Use repl buffer as connection buffer

  Ancillary changes:

 - new functions `nrepl-start-client-process' and `nrepl-start-server-process'.
 - `cider-init-repl-buffer' and `cider-create-repl-buffer' have clear cut
    separation of functionality
 - `nrepl-make-buffer-name` and all `cider-create-xxx-buffer-name` take explicit
    dir, port and host variables.
 - increase `nrepl-decode-timeout` to 0.025 for greater reliability
 - merge `nrepl--handle-process-output` into client process filter
 - remove `nrepl-connect' in favor of `nrepl-start-client-process'

CHANGELOG.md

@@ -18,6 +18,10 @@ are used to translate filenames from/to the nREPL server (default Cygwin impleme
 
 ### Changes
 
+* REPL buffers are now connection buffers for REPL client connections.
+* Server and client cranking were isolated into `nrepl-start-server-process` and
+  `nrepl-start-client-process`.
+
 * nrepl-client.el refactoring:
 
   - `nrepl-send-request-sync` was renamed into `nrepl-send-sync-request` to comply

cider-interaction.el

@@ -156,7 +156,7 @@ Signal an error if it is not supported."
   (unless (nrepl-op-supported-p op)
     (error "Can't find nREPL middleware providing op \"%s\".  Please, install (or update) cider-nrepl %s and restart CIDER" op cider-version)))
 
-(defun cider-verify-required-nrepl-ops ()
+(defun cider--check-required-nrepl-ops ()
   "Check whether all required nREPL ops are present."
   (let ((missing-ops (-remove 'nrepl-op-supported-p cider-required-nrepl-ops)))
     (when missing-ops
@@ -317,7 +317,7 @@ of the namespace in the Clojure source buffer."
   (let ((buffer (current-buffer)))
     (when (eq 4 arg)
       (cider-repl-set-ns (cider-current-ns)))
-    (pop-to-buffer (cider-find-or-create-repl-buffer))
+    (pop-to-buffer (cider-get-repl-buffer))
     (cider-remember-clojure-buffer buffer)
     (goto-char (point-max))))
 

cider-repl.el

@@ -43,6 +43,7 @@
   (defvar paredit-version)
   (defvar paredit-space-for-delimiter-predicates))
 
+
 (defgroup cider-repl nil
   "Interaction with the REPL."
   :prefix "cider-repl-"
@@ -115,6 +116,7 @@ you'd like to use the default Emacs behavior use
   :type 'symbol
   :group 'cider-repl)
 
+
 ;;;; REPL buffer local variables
 (defvar-local cider-repl-input-start-mark nil)
 
@@ -151,31 +153,42 @@ joined together.")
     (set markname (make-marker))
     (set-marker (symbol-value markname) (point))))
 
