;;; ess-mode.el --- Support for editing ESS source code

;; Copyright (C) 1989-1994 Doug Bates, Ed Kademan, Frank Ritter, David Smith.
;; Copyright (C) 1997--2006 A.J. Rossini, Rich M. Heiberger, Martin
;;	Maechler, Kurt Hornik, Rodney Sparapani, and Stephen Eglen.

;; Original Author: David Smith <dsmith@stats.adelaide.edu.au>
;; Created: 7 Jan 1994
;; Maintainers: 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.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.	If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Commentary:

;; Code for editing ESS source code.

;;; Code:

 ; Requires and autoloads

(require 'ess); includes ess-custom.el

;;; AJR: THIS IS GROSS AND DISGUSTING (but I wrote it).
;;; MM:	 and I had to add all other 'ess-eval-*** ...
;;; >>> why not just do the obvious instead of all these ? Namely,
;;; (require 'ess-inf)
;;; ------------------ ?
;;; AJR: The reason is that we ONLY need to load ess-inf for the
;;; functions which are interactive in nature.	 We don't want to load
;;; it when we are only editing.

(autoload 'ess-mode-minibuffer-map	"ess-inf" "" nil 'keymap)
(autoload 'ess-read-object-name		"ess-inf" "" nil)
(autoload 'ess-list-object-completions	"ess-inf" "" nil)

(autoload 'ess-eval-buffer		"ess-inf" "" nil)
(autoload 'ess-eval-buffer-and-go	"ess-inf" "" nil)
(autoload 'ess-eval-function		"ess-inf" "" nil)
(autoload 'ess-eval-function-and-go	"ess-inf" "" nil)
(autoload 'ess-eval-function-or-paragraph-and-step
                                        "ess-inf" "" nil)
(autoload 'ess-eval-line		"ess-inf" "" nil)
(autoload 'ess-eval-line-and-go		"ess-inf" "" nil)
(autoload 'ess-eval-line-and-step	"ess-inf" "" nil)
(autoload 'ess-eval-linewise		"ess-inf" "" nil)
(autoload 'ess-eval-paragraph		"ess-inf" "" nil)
(autoload 'ess-eval-paragraph-and-go    "ess-inf" "" nil)
(autoload 'ess-eval-paragraph-and-step  "ess-inf" "" nil)
(autoload 'ess-eval-region		"ess-inf" "" nil)
(autoload 'ess-eval-region-and-go	"ess-inf" "" nil)

(autoload 'ess-load-file		"ess-inf" "" nil)
(autoload 'ess-switch-process		"ess-inf" "" nil)
(autoload 'ess-switch-to-ESS		"ess-inf" "" nil)
(autoload 'ess-request-a-process	"ess-inf" "" nil)
(autoload 'get-ess-process		"ess-inf" "" nil)
(autoload 'ess-command			"ess-inf" "" nil)
(autoload 'ess-create-temp-buffer	"ess-inf" "" nil)
(autoload 'ess-display-temp-buffer	"ess-inf" "" nil)
(autoload 'ess-force-buffer-current	"ess-inf" "" nil)
(autoload 'ess-make-buffer-current	"ess-inf" "" nil)
(autoload 'ess-modtime-gt		"ess-inf" "" nil)
(autoload 'ess-object-modtime		"ess-inf" "" nil)
(autoload 'ess-quit			"ess-inf" "" nil)

(autoload 'ess-ddeclient-p		"ess-inf" "(autoload)" nil)
(autoload 'ess-dump-object-ddeclient	"ess-dde" "(autoload)" nil)

(defun ess-line-end-position (&optional N)
  "return the 'point' at the end of N lines. N defaults to 1, i.e., current line."
  (save-excursion
    (end-of-line N)
    (point)))


 ; ESS mode
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; In this section:
;;;;
;;;; * The major mode ess-mode
;;;; * Commands for ess-mode
;;;; * Code evaluation commands
;;;; * Indenting code and commands
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;*;; Major mode definition

(if ess-eval-map
    nil
  (if (featurep 'xemacs)
      ;; Code for XEmacs
      (setq ess-eval-map (make-keymap))
    ;; else code for GNU Emacs
    (setq ess-eval-map (make-sparse-keymap)))

  (define-key ess-eval-map "\C-r"    'ess-eval-region)
  (define-key ess-eval-map "\M-r"    'ess-eval-region-and-go)
  (define-key ess-eval-map "\C-b"    'ess-eval-buffer)
  (define-key ess-eval-map "\M-b"    'ess-eval-buffer-and-go)
  (define-key ess-eval-map "\C-f"    'ess-eval-function)
  (define-key ess-eval-map "\M-f"    'ess-eval-function-and-go)
  (define-key ess-eval-map "\C-x"    'ess-eval-function)
  (define-key ess-eval-map "\C-n"    'ess-eval-line-and-step)
  (define-key ess-eval-map "\C-j"    'ess-eval-line)
  (define-key ess-eval-map "\M-j"    'ess-eval-line-and-go))


(if ess-mode-map
    nil

  (if (featurep 'xemacs)
      (progn ;; Code for XEmacs
	(setq ess-mode-map (make-keymap))
	(set-keymap-parent ess-mode-map text-mode-map)) ;; was comint?!?
    ;; else code for GNU Emacs
    (setq ess-mode-map (make-sparse-keymap)))

  ;; By popular demand:
  (define-key ess-mode-map "\C-m"	'newline-and-indent); = [RETURN]

  (define-key ess-mode-map "\C-c\C-r"	'ess-eval-region)
  (define-key ess-mode-map "\C-c\M-r"	'ess-eval-region-and-go)
  (define-key ess-mode-map "\C-c\C-b"	'ess-eval-buffer)
  (define-key ess-mode-map "\C-c\M-b"	'ess-eval-buffer-and-go)
  (define-key ess-mode-map (kbd "C-c C-<up>")   'ess-eval-buffer-from-beg-to-here)
  (define-key ess-mode-map (kbd "C-c C-<down>") 'ess-eval-buffer-from-here-to-end)
  (define-key ess-mode-map "\C-c\C-f"	'ess-eval-function)
  (define-key ess-mode-map "\C-c\M-f"	'ess-eval-function-and-go)
  (define-key ess-mode-map "\C-c\C-c"	'ess-eval-function-or-paragraph-and-step)
  (define-key ess-mode-map "\C-c\C-p"	'ess-eval-paragraph-and-step)
  (define-key ess-mode-map "\C-c\M-p"	'ess-eval-paragraph-and-go)
  (define-key ess-mode-map "\C-\M-x"	'ess-eval-function)
  (define-key ess-mode-map "\C-c\C-n"	'ess-eval-line-and-step)
  (define-key ess-mode-map "\C-c\C-j"	'ess-eval-line)
  (define-key ess-mode-map "\C-c\M-j"	'ess-eval-line-and-go)
  ;; the next three can only work in S/R - mode {FIXME}
  (define-key ess-mode-map "\C-\M-a"	'ess-beginning-of-function)
  (define-key ess-mode-map "\C-\M-e"	'ess-end-of-function)
  (define-key ess-mode-map "\C-xnd"	'ess-narrow-to-defun)
  (define-key ess-mode-map "\C-c\C-y"	'ess-switch-to-ESS)
  (define-key ess-mode-map "\C-c\C-z"	'ess-switch-to-end-of-ESS)
  (define-key ess-mode-map "\C-c\C-l"	'ess-load-file)
  (define-key ess-mode-map "\C-c\C-v"	'ess-display-help-on-object)
  (define-key ess-mode-map "\C-c\C-d"	'ess-dump-object-into-edit-buffer)
;(define-key ess-mode-map "\C-c5\C-d"'ess-dump-object-into-edit-buffer-other-frame)
  (define-key ess-mode-map "\C-c\C-s"	'ess-switch-process) ; use a
					; different process for the buffer.
  (define-key ess-mode-map "\C-c\C-t"	'ess-execute-in-tb)
  (define-key ess-mode-map "\C-c\t"	'ess-complete-object-name)
  (define-key ess-mode-map "\M-\t"	'comint-replace-by-expanded-filename)
  (define-key ess-mode-map "\M-?"	'ess-list-object-completions)
  ;; wrong here (define-key ess-mode-map "\C-c\C-k" 'ess-request-a-process)
  (define-key ess-mode-map "\C-c\C-k"	'ess-force-buffer-current)
  (define-key ess-mode-map "\C-c`"	'ess-parse-errors) ; \C-x reserved!
  (define-key ess-mode-map "{"		'ess-electric-brace)
  (define-key ess-mode-map "}"		'ess-electric-brace)
  (define-key ess-mode-map "\C-\M-q"	'ess-indent-exp)
  (define-key ess-mode-map "\C-\M-h"	'ess-mark-function)
  (if (featurep 'xemacs) ;; work around Xemacs bug (\C-\M-h redefines M-BS):
      (define-key ess-mode-map [(meta backspace)] 'backward-kill-word))
  ;(define-key ess-mode-map [delete]	'backward-delete-char-untabify)
  (define-key ess-mode-map "\t"		'ess-indent-command)
  (define-key ess-mode-map "\C-c\C-q"	'ess-quit)
  (define-key ess-mode-map "\C-c\C-e"	ess-eval-map))

