nil))
+
+(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")
+  (let* ((impl (or impl geiser-impl--implementation))
+         (in-repl (eq major-mode 'geiser-repl-mode))
+         (in-live-repl (and in-repl (get-buffer-process (current-buffer))))
+         (repl (cond ((and (not ask)
+                           (not impl)
+                           (not in-repl)
+                           (or geiser-repl--repl (car geiser-repl--repls))))
+                     ((and (not ask)
+                           (not in-repl)
+                           impl
+                           (geiser-repl--repl/impl impl)))))
+         (pop-up-windows geiser-repl-window-allow-split))
+    (cond ((or in-live-repl
+               (and (eq (current-buffer) repl) (not (eq repl buffer))))
+           (when (buffer-live-p geiser-repl--last-scm-buffer)
+             (pop-to-buffer geiser-repl--last-scm-buffer)))
+          (repl (pop-to-buffer repl))
+          (geiser-repl--remote-p (geiser-connect impl))
+          (t (run-geiser impl)))
+    (when (and buffer (eq major-mode 'geiser-repl-mode))
+      (setq geiser-repl--last-scm-buffer buffer))))
+
+(defun switch-to-geiser-module (&optional module buffer)
+  "Switch to running Geiser REPL and try to enter a given module."
+  (interactive)
+  (let* ((module (or module
+                     (geiser-completion--read-module
+                      "Switch to module (default top-level): ")))
+         (cmd (and module
+                   (geiser-repl--enter-cmd geiser-impl--implementation
+                                           module))))
+    (unless (eq major-mode 'geiser-repl-mode)
+      (switch-to-geiser nil nil (or buffer (current-buffer))))
+    (geiser-repl--send cmd)))
+
+(defun geiser-repl-import-module (&optional module)
+  "Import a given module in the current namespace of the REPL."
+  (interactive)
+  (let* ((module (or module
+                     (geiser-completion--read-module "Import module: ")))
+         (cmd (and module
+                   (geiser-repl--import-cmd geiser-impl--implementation
+                                            module))))
+    (switch-to-geiser nil nil (current-buffer))
+    (geiser-repl--send cmd)))
+
+(defun geiser-repl-exit (&optional arg)
+  "Exit the current REPL.
+With a prefix argument, force exit by killing the scheme process."
+  (interactive "P")
+  (when (or (not geiser-repl-query-on-exit-p)
+            (y-or-n-p "Really quit this REPL? "))
+    (let ((cmd (and (not arg)
+                    (geiser-repl--exit-cmd geiser-impl--implementation))))
+      (if cmd
+          (when (stringp cmd) (geiser-repl--send cmd))
+        (comint-kill-subjob)))))
+
+
 ;;; Unload:
 
 (defun geiser-repl--repl-list ()
diff --git a/scheme/racket/geiser/user.rkt b/scheme/racket/geiser/user.rkt
index 37763b9..412cfe7 100644
--- a/scheme/racket/geiser/user.rkt
+++ b/scheme/racket/geiser/user.rkt
@@ -32,11 +32,8 @@
 (define orig-loader (current-load/use-compiled))
 (define geiser-loader (module-loader orig-loader))
 
-(define geiser-send-null (make-parameter #f))
-
 (define (geiser-eval)
   (define geiser-main (module->namespace 'geiser/main))
-  (geiser-send-null #t)
   (let* ([mod (read)]
          [lang (read)]
          [form (read)])
@@ -49,10 +46,7 @@
                                [else ((geiser:eval lang) form mod)])))))
 
 (define (geiser-read)
-  (if (geiser-send-null)
-      (begin (geiser-send-null #f)
-	     (write-char #\nul))
-      (printf "racket@~a> " (namespace->module-name (current-namespace))))
+  (printf "racket@~a> " (namespace->module-name (current-namespace)))
   (flush-output)
   (let* ([in (current-input-port)]
 	 [form ((current-read-interaction) (object-name in) in)])