+
 ;;; REPL init
-(defun cider-repl-buffer-name ()
-  "Generate a REPL buffer name based on current connection buffer."
-  (with-current-buffer (get-buffer (nrepl-current-connection-buffer))
-    (nrepl-make-buffer-name nrepl-repl-buffer-name-template)))
-
-(defun cider-create-repl-buffer ()
-  "Create a REPL buffer."
-  (cider-init-repl-buffer
-   (let ((buffer-name (cider-repl-buffer-name)))
-     (if cider-repl-display-in-current-window
-         (add-to-list 'same-window-buffer-names buffer-name))
-     (if cider-repl-pop-to-buffer-on-connect
-         (pop-to-buffer buffer-name)
-       (generate-new-buffer buffer-name))
-     buffer-name)))
-
-(defun cider-make-repl (process)
-  "Make a REPL for the connection PROCESS."
-  (let ((connection-buffer (process-buffer process))
-        (repl-buffer (cider-create-repl-buffer)))
-    (with-current-buffer repl-buffer
-      (setq nrepl-connection-buffer (buffer-name connection-buffer)))
-    (with-current-buffer connection-buffer
-      (setq nrepl-repl-buffer (buffer-name repl-buffer)))))
+(defun cider-repl-buffer-name (&optional project-dir host port)
+  "Generate a REPL buffer name based on current connection buffer.
+PROJECT-DIR, PORT and HOST are as in `nrepl-make-buffer-name'."
+  (with-current-buffer (or (get-buffer (nrepl-current-connection-buffer))
+                           (current-buffer))
+    (nrepl-make-buffer-name nrepl-repl-buffer-name-template project-dir host port)))
+
+(defun cider-repl-create (&optional project-dir host port)
+  "Create a REPL buffer and install `cider-repl-mode'.
+PROJECT-DIR, PORT and HOST are as in `nrepl-make-buffer-name'."
+  ;; Connection might not have been set as yet. Please don't send requests here.
+  (let ((buf (nrepl-make-buffer-name nrepl-repl-buffer-name-template
+                                     project-dir host port)))
+    (with-current-buffer (get-buffer-create buf)
+      (unless (derived-mode-p 'cider-repl-mode)
+        (cider-repl-mode))
+      (cider-repl-reset-markers))
+    buf))
+
+(defun cider-repl-init (buffer &optional no-banner)
+  "Initialize the REPL in BUFFER.
+BUFFER must be a REPL buffer with `cider-repl-mode' and a running
+clienprocessL connection. Unless NO-BANNER is non-nil, insert a banner."
+  (with-current-buffer buffer
+    ;; honor :init-ns from lein's :repl-options on startup
+    (setq nrepl-buffer-ns (cider-eval-and-get-value "(str *ns*)"))
+    (unless no-banner
+      (cider-repl--insert-banner-and-prompt nrepl-buffer-ns))
+    (when cider-repl-display-in-current-window
+      (add-to-list 'same-window-buffer-names buf))
+    (when cider-repl-pop-to-buffer-on-connect
+      (pop-to-buffer buffer))
+    (cider-remember-clojure-buffer cider-current-clojure-buffer)
+    buffer))
 
 (defun cider-repl--banner ()
   "Generate the welcome REPL buffer banner."
@@ -194,33 +207,14 @@ joined together.")
   (cider-repl--mark-input-start)
   (cider-repl--insert-prompt ns))
 
-(defun cider-init-repl-buffer (buffer &optional noprompt)
-  "Initialize the REPL in BUFFER.
-Insert a banner, unless NOPROMPT is non-nil."
-  (with-current-buffer buffer
-    (unless (eq major-mode 'cider-repl-mode)
-      (cider-repl-mode))
-    (cider-repl-reset-markers)
-    (unless noprompt
-      (cider-repl--insert-banner-and-prompt nrepl-buffer-ns))
-    (cider-remember-clojure-buffer cider-current-clojure-buffer)
-    (current-buffer)))
-
-(defun cider-find-or-create-repl-buffer ()
-  "Return the REPL buffer, create it if necessary."
-  (let ((buffer (cider-current-repl-buffer)))
-        (if (null buffer)
-                (error "No active nREPL connection")
-          (let ((buffer (get-buffer buffer)))
-                (or (when (buffer-live-p buffer) buffer)
-                        (let ((buffer (nrepl-current-connection-buffer)))
-                          (if (null buffer)
-                                  (error "No active nREPL connection")
-                                (cider-init-repl-buffer
-                                 (get-process buffer)
-                                 (get-buffer-create
-                                  (cider-repl-buffer-name))))))))))
+(defun cider-get-repl-buffer ()
+  "Return the REPL buffer for current connection."
+  (let ((buffer (get-buffer-create (cider-current-repl-buffer))))
+    (if (buffer-live-p buffer)
+        buffer
+      (error "No active REPL"))))
 
+
 ;;; REPL interaction
 
 (defun cider-repl--in-input-area-p ()
@@ -685,6 +679,7 @@ namespace to switch to."
          (cider-repl-handler (current-buffer))))
     (error "Cannot determine the current namespace")))
 
+
 ;;;;; History
 
 (defcustom cider-repl-wrap-history nil
@@ -904,6 +899,7 @@ constructs."
   (append (cl-subseq session-hist 0 n-added-items)
           file-hist))
 
+
 ;;; REPL shortcuts
 (defcustom cider-repl-shortcut-dispatch-char ?\,
   "Character used to distinguish REPL commands from Lisp forms."
@@ -952,7 +948,7 @@ constructs."
          (call-interactively (gethash command cider-repl-shortcuts))
        (error "No command selected")))))
 
-
+
 ;;;;; CIDER REPL mode
 
 ;;; Prevent paredit from inserting some inappropriate spaces.

cider-selector.el

@@ -32,7 +32,7 @@
 
 (require 'cider-client)
 (require 'cider-interaction)
-(require 'cider-repl) ; for cider-find-or-create-repl-buffer
+(require 'cider-repl) ; for cider-get-repl-buffer
 
 (defconst cider-selector-help-buffer "*Selector Help*"
   "The name of the selector's help buffer.")
@@ -135,7 +135,7 @@ is chosen.  The returned buffer is selected with
 
 (def-cider-selector-method ?r
   "Current REPL buffer."
-  (cider-find-or-create-repl-buffer))
+  (cider-get-repl-buffer))
 
 (def-cider-selector-method ?n
   "Connections browser buffer."
@@ -153,7 +153,7 @@ is chosen.  The returned buffer is selected with
 (def-cider-selector-method ?s
  "Cycle to the next CIDER connection's REPL."
  (cider-rotate-connection)
- (cider-find-or-create-repl-buffer))
+ (cider-get-repl-buffer))
 
 (provide 'cider-selector)
 

cider.el

@@ -117,28 +117,17 @@ start the server."
       (let* ((project (when prompt-project
                         (read-directory-name "Project: ")))
              (project-dir (nrepl-project-directory-for
-                           (or project (nrepl-current-dir)))))
+                           (or project (nrepl-current-dir))))
+             (lein-params (if prompt-project
+                              (read-string (format "nREPL server command: %s "
+                                                   cider-lein-command)
+                                           cider-lein-parameters)
+                            cider-lein-parameters))
+             (cmd (format "%s %s" cider-lein-command lein-params)))
         (when (nrepl-check-for-repl-buffer nil project-dir)
-          (let* ((nrepl-project-dir project-dir)
-                 (lein-params (if prompt-project
-                                 (read-string (format "nREPL server command: %s " cider-lein-command) cider-lein-parameters)
-                               cider-lein-parameters))
-                 (cmd (format "%s %s" cider-lein-command lein-params))
-                 (default-directory (or project-dir default-directory))
-                 (serv-buf-name (generate-new-buffer-name (nrepl-server-buffer-name)))
-                 (process
-                  (progn
-                    ;; the buffer has to be created before the proc:
-                    (get-buffer-create serv-buf-name)
-                    (start-file-process-shell-command "nrepl-server" serv-buf-name cmd))))
-            (set-process-filter process 'nrepl-server-filter)
-            (set-process-sentinel process 'nrepl-server-sentinel)
-            (set-process-coding-system process 'utf-8-unix 'utf-8-unix)
-            (with-current-buffer (process-buffer process)
-              (setq nrepl-project-dir project-dir))
-            (message "Starting nREPL server via %s..."
-                     (propertize cmd 'face 'font-lock-keyword-face)))))
-    (message "The %s executable (specified by `cider-lein-command') isn't on your exec-path" cider-lein-command)))
+          (nrepl-start-server-process project-dir cmd)))
+    (message "The %s executable (specified by `cider-lein-command') isn't on your exec-path"
+             cider-lein-command)))
 
 (defun cider-known-endpoint-candidates ()
   "Known endpoint candidates for establishing an nREPL connection.
@@ -162,7 +151,8 @@ The returned endpoint has the label removed."
 
 ;;;###autoload
 (defun cider-connect (host port)
-  "Connect to an nREPL server identified by HOST and PORT."
+  "Connect to an nREPL server identified by HOST and PORT.
+Create REPL buffer and start an nREPL client connection."
   (interactive (let ((known-endpoint (when cider-known-endpoints
                                        (cider-select-known-endpoint))))
                  (list (or (car known-endpoint)
@@ -171,7 +161,7 @@ The returned endpoint has the label removed."
                                            (read-string "Port: " port nil port))))))
   (setq cider-current-clojure-buffer (current-buffer))
   (when (nrepl-check-for-repl-buffer `(,host ,port) nil)
-    (nrepl-connect host port)))
+    (nrepl-start-client-process default-directory host port t)))
 
 (define-obsolete-function-alias
   'cider