(require 'noweb-mode)
(easy-menu-define
 ess-mode-menu ess-mode-map
 "Menu for use in `ess-mode'."
 '("ESS" ; ESS-mode
   ["What is this? (beta)"    ess-mouse-me			t]
   ["Load file"		ess-load-file t]
   ["Eval func/para & step" ess-eval-function-or-paragraph-and-step t]
   ["Enter expression"	ess-execute-in-tb		  t]
   ;; sub menus
   ("Eval and Go"
    ["Eval buffer"	ess-eval-buffer-and-go		  t]
    ["Eval region"	ess-eval-region-and-go		  t]
    ["Eval function"	ess-eval-function-and-go	  t]
    ["Eval line"	ess-eval-line-and-go		  t]
    ["Eval paragraph"   ess-eval-paragraph-and-go	  t]
    ["Eval chunk"	ess-eval-chunk-and-go	 noweb-mode]
    ["Eval thread"	ess-eval-thread-and-go	 noweb-mode]
    ["About"		(ess-goto-info "Evaluating code") t]
    )
   ("ESS Eval"
    ["Eval buffer"	ess-eval-buffer			  t]
    ["Eval buffer till here" ess-eval-buffer-from-beg-to-here t]
    ["Eval buffer from here" ess-eval-buffer-from-here-to-end t]
    ["Eval region"	ess-eval-region			  t]
    ["Eval function"	ess-eval-function		  t]
    ["Eval func/para & step" ess-eval-function-or-paragraph-and-step t]
    ["Eval line"	ess-eval-line			  t]
    ["Eval line & step" ess-eval-line-and-step		  t]
    ["Eval paragraph"   ess-eval-paragraph		  t]
    ["Eval para. & step" ess-eval-paragraph-and-step	  t]
    ["Eval chunk"	ess-eval-chunk		 noweb-mode]
    ["Eval thread"	ess-eval-thread		 noweb-mode]
    ["About"		(ess-goto-info "Evaluating code") t]
    )
   ("Motion..."
    ["Edit new object"		ess-dump-object-into-edit-buffer t]
    ["Goto end of ESS buffer"	ess-switch-to-end-of-ESS	t]
    ["Switch to ESS buffer"	ess-switch-to-ESS		t]
    ["Beginning of function"	ess-beginning-of-function	t]
    ["End of function"		ess-end-of-function		t]
    )
   ("ESS list..."
    ["Backward list"		backward-list			t]
    ["Forward list"		forward-list			t]
    ["Next parenthesis"		down-list			t]
    ["Enclosing parenthesis"	backward-up-list		t]
    ["Backward sexp"		backward-sexp			t]
    ["Forward sexp"		forward-sexp			t]
    ["About"			(Info-goto-node "(Emacs)Lists") t]
    )
   ("ESS Edit"
    ["Complete Filename" comint-replace-by-expanded-filename	t]
    ["Complete Object"	 ess-complete-object-name		t]
    ["Kill sexp"	 kill-sexp				t]
    ["Mark function"	 ess-mark-function			t]
    ["Indent expression" ess-indent-exp				t]
    ["Indent line"	 ess-indent-command			t]
    ["Toggle Auto-Fill Mode" auto-fill-mode			t]
    ["Undo"		 undo					t]
    ["About"		 (ess-goto-info "Edit buffer")		t]
    )
   ("Roxygen"
    ["Update/Generate Template" ess-roxy-update-entry	        t]
    ["Preview Rd"	 ess-roxy-preview-Rd     		t]
    ["Preview HTML"	 ess-roxy-preview-HTML     		t]
    ["Toggle Roxygen Prefix"	 ess-roxy-toggle-roxy-region    t]
    )
   ("Start Process"
    ;; SJE - :help not yet recognised in XEmacs.
    ["R"     R	 t] ;; :help "Start a new R process" :active t
    ["S"     S	 t] ;; :help "Start a new S process" :active t
    ["Sqpe" Sqpe ess-microsoft-p] ;; :help "Start a new Sqpe process" :active t
    ["S+6-exisiting" S+6-existing ess-microsoft-p] ;; :help "Access an existing S process" :active t
    ["SAS"   SAS-menu t] ;;  :help "Start a new SAS process" :active t
    ;; The following menu item "Other" is a place-holder that will
    ;; be replaced with the other versions of R and Sqpe that can be run.
    ;; See `ess-r-versions-create' and ess-site.el
    ("Other"
     ["No other R or Sqpe versions" nil nil])
    ["About"
     (ess-