;;; ess-inf.el --- Support for running S as an inferior Emacs process

;; Copyright (C) 1989-1994 Bates, Kademan, Ritter and Smith
;; Copyright (C) 1997-1999 A.J. Rossini <rossini@u.washington.edu>,
;;      Martin Maechler <maechler@stat.math.ethz.ch>.
;; Copyright (C) 2000--2010 A.J. Rossini, Richard M. Heiberger, Martin
;;      Maechler, Kurt Hornik, Rodney Sparapani, and Stephen Eglen.
;; Copyright (C) 2011--2012 A.J. Rossini, Richard M. Heiberger, Martin Maechler,
;;      Kurt Hornik, Rodney Sparapani, Stephen Eglen and Vitalie Spinu.

;; Author: David Smith <dsmith@stats.adelaide.edu.au>
;; Created: 7 Jan 1994
;; Maintainer: ESS-core <ESS-core@r-project.org>

;; This file is part of ESS

;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; This file is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; A copy of the GNU General Public License is available at
;; http://www.r-project.org/Licenses/

;;; Commentary:

;; Code for handling running ESS processes.

;;; Code:

 ; Requires and autoloads

;; Silence byte-compiler
(require 'ess-generics)
(require 'ess-utils)
(require 'tramp)
(require 'newcomment nil t)
(require 'comint)
(require 'overlay)
(require 'compile)
(require 'format-spec)
(require 'ess-tracebug)

 ;;*;; Process handling

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; In this section:
;;;
;;; * User commands for starting an ESS process
;;; * Functions called at startup
;;; * Process handling code
;;; * Multiple process implementation
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;*;; Starting a process

(defun ess-proc-name (n name)
  "Return name of process N, as a string, with NAME prepended.
If ess-plain-first-buffername, then initial process is number-free."
  (concat name
          (if (not (and ess-plain-first-buffername
                        (= n 1))) ; if not both first and plain-first add number
              (concat ":" (number-to-string n)))))

(defun inferior-ess (&optional ess-start-args customize-alist no-wait)
  "Start inferior ESS process.

Without a prefix argument, starts a new ESS process, or switches
  to the ESS process associated with the current buffer.
With a prefix, starts the process with those args.
The current buffer is used if it is an `inferior-ess-mode'
or `ess-transcript-mode' buffer.

If `ess-ask-about-transfile' is non-nil, you will be asked for a
transcript file to use. If there is no transcript file, the buffer
name will be like *R* or *R2*, determined by `ess-gen-proc-buffer-name-function'.

Takes the program name from the variable `inferior-ess-program'.
An initialization file (dumped into the process) is specified by
`inferior-ess-start-file', and `inferior-ess-start-args' is used to
accompany the call for `inferior-ess-program'.

When creating a new process, the process buffer replaces the
current window if `inferior-ess-same-window' is non-nil.
Alternatively, it can appear in its own frame if
`inferior-ess-own-frame' is non-nil.

\(Type \\[describe-mode] in the process buffer for a list of commands.)"

  ;; Use the current buffer if it is in inferior-ess-mode or ess-trans-mode
  ;; If not, maybe ask about starting directory and/or transcript file.
  ;; If no transfile, use buffer *S*
  ;;
  ;; This function is primarily used to figure out the Process and
  ;; buffer names to use for inferior-ess.

  ;; Once, long ago, it was used for switching buffers, but we don't
  ;; do that any more (at least not from here).

  (interactive)

  (let* ((ess-customize-alist (or customize-alist
                                  ess-customize-alist))
         (temp-ess-dialect (eval (cdr (assoc 'ess-dialect
                                             ess-customize-alist))))
         (temp-ess-lang (eval (cdr (assoc 'ess-language
                                          ess-customize-alist)))))

    (run-hooks 'ess-pre-run-hook)
    (ess-write-to-dribble-buffer
     (format "(inf-ess 1): lang=%s, dialect=%s, tmp-dialect=%s, buf=%s\n"
             ess-language ess-dialect temp-ess-dialect (current-buffer)))
    (let* ((process-environment process-environment)
           ;; Use temp-ess-dialect if not R, R program name otherwise
           (temp-dialect (if ess-use-inferior-program-name-in-buffer-name ;VS[23-02-2013]: fixme: this should not be here
                             (if (string-equal temp-ess-dialect "R")
                                 inferior-ess-r-program-name
                               temp-ess-dialect)
                           temp-ess-dialect))
           (temp-lang temp-ess-lang)
           ;; Find the next non-existent process N (*R:N*)
           (procname (let ((ntry 1))
                       (while (get-process (ess-proc-name ntry temp-dialect))
                         (setq ntry (1+ ntry)))
                       (ess-proc-name ntry temp-dialect)))
           (buf-name-str (funcall ess-gen-proc-buffer-name-function procname))
           startdir buf method)

      (ess-write-to-dribble-buffer
       (format "(inf-ess 1.1): procname=%s temp-dialect=%s, buf-name=%s \n"
               procname temp-dialect buf-name-str))

      (cond
       ;; 1) try to use current buffer, if inferior-ess-mode but no process
       ((and (not (comint-check-proc (current-buffer)))
             (eq major-mode 'inferior-ess-mode))
        (setq startdir (inferior-ess--maybe-prompt-startup-directory procname temp-dialect))
        (setq buf (current-buffer))
        ;; don't change existing buffer name in this case; It is very
        ;; commong to restart the process in the same buffer.
        (setq buf-name-str (buffer-name))
        (setq method 1))

       ;; 2)  Take the *R:N* buffer if already exists (and contains dead proc!)
       ;; fixme: buffer name might have been changed, iterate over all
       ;; inferior-ess buffers
       ((get-buffer buf-name-str)
        (setq buf (get-buffer buf-name-str))
        (setq method 2))

       ;; 3)  Pick up a transcript file or create a new buffer
       (t
        (setq startdir (inferior-ess--maybe-prompt-startup-directory procname temp-dialect))
        (setq buf (if ess-ask-about-transfile
                      (let ((transfilename (read-file-name "Use transcript file (default none):"
                                                           startdir "")))
                        (if (string= transfilename "")
                            (get-buffer-create buf-name-str)
                          (find-file-noselect (expand-file-name  transfilename))))
                    (get-buffer-create buf-name-str)))
        (setq method 3)))

      (ess-write-to-dribble-buffer
       (format "(inf-ess 2.0) Method #%d start=%s buf=%s\n" method startdir buf))

      ;; Now that we have the buffer, set buffer-local variables.
      (set-buffer buf)
      (ess-setq-vars-local ess-customize-alist)

      (ess-write-to-dribble-buffer
       (format "(inf-ess 2.1): ess-language=%s, ess-dialect=%s buf=%s \n"
               ess-language  ess-dialect (current-buffer)))

      (when startdir (setq default-directory startdir))
      (let* ((ess-directory (or startdir
                                ess-directory))
             (infargs (or ess-start-args
                          inferior-ess-start-args))
             (special-display-regexps nil)
             (special-display-frame-alist inferior-ess-frame-alist)
             (proc (get-process procname)))
        (if inferior-ess-own-frame
            (setq special-display-regexps '(".")))
        ;; If ESS process NAME is running, switch to it
        (if (and proc (comint-check-proc (process-buffer proc)))
            (progn ;; fixme: when does this happen? -> log:
              (ess-write-to-dribble-buffer (format "(inf-ess ..): popping to proc\n"))
              (pop-to-buffer (process-buffer proc)))

          ;; Otherwise, crank up a new process
          (let* ((symbol-string
                  (concat "inferior-" inferior-ess-program "-args"))
                 (switches-symbol (intern-soft symbol-string))
                 (switches
                  (if (and switches-symbol (boundp switches-symbol))
                      (symbol-value switches-symbol))))
            (set-buffer buf)
            (inferior-ess-mode)
            (ess-write-to-dribble-buffer
             (format "(inf-ess 3.0): prog=%s, start-args=%s, echoes=%s\n"
                     inferior-ess-program infargs comint-process-echoes))
            (setq ess-local-process-name procname)
            (goto-char (point-max))
            ;; load past history

            ;; Set up history file
            (if ess-history-file
                (if (eq t ess-history-file)
                    (set (make-local-variable 'ess-history-file)
                         (concat "." ess-dialect "history"))
                  ;; otherwise must be a string "..."
                  (unless (stringp ess-history-file)
                    (error "`ess-history-file' must be nil, t, or a string"))))

            (when ess-history-file
              (setq comint-input-ring-file-name
                    (expand-file-name ess-history-file
                                      (or ess-history-directory ess-directory)))
              (comint-read-input-ring))

            ;; create and run process.
            (set-buffer
             (if switches
                 (inferior-ess-make-comint buf-name-str
                                           procname
                                           infargs
                                           switches)
               (inferior-ess-make-comint buf-name-str
                                         procname
                                         infargs)))

            ;; Set the process sentinel to save the history
            (set-process-sentinel (get-process procname) 'ess-process-sentinel)
            ;; Add this process to ess-process-name-list, if needed
            (let ((conselt (assoc procname ess-process-name-list)))
              (if conselt nil
                (setq ess-process-name-list
                      (cons (cons procname nil) ess-process-name-list))))
            (ess-make-buffer-current)
            (goto-char (point-max))
            (setq ess-sl-modtime-alist nil)

            ;; Add the process filter to catch certain output.
            (set-process-filter (get-process procname)
                                'inferior-ess-output-filter)
            ;; (inferior-ess-wait-for-prompt)
            (inferior-ess-mark-as-busy (get-process procname))
            (process-send-string (get-process procname) "\n") ;; to be sure we catch the prompt if user comp is super-duper fast.
            (unless no-wait
              (ess-write-to-dribble-buffer "(inferior-ess: waiting for process to start (before hook)\n")
              (ess-wait-for-process (get-process procname) nil 0.01))

            ;; arguments cache
            (ess-process-put 'funargs-cache (make-hash-table :test 'equal))
            (ess-process-put 'funargs-pre-cache nil)

            ;; set accumulation buffer name (buffer to cache output for faster display)
            (process-put (get-process procname) 'accum-buffer-name
                         (format " *%s:accum*" procname))


            ;; don't font-lock strings over process prompt
            (set (make-local-variable 'syntax-begin-function)
                 #'inferior-ess-goto-last-prompt-if-close)
            (set (make-local-variable 'font-lock-fontify-region-function)
                 #'inferior-ess-fontify-region)

            (run-hooks 'ess-post-run-hook)

            ;; EXTRAS
            (ess-load-extras t)
            ;; user initialization can take some time ...
            (unless no-wait
              (ess-write-to-dribble-buffer "(inferior-ess 3): waiting for process after hook")
              (ess-wait-for-process (get-process procname))))

          (with-current-buffer buf
            (rename-buffer buf-name-str t))

          (if (and inferior-ess-same-window (not inferior-ess-own-frame))
              (switch-to-buffer buf)
            (pop-to-buffer buf)))))))


(defvar inferior-ess-objects-command nil
  "The language/dialect specific command for listing objects.
It is initialized from the corresponding inferior-<lang>-objects-command
and then made buffer local."); and the *-<lang>-* ones are customized!
(make-variable-buffer-local 'inferior-ess-objects-command)

(defvar ess-save-lastvalue-command nil
  "The command to save the last value.  See S section for more details.
Default depends on the ESS language/dialect and hence made buffer local")
(make-variable-buffer-local 'ess-save-lastvalue-command)

(defvar ess-retr-lastvalue-command nil
  "The command to retrieve the last value.  See S section for more details.
Default depends on the ESS language/dialect and hence made buffer local")
(make-variable-buffer-local 'ess-retr-lastvalue-command)

;;; A note on multiple processes: the following variables
;;;     ess-local-process-name
;;;     ess-sl-modtime-alist
;;;     ess-prev-load-dir/file
;;;     ess-directory
;;;     ess-object-list
;;; are specific to each ess-process and are buffer-local variables
;;; local to the ESS process buffer. If required, these variables should
;;; be accessed with the function ess-get-process-variable


(defun inferior-ess-goto-last-prompt-if-close (&optional pos)
  "Staging from POS go to previous primary prompt and return the position.
Look only for primary or secondary prompt on the current line. If
found, return the starting position of the prompt, otherwise stay
at current position and return nil. POS defaults to `point'."

  (let* ((pos (or pos (point)))
         (new-pos (save-excursion
                    (beginning-of-line)
                    (if (looking-at inferior-ess-primary-prompt)
                        pos
                      (when  (and inferior-ess-secondary-prompt
                                  (looking-at inferior-ess-secondary-prompt))
                        (re-search-backward (concat "^" inferior-ess-primary-prompt))
                        pos)))))
    (when new-pos
      (goto-char new-pos))))

(defvar compilation--parsed)
(defvar ess--tb-last-input)
(defvar compilation--parsed)
(defun inferior-ess-fontify-region (beg end &optional verbose)
  "Fontify output by output within the beg-end region to avoid
fontification spilling over prompts."
  (let* ((buffer-undo-list t)
	 (inhibit-point-motion-hooks t)
         (font-lock-dont-widen t)
         (buff (current-buffer))
         (pos0 (or (inferior-ess-goto-last-prompt-if-close beg)
                   beg))
         (pos1 pos0) pos2)
    (when (< pos0 end)
      (with-silent-modifications
        ;; fontify chunks from prompt to prompt
        (while (< pos1 end)
          (goto-char pos1)
          (comint-next-prompt 1)
          (setq pos2 (min (point) end))
          (save-restriction
            (narrow-to-region pos1 pos2)
            (font-lock-default-fontify-region pos1 pos2 verbose))
          (setq pos1 pos2))
        ;; highlight errors
        (setq compilation--parsed beg)
        ;; emacs 23 doesn't have this function
        (when (fboundp 'compilation--ensure-parse)
          ;; this line is a workaround for occasional incomplete highlighting of
          ;; compilation errors on remotes, but it causes an incredible
          ;; slowdown. See https://github.com/emacs-ess/ESS/issues/258.
          ;; (compilation--ensure-parse end)
          )
        `(jit-lock-bounds ,pos0 . ,end)))))

(defun ess-gen-proc-buffer-name:simple (proc-name)
  "Function to generate buffer name by wrapping PROC-NAME in *proc-name*.
See `ess-gen-proc-buffer-name-function'."
  (format "*%s*" proc-name))

(defun ess-gen-proc-buffer-name:directory (proc-name)
  "Function to generate buffer name by wrapping PROC-NAME in *PROC-NAME:DIR-NAME*.
DIR-NAME is a short directory name. See
`ess-gen-proc-buffer-name-function'."
  (format "*%s:%s*" proc-name (file-name-nondirectory
                               (directory-file-name default-directory))))

(defun ess-gen-proc-buffer-name:abbr-long-directory (proc-name)
  "Function to generate buffer name in the form *PROC-NAME:ABBREVIATED-LONG-DIR-NAME*.
PROC-NAME is a string representing an internal process
name. ABBREVIATED-LONG-DIR-NAME is an abbreviated full directory
name. Abbreviation is performed by `abbreviate-file-name'. See
`ess-gen-proc-buffer-name-function'."
  (format "*%s:%s*" proc-name (abbreviate-file-name default-directory)))

(defun ess-gen-proc-buffer-name:projectile-or-simple (proc-name)
  "Function to generate buffer name in the form *PROC-NAME:PROJECTILE-ROOT*.
PROC-NAME is a string representing an internal process
name. PROJECTILE-ROOT is directory name returned by
`projectile-project-root' if defined. If
`projectile-project-root' is undefined or no project directory
has been found use `ess-gen-proc-buffer-name:simple'. See
`ess-gen-proc-buffer-name-function'."
  (let ((proj (and (fboundp 'projectile-project-root)
		   (projectile-project-p))))
    (if proj
	(format "*%s:%s*" proc-name (file-name-nondirectory
				     (directory-file-name proj)))
      (ess-gen-proc-buffer-name:simple proc-name))))

(defun ess-gen-proc-buffer-name:projectile-or-directory (proc-name)
  "Function to generate buffer name in the form *PROC-NAME:PROJECTILE-ROOT*.
PROC-NAME is a string representing an internal process
name. PROJECTILE-ROOT is directory name returned by
`projectile-project-root' if defined. If
`projectile-project-root' is undefined, or no project directory
has been found, use `ess-gen-proc-buffer-name:directory'. See
`ess-gen-proc-buffer-name-function'."
  (let ((proj (and (fboundp 'projectile-project-root)
		   (projectile-project-p))))
    (if proj
	(format "*%s:%s*" proc-name (file-name-nondirectory
				     (directory-file-name proj)))
      (ess-gen-proc-buffer-name:directory proc-name))))

(defun inferior-ess-set-status (proc string &optional no-timestamp)
  "Internal function to set the satus of the PROC
If no-timestamp, don't set the last-eval timestamp.
Return the 'busy state."
  ;; todo: do it in one search, use starting position, use prog1
  (let ((busy (not (string-match (concat "\\(" inferior-ess-primary-prompt "\\)\\'") string))))
    (process-put proc 'busy-end? (and (not busy)
                                      (process-get proc 'busy)))
    (when (not busy)
      (process-put proc 'running-async? nil))
    (process-put proc 'busy busy)
    (process-put proc 'sec-prompt
                 (when inferior-ess-secondary-prompt
                   (string-match (concat "\\(" inferior-ess-secondary-prompt "\\)\\'") string)))
    (unless no-timestamp
      (process-put proc 'last-eval (current-time)))
    busy))

(defun inferior-ess-mark-as-busy (proc)
  (process-put proc 'busy t)
  (process-put proc 'sec-prompt nil))

(defun inferior-ess-run-callback (proc string)
  ;; callback is stored in 'callbacks proc property. Callbacks is a list that
  ;; can contain either functions to be called with two artuments PROC and
  ;; STRING, or cons cells of the form (func . suppress). If SUPPRESS is non-nil
  ;; next process output will be suppressed.
  (unless (process-get proc 'busy)
    ;; only one callback is implemented for now
    (let* ((cb (car (process-get proc 'callbacks)))
           (listp (not (functionp cb)))
           (suppress (and listp (consp cb) (cdr cb)))
           (cb (if (and listp (consp cb))
                   (car cb)
                 cb)))
      (when cb
        (when ess-verbose
            (ess-write-to-dribble-buffer "executing callback ...\n"))
        (when suppress
          (process-put proc 'suppress-next-output? t))
        (process-put proc 'callbacks nil)
        (condition-case err
            (funcall cb proc string)
          (error (message "%s" (error-message-string err))))))))

(defun ess--if-verbose-write-process-state (proc string &optional filter)
  (ess-if-verbose-write
   (format "\n%s:
    --> busy:%s busy-end:%s sec-prompt:%s interruptable:%s <--
    --> running-async:%s callback:%s suppress-next-output:%s <--
    --> dbg-active:%s is-recover:%s <--
    --> string:%s\n"
           (or filter "NORMAL-FILTER")
           (process-get proc 'busy)
           (process-get proc 'busy-end?)
           (process-get proc 'sec-prompt)
           (process-get proc 'interruptable?)
           (process-get proc 'running-async?)
           (if (process-get proc 'callbacks) "yes")
           (process-get proc 'suppress-next-output?)
           (process-get proc 'dbg-active)
           (process-get proc 'is-recover)
           (if (> (length string) 150)
               (format "%s .... %s" (substring string 0 50) (substring string -50))
             string))))

(defun inferior-ess-output-filter (proc string)
  "Standard output filter for the inferior ESS process.
Ring Emacs bell if process output starts with an ASCII bell, and pass
the rest to `comint-output-filter'.
Taken from octave-mod.el."
  (inferior-ess-set-status proc string)
  (ess--if-verbose-write-process-state proc string)
  (inferior-ess-run-callback proc string)
  (if (process-get proc 'suppress-next-output?)
      ;; works only for surpressing short output, for time being is enough (for callbacks)
      (process-put proc 'suppress-next-output? nil)
    (comint-output-filter proc (inferior-ess-strip-ctrl-g string))
    (ess--show-process-buffer-on-error string proc)))


(defun ess--show-process-buffer-on-error (string proc)
  (let ((case-fold-search nil))
    (when (string-match "Error\\(:\\| +in\\)" string)
      (ess-show-buffer (process-buffer proc)))))

(defun inferior-ess-strip-ctrl-g (string)
  "Strip leading `^G' character.
If STRING starts with a `^G', ring the Emacs bell and strip it.
Depending on the value of `visible-bell', either the frame will
flash or you'll hear a beep.  Taken from octave-mod.el."
  (if (string-match "^\a" string)
      (progn
        (ding)
        (setq string (substring string 1))))
  string)


(defun ess-process-sentinel (proc message)
  "Sentinel for use with ESS processes.
This marks the process with a message, at a particular time point."
  (save-excursion
    (setq message (substring message 0 -1)) ; strip newline
    (set-buffer (process-buffer proc))
    (comint-write-input-ring)
    (goto-char (point-max))
    (insert-before-markers
     (format "\nProcess %s %s at %s\n"
             (process-name proc) message (current-time-string)))))

(defun inferior-ess-make-comint (bufname
                                 procname
                                 infargs
                                 &rest switches)
  "Make an S comint process in buffer BUFNAME with process PROCNAME."
;;; This function is a modification of make-comint from the comint.el
;;; code of Olin Shivers.
  (let*  ((buffer (get-buffer-create bufname))
          (proc (get-process procname)))
    ;; If no process, or nuked process, crank up a new one and put buffer in
    ;; comint mode. Otherwise, leave buffer and existing process alone.
    (cond ((or (not proc) (not (memq (process-status proc) '(run stop))))
           (with-current-buffer  buffer
             (if ess-directory (setq default-directory ess-directory))
             (if (eq (buffer-size) 0) nil
               (goto-char (point-max))
               (insert "\^L\n")))    ; page boundaries = Interactive sessions
           (let ((process-environment
                  (nconc
                   (list "STATATERM=emacs"
                         (format "PAGER=%s" inferior-ess-pager))
                   process-environment))
                 (tramp-remote-process-environment
                  (nconc ;; it contains a pager already, so append
                   (when (boundp 'tramp-remote-process-environment)
                     (copy-sequence tramp-remote-process-environment))
                   (list "STATATERM=emacs"
                         (format "PAGER=%s" inferior-ess-pager)))))
             (ess-write-to-dribble-buffer "Making Process...")
             (ess-write-to-dribble-buffer
              (format "Buf %s, :Proc %s, :Prog %s\n :Args= %s\nStart File=%s\n"
                      buffer
                      procname
                      inferior-ess-program
                      infargs
                      inferior-ess-start-file))
             (comint-exec buffer
                          procname
                          inferior-ess-program
                          inferior-ess-start-file
                          (ess-line-to-list-of-words
                           infargs)))))
    buffer))


;;*;; Requester functions called at startup

;; FIXME EMACS 25.1:
;; Deprecate `ess-directory-function' in favour of `project-find-functions'?
(defun inferior-ess--get-startup-directory ()
  (let ((dir (or (and ess--enable-experimental-projects
                      (fboundp 'project-current)
                      (cdr (project-current)))
                 (and ess-directory-function
                      (funcall ess-directory-function))
                 ess-startup-directory
                 default-directory)))
    (directory-file-name dir)))

;; FIXME: Move all that R stuff elsewhere
(defun inferior-ess-r--adjust-startup-directory (dir dialect)
  (if (string= dialect "R")
      (let* ((project-dir (cdr (ess-r-package-project)))
             (tests-dir (expand-file-name (file-name-as-directory "tests")
                                          project-dir)))
        ;; Prefer the `tests' directory but only if the package
        ;; directory was selected in the first place
        (if (and project-dir
                 (string= project-dir dir)
                 (string= default-directory tests-dir))
            tests-dir
          dir))
    dir))

(defun inferior-ess--maybe-prompt-startup-directory (procname dialect)
  (let ((default-dir (inferior-ess-r--adjust-startup-directory
                      (inferior-ess--get-startup-directory)
                      dialect)))
    (if ess-ask-for-ess-directory
        (let* ((prog (cond ((string= dialect "R")
                            ;; Includes R-X.Y versions
                            (concat ", " inferior-R-version))
                           (inferior-ess-program
                            (concat ", " inferior-ess-program ))
                           (t "")))
               (prompt (format "%s starting project directory? "
                               procname
                               prog)))
          (ess-prompt-for-directory default-dir prompt))
      default-dir)))

(defun ess-prompt-for-directory (default prompt)
  "`prompt' for a directory, using `default' as the usual."
  (let* ((def-dir (file-name-as-directory default))
         (the-dir (expand-file-name
                   (file-name-as-directory
                    (read-directory-name prompt def-dir def-dir t nil)))))
    (if (file-directory-p the-dir) nil
      (error "%s is not a valid directory" the-dir))
    the-dir))


;;*;; General process handling code
(defmacro with-ess-process-buffer (no-error &rest body)
  "Execute BODY with current-buffer set to the process buffer of ess-current-process-name.
If NO-ERROR is t don't trigger error when there is not current
process.

Symbol *proc* is bound to the current process during the evaluation of BODY."
  (declare (indent 1) (debug t))
  `(let ((*proc* (and ess-local-process-name (get-process ess-local-process-name))))
     (if *proc*
         (with-current-buffer (process-buffer *proc*)
           ,@body)
       (unless ,no-error
         (error "No current ESS process")))))

(defmacro ess-with-current-buffer (buffer &rest body)
  "Like `with-current-buffer' but with transfer of some essential
local ESS vars like `ess-local-process-name'"
  (declare (indent 1) (debug t))
  (let ((lpn (make-symbol "lpn"))
        (alist (make-symbol "alist")))
    `(let ((,lpn ess-local-process-name)
            (,alist ess-local-customize-alist))
       (with-current-buffer ,buffer
         (ess-setq-vars-local (eval ,alist))
         (setq ess-local-process-name ,lpn)
         ,@body))))

(dolist (mode '(emacs-lisp-mode lisp-interaction-mode))
  (font-lock-add-keywords
   mode
   '(("(\\(ess-with-current-buffer\\)\\s +\\(\\(\\w\\|\\s_\\)+\\)"
      (1 font-lock-keyword-face)
      (2 font-lock-variable-name-face)))))

(defun ess-get-process (&optional name use-another)
  "Return the ESS process named by NAME.  If USE-ANOTHER is non-nil,
and the process NAME is not running (anymore), try to connect to another if
there is one.  By default (USE-ANOTHER is nil), the connection to another
process happens interactively (when possible)."
  (setq name (or name ess-local-process-name))
  (if (null name)           ; should almost never happen at this point
      (error "No ESS process is associated with this buffer now"))
  (update-ess-process-name-list)
  (if (assoc name ess-process-name-list)
      (get-process name)
    ;; else :
    ;; was (error "Process %s is not running" name)
    (ess-write-to-dribble-buffer
     (format "ess-get-process: process '%s' not running" name))
    (if (= 0 (length ess-process-name-list))
        (save-current-buffer
          (ess-write-to-dribble-buffer
           (format " .. restart proc %s for language %s (buf %s)\n"
                   name ess-language (current-buffer)))
          (message "trying to (re)start process %s for language %s ..."
                   name ess-language)
          (ess-start-process-specific ess-language ess-dialect)
          ;; and return the process: "call me again"
          (ess-get-process name))

      ;; else: there are other running processes
      (if use-another ; connect to another running process : the first one
          (let ((other-name (car (elt ess-process-name-list 0))))
            ;; "FIXME": try to find the process name that matches *closest*
            (message "associating with *other* process '%s'" other-name)
            (ess-get-process other-name))
        ;; else
        (ding)
        (if (y-or-n-p
             (format "Process %s is not running, but others are. Switch? " name))
            (progn
              (ess-force-buffer-current
               (concat ess-dialect " process to use: ") 'force)
              (ess-get-process ess-current-process-name))
          (error "Process %s is not running" name))))))


;; (defun inferior-ess-wait-for-prompt ()
;;   "Wait until the ESS process is ready for input."
;;   (let* ((cbuffer (current-buffer))
;;       (sprocess (ess-get-process ess-current-process-name))
;;       (sbuffer (process-buffer sprocess))
;;       (r nil)
;;       (timeout 0))
;;     (set-buffer sbuffer)
;;     (while (progn
;;           (if (not (eq (process-status sprocess) 'run))
;;               (ess-error "ESS process has died unexpectedly.")
;;             (if (> (setq timeout (1+ timeout)) ess-loop-timeout)
;;                 (ess-error "Timeout waiting for prompt. Check inferior-ess-prompt or ess-loop-timeout."))
;;             (accept-process-output)
;;             (goto-char (point-max))
;;             (beginning-of-line); bol ==> no need for "^" in *-prompt! (MM?)
;;             ;; above, except for Stata, which has "broken" i/o,
;;             ;; sigh... (AJR)
;;             (setq r (looking-at inferior-ess-prompt))
;;             (not (or r (looking-at ".*\\?\\s *"))))))
;;     (goto-char (point-max))
;;     (set-buffer cbuffer)
;;     (symbol-value r)))

;;--- Unfinished idea (ESS-help / R-help ) -- probably not worth it...
;;- (defun ess-set-inferior-program-name (filename)
;;-   "Allows to set or change `inferior-ess-program', the program (file)name."
;;-   (interactive "fR executable (script) file: ")
;;-   ;; "f" : existing file {file name completion} !
;;-   (setq inferior-ess-program filename))
;; the inferior-ess-program is initialized in the customize..alist,
;; e.g. from  inferior-ess-r-program-name ... --> should change rather these.
;; However these really depend on the current ess-language!
;; Plan: 1) must know and use ess-language
;;       2) change the appropriate  inferior-<ESSlang>-program-name
;; (how?) in R/S : assign(paste("inferior-",ESSlang,"-p...."),  filename))

;;*;; Multiple process handling code

(defun ess-make-buffer-current nil
  "Make the process associated with the current buffer the current ESS process.
Returns the name of the process, or nil if the current buffer has none."
  (update-ess-process-name-list)
  ;; (if ess-local-process-name
  ;;     (setq ess-current-process-name ess-local-process-name))
  ess-local-process-name)

(defun ess-get-process-variable (var)
  "Return the variable VAR (symbol) local to ESS process called NAME (string)."
  (buffer-local-value var (process-buffer (ess-get-process ess-local-process-name))))

(defun ess-set-process-variable (var val)
  "Set variable VAR (symbol) local to ESS process called NAME (string) to VAL."
  (with-current-buffer (process-buffer (ess-get-process ess-local-process-name))
    (set var val)))

;; emacs 23 compatibility
(unless (fboundp 'process-live-p)
  (defun process-live-p (process)
    "Returns non-nil if PROCESS is alive.
A process is considered alive if its status is `run', `open',
`listen', `connect' or `stop'."
    (memq (process-status process)
          '(run open listen connect stop))))

(defun ess-process-live-p ()
  "Check if the local ess process is alive.
Return nil if current buffer has no associated process, or
process was killed."
  (and ess-local-process-name
       (let ((proc (get-process ess-local-process-name)))
         (and (processp proc)
              (process-live-p proc)))))

(defun ess-process-get (propname)
  "Return the variable PROPNAME (symbol) from the plist of the
current ESS process."
  (process-get (get-process ess-local-process-name) propname))

(defun ess-process-put (propname value)
  "Set the variable PROPNAME (symbol) to VALUE in the plist of
the current ESS process."
  (process-put (get-process ess-local-process-name) propname value))

(defun ess-start-process-specific (language dialect)
  "Start an ESS process typically from a language-specific buffer, using
LANGUAGE (and DIALECT)."

  (unless dialect
    (error "The value of `dialect' is nil"))

  (save-current-buffer
    (let ((dsymb (intern dialect)))
      (ess-write-to-dribble-buffer
       (format " ..start-process-specific: lang:dialect= %s:%s, current-buf=%s\n"
               language dialect (current-buffer)))
      (cond ;; ((string= dialect "R") (R))
            ;; ((string= language "S") ;
            ;;  (message "ESS process not running, trying to start R, since language = 'S")
            ;;  (R))
            ;; ((string= dialect STA-dialect-name) (stata))
            ;;general case
            ((fboundp dsymb)
             (funcall dsymb))
            (t ;; else: ess-dialect is not a function

             ;; Typically triggered from
             ;; ess-force-buffer-current("Process to load into: ")
             ;;  \-->  ess-request-a-process("Process to load into: " no-switch)
             (error "No ESS processes running; not yet implemented to start (%s,%s)"
                    language dialect)))
      ;; save excursion is not working here !!! bad bad bad !!
      )))

(defun ess-request-a-process (message &optional noswitch ask-if-1)
  "Ask for a process, and make it the current ESS process.
If there is exactly one process, only ask if ASK-IF-1 is non-nil.
Also switches to the process buffer unless NOSWITCH is non-nil.  Interactively,
NOSWITCH can be set by giving a prefix argument.
Returns the name of the selected process."
  (interactive
   (list "Switch to which ESS process? " current-prefix-arg))
                                        ; prefix sets 'noswitch
  (ess-write-to-dribble-buffer "ess-request-a-process: {beginning}\n")
  (update-ess-process-name-list)

  (setq ess-dialect (or ess-dialect
                        (ess-completing-read
                         "Set `ess-dialect'"
                         (delete-dups (list "R" "S+" S+-dialect-name
                                            "stata" STA-dialect-name
                                            "julia" "SAS" "XLS"  "ViSta")))))

  (let* ((pname-list (delq nil ;; keep only those mathing dialect
                           (append
                            (mapcar (lambda (lproc)
                                      (and (equal ess-dialect
                                                  (buffer-local-value
                                                   'ess-dialect
                                                   (process-buffer (get-process (car lproc)))))
                                           (not (equal ess-local-process-name (car lproc)))
                                           (car lproc)))
                                    ess-process-name-list)
                            ;; append local only if running
                            (when (assoc ess-local-process-name ess-process-name-list)
                              (list ess-local-process-name)))))
         (num-processes (length pname-list))
         (inferior-ess-same-window nil) ;; this should produce the inferior process in other window
         (auto-started?))
    (if (or (= 0 num-processes)
            (and (= 1 num-processes)
                 (not (equal ess-dialect ;; don't auto connect if from different dialect
                             (buffer-local-value
                              'ess-dialect
                              (process-buffer (get-process
                                               (car pname-list))))))))
        ;; try to start "the appropriate" process
        (progn
          (ess-write-to-dribble-buffer
           (concat " ... request-a-process:\n  "
                   (format
                    "major mode %s; current buff: %s; ess-language: %s, ess-dialect: %s\n"
                    major-mode (current-buffer) ess-language ess-dialect)))
          (ess-start-process-specific ess-language ess-dialect)
          (ess-write-to-dribble-buffer
           (format "  ... request-a-process: buf=%s\n" (current-buffer)))
          (setq num-processes 1
                pname-list (car ess-process-name-list)
                auto-started? t)))
    ;; now num-processes >= 1 :
    (let* ((proc-buffers (mapcar (lambda (lproc)
                                   (buffer-name (process-buffer (get-process lproc))))
                                 pname-list))
           (proc
            (if (or auto-started?
                    (and (not ask-if-1) (= 1 num-processes)))
                (progn
                  (message "using process '%s'" (car proc-buffers))
                  (car pname-list))
              ;; else
              (unless (and ess-current-process-name
                           (get-process ess-current-process-name))
                (setq ess-current-process-name nil))
              (when message
                (setq message (replace-regexp-in-string ": +\\'" "" message))) ;; <- why is this here??
              ;; ask for buffer name not the *real* process name:
              (let ((buf (ess-completing-read message (append proc-buffers (list "*new*")) nil t nil nil)))
                (if (equal buf "*new*")
                    (progn
                      (ess-start-process-specific ess-language ess-dialect) ;; switches to proc-buff
                      (caar ess-process-name-list))
                  (process-name (get-buffer-process buf))
                  ))
              )))
      (if noswitch
          (pop-to-buffer (current-buffer)) ;; VS: this is weired, but is necessary
        (pop-to-buffer (buffer-name (process-buffer (get-process proc))) t))
      proc)))

(defun ess-force-buffer-current (&optional prompt force no-autostart ask-if-1)
  "Make sure the current buffer is attached to an ESS process.
If not, or FORCE (prefix argument) is non-nil, prompt for a
process name with PROMPT. If NO-AUTOSTART is nil starts the new
process if process associated with current buffer has
died. `ess-local-process-name' is set to the name of the process
selected.  `ess-dialect' is set to the dialect associated with
the process selected. ASK-IF-1 asks user for the process, even if
there is only one process running."
  (interactive
   (list (concat ess-dialect " process to use: ") current-prefix-arg nil))
  ;; fixme: why the above interactive is not working in emacs 24?
  (setq prompt (or prompt "Process to use: "))
  (let ((proc-name (ess-make-buffer-current)))
    (if (and (not force) proc-name (get-process proc-name))
        nil ; do nothing
      ;; Make sure the source buffer is attached to a process
      (if (and ess-local-process-name (not force) no-autostart)
          (error "Process %s has died" ess-local-process-name)
        ;; ess-local-process-name is nil -- which process to attach to
        (let ((proc (ess-request-a-process prompt 'no-switch ask-if-1))
              temp-ess-help-filetype  dialect)
          (with-current-buffer (process-buffer (get-process proc))
            (setq temp-ess-help-filetype inferior-ess-help-filetype))
          (setq ess-local-process-name proc)
          (setq inferior-ess-help-filetype temp-ess-help-filetype))))))

(defalias 'inferior-ess-force #'ess-force-buffer-current)

(defun ess-switch-process ()
  "Force a switch to a new underlying process."
  (interactive)
  (ess-force-buffer-current "Process to use: " 'force nil 'ask-if-1))

(defun ess-get-next-available-process (&optional dialect ignore-busy)
  "Return first available (aka not busy) process of dialect DIALECT.
DIALECT defaults to the local value of ess-dialect. Return nil if
no such process has been found."
  (setq dialect (or dialect ess-dialect))
  (when dialect
    (let (proc)
     (catch 'found
       (dolist (p (cons ess-local-process-name
                        (mapcar 'car ess-process-name-list)))
         (when p
           (setq proc (get-process p))
           (when (and proc
                      (process-live-p proc)
                      (equal dialect
                             (buffer-local-value 'ess-dialect (process-buffer proc)))
                      (or ignore-busy
                          (not (process-get proc 'busy))))
             (throw 'found proc))))))))


;;*;;; Commands for switching to the process buffer

(defun ess-switch-to-ESS (eob-p)
  "Switch to the current inferior ESS process buffer.
With (prefix) EOB-P non-nil, positions cursor at end of buffer.
This function should follow the description in `ess-show-buffer'
for showing the iESS buffer, except that the iESS buffer is also
made current."
  (interactive "P")
  (ess-force-buffer-current)
  (if (and ess-current-process-name (get-process ess-current-process-name))
      (progn
        ;; Display the buffer, but don't select it yet.
        (ess-show-buffer
         (buffer-name (process-buffer (get-process ess-current-process-name)))
         t)
        (if eob-p (goto-char (point-max))))
    (message "No inferior ESS process")
    (ding)))

(defun ess-switch-to-ESS-deprecated (eob-p)
  (interactive "P")
  (ess-switch-to-ESS eob-p)
  (message "C-c C-y is deprecated, use C-c C-z instead (ess-switch-to-inferior-or-script-buffer)"))


(defun ess-switch-to-end-of-ESS ()
  "Switch to the end of the inferior ESS process buffer."
  (interactive)
  (ess-switch-to-ESS t))

(defun ess-switch-to-inferior-or-script-buffer (toggle-eob)
  "If in script, switch to the iESS. If in iESS switch to most recent script buffer.

This is a single-key command. Assuming that it is bound to C-c C-z,
you can navigate back and forth between iESS and script buffer
with C-c C-z C-z C-z ...

If variable `ess-switch-to-end-of-proc-buffer' is t (the default)
 this function switches to the end of process buffer.

If TOGGLE-EOB is given, the value of
`ess-switch-to-end-of-proc-buffer' is toggled.
"
  (interactive "P")
  (let ((map (make-sparse-keymap))
        (EOB (if toggle-eob
                 (not ess-switch-to-end-of-proc-buffer)
               ess-switch-to-end-of-proc-buffer)))
    (define-key map (vector last-command-event)
      (lambda (ev eob) (interactive)
        (if (not (eq major-mode 'inferior-ess-mode))
            (ess-switch-to-ESS eob)
          (let ((dialect ess-dialect)
                (loc-proc-name ess-local-process-name)
                (blist (cdr (buffer-list))))
            (while (and blist
                        (with-current-buffer (car blist)
                          (not (or (and
                                    (memq major-mode '(ess-mode ess-julia-mode))
                                    (equal dialect ess-dialect)
                                    (null ess-local-process-name))
                                   (and
                                    (memq major-mode '(ess-mode ess-julia-mode))
                                    (equal loc-proc-name ess-local-process-name))
                                   ))))
              (pop blist))
            (if blist
                (ess-show-buffer (car blist) t)
              (message "Found no buffers for ess-dialect %s associated with process %s"
                       dialect loc-proc-name))))))
    (ess--execute-electric-command map nil nil nil EOB)))


(defun ess-get-process-buffer (&optional name)
  "Return the buffer associated with the ESS process named by NAME."
  (process-buffer (ess-get-process (or name ess-local-process-name))))

(defun update-ess-process-name-list ()
  "Remove names with no process."
  (let (defunct)
    (dolist (conselt ess-process-name-list)
      (let ((proc (get-process (car conselt))))
        (unless (and proc (eq (process-status proc) 'run))
          (push conselt defunct))))
    (dolist (pointer defunct)
      (setq ess-process-name-list (delq pointer ess-process-name-list))))
  (if (eq (length ess-process-name-list) 0)
      (setq ess-current-process-name nil)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; ess-show-buffer
;; Something like this almost works, but problems with XEmacs and Emacs
;; differing implementations of the args to display-buffer make this
;; too tough to pursue.  The longer version below works.
;; (defun ess-show-buffer (buf)
;;   "Display the buffer BUF, a string, but do not select it.
;; Returns the window corresponding to the buffer."
;;   ;; On XEmacs, I get an error if third arg to display-buffer is t and
;;   ;; the BUF is in another frame.  Emacs does not have this problem.
;;   (if (featurep 'xemacs)
;;       (display-buffer buf nil (get-frame-for-buffer buf))
;;     (display-buffer buf nil t)))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defcustom ess-show-buffer-action
  '((display-buffer-pop-up-window display-buffer-use-some-window))
  "Actions for `ess-show-buffer', passed to `display-buffer'."
  :group 'ess
  :type 'list)
(defun ess-show-buffer (buf &optional visit)
  "Ensure the ESS buffer BUF is visible.
The buffer, specified as a string, is typically an iESS (e.g. *R*) buffer.

This handles several cases:

1. If BUF is visible in the current frame, nothing is done.
2. If BUF is visible in another frame, then we ensure that frame is
visible (it may have been iconified).
3. If buffer is not visible in any frame, simply show it in another window
in the current frame.

If VISIT is non-nil, as well as making BUF visible, we also select it
as the current buffer."
  (let ((frame))
    (if (ess-buffer-visible-this-frame buf)
        ;;1. Nothing to do, BUF visible in this frame; just return window
        ;; where this buffer is.
        t

      ;; 2. Maybe BUF visible in another frame.
      (setq frame (ess-buffer-visible-other-frame buf))
      (if frame
          ;; BUF is visible in frame, so just check frame is raised.
          (if (not (eq (frame-visible-p frame) t))
              ;; frame is not yet visible, so raise it.
              (raise-frame frame))
        ;; 3. else BUF not visible in any frame, so show it (but do
        ;; not select it) in another window in current frame.
        (display-buffer buf ess-show-buffer-action)))
    ;; At this stage, the buffer should now be visible on screen,
    ;; although it won't have been made current.
    (when visit
      ;; Need to select the buffer.
      ;;
      ;; First of all, check case 2 if buffer is in another frame
      ;; but that frame may not be selected.
      (if frame
          (ess-select-frame-set-input-focus frame))
      (select-window (get-buffer-window buf 0)))))


(defvar ess-bufs-in-frame nil)          ;silence the compiler.
;; The next few functions are copied from my (SJE) iswitchb library.
(defun ess-get-bufname (win)
  "Used by `ess-get-buffers-in-frames' to walk through all windows."
  (let ((buf (buffer-name (window-buffer win))))
    (if (not (member buf ess-bufs-in-frame))
        ;; Only add buf if it is not already in list.
        ;; This prevents same buf in two different windows being
        ;; put into the list twice.
        (setq ess-bufs-in-frame
              (cons buf ess-bufs-in-frame)))))

(defun ess-get-buffers-in-frames (&optional current)
  "Return the list of buffers that are visible in the current frame.
If optional argument CURRENT is given, restrict searching to the
current frame, rather than all frames."
  (let ((ess-bufs-in-frame nil))
    (walk-windows 'ess-get-bufname nil (if current nil 0))
    ess-bufs-in-frame))

(defun ess-buffer-visible-this-frame (buf)
  "Return t if BUF is visible in current frame."
  (member buf (ess-get-buffers-in-frames t)))

(defun ess-buffer-visible-other-frame (buf)
  "Return t if BUF is visible in another frame.
Assumes that buffer has not already been in found in current frame."
  (if (member (buffer-name (get-buffer buf)) (ess-get-buffers-in-frames))
      (window-frame (get-buffer-window buf 0))
    nil))


 ; Functions for evaluating code

;;*;; Utils for evaluation

(ess-defgeneric ess-build-eval-command (string &optional visibly output file &rest args)
  "Format an evaluation command.
Wrap STRING with `ess-quote-special-chars' and dispatch on the
dialect-specific `ess-build-eval-command' function and
`ess-eval-command', in that order. If none of the above is
defined, return nil."
  (setq string (ess-quote-special-chars string))
  (:override
   (and ess-eval-command
        (format-spec ess-eval-command
                     `((?s . ,string)
                       (?f . ,file))))))

(ess-defgeneric ess-build-load-command (file &optional visibly output &rest args)
  "Format a loading command.
Dispatches on the dialect-specific `ess-build-load-command'
and `ess-load-command', in that order."
  (:override
   (and ess-load-command
        (format ess-load-command file))))

(defun ess-wait-for-process (&optional proc sec-prompt wait force-redisplay)
  "Wait for 'busy property of the process to become nil.
If SEC-PROMPT is non-nil return if secondary prompt is detected
regardless of whether primary prompt was detected or not.  If
WAIT is non-nil wait for WAIT seconds for process output before
the prompt check, default 0.002s. When FORCE-REDISPLAY is non-nil
force redisplay. You better use WAIT >= 0.1 if you need
FORCE-REDISPLAY to avoid excesive redisplay."
  (setq proc (or proc (get-process ess-local-process-name)))
  (unless (eq (process-status proc) 'run)
    (ess-error "ESS process has died unexpectedly"))
  ;; 2ms is a good default for remotes
  (setq wait (or wait 0.002))
  (let ((start-time (float-time)))
    (save-excursion
      (while (or (accept-process-output proc wait)
                 (unless (and sec-prompt (process-get proc 'sec-prompt))
                   (process-get proc 'busy)))
        (when force-redisplay
          (redisplay 'force))
        (when (> (- (float-time) start-time) .5)
          (setq wait .5))))))

(defun inferior-ess-ordinary-filter (proc string)
  (inferior-ess-set-status proc string t)
  (ess--if-verbose-write-process-state proc string "ordinary-filter")
  (inferior-ess-run-callback proc string)
  (with-current-buffer (process-buffer proc)
    ;; (princ (format "%s:" string))
    (insert string)))

(defvar ess-presend-filter-functions nil
  "List of functions to call before sending the input string to the process.
Each function gets one argument, a string containing the text to
be send to the subprocess.  It should return the string sent,
perhaps the same string that was received, or perhaps a modified
or transformed string.

The functions on the list are called sequentially, and each one is
given the string returned by the previous one.  The string returned by
the last function is the text that is actually sent to the process.

You can use `add-hook' to add functions to this list either
globally or locally.

The hook is executed in current buffer. Before execution, the
local value of this hook in the process buffer is appended to the
hook from the current buffer.")

(defvar ess--inhibit-presend-hooks nil
  "If non-nil don't run presend hooks.")

(defun ess--run-presend-hooks (process string)
  ;; run ess-presend-filter-functions and comint-input-filter-functions
  (if ess--inhibit-presend-hooks
      string
    ;;return modified string
    (let* ((pbuf (process-buffer process))
           ;; also run proc buffer local hooks
           (functions (unless (eq pbuf (current-buffer))
                        (buffer-local-value 'ess-presend-filter-functions pbuf))))
      (setq functions (append  (delq t (copy-sequence functions)) ;; even in let, delq distructs
                               ess-presend-filter-functions))
      (while (and functions string)
        ;; cannot use run-hook-with-args here because string must be passed from one
        ;; function to another
        (if (eq (car functions) t)
            (let ((functions
                   (default-value 'ess-presend-filter-functions)))
              (while (and functions string)
                (setq string (funcall (car functions) string))
                (setq functions (cdr functions))))
          (setq string (funcall (car functions) string)))
        (setq functions (cdr functions)))

      (with-current-buffer pbuf
        (run-hook-with-args 'comint-input-filter-functions string))

      string)))

(defun ess--concat-new-line-maybe (string)
  "Append \\n at the end of STRING if missing."
  (if (string-match "\n\\'" string (max (- (length string) 2) 0))
      string
    (concat string "\n")))

(defvar ess--dbg-del-empty-p t
  "Internal variable to control removal of empty lines during the
debugging.  Let-bind it to nil before calling
`ess-send-string' or `ess-send-region' if no
removal is necessary.")

(defun inferior-ess--interrupt-subjob-maybe (proc)
  "Internal. Interrupt the process if interruptable? process variable is non-nil.
Hide all the junk output in temporary buffer."
  (when (process-get proc 'interruptable?)
    (let ((cb (cadr (process-get proc 'callbacks)))
          (buf (get-buffer-create " *ess-temp-buff*"))
          (old-filter (process-filter proc))
          (old-buff (process-buffer proc)))
      (unwind-protect
          (progn
            (ess-if-verbose-write "interrupting subjob ... start")
            (process-put proc 'interruptable? nil)
            (process-put proc 'callbacks nil)
            (process-put proc 'running-async? nil)
            ;; this is to avoid putting junk in user's buffer on process
            ;; interruption
            (set-process-buffer proc buf)
            (set-process-filter proc 'inferior-ess-ordinary-filter)
            (interrupt-process proc)
            (when cb
              (ess-if-verbose-write "executing interruption callback ... ")
              (funcall cb proc))
            ;; should be very fast as it inputs only the prompt
            (ess-wait-for-process proc)
            (ess-if-verbose-write "interrupting subjob ... finished")
            )
        (set-process-buffer proc old-buff)
        (set-process-filter proc old-filter)))))


;;*;; Evaluation primitives

(ess-defgeneric ess-send-string (process string &optional visibly message type)
  "ESS wrapper for `process-send-string'.
Run `comint-input-filter-functions' and current buffer's and
PROCESS' `ess-presend-filter-functions' hooks on the input
STRING. VISIBLY can be nil, t, 'nowait or a string.  If string
the behavior is as with 'nowait with the differences that
inserted string is VISIBLY instead of STRING (evaluated command
is still STRING).  In all other cases the behavior is as
described in `ess-eval-visibly'. STRING need not end with
\\n. TYPE is a symbol indicating type of the string."
  ;; No support of `visibly' when there's no secondary prompt
  (let ((visibly (if (and (eq visibly t)
                          (null inferior-ess-secondary-prompt))
                     'nowait
                   visibly))
        (string (ess--run-presend-hooks process string)))
    (inferior-ess--interrupt-subjob-maybe process)
    (inferior-ess-mark-as-busy process)
    (:override
     (cond
      ;; Wait after each line
      ((eq visibly t)
       (let ((ess--inhibit-presend-hooks t))
         (ess-eval-linewise string)))
      ;; Insert command and eval invisibly
      ((or (stringp visibly)
           (eq visibly 'nowait))
       (with-current-buffer (process-buffer process)
         (save-excursion
           (goto-char (process-mark process))
           (insert-before-markers
            (propertize (format "%s\n"
                                (replace-regexp-in-string
                                 "\n[ \t]" "\n+ "
                                 (if (stringp visibly) visibly string)))
                        'font-lock-face 'comint-highlight-input)))
         (process-send-string process (ess--concat-new-line-maybe string))))
      (t
       (process-send-string process (ess--concat-new-line-maybe string))))
     (when message
       (message message)))))

(ess-defgeneric ess-send-region (process start end &optional visibly message type)
  "Low level ESS version of `process-send-region'.
If VISIBLY call `ess-eval-linewise', else call
`ess-send-string'. If MESSAGE is supplied, display it at the
end. Run current buffer's and PROCESS'
`ess-presend-filter-functions' hooks. TYPE is a symbol indicating
type of the region."
  (cond
   ((ess-tracebug-p)
    (ess-tracebug-send-region proc start end visibly message type))
   (t (:override
       (ess-send-string process (buffer-substring start end) visibly message type)))))

;;*;; Evaluation commands

(defun ess-load-file--normalise-file (file)
  "Handle Tramp and system peculiarities."
  (let* ((file (if (and (fboundp 'tramp-tramp-file-p)
                        (tramp-tramp-file-p file))
                   (tramp-file-name-localname (tramp-dissect-file-name file))
                 file))
         (file (if ess-microsoft-p
                   (ess-replace-in-string file "[\\]" "/")
                 file)))
    file))

(defun ess-load-file--normalise-buffer (file)
  (when (ess-check-source file)
      (error "Buffer %s has not been saved" (buffer-name file)))
  (let ((source-buffer (get-file-buffer file)))
    (if source-buffer
        (with-current-buffer source-buffer
          (when (buffer-modified-p) (save-buffer))
          (ess-force-buffer-current "Process to load into: ")
          (ess-check-modifications))
      (ess-force-buffer-current "Process to load into: "))))

(ess-defgeneric ess-load-file (&optional filename)
  "Load a source file into an inferior ESS process.

This handles Tramp when working on a remote."
  (interactive (list (or (and (memq major-mode '(ess-mode ess-julia-mode))
                              (buffer-file-name))
                         (expand-file-name
                          (read-file-name "Load source file: " nil nil t)))))
  (ess-load-file--normalise-buffer filename)
  ;; Pop up an inferior window
  (save-selected-window
    (ess-switch-to-ESS t))
  (:override
   (let ((file (ess-load-file--normalise-file filename)))
     (let ((command (ess-build-load-command file nil t)))
       (ess-send-string (ess-get-process) command t)))))

;; C-c C-l  *used to* eval code:
(defun ess-msg-and-comint-dynamic-list-input-ring ()
 "Display a list of recent inputs entered into the current buffer."
  (interactive)
  (message "C-c C-l  no longer loads a source file in [iESS], rather use C-c M-l instead")
  (comint-dynamic-list-input-ring))

;; ;;; VS[03-09-2012]: Test Cases:
;; (ess-command "a<-0\n" nil nil nil nil (get-process "R"))
;; (ess-async-command-delayed "Sys.sleep(5);a<-a+1;cat(1:10)\n" nil
;;                            (get-process "R") (lambda (proc) (message "done")))

;; (ess-async-command-delayed "Sys.sleep(5)\n" nil (get-process "R")
;;                            (lambda (proc) (message "done")))

;; (process-get (get-process "R") 'running-async?)

(defun ess-command--normalise-proc (proc no-prompt-check)
  (let ((proc (cond
               (proc
                ;; This lets external functions call this command
                (unless ess-local-process-name
                  (setq ess-local-process-name (process-name proc)))
                proc)
               (t
                (ess-get-process ess-local-process-name)))))
    (unless no-prompt-check
      (when (process-get proc 'busy)
        (ess-error
         "ESS process not ready. Finish your command before trying again.")))
    proc))

(ess-defgeneric ess-command (cmd &optional out-buffer sleep no-prompt-check wait proc force-redisplay)
  "Send the ESS process command CMD and delete the output from
the ESS process buffer.  If an optional second argument
OUT-BUFFER exists save the output in that buffer.  OUT-BUFFER is
erased before use.  CMD should have a terminating newline.
Guarantees that the value of `.Last.value' will be preserved.

SLEEP is deprecated and no longer has any effect. WAIT and
FORCE-REDISPLAY are as in `ess-wait-for-process' and are passed
to `ess-wait-for-process'.

PROC should be a process, if nil the process name is taken from
`ess-local-process-name'.  This command doesn't set 'last-eval
process variable.

Note: for critical, or error prone code you should consider
wrapping the code into:

 local({
    olderr <- options(error=NULL)
    on.exit(options(olderr))
    ...
 })"
  (:override
   (let ((out-buffer (or out-buffer (get-buffer-create " *ess-command-output*")))
         (proc (ess-command--normalise-proc proc no-prompt-check)))
     (with-current-buffer (process-buffer proc)
       (let ((primary-prompt inferior-ess-primary-prompt)
             (oldpb (process-buffer proc))
             (oldpf (process-filter proc))
             (oldpm (marker-position (process-mark proc))))
         (ess-if-verbose-write (format "(ess-command %s ..)" cmd))
         ;; Swap the process buffer with the output buffer before
         ;; sending the command
         (unwind-protect
             (progn
               (set-process-buffer proc out-buffer)
               (set-process-filter proc 'inferior-ess-ordinary-filter)
               (with-current-buffer out-buffer
                 (setq inferior-ess-primary-prompt primary-prompt)
                 (setq buffer-read-only nil)
                 (erase-buffer)
                 (set-marker (process-mark proc) (point-min))
                 (inferior-ess-mark-as-busy proc)
                 (process-send-string proc cmd)
                 ;; Need time for ess-create-object-name-db on PC
                 (if no-prompt-check
                     (sleep-for 0.02)   ; 0.1 is noticeable!
                   (ess-wait-for-process proc nil wait force-redisplay)
                   (ess-mpi-handle-messages (current-buffer))
                   ;; Remove prompt
                   ;; If output is cat(..)ed this deletes the output
                   (goto-char (point-max))
                   (delete-region (point-at-bol) (point-max)))
                 (ess-if-verbose-write " .. ok{ess-command}")))
           (ess-if-verbose-write " .. exiting{ess-command}\n")
           ;; Restore the process buffer in its previous state
           (set-process-buffer proc oldpb)
           (set-process-filter proc oldpf)
           (set-marker (process-mark proc) oldpm))))
     out-buffer)))

(defun ess-boolean-command (com &optional buf wait)
  "Like `ess-command' but expects COM to print TRUE or FALSE.
If TRUE (or true) is found return non-nil otherwise nil.

Example: (ess-boolean-command \"2>1\n\")"
  (with-current-buffer (ess-command com buf nil nil wait)
    (goto-char (point-min))
    (let ((case-fold-search t))
      (re-search-forward "true" nil t))))

(defun ess-string-command (com &optional buf wait)
  "Returns the output of COM as a string."
  (with-current-buffer (ess-command com buf nil nil wait)
    (ess-kill-last-line)
    (buffer-substring (point-min) (point-max))))

;; (ess-async-command "{cat(1:5);Sys.sleep(5);cat(2:6)}\n" nil (get-process "R")
;;                    (lambda (proc) (message "done")))
;; (ess-async-command "{cat(1:5);Sys.sleep(5);cat(2:6)}\n" nil (get-process "R")
;;                    (lambda (proc) (message "done"))
;;                    t)
;; (ess-async-command "{cat(1:5);Sys.sleep(5);cat(2:6)}\n" nil (get-process "R")
;;                    (lambda (proc) (message "done"))
;;                    (lambda (proc2) (message "name: %s" (process-name proc2))))

(defun ess-async-command (com &optional buf proc callback interrupt-callback )
  "Asynchronous version of ess-command.
COM, BUF, WAIT and PROC are as in `ess-command'.

CALLBACK is a function of two arguments (PROC STRING) to run
after the successful execution. When INTERRUPT-CALLBACK is
non-nil, user evaluation can interrupt the
job. INTERRUPT-CALLBACK should be either t or a function of one
argument (PROC) to be called on interruption.

NOTE: Currently this function should be used only for background
jobs like caching. ESS tries to suppress any output from the
asynchronous command, but long output of COM will most likely end
up in user's main buffer.
"
  (let ((proc (or proc (get-process ess-local-process-name))))
    (if (not (and proc
                  (eq (process-status proc) 'run)))
        (error "Process %s is dead" ess-local-process-name)
      (if (or (process-get proc 'busy)
              (process-get proc 'running-async?))
          (error "Process %s is busy or already running an async command." ess-local-process-name)
        (when (eq interrupt-callback t)
          (setq interrupt-callback (lambda (proc))))
        (process-put proc 'callbacks (list (cons callback 'suppress-output)
                                           interrupt-callback))
        (process-put proc 'interruptable? (and interrupt-callback t))
        (process-put proc 'running-async? t)
        (ess-command com buf nil 'no-prompt-check .01 proc)))))

(defun ess-async-command-delayed (com &optional buf proc callback delay)
  "Delayed asynchronous ess-command.
COM and BUF are as in `ess-command'. DELAY is a number of idle
seconds to wait before starting the execution of the COM. On
interruption (by user's evaluation) ESS tries to rerun the job
after next DELAY seconds, and the whole process repeats itself
until the command manages to run completely.

DELAY defaults to `ess-idle-timer-interval' + 3 seconds

You should always provide PROC for delayed evaluation, as the
current process might change, leading to unpredictable
consequences.

This function is a wrapper of `ess-async-command' with an
explicit interrupt-callback."
  (unless proc
    (error "You must provide PROC argument to ess-async-command-delayed"))
  (let* ((timer (make-symbol "timer"))
         (delay (or delay
                    (+ ess-idle-timer-interval 3)))
         (int-cb  `(lambda (proc)
                     (ess-async-command-delayed ,com ,buf proc ,callback ,delay)))
         (com-fun `(lambda ()
                     (when (eq (process-status ,proc)  'run) ; do nothing if not running
                       (if (or (process-get ,proc 'busy) ; if busy, try later
                               (process-get ,proc 'running-async?))
                           ;; idle timer doesn't work here
                           (run-with-timer ,delay nil 'ess-async-command-delayed
                                           ,com ,buf ,proc ,callback ,delay))
                         (ess-async-command ,com ,buf ,proc ,callback ',int-cb)))))
    (run-with-idle-timer delay nil com-fun)))


;;*;;  Evaluating lines, paragraphs, regions, and buffers.

(ess-defgeneric ess-eval-linewise
  (text &optional invisibly eob even-empty wait-last-prompt sleep-sec wait-sec)
  "Evaluate TEXT in the ESS process buffer as if typed in w/o tabs.
Waits for prompt after each line of input, so won't break on large texts.

If optional second arg INVISIBLY is non-nil, don't echo commands.
If it is a string, just include that string. If optional third
arg EOB is non-nil go to end of ESS process buffer after
evaluation.  If optional 4th arg EVEN-EMPTY is non-nil, also send
empty text (e.g. an empty line).  If 5th arg WAIT-LAST-PROMPT is
non-nil, also wait for the prompt after the last line; if 6th arg
SLEEP-SEC is a number, ESS will call '(\\[sleep-for] SLEEP-SEC)
at the end of this function.  If the 7th arg WAIT-SEC is set, it
will be used instead of the default .001s and be passed to
\\[ess-wait-for-process].

Run `comint-input-filter-functions' and
`ess-presend-filter-functions' of the associated PROCESS on the
TEXT."
  (unless (numberp wait-sec)
    (setq wait-sec 0.001))

  (ess-force-buffer-current "Process to use: ")

  (:override
   ;; Use this to evaluate some code, but don't wait for output.
   (let* ((deactivate-mark)           ; keep local {do *not* deactivate wrongly}
          (cbuffer (current-buffer))
          (sprocess (ess-get-process ess-current-process-name))
          (sbuffer (process-buffer sprocess))
          (win (get-buffer-window sbuffer t)))

     (setq text (ess--concat-new-line-maybe
                 (ess--run-presend-hooks sprocess text)))

     (with-current-buffer sbuffer
       (setq text (propertize text 'field 'input 'front-sticky t))

       (goto-char (marker-position (process-mark sprocess)))
       (if (stringp invisibly)
           (insert-before-markers (concat "*** " invisibly " ***\n")))
       ;; dbg:
       ;; dbg (ess-write-to-dribble-buffer
       ;; dbg  (format "(eval-visibly 2): text[%d]= '%s'\n" (length text) text))
       (while (or (> (length text) 0) even-empty)
         (setq even-empty nil)
         (let* ((pos (string-match "\n\\|$" text))
                (input (if (= (length text) 0)
                           "\n"
                         (concat (substring text 0 pos) "\n"))))
           (setq text (substring text (min (length text) (1+ pos))))
           (goto-char (marker-position (process-mark sprocess)))
           (if win (set-window-point win (process-mark sprocess)))
           (unless invisibly
             ;; for consistency with comint :(
             (insert (propertize input 'font-lock-face 'comint-highlight-input))
             (set-marker (process-mark sprocess) (point)))
           (inferior-ess-mark-as-busy sprocess)
           (process-send-string sprocess input))
         (when (or (> (length text) 0)
                   wait-last-prompt)
           (ess-wait-for-process sprocess t wait-sec)))
       (if eob (ess-show-buffer (buffer-name sbuffer) nil))
       (goto-char (marker-position (process-mark sprocess)))
       (when win
         (with-selected-window win
           (goto-char (point))
           ;; this is crucial to avoid reseting window-point
           (recenter (- -1 scroll-margin)))))))
  (if (numberp sleep-sec)
      (sleep-for sleep-sec)))


;;;*;;; Evaluate only

(defun ess-eval-region--normalise-region ()
  "Clean the region for evaluation.

This trims newlines at beginning and end of the region because
they might throw off the debugger."
  (save-excursion
    (goto-char start)
    (skip-chars-forward "\n\t ")
    (setq start (point))

    (unless mark-active
      (ess-blink-region start end))

    (goto-char end)
    (skip-chars-backward "\n\t ")
    (setq end (point))))

(defun ess-eval-region (start end toggle &optional message type)
  "Send the current region to the inferior ESS process.
With prefix argument toggle the meaning of `ess-eval-visibly';
this does not apply when using the S-plus GUI, see
`ess-dde-send-region'. TYPE is a symbol indicating what type of
region this is."
  (interactive "r\nP")

  (ess-force-buffer-current "Process to use: ")
  (message "Starting evaluation...")

  (unless ess-local-customize-alist
    ;; External applications might call ess-eval-* functions; make it
    ;; easier for them
    (ess-setq-vars-local (symbol-value (ess-get-process-variable 'ess-local-customize-alist))))

  (ess-eval-region--normalise-region)

  (let ((visibly (if toggle (not ess-eval-visibly) ess-eval-visibly))
        (message (or message "Eval region"))
        (proc (ess-get-process)))
    (save-excursion
      (ess-send-region proc start end visibly message type)))

  (when ess-eval-deactivate-mark
    (ess-deactivate-mark))

  (list start end))

(defun ess-eval-buffer (vis)
  "Send the current buffer to the inferior ESS process.
VIS has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-region (point-min) (point-max) vis "Eval buffer" 'buffer))

(defun ess-eval-buffer-from-beg-to-here (vis)
  "Send region from beginning to point to the inferior ESS process.
VIS has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-region (point-min) (point) vis "Eval buffer till point"))

(defun ess-eval-buffer-from-here-to-end (vis)
  "Send region from point to end of buffer to the inferior ESS process.
VIS has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-region (point) (point-max) vis "Eval buffer till end"))


(defun ess-eval-function (vis &optional no-error)
  "Send the current function to the inferior ESS process.
Prefix argument VIS toggles the meaning of `ess-eval-visibly'.

If NO-ERROR is non-nil and the function was successfully
evaluated, return '(beg end) representing the beginning and end
of the current function, otherwise (in case of an error) return
nil."
  (interactive "P")
  (ess-force-buffer-current "Process to use: ")
  (save-excursion
    (ignore-errors
      ;; Evaluation is forward oriented
      (forward-line -1)
      (ess-next-code-line 1))
    (let ((beg-end (ess-end-of-function nil no-error)))
      (when beg-end
        (let* ((beg (nth 0 beg-end))
               (end (nth 1 beg-end))
               (proc (get-process ess-local-process-name))
               ;; FIXME: func names starting with . are not recognized??
               (name (progn (goto-char beg)
                            (forward-word)
                            (ess-read-object-name-default)))
               (msg (format "Eval function %s"
                            (propertize (or name "???")
                                        'face 'font-lock-function-name-face)))
               (visibly (if vis (not ess-eval-visibly) ess-eval-visibly)))
          (ess-blink-region beg end)
          (cond
           ((ess-tracebug-p)
            (ess-tracebug-send-function proc beg end visibly msg))
           (t
            (ess-send-region proc beg end visibly msg)))
          beg-end)))))


;; This is from  Mary Lindstrom <lindstro@Biostat.Wisc.Edu>
;; 31 Aug 1995 14:11:43         To: S-mode@stat.math.ethz.ch
(defun ess-eval-paragraph (vis)
  "Send the current paragraph to the inferior ESS process.
Prefix arg VIS toggles visibility of ess-code as for `ess-eval-region'."
  (interactive "P")
  (save-excursion
    (forward-paragraph)
    ;; Skip blank code to avoid sending surrounding comments
    (ess-skip-blanks-backward 'multiline)
    (let ((end (point)))
      (backward-paragraph)
      (ess-skip-blanks-forward 'multiline)
      (ess-eval-region (point) end vis "Eval paragraph"))))

;; ;; Experimental - after suggestion from Jenny Brian for an 'eval-multiline'
;; ;; 'sentence' is too much : almost like 'paragraph'
;; ;; 'sexp'     is close, but too little [when point is inside function call;
;; ;;         it moves all the way to the end - which is fine]
;; (defun ess-eval-sexp (vis)
;;   "Send the current sexp to the inferior ESS process.
;; Prefix arg VIS toggles visibility of ess-code as for `ess-eval-region'."
;;   (interactive "P")
;;   (save-excursion
;;     (forward-sexp)
;;     (let ((end (point)))
;;       (backward-sexp)
;;       (ess-eval-region (point) end vis "Eval sexp"))))

(defun ess-eval-function-or-paragraph (vis)
  "Send the current function if \\[point] is inside one, otherwise the current
paragraph other to the inferior ESS process.
Prefix arg VIS toggles visibility of ess-code as for `ess-eval-region'."
  (interactive "P")
  (let ((beg-end (ess-eval-function vis 'no-error)))
    (if (null beg-end) ; not a function
        (ess-eval-paragraph vis))))

(defun ess-eval-function-or-paragraph-and-step (vis)
  "Send the current function if \\[point] is inside one, otherwise the current
paragraph other to the inferior ESS process.
Prefix arg VIS toggles visibility of ess-code as for `ess-eval-region'."
  (interactive "P")
  (let ((beg-end (ignore-errors (ess-eval-function vis 'no-error)))) ;; ignore-errors is a hack, ess-eval-function gives stupid errors sometimes
    (if (null beg-end) ; not a function
        (ess-eval-paragraph-and-step vis)
      (goto-char (cadr beg-end))
      (if ess-eval-empty
          (forward-line 1)
        (ess-next-code-line 1)))))

(defun ess-eval-region-or-function-or-paragraph (vis)
  "Send the current region if mark is active, if not, send
function if \\[point] is inside one, otherwise the current
paragraph.

 Prefix arg VIS toggles visibility of ess-code as for
`ess-eval-region'."
  (interactive "P")
  (if (use-region-p)
      (ess-eval-region (region-beginning) (region-end) vis)
    (ess-eval-function-or-paragraph vis)))

(defun ess-eval-region-or-function-or-paragraph-and-step (vis)
  "Send the current region if mark is active, if not, send
function if \\[point] is inside one, otherwise the current
paragraph. After evaluation step to the next code line or to the
end of region if region was active.

 Prefix arg VIS toggles visibility of ess-code as for
`ess-eval-region'."
  (interactive "P")
  (if (use-region-p)
      (let ((end (region-end)))
        (ess-eval-region (region-beginning) end vis)
        (goto-char end))
    (ess-eval-function-or-paragraph-and-step vis)))

(defun ess-eval-line (&optional vis)
  "Send the current line to the inferior ESS process.
Arg has same meaning as for `ess-eval-region'."
  (interactive "P")
  (save-excursion
    (end-of-line)
    (let ((end (point)))
      (beginning-of-line)
      (princ (concat "Loading line: " (ess-extract-word-name) " ...") t)
      (ess-eval-region (point) end vis "Eval line"))))

(defun ess-next-code-line (&optional arg skip-to-eob)
  "Move ARG lines of code forward (backward if ARG is negative).
Skips past all empty and comment lines.  Default for ARG is 1.
Don't skip the last empty and comment lines in the buffer unless
SKIP-TO-EOB is non-nil.

On success, return 0.  Otherwise, go as far as possible and return -1."
  (interactive "p")
  (or arg (setq arg 1))
  (beginning-of-line)
  (let ((pos (point))
        (n 0)
        (inc (if (> arg 0) 1 -1)))
    (while (and (/= arg 0) (= n 0))
      (setq n (forward-line inc)); n=0 is success
      (if (not (fboundp 'comment-beginning))
          (while (and (= n 0)
                      (looking-at "\\s-*\\($\\|\\s<\\)"))
            (setq n (forward-line inc)))
        (comment-beginning)
        (beginning-of-line)
        (forward-comment (* inc (buffer-size))) ;; as suggested in info file
        )
      (if (or skip-to-eob
              (not (looking-at ess-no-skip-regexp))) ;; don't go to eob or whatever
          (setq arg (- arg inc))
        (goto-char pos)
        (setq arg 0)
        (forward-line 1));; stop at next empty line
      (setq pos (point)))
    (goto-char pos)
    n))

(defun ess-eval-line-and-step (&optional simple-next even-empty invisibly)
  "Evaluate the current line visibly and step to the \"next\" line.
If SIMPLE-NEXT is non-nil, possibly via prefix arg, first skip
empty and commented lines. If 2nd arg EVEN-EMPTY [prefix as
well], also send empty lines.  When the variable `ess-eval-empty'
is non-nil both SIMPLE-NEXT and EVEN-EMPTY are interpreted as
true."
  ;; From an idea by Rod Ball (rod@marcam.dsir.govt.nz)
  (interactive "P\nP"); prefix sets BOTH !
  (ess-force-buffer-current "Process to load into: ")
  (save-excursion
    (end-of-line)
    (let ((end (point)))
      (beginning-of-line)
      ;; go to end of process buffer so user can see result
      (ess-eval-linewise (buffer-substring (point) end)
                         invisibly 'eob (or even-empty ess-eval-empty))))
  (if (or simple-next ess-eval-empty even-empty)
      (forward-line 1)
    (ess-next-code-line 1)))

(defun ess-eval-region-or-line-and-step (&optional vis)
  "Evaluate region if there is an active one, otherwise the current line.

 Prefix arg VIS toggles visibility of ess-code when evaluating
 the region (as for `ess-eval-region') and has no effect for
 evaluation of the line.
"
  (interactive "P")
  (if (use-region-p)
      (ess-eval-region (region-beginning) (region-end) vis)
    (ess-eval-line-and-step)))

(defun ess-eval-line-and-step-invisibly ()
  "Evaluate the current line invisibly and step to the next line.
Evaluate all comments and empty lines."
  (interactive)
  (ess-eval-line-and-step t t t))

;; goes to the real front, in case you do double function definition
;; 29-Jul-92 -FER
;; don't know why David changed it.

;; FER's versions don't work properly with nested functions. Replaced
;; mine. DMS 16 Nov 92


;;;*;;; Evaluate and switch to S

(defun ess-eval-region-and-go (start end vis)
  "Send the current region to the inferior S and switch to the process buffer.
Arg has same meaning as for `ess-eval-region'."
  (interactive "r\nP")
  (ess-eval-region start end vis)
  (ess-switch-to-ESS t))

(defun ess-eval-buffer-and-go (vis)
  "Send the current buffer to the inferior S and switch to the process buffer.
Arg has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-buffer vis)
  (ess-switch-to-ESS t))

(defun ess-eval-function-and-go (vis)
  "Send the current function to the inferior ESS process and switch to
the process buffer. Arg has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-function vis)
  (ess-switch-to-ESS t))

(defun ess-eval-line-and-go (vis)
  "Send the current line to the inferior ESS process and switch to the
process buffer. Arg has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-line vis)
  (ess-switch-to-ESS t))

(defun ess-eval-paragraph-and-go (vis)
  "Send the current paragraph to the inferior ESS process and switch to the
process buffer. Arg has same meaning as for `ess-eval-region'."
  (interactive "P")
  (ess-eval-paragraph vis)
  (ess-switch-to-ESS t))

(defun ess-eval-paragraph-and-step (vis)
  "Send the current paragraph to the inferior ESS process and
move forward to the first line after the paragraph.  If not
inside a paragraph, evaluate next one. Arg has same meaning as
for `ess-eval-region'."
  (interactive "P")
  (let ((beg-end (ess-eval-paragraph vis)))
    (goto-char (cadr beg-end))
    (if ess-eval-empty
        (forward-line 1)
      (ess-next-code-line 1))))

 ; Inferior S mode
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; In this section:
;;;;
;;;; * The major mode inferior-ess-mode
;;;; * Process handling code
;;;; * Completion code
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;*;; Major mode definition

(defvar inferior-ess-mode-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map comint-mode-map)

    (define-key map "\C-y"              'ess-yank)
    ;; Use syntax valid *both* for GNU emacs and XEmacs :
    (define-key map "\r"       'inferior-ess-send-input)
    (define-key map "\C-a"     'comint-bol)

    ;; 2010-06-03 SJE
    ;; disabled this in favour of ess-dirs.  Martin was not sure why this
    ;; key was defined anyway in this mode.
    ;;(define-key map "\M-\r"    'ess-transcript-send-command-and-move)
    (define-key map "\C-c\M-l" 'ess-load-file);; no longer overwrites C-c C-l;
    ;; but for now the user deserves a message:
    (define-key map "\C-c\C-l" 'ess-msg-and-comint-dynamic-list-input-ring)
    (define-key map "\C-c`"      'ess-show-traceback)
    (define-key map [(control ?c) ?~] 'ess-show-call-stack)
    (define-key map "\C-c\C-d" 'ess-dump-object-into-edit-buffer)
    (define-key map "\C-c\C-v" 'ess-display-help-on-object)
    (define-key map "\C-c\C-q" 'ess-quit)
    (define-key map "\C-c\C-s" 'ess-execute-search)
    (define-key map "\C-c\C-x" 'ess-execute-objects)
    (define-key map "\C-c\034" 'ess-abort) ; \C-c\C-backslash
    (define-key map "\C-c\C-z" 'ess-switch-to-inferior-or-script-buffer) ; mask comint map
    (define-key map "\C-d"     'delete-char)   ; EOF no good in S
    (if (>= emacs-major-version 24)
        (define-key map "\t"       'completion-at-point)
      (define-key map "\t"       'comint-dynamic-complete)
      (define-key map "\M-\t"    'comint-dynamic-complete))
    (define-key map "\C-c\t"   'ess-complete-object-name-deprecated)
    (define-key map "\M-?"     'ess-list-object-completions)
    (define-key map "\C-c\C-k" 'ess-request-a-process)
    (define-key map ","        'ess-smart-comma)

    (define-key map "\C-c\C-d"   'ess-doc-map)
    (define-key map "\C-c\C-e"   'ess-extra-map)
    (define-key map "\C-c\C-t"   'ess-dev-map)
    map)
  "Keymap for `inferior-ess' mode.")

(easy-menu-define
  inferior-ess-mode-menu inferior-ess-mode-map
  "Menu for use in Inferior S mode"
  '("iESS"
    ["What is this? (beta)"   ess-mouse-me                  t]
    ["Quit"                 ess-quit                        t]
    ;; ["Send and move"  ess-transcript-send-command-and-move  t]
    ["Copy command"   comint-copy-old-input                 t]
    ["Send command"   inferior-ess-send-input               t]
    ["Switch to Script Buffer" ess-switch-to-inferior-or-script-buffer t]
    ["Get help on S object"   ess-display-help-on-object    t]
    "------"
    ("Process"
     ["Process Echoes" (lambda () (interactive)
                         (setq comint-process-echoes (not comint-process-echoes)))
      :active t
      :style toggle
      :selected comint-process-echoes]
     ("Eval visibly "
      :filter ess--generate-eval-visibly-submenu ))
    "------"
    ("Utils"
     ;; need a toggle switch for above, AJR.
     ["Attach directory"        ess-execute-attach      t]
     ["Display object list"     ess-execute-objects	t]
     ["Display search list"     ess-execute-search	t]
     ["Edit S Object"	ess-dump-object-into-edit-buffer t]
     ["Enter S command"         ess-execute             t]
     ["Jump to Error"           ess-parse-errors        t]
     ["Load source file"  	ess-load-file           t]
     ["Resynch S completions"	ess-resynch		t]
     ["Recreate R and S versions known to ESS" (ess-r-s-versions-creation+menu) t]
     )
    "------"
    ("start-dev" :visible nil); <-- ??
    ("end-dev" :visible nil)
    "------"
    ("Font Lock"
     :active inferior-ess-font-lock-keywords
     :filter ess--generate-font-lock-submenu)
    "------"
    ["Describe"         describe-mode                       t]
    ["Send bug report"  ess-submit-bug-report               t]
    ["About"            (ess-goto-info "Entering Commands") t]
    ))


(defvar ess-mode-minibuffer-map
  (let ((map (make-sparse-keymap)))
    (set-keymap-parent map minibuffer-local-map)

    (define-key map "\t" 'ess-complete-object-name)
    (define-key map "\C-\M-i" 'ess-complete-object-name) ;; doesn't work:(
    (define-key map "\C-c\C-s" 'ess-execute-search)
    (define-key map "\C-c\C-x" 'ess-execute-objects)
    map)
  "Keymap used in `ess-execute'")

(defun inferior-ess-mode ()
  "Major mode for interacting with an inferior ESS process.
Runs an S interactive job as a subprocess of Emacs, with I/O through an
Emacs buffer.  Variable `inferior-ess-program' controls which S
is run.

Commands are sent to the ESS process by typing them, and pressing
\\[inferior-ess-send-input].  Pressing \\[complete-dynamic-complete]
completes known object names or filenames, as appropriate.  Other
keybindings for this mode are:

\\{inferior-ess-mode-map}

When editing S objects, the use of \\[ess-load-file] is advocated.
`ess-load-file' keeps source files (if `ess-keep-dump-files' is non-nil) in
the directory specified by `ess-source-directory', with the
filename chosen according to `ess-dump-filename-template'. When a file is
loaded, `ess-mode' parses error messages and jumps to the appropriate file
if errors occur. The ess-eval- commands do not do this.

Customization: Entry to this mode runs the hooks on `comint-mode-hook' and
`inferior-ess-mode-hook' (in that order).

You can send text to the inferior ESS process from other buffers containing
S source. The key bindings of these commands can be found by typing
C-h m (help for mode) in the other buffers.
    `ess-eval-region' sends the current region to the ESS process.
    `ess-eval-buffer' sends the current buffer to the ESS process.
    `ess-eval-function' sends the current function to the ESS process.
    `ess-eval-line' sends the current line to the ESS process.
    `ess-beginning-of-function' and `ess-end-of-function' move the point to
        the beginning and end of the current S function.
    `ess-switch-to-ESS' switches the current buffer to the ESS process buffer.
    `ess-switch-to-end-of-ESS' switches the current buffer to the ESS process
        buffer and puts point at the end of it.

    `ess-eval-region-and-go', `ess-eval-buffer-and-go',
        `ess-eval-function-and-go', and `ess-eval-line-and-go' switch to the S
        process buffer after sending their text.
    `ess-dump-object-into-edit-buffer' moves an S object into a temporary file
        and buffer for editing
    `ess-load-file' sources a file of commands to the ESS process.

Commands:
Return after the end of the process' output sends the text from the
    end of process to point.
Return before the end of the process' output copies the sexp ending at point
    to the end of the process' output, and sends it.
Delete converts tabs to spaces as it moves back.
C-M-q does Tab on each line starting within following expression.
Paragraphs are separated only by blank lines.  Crosshatches start comments.
If you accidentally suspend your process, use \\[comint-continue-subjob]
to continue it."
  (interactive)
  (delay-mode-hooks
    (comint-mode))
  (set (make-local-variable 'comint-input-sender) 'inferior-ess-input-sender)
  (set (make-local-variable 'process-connection-type) t)
  ;; initialize all custom vars:
  (ess-setq-vars-local ess-customize-alist) ; (current-buffer))

  ;; If comint-process-echoes is t  inferior-ess-input-sender
  ;; recopies the input, otherwise not. VS[03-09-2012]: should be in customize-alist
  (set (make-local-variable 'comint-process-echoes)
       (not (member ess-language '("SAS" "XLS" "OMG" "julia")))) ;; these don't echo

  (when (and (member ess-dialect '("R")) ;; S+ echoes!!
             (not (eq ess-eval-visibly t)))
    ;; when 'nowait or nil, don't wait for process
    (setq comint-process-echoes nil))

  (when comint-use-prompt-regexp ;; why comint is not setting this? bug?
    (set (make-local-variable 'inhibit-field-text-motion) t))

  (unless inferior-ess-prompt ;; build when unset
    (setq inferior-ess-prompt
          (concat "\\("
                  inferior-ess-primary-prompt
                  (when inferior-ess-secondary-prompt "\\|")
                  inferior-ess-secondary-prompt
                  "\\)")))
  (setq comint-prompt-regexp (concat "^" inferior-ess-prompt))
  (setq comint-get-old-input 'inferior-ess-get-old-input) ;; todo: this is R specific
  (add-hook 'comint-input-filter-functions 'ess-search-path-tracker nil 'local) ;; R and S specific

  (setq major-mode 'inferior-ess-mode)
  (setq mode-name "iESS")               ;(concat "iESS:" ess-dialect))
  (setq mode-line-process
        '(" ["
          ess--mode-line-process-indicator
          ess--local-mode-line-process-indicator
          "]: %s"))
  (use-local-map inferior-ess-mode-map)
  (let ((inf-syntax-table (or inferior-ess-mode-syntax-table
                              ess-mode-syntax-table)))
    (when inf-syntax-table
      (set-syntax-table inf-syntax-table)))

  (ess-write-to-dribble-buffer
   (format "(i-ess 1): buf=%s, lang=%s, comint..echo=%s, comint..sender=%s,\n"
           (current-buffer) ess-language
           comint-process-echoes comint-input-sender))

  (when (string= ess-language "S") ;; todo: what is this doing here?
    (local-set-key "\M-\r"    'ess-dirs))

  ;; Font-lock support
  ;; AJR: This (the following local-var is already the case!
  ;; KH sez: only in XEmacs :-(.  (& Emacs 22.1, SJE).
  (when inferior-ess-font-lock-keywords ;; new system
    (setq inferior-ess-font-lock-defaults
          (ess--extract-default-fl-keywords inferior-ess-font-lock-keywords)))

  (set (make-local-variable 'font-lock-defaults)
       '(inferior-ess-font-lock-defaults nil nil ((?\. . "w") (?\_ . "w") (?' . "."))))

  ;; SJE 2007-06-28: Emacs 22.1 has a bug in that comint-mode will set
  ;; this variable to t, when we need it to be nil.  The Emacs 22
  ;; solution to this bug is to use define-derived-mode to derive
  ;; inferior-ess-mode from comint-mode.  Not sure if we can go down
  ;; that route yet.  I've used the when condition so that if the var
  ;; is nil, don't bother setting it -- as setting it will make a new
  ;; local var.
  (when font-lock-keywords-only
    (setq font-lock-keywords-only nil))

  ;;; Completion support ----------------

  ;; SJE: comint-dynamic-complete-functions is regarded as a hook, rather
  ;; than a regular variable.  Note order of completion (thanks David Brahm):

  (if (and (featurep 'emacs ) (>= emacs-major-version 24))
      (progn
        (remove-hook 'completion-at-point-functions 'comint-completion-at-point t) ;; reset the thook
        (add-hook 'completion-at-point-functions 'comint-c-a-p-replace-by-expanded-history nil 'local)
        (add-hook 'completion-at-point-functions 'ess-filename-completion nil 'local))
    (add-hook 'comint-dynamic-complete-functions
              'ess-complete-filename 'append 'local)
    (add-hook 'comint-dynamic-complete-functions ;; only for R, is it ok?
              'ess-complete-object-name 'append 'local)
    (add-hook 'comint-dynamic-complete-functions
              'comint-replace-by-expanded-history 'append 'local)

    ;; When a hook is buffer-local, the dummy function `t' is added to
    ;; indicate that the functions in the global value of the hook
    ;; should also be run.  SJE: I have removed this, as I think it
    ;; interferes with our normal completion.
    (remove-hook 'comint-dynamic-complete-functions 't 'local))

  ;; (setq comint-completion-addsuffix nil) ; To avoid spaces after filenames
  ;; KH: next 2 lines solve.
  (set (make-local-variable 'comint-completion-addsuffix)
       (cons "/" ""))

  (setq comint-input-autoexpand t) ; Only for completion, not on input.

  ;; timers
  ;; (add-hook 'ess-idle-timer-functions 'ess-cache-search-list nil 'local)
  ;; (add-hook 'ess-idle-timer-functions 'ess-synchronize-dirs nil 'local)

  ;;; Keep <tabs> out of the code.
  (set (make-local-variable 'indent-tabs-mode) nil)

  (set (make-local-variable 'paragraph-start)
       (concat inferior-ess-primary-prompt "\\|\^L"))
  (set (make-local-variable 'paragraph-separate) "\^L")
  (if (featurep 'jit-lock)
      (setq-local jit-lock-chunk-size inferior-ess-jit-lock-chunk-size))
  (make-local-variable 'kill-buffer-hook)
  (add-hook 'kill-buffer-hook 'ess-kill-buffer-function)
  (run-mode-hooks 'inferior-ess-mode-hook)
  (ess-write-to-dribble-buffer
   (format "(i-ess end): buf=%s, lang=%s, comint..echo=%s, comint..sender=%s,\n"
           (current-buffer) ess-language
           comint-process-echoes comint-input-sender))
  (message
   (concat (substitute-command-keys
            "Type \\[describe-mode] for help on ESS version ")
           ess-version)))

;;*;; Commands used exclusively in inferior-ess-mode

;;;*;;; Main user commands

(defun inferior-ess-input-sender (proc string)
  (inferior-ess--interrupt-subjob-maybe proc)
  (let ((comint-input-filter-functions nil)) ; comint runs them, don't run twise.
    (if comint-process-echoes
        (ess-eval-linewise string nil nil ess-eval-empty)
      (ess-send-string proc string))))

(defvar ess-help-arg-regexp "\\(['\"]?\\)\\([^,=)'\"]*\\)\\1"
  "Reg(ular) Ex(pression) of help(.) arguments.  MUST: 2nd \\(.\\) = arg.")

(defun inferior-ess-send-input ()
  "Sends the command on the current line to the ESS process."
  (interactive)
  (run-hooks 'ess-send-input-hook)
  ;; (let ((proc (get-buffer-process (current-buffer))))
  ;;   (if (not proc)
  ;;       (user-error "Current buffer has no process")
  ;;     (let ((comint-process-echoes (or comint-process-echoes
  ;;                                      (< (point) (marker-position (process-mark proc))))))
  ;;       (comint-send-input))))
  (comint-send-input)
  (setq ess-object-list nil)) ;; Will be reconstructed from cache if needs be

(defun inferior-ess--goto-input-start:field ()
  "Move point to the begining of input skiping all continuation lines.
If in the output field, goes to the begining of previous input
field.
Note: inferior-ess-secondary-prompt should match exactly.
"
  (goto-char (field-beginning))
  ;; move to the begining of non-output field
  (while (and (not (= (point) (point-min)))
              (eq (field-at-pos (point)) 'output))
    (goto-char (field-beginning nil t)))
  ;; skip all secondary prompts
  (let ((pos (field-beginning (point) t))
        (secondary-prompt (concat "^" inferior-ess-secondary-prompt)))
    (while (and pos
                (if (eq (get-text-property pos 'field) 'output)
                    (string-match secondary-prompt (field-string-no-properties pos))
                  t))
      (goto-char pos)
      (setq pos (previous-single-property-change pos 'field)))))

(defun inferior-ess--goto-input-end:field ()
  "Move point to the end of input skiping all continuation lines.
If in the output field,  goes to the begining of previous input field.

NOTE: to be used only with fields, see `comint-use-prompt-regexp'.
" ;; this func is not used but might be useful some day
  (goto-char (field-end))
  (let ((pos (point))
        (secondary-prompt (concat "^" inferior-ess-secondary-prompt)))
    (while (and pos
                (if (eq (get-text-property pos 'field) 'output)
                    (string-match secondary-prompt (field-string-no-properties pos))
                  t))
      (goto-char pos)
      (setq pos (next-single-property-change pos 'field)))))

(defun inferior-ess--get-old-input:field ()
  "Return the ESS command surrounding point (use with fields)."
  (save-excursion
    (if (eq (field-at-pos (point)) 'output)
        (if (called-interactively-p 'any)
            (error "No command on this line")
          ;; else, just return ""
          "")
      (inferior-ess--goto-input-start:field)
      (let ((command (field-string-no-properties (point)))
            (pos (next-single-property-change (point) 'field ))
            (secondary-prompt (concat "^" inferior-ess-secondary-prompt)))
        (while (and pos
                    (cond
                     ((eq (get-text-property pos 'field) 'input)
                      (setq command (concat command "\n" (field-string-no-properties pos))))
                     ((eq (get-text-property pos 'field) 'output)
                      (string-match secondary-prompt (field-string-no-properties pos)))
                     (t)));; just skip if unknown
          (setq pos (next-single-property-change pos 'field)))
        command))))

;; todo: error when entering a multiline function
;; check.integer <- function(N){
;;      is.integer(N) | !length(grep("[^[:digit:]]", as.character(N)))
;; }
(defun inferior-ess--goto-input-start:regexp ()
  "Move point to the begining of input skiping all continuation lines.
If in the output field, goes to the begining of previous input.
"
  (beginning-of-line)
  (unless (looking-at inferior-ess-prompt)
    (re-search-backward (concat "^" inferior-ess-prompt)))
  ;; at bol
  (when (and inferior-ess-secondary-prompt
             (looking-at inferior-ess-secondary-prompt))
    (while (and (> (forward-line -1) -1)
                (looking-at inferior-ess-secondary-prompt))))
  (unless (looking-at inferior-ess-prompt)
    (ess-error "Beggining of input not found"))
  (comint-skip-prompt))

(defun inferior-ess--get-old-input:regexp ()
  "Return the ESS command surrounding point (use regexp)."
  ;;VS[03-09-2012]: This should not rise errors!! Troubles comint-interrupt-subjob
  (save-excursion
    (let* ((inhibit-field-text-motion t)
           command)
      (beginning-of-line)
      (when  (and inferior-ess-secondary-prompt
                  (looking-at inferior-ess-secondary-prompt))
        (inferior-ess--goto-input-start:regexp))
      (beginning-of-line)
      (if (looking-at inferior-ess-prompt) ; cust.var, might not include sec-prompt
          (progn
            (comint-skip-prompt)
            (setq command (buffer-substring-no-properties (point) (point-at-eol)))
            (when inferior-ess-secondary-prompt
              (while (progn (forward-line 1)
                            (looking-at inferior-ess-secondary-prompt))
                (re-search-forward inferior-ess-secondary-prompt (point-at-eol))
                (setq command (concat command "\n"
                                      (buffer-substring-no-properties (point) (point-at-eol))))
                ))
            (forward-line -1)
            (setq ess-temp-point (point)) ;; this is ugly, used by transcript
            command)
        (message "No command at this point")
        ""))))

(defun inferior-ess-get-old-input ()
  "Return the ESS command surrounding point."
  (if comint-use-prompt-regexp
      (inferior-ess--get-old-input:regexp)
    (inferior-ess--get-old-input:field)))

;;;*;;; Hot key commands

(defun ess-execute-objects (posn)
  "Send the objects() command to the ESS process.
By default, gives the objects at position 1.
A prefix argument toggles the meaning of `ess-execute-in-process-buffer'.
A prefix argument of 2 or more means get objects for that position.
A negative prefix argument gets the objects for that position
  and toggles `ess-execute-in-process-buffer' as well."
  (interactive "P")
  (ess-make-buffer-current)
  (let* ((num-arg (if (listp posn)
                      (if posn -1 1)
                    (prefix-numeric-value posn)))
         (the-posn (if (< num-arg 0) (- num-arg) num-arg))
         (invert (< num-arg 0))
         (the-command (format inferior-ess-objects-command the-posn ".*"))
         (the-message (concat ">>> Position "
                              (number-to-string the-posn)
                              " ("
                              (nth (1- the-posn) (ess-search-list))
                              ")\n")))
    (ess-execute the-command invert "S objects" the-message)))

(defun ess-execute-search (invert)
  "Send the `inferior-ess-search-list-command' command to the `ess-language' process.
 [search(..) in S]"
  (interactive "P")
  (ess-execute inferior-ess-search-list-command  invert "S search list"))

;; FIXME --- this *only* works in S / S-plus; not in R
;; -----     ("at least" is not assigned to any key by default)
(defun ess-execute-attach (dir &optional posn)
  "Attach a directory in the `ess-language' process with the attach() command.
When used interactively, user is prompted for DIR to attach and
prefix argument is used for POSN (or 2, if absent.)
Doesn't work for data frames."
  (interactive "Attach directory: \nP")
  (ess-execute (concat "attach(\""
                       (directory-file-name (expand-file-name dir))
                       "\""
                       (if posn (concat "," (number-to-string
                                             (prefix-numeric-value posn))))
                       ")") 'buffer)
  (ess-process-put 'sp-for-help-changed? t))

(defun ess-execute-screen-options (&optional invisibly)
  "Cause S to set the \"width\" option to 1 less than the window width.
Also sets the \"length\" option to 99999. When INVISIBLY is
non-nil, don't echo to R subprocess.

This is a good thing to put in `ess-r-post-run-hook' or
`ess-S+-post-run-hook'."
  (interactive)
  (if (null ess-execute-screen-options-command)
      (message "Not implemented for '%s'" ess-dialect)
    ;; We cannot use (window-width) here because it returns sizes in default
    ;; (frame) characters which leads to incorrect sizes with scaled fonts.To
    ;; solve this we approximate font width in pixels and use window-pixel-width
    ;; to compute the approximate number of characters that fit into line.
    (let* ((wedges (window-inside-pixel-edges))
           (wwidth (- (nth 2 wedges) (nth 0 wedges)))
           (nchars (if (fboundp 'default-font-width)
                       (floor (/ wwidth (default-font-width)))
                     ;; emacs 24
                     (if (display-graphic-p)
                         (let* ((r (/ (float (frame-char-height)) (frame-char-width)))
                                (charh (aref (font-info (face-font 'default)) 3))
                                (charw (/ charh  r)))
                           (- (floor (/ wwidth charw)) 1))
                       ;; e.g., no X11 as in  'emacs -nw'
                       (- (window-width) 2))))
           (command (format ess-execute-screen-options-command nchars)))
      (if invisibly
          (ess-command command)
        (ess-eval-linewise command nil nil nil 'wait-prompt)))))

(defun ess-execute (command &optional invert buff message)
  "Send a command to the ESS process.
A newline is automatically added to COMMAND.  Prefix arg (or second arg
INVERT) means invert the meaning of
`ess-execute-in-process-buffer'.  If INVERT is 'buffer, output is
forced to go to the process buffer.  If the output is going to a
buffer, name it *BUFF*.  This buffer is erased before use.  Optional
fourth arg MESSAGE is text to print at the top of the buffer (defaults
to the command if BUFF is not given.)"
  (interactive (list
                ;; simpler way to set proc name in mb?
                (let ((enable-recursive-minibuffers t)
                      (proc-name (progn (ess-force-buffer-current)
                                        ess-local-process-name)))
                  (with-current-buffer (get-buffer " *Minibuf-1*") ;; fixme: hardcoded name
                    (setq ess-local-process-name proc-name))
                  (read-from-minibuffer "Execute> " nil
                                        ess-mode-minibuffer-map))
                current-prefix-arg))
  (ess-make-buffer-current)
  (let ((the-command (concat command "\n"))
        (buff-name (concat "*" (or buff "ess-output") "*"))
        (in-pbuff (if invert (or (eq invert 'buffer)
                                 (not ess-execute-in-process-buffer))
                    ess-execute-in-process-buffer)))
    (if in-pbuff
        (ess-eval-linewise the-command)
      (let ((buff (ess-create-temp-buffer buff-name)))
        (ess-command the-command buff);; sleep?
        (with-current-buffer buff
          (goto-char (point-min))
          (if message (insert message)
            (if buff nil
              ;; Print the command in the buffer if it has not been
              ;; given a special name
              (insert "> " the-command)))
          (setq ess-local-process-name ess-current-process-name))
        (ess-display-temp-buffer buff)))))

;;;*;;; Quitting

(ess-defgeneric ess-quit (&rest args)
  "Issue an exiting command to the inferior process, additionally
also running \\[ess-cleanup]."
  (interactive)
  (ess-force-buffer-current "Process to quit: " nil 'no-autostart)
  (ess-interrupt)
  (ess-make-buffer-current)
  (:override
   (let ((proc (ess-get-process)))
     (ess-cleanup)
     (goto-char (marker-position (process-mark proc)))
     (insert inferior-ess-exit-command)
     (process-send-string proc inferior-ess-exit-command))))

(defun ess-interrupt ()
  "Interrupt the inferior process.
This sends an interrupt and quits a debugging session."
  (interactive)
  (inferior-ess-force)
  (let ((proc (ess-get-process)))
    ;; Interrupt current task before reloading. Useful if the process is
    ;; prompting for input, for instance in R in case of a crash
    (interrupt-process proc comint-ptyp)
    ;; Workaround for Windows terminals
    (unless (memq system-type '(gnu/linux darwin))
      (process-send-string nil "\n"))
    (ess-wait-for-process proc)
    ;; Quit debugging session before reloading
    (when (ess-debug-active-p)
      (ess-debug-command-quit)
      (ess-wait-for-process proc))))

(defun ess-abort ()
  "Kill the ESS process, without executing .Last or terminating devices.
If you want to finish your session, use \\[ess-quit] instead."
;;; Provided as a safety measure over the default binding of C-c C-z in
;;; comint-mode-map.
  (interactive)
  (ding)
  (message "WARNING: \\[inferior-ess-exit-command] will not be executed and graphics devices won't finish properly!")
  (sit-for 2)
  (if (y-or-n-p "Still abort? ")
      (comint-quit-subjob)
    (message "Good move.")))

(defun ess-cleanup ()
  "Possibly kill or offer to kill, depending on the value of
`ess-S-quit-kill-buffers-p', all buffers associated with this ESS process.
Leaves you in the ESS process buffer.  It's a good idea to run this
before you quit.  It is run automatically by \\[ess-quit]."
  (interactive)
  (let ((the-procname (or (ess-make-buffer-current) ess-local-process-name)))
    (unless the-procname
      (error "I don't know which ESS process to clean up after!"))
    (when
        (or (eq ess-S-quit-kill-buffers-p t)
            (and
             (eq ess-S-quit-kill-buffers-p 'ask)
             (y-or-n-p
              (format
               "Delete all buffers associated with process %s? " the-procname))))
      (dolist (buf (buffer-list))
        (with-current-buffer buf
          ;; Consider buffers for which ess-local-process-name is
          ;; the same as the-procname
          (when (and (not (get-buffer-process buf))
                     ess-local-process-name
                     (equal ess-local-process-name the-procname))
            (kill-buffer buf)))))
    (ess-switch-to-ESS nil)))

(ess-defgeneric inferior-ess-reload (&optional start-args)
  "Reload the inferior process."
  (interactive)
  (inferior-ess-force)
  ;; Interrupt early so we can get working directory
  (ess-interrupt)
  (save-window-excursion
    ;; Make sure we don't ask for directory again
    ;; Use current working directory as default
    (let ((project-find-functions nil)
          (ess-directory-function nil)
          (ess-startup-directory (ess-get-working-directory))
          (ess-ask-for-ess-directory nil))
      (ess-quit 'no-save)
      (inferior-ess--wait-for-exit (ess-get-process))
      (:override
       (error "Unimplemented for this dialect")))))

(defun inferior-ess--wait-for-exit (proc)
  "Wait for process exit.
This should be used instead of `ess-wait-for-process' for waiting
after issuing a quit command as the latter assumes a live process."
  (let ((start-time (float-time)))
    (while (eq (process-status proc) 'run)
      (accept-process-output proc 0.002)
      (when (> (- (float-time) start-time) 1)
        (error "Timeout while quitting process")))))

(defun ess-kill-buffer-function ()
  "Function run just before an ESS process buffer is killed."
  ;; This simply deletes the buffers process to avoid an Emacs bug
  ;; where the sentinel is run *after* the buffer is deleted
  (let ((proc (get-buffer-process (current-buffer))))
    (if (processp proc) (delete-process proc))))


(defun ess-list-object-completions nil
  "List all possible completions of the object name at point."
  (interactive)
  (ess-complete-object-name))

;;;*;;; Support functions
(defun ess-extract-onames-from-alist (alist posn &optional force)
  "Return the object names in position POSN of ALIST.
ALIST is an alist like `ess-sl-modtime-alist'. POSN should be in 1 .. (length
ALIST).  If optional third arg FORCE is t, the corresponding element
of the search list is re-read. Otherwise it is only re-read if it's a
directory and has been modified since it was last read."
  (let* ((entry (nth (1- posn) alist))
         (dir (car entry))
         (timestamp (car (cdr entry)))
         (new-modtime (and timestamp
                           (ess-dir-modtime dir))))
    ;; Refresh the object listing if necessary
    (if (or force (not (equal new-modtime timestamp)))
        (setcdr (cdr entry) (ess-object-names dir posn)))
    (cdr (cdr entry))))

(defun ess-dir-modtime (dir)
  "Return the last modtime if DIR is a directory, and nil otherwise."
  (and ess-filenames-map
       (file-directory-p dir)
       (nth 5 (file-attributes dir))))

(defun ess-object-modtime (object)
  "Return the modtime of the S object OBJECT (a string).
Searches along the search list for a file named OBJECT and returns its modtime
Returns nil if that file cannot be found, i.e., for R or any non-S language!"
  (let ((path (ess-search-list))
        result)
    (while (and (not result) path)
      (setq result (file-attributes
                    (concat (file-name-as-directory (car path))
                            object)))
      (setq path (cdr path)))
    (nth 5 result)))

(defun ess-modtime-gt (mod1 mod2)
  "Return t if MOD1 is later than MOD2."
  (and mod1
       (or (> (car mod1) (car mod2))
           (and (= (car mod1) (car mod2))
                (> (car (cdr mod1)) (car (cdr mod2)))))))

(defun ess-get-object-list (name &optional exclude-first)
  "Return a list of current S object names associated with process NAME,
using `ess-object-list' if that is non-nil.
If exclude-first is non-nil, don't return objects in first positon (.GlobalEnv)."
  (or ess-object-list ;; <<-  MM: this is now always(?) nil; we cache the *-modtime-alist
      (with-current-buffer (process-buffer (ess-get-process name))
        (ess-make-buffer-current)
        (ess-write-to-dribble-buffer (format "(get-object-list %s) .." name))
        (if (or (not ess-sl-modtime-alist)
                (ess-process-get 'sp-for-help-changed?))
            (progn (ess-write-to-dribble-buffer "--> (ess-get-modtime-list)\n")
                   (ess-get-modtime-list))
          ;;else
          (ess-write-to-dribble-buffer " using existing ess-sl-modtime-alist\n"))
        (let* ((alist ess-sl-modtime-alist)
               (i 2)
               (n (length alist))
               result)
          (ess-write-to-dribble-buffer (format " (length alist) : %d\n" n))
          (unless exclude-first
            ;; re-read of position 1 :
            (setq result (ess-extract-onames-from-alist alist 1 'force)))
          (ess-write-to-dribble-buffer
           (format " have re-read pos=1: -> length %d\n" (length result)))
          ;; Re-read remaining directories if necessary.
          (while (<= i n)
            (setq result
                  (append result
                          (ess-extract-onames-from-alist alist i)))
            (setq i (1+ i)))
          (setq ess-object-list (ess-uniq-list result))))))

(defun ess-get-words-from-vector (command &optional no-prompt-check wait proc)
  "Evaluate the S command COMMAND, which returns a character vector.
Return the elements of the result of COMMAND as an alist of
strings.  COMMAND should have a terminating newline.  NO-PROMPT-CHECK,
WAIT, and PROC are passed to `ess-command'.  FILTER may be the
keyword 'non-... or nil.

To avoid truncation of long vectors, wrap your
command (%s) like this, or a version with explicit options(max.print=1e6):

local({ out <- try({%s}); print(out, max=1e6) })\n
"
  (let* ((tbuffer (get-buffer-create
                  " *ess-get-words*")); initial space: disable-undo
         (word-RE
          (concat "\\("
                  "\\\\\\\"" "\\|" "[^\"]" ;  \" or non-"-char
                  "\\)*"))
         (full-word-regexp
          (concat "\"" "\\(" word-RE "\\)"
                   "\""
                   "\\( \\|$\\)"; space or end
                   ))
         words)
    (ess-if-verbose-write
     (format "(ess-get-words-* command=%s full-word-regexp=%S)\n"
                                  command full-word-regexp))
    (ess-command command tbuffer 'sleep no-prompt-check wait proc)
    (ess-if-verbose-write " [ok] ..")
    (with-current-buffer tbuffer
      (goto-char (point-min))
      (while (re-search-forward full-word-regexp nil t)
        (setq words (cons (buffer-substring (match-beginning 1) (match-end 1))
                          words))))
    (ess-if-verbose-write
     (if (> (length words) 5)
         (format " |-> (length words)= %d\n" (length words))
       (format " |-> words= '%s'\n" words)))
    (reverse words)))

(defun ess-compiled-dir (dir)
  "Return non-nil if DIR is an S object directory with special files.
I.e. if the filenames in DIR are not representative of the objects in DIR."
  (or (file-exists-p (concat (file-name-as-directory dir) "___nonfile"))
      (file-exists-p (concat (file-name-as-directory dir) "__BIGIN"))
      (file-exists-p (concat (file-name-as-directory dir) "___NONFI"))))

(defun ess-object-names (obj &optional pos)
  "Return alist of S object names in directory (or object) OBJ.
If OBJ is a directory name (begins with `/') returns a listing of that dir.
   This may use the search list position POS if necessary.
If OBJ is an object name, returns result of the command `inferior-ess-safe-names-command'.
If POS is supplied return the result of the command in `inferior-ess-objects-command'
If OBJ is nil or not a directory, POS must be supplied.
In all cases, the value is an list of object names."

  (cond ((and (stringp obj)
              (string-match-p "ESSR" obj))
         nil)
        ;; FIXME: in both cases below, the same fallback "objects(POS)" is used -- merge!
        ((and obj (file-accessible-directory-p obj))
         ;; Check the pre-compiled object list in ess-object-name-db first

         ;; FIXME: If used at all, ess-object-name-db should not only
         ;; -----  be used in the directory case !!
         (or (cdr-safe (assoc obj ess-object-name-db))
             ;; Take a directory listing
             (and ess-filenames-map
                  ;; first try .Data subdirectory:
                  ;;FIXME: move ".Data" or ``this function'' to ess-sp6-d.el etc:
                  (let ((dir (concat (file-name-as-directory obj) ".Data")))
                    (if (not (file-accessible-directory-p dir))
                        (setq dir obj))
                    (and (not (ess-compiled-dir dir))
                         (directory-files dir))))
             ;; Get objects(pos) instead
             (and (or (ess-write-to-dribble-buffer
                       (format "(ess-object-names ..): directory %s not used\n" obj))
                      t)
                  pos
                  (ess-get-words-from-vector
                   (format inferior-ess-objects-command pos)))))
        ((and obj ;; want names(obj)
              (ess-get-words-from-vector
               (format inferior-ess-safe-names-command obj))))
        (pos
         (ess-get-words-from-vector
          (format inferior-ess-objects-command pos)))))

(defun ess-slot-names (obj)
  "Return alist of S4 slot names of S4 object OBJ."
  (ess-get-words-from-vector (format "slotNames(%s)\n" obj)))


;;; SJE: Wed 29 Dec 2004 --- remove this function.
;;; rmh: Wed 5 Jan 2005 --- bring it back for use on Windows
(defun ess-create-object-name-db ()
  "Create a database of object names in standard S directories.  This
database is saved in the file specified by `ess-object-name-db-file',
and is loaded when `ess-mode' is loaded. It defines the variable
`ess-object-name-db', which is used for completions.

Before you call this function, modify the S search list so that it contains
all the non-changing (i.e. system) S directories.  All positions of the search
list except for position 1 are searched and stored in the database.

After running this command, you should move ess-namedb.el to a directory in
the `load-path'."
  (interactive)
  (setq ess-object-name-db nil)
  (let ((search-list (cdr (ess-search-list)))
        (pos 2)
        name
        (buffer (get-buffer-create " *ess-db*"))
        (temp-object-name-db nil)
        (temp-object-name-db-file ess-object-name-db-file))

    (ess-write-to-dribble-buffer
     (format "(object db): search-list=%s \n " search-list))
    (while search-list
      (message "Searching %s" (car search-list))
      (setq temp-object-name-db (cons (cons (car search-list)
                                            (ess-object-names nil pos))
                                      temp-object-name-db))
      (setq search-list (cdr search-list))
      (ess-write-to-dribble-buffer
       (format "(object db): temp-obj-name-db=%s \n pos=%s"
               temp-object-name-db pos))
      (setq pos (1+ pos)))

    (with-current-buffer buffer
      (erase-buffer)
      (insert "(setq ess-object-name-db '")
      (prin1 temp-object-name-db (current-buffer))
      (insert ")\n")
      (setq name (expand-file-name ess-object-name-db-file))
      (write-region (point-min) (point-max) name)
      (message "Wrote %s" name))
    (kill-buffer buffer)
    (setq ess-object-name-db temp-object-name-db)))

(defun ess-resynch nil
  "Reread all directories/objects in variable `ess-search-list' to
form completions."
  (interactive)

  (if (ess-make-buffer-current) nil
    (error "Not an ESS process buffer"))
  (setq ess-sl-modtime-alist nil)
  (setq ess-object-list nil)
  (setq ess-object-name-db nil)         ; perhaps it would be better to reload?
  (ess-process-put 'sp-for-help-changed? t)
  (ess-get-modtime-list))

(defun ess-filename-completion ()
  ;; > emacs 24
  "Return completion only within string or comment."
  (save-restriction ;; explicitely handle inferior-ess
    (ignore-errors
      (when (and (eq major-mode 'inferior-ess-mode)
                 (> (point) (process-mark (get-buffer-process (current-buffer)))))
        (narrow-to-region (process-mark (get-buffer-process (current-buffer)))
                          (point-max))))
    (when (ess-inside-string-or-comment-p (point))
      (append (comint-filename-completion) '(:exclusive no)))))


(defun ess-complete-filename ()
  "Do file completion only within strings."
  (save-restriction ;; explicitely handle inferior-ess
    (ignore-errors
      (when (and (eq major-mode 'inferior-ess-mode)
                 (> (point) (process-mark (get-buffer-process (current-buffer)))))
        (narrow-to-region (process-mark (get-buffer-process (current-buffer)))
                          (point-max))))
    (when (or (ess-inside-string-or-comment-p (point))) ;; usable within ess-mode as well
      (comint-dynamic-complete-filename))))

(defun ess-after-pathname-p nil
  ;; Heuristic: after partial pathname if it looks like we're in a
  ;; string, and that string looks like a pathname. Not the best for
  ;; use with unix() (or it's alias, !). Oh well.
  (save-excursion
    (save-match-data
      (let ((opoint (point)))
        (and (re-search-backward "\\(\"\\|'\\)[~/#$.a-zA-Z0-9][^ \t\n\"']*"
                                 nil t)
             (eq opoint (match-end 0)))))))

;;*;; Functions handling the search list

(defun ess-search-list (&optional force-update)
  "Return the current search list as a list of strings.
Elements which are apparently directories are expanded to full dirnames.
Don't try to use cache if FORCE-UPDATE is non-nil.

Is *NOT* used by \\[ess-execute-search],
but by \\[ess-resynch], \\[ess-get-object-list], \\[ess-get-modtime-list],
\\[ess-execute-objects], \\[ess-object-modtime], \\[ess-create-object-name-db],
and (indirectly) by \\[ess-get-help-files-list]."
  (with-current-buffer
      (ess-get-process-buffer ess-current-process-name);to get *its* local vars
    (let ((result nil)
          (slist (ess-process-get 'search-list))
          (tramp-mode nil)) ;; hack for bogus file-directory-p below
      (if (and slist
               (not force-update)
               (not (ess-process-get 'sp-for-help-changed?)))
          slist
        ;; else, re-compute:
        (ess-write-to-dribble-buffer " (ess-search-list ... ) ")
        (let ((tbuffer (get-buffer-create " *search-list*"))
              (homedir ess-directory)
              (my-search-cmd inferior-ess-search-list-command); from ess-buffer
              elt)
          (ess-command my-search-cmd tbuffer 0.05); <- sleep for dde only; does (erase-buffer)
          (with-current-buffer tbuffer
            ;; guaranteed by the initial space in its name: (buffer-disable-undo)
            (goto-char (point-min))
            (ess-write-to-dribble-buffer
             (format "after '%s', point-max=%d\n" my-search-cmd (point-max)))
            (while (re-search-forward "\"\\([^\"]*\\)\"" nil t)
              (setq elt (buffer-substring (match-beginning 1) (match-end 1)))
              ;;Dbg: (ess-write-to-dribble-buffer (format "  .. elt= %s \t" elt))
              (if (and (string-match "^[^/]" elt)
                       (file-directory-p (concat ess-directory elt)))
                  (progn
                    ;;Dbg: (ess-write-to-dribble-buffer "*IS* directory\n")
                    (setq elt (concat homedir elt)))
                ;;else
                ;;dbg
                ;;-             (ess-write-to-dribble-buffer "not dir.\n")
                )
              (setq result (append result (list elt))))
            (kill-buffer tbuffer)))
        result))))

;;; ess-sl-modtime-alist is a list with elements as follows:
;;;  * key             (directory or object name)
;;;  * modtime         (list of 2 integers)
;;;  * name, name ...  (accessible objects in search list posn labeled by key)
;;; It is a buffer-local variable (belonging to e.g. *R*, *S+6*, .. etc)
;;; and has the same number of elements and is in the same order as the
;;; S search list

(defun ess-get-modtime-list (&optional cache-var-name exclude-first)
  "Record directories in the search list, and the objects in those directories.
The result is stored in CACHE-VAR-NAME. If nil, CACHE-VAR-NAME
defaultst to `ess-sl-modtime-alist'. If EXCLUDE-FIRST is non-nil
don't recompile first object in the search list."
  ;; Operation applies to process of current buffer
  (let* ((searchlist (if exclude-first
                         (cdr (ess-search-list))
                       (ess-search-list)))
         (index (if exclude-first 2 1))
         (cache-name (or cache-var-name 'ess-sl-modtime-alist))
         pack newalist)
    (while searchlist
      (setq pack (car searchlist))
      (setq newalist
            (append
             newalist
             (list (or (assoc pack (symbol-value cache-name))
                       (append
                        (list pack (ess-dir-modtime pack))
                        (prog2
                            (message "Forming completions for %s..." pack)
                            (ess-object-names pack index)
                          (message "Forming completions for %s...done" pack)))))))
      (setq index (1+ index))
      (setq searchlist (cdr searchlist)))
    ;;DBG:
    (ess-write-to-dribble-buffer
     (format "(%s): created new alist of length %d\n"
             cache-var-name (length newalist)))
    (set cache-name newalist)))


(defun ess-search-path-tracker (str)
  "Check if input STR changed the search path.
This function monitors user input to the inferior ESS process so
that Emacs can keep the process variable 'search-list' up to
date. `ess-completing-read' in \\[ess-read-object-name] uses this
list indirectly when it prompts for help or for an object to
dump.

From ESS 12.09 this is not necessary anymore, as the search path
is checked on idle time. It is kept for robustness and backward
compatibility only."
  (when ess-change-sp-regexp
    (if (string-match ess-change-sp-regexp str)
        (ess-process-put 'sp-for-help-changed? t))))

 ; Miscellaneous routines

;;;*;;; Routines for reading object names
(ess-defgeneric ess-read-object-name (p-string)
  "Read an object name from the minibuffer with completion, and return it.
P-STRING is the prompt string."
  (:override
   (let* ((default (ess-read-object-name-dump))
          (object-list (ess-get-object-list ess-local-process-name))
          (spec (ess-completing-read p-string object-list nil nil nil nil default)))
     (list (cond
            ((string= spec "") default)
            (t spec))))))

(defun ess-read-object-name-default ()
  "Return the object name at point, or nil if none."
  (ignore-errors
    (save-excursion
      ;; The following line circumvents an 18.57 bug in following-char
      (if (eobp) (backward-char 1))   ; Hopefully buffer is not empty!
      ;; Get onto a symbol
      (catch 'nosym          ; bail out if there's no symbol at all before point
        (while (let ((sc (char-syntax (following-char))))
                 (not (or (= sc ?w) (= sc ?_))))
          (if (bobp) (throw 'nosym nil) (backward-char 1))))
      (let*
          ((end (progn (forward-sexp 1) (point)))
           (beg (progn (backward-sexp 1) (point))))
        (buffer-substring-no-properties beg end)))))

(defun ess-read-object-name-dump ()
  "Return the object name at point, or \"Temporary\" if none."
  (ignore-errors
    (save-excursion
      ;; Get onto a symbol
      (catch 'nosym ; bail out if there's no symbol at all before point
        (while (/= (char-syntax (following-char)) ?w)
          (if (bobp) (throw 'nosym nil) (backward-char 1)))
        (let*
            ((end (progn (forward-sexp 1) (point)))
             (beg (progn (backward-sexp 1) (point)))
             (object-name (buffer-substring beg end)))
          (or object-name "Temporary"))))))

;;;; start of ess-smart-operators
;;;; inspired by slime repl shortcuts

(defvar ess--handy-history nil)

(defun ess-handy-commands ()
  "Request and execute a command from `ess-handy-commands' list."
  (interactive)
  (let* ((commands (or ess--local-handy-commands
                       ess-handy-commands))
         (hist (and (assoc (car ess--handy-history)
                           commands)
                    (car ess--handy-history))))
    (call-interactively
     (cdr (assoc (ess-completing-read "Execute"
                                      (sort (mapcar 'car commands)
                                            'string-lessp) nil t nil
                                            'ess--handy-history hist)
                 commands)))))

(defun ess-smart-comma ()
  "If comma is invoked at the process marker of an ESS inferior
buffer, request and execute a command from `ess-handy-commands'
list."
  (interactive)
  (let ((proc (get-buffer-process (current-buffer))))
    (if (and proc
             (eq (point) (marker-position (process-mark proc))))
        (ess-handy-commands)
      (if ess-smart-operators
          (progn
            (delete-horizontal-space)
            (insert ", ")
            (unless (eq major-mode 'inferior-ess-mode)
             (indent-according-to-mode)))
        (insert ",")))))

 ; directories
(defun ess-set-working-directory (path &optional no-error)
  "Set the current working directory to PATH for both ESS
subprocess and Emacs buffer `default-directory'."
  (interactive "DChange working directory to: ")
  (if ess-setwd-command
      (let* ((remote (file-remote-p path))
             (path (if remote
                       (tramp-sh-handle-expand-file-name path)
                     path))
             (lpath (if remote
                        (with-parsed-tramp-file-name path v v-localname)
                      path)))
        (ess-eval-linewise (format ess-setwd-command lpath))
        ;; use file-name-as-directory to ensure it has trailing /
        (setq default-directory (file-name-as-directory path)))
    (unless no-error
      (error "Not implemented for dialect %s" ess-dialect))))

(defalias 'ess-change-directory 'ess-set-working-directory)

(defun ess-get-working-directory (&optional no-error)
  "Retrive the current working directory from the current ess process."
  (if ess-getwd-command
      (car (ess-get-words-from-vector ess-getwd-command))
    (unless no-error
      (error "Not implemented for dialect %s" ess-dialect))))


(defun ess-synchronize-dirs ()
  "Set Emacs' current directory to be the same as the subprocess directory.
To be used in `ess-idle-timer-functions'."
  (when (and ess-can-eval-in-background
             ess-getwd-command)
    (ess-when-new-input last-sync-dirs
      (ess-if-verbose-write "\n(ess-synchronize-dirs)\n")
      (setq default-directory
            (car (ess-get-words-from-vector ess-getwd-command)))
      default-directory)))

(defun ess-dirs ()
  "Set Emacs' current directory to be the same as the *R* process."
  ;; Note: This function is not necessary anymore. The Emacs
  ;; default-directory and subprocess working directory are
  ;; synchronized automatically.
  (interactive)
  (let ((dir (car (ess-get-words-from-vector "getwd()\n"))))
    (message "(ESS / default) directory: %s" dir)
    (setq default-directory (file-name-as-directory dir))))

;; (make-obsolete 'ess-dirs 'ess-synchronize-dirs "ESS 12.09")

;; search path
(defun ess--mark-search-list-as-changed ()
  "Internal. Marks all the search-list related variables as
changed."
  ;; other guys might track their own
  (ess-process-put 'sp-for-help-changed? t)
  (ess-process-put 'sp-for-ac-changed? t))

(defun ess-cache-search-list ()
  "To be used in `ess-idle-timer-functions', to set
search path related variables."
  (when (and ess-can-eval-in-background
             inferior-ess-search-list-command)
    (ess-when-new-input last-cache-search-list
      (let ((path (ess-search-list 'force))
            (old-path (process-get *proc* 'search-list)))
        (when (not (equal path old-path))
          (process-put *proc* 'search-list path)
          (ess--mark-search-list-as-changed)
          path)))))


;;*;; Temporary buffer handling

;; (defun ess-create-temp-buffer (name)
;;  "Create an empty buffer called NAME, but doesn't display it."
;;  (let ((buff (get-buffer-create name)))
;;    (save-excursion
;;      (set-buffer buff)
;;      (erase-buffer))
;;    buff))


;; Ed Kademan's version:
;; From: Ed Kademan <kademan@phz.com>
;; Subject: Re: ess-mode 5.1.16; search list
;; To: rossini@biostat.washington.edu (A.J. Rossini)
;; Cc: Martin Maechler <maechler@stat.math.ethz.ch>, ess-bugs@stat.math.ethz.ch
;; Date: 26 Jul 2000 16:12:12 -0400

;; Dear Tony Rossini,

;; I was having trouble looking at the search list under ess.  When I
;; started up multiple inferior processes---each for a different
;; dialect---ess-mode would issue the wrong variant of the "search"
;; command when I typed C-c C-s.  In case it is useful let me tell you
;; what I did to get it to work for me.

;; I added the component:
;;  (inferior-ess-search-list-command . "search()\n")
;; to S+3-customize-alist and ess-r-customize-alist, and then I redefined the
;; ess-create-temp-buffer function as follows:
(defun ess-create-temp-buffer (name)
  "Create an empty buffer called NAME."
  (let ((buff (get-buffer-create name))
        (elca (eval ess-local-customize-alist)))
    (with-current-buffer buff
      (erase-buffer)
      (ess-setq-vars-local elca buff))
    buff))
;;These two steps seem to insure that the temporary buffer in which the
;;search results appear has the correct version of the local variables.
;;I am not that well acquainted with the ess code and don't know whether
;;this is a good fundamental way of fixing the problem, or even whether
;;or not this breaks some other feature of ess-mode that I never use.
;;Thanks for listening.
;;Ed K.
;;--
;;Ed Kademan              508.651.3700
;;PHZ Capital Partners    508.653.1745 (fax)
;;321 Commonwealth Road   <kademan@phz.com>
;;Wayland, MA 01778



(defun ess-display-temp-buffer (buff)
  "Display the buffer BUFF using `temp-buffer-show-function' and respecting
`ess-display-buffer-reuse-frames'."
  (let ((display-buffer-reuse-frames ess-display-buffer-reuse-frames))
    (funcall (or temp-buffer-show-function 'display-buffer) buff)))

;;*;; Error messages

(defun ess-error (msg)
  "Something bad has happened.
Display the S buffer, and cause an error displaying MSG."
  (display-buffer (process-buffer (ess-get-process ess-current-process-name)))
  (error msg))

 ; Provide package

(provide 'ess-inf)
 ; Local variables section

;;; This file is automatically placed in Outline minor mode.
;;; The file is structured as follows:
;;; Chapters:     ^L ;
;;; Sections:    ;;*;;
;;; Subsections: ;;;*;;;
;;; Components:  defuns, defvars, defconsts
;;;              Random code beginning with a ;;;;* comment

;;; Local variables:
;;; mode: emacs-lisp
;;; outline-minor-mode: nil
;;; mode: outline-minor
;;; outline-regexp: "\^L\\|\\`;\\|;;\\*\\|;;;\\*\\|(def[cvu]\\|(setq\\|;;;;\\*"
;;; End:

;;; ess-inf.el ends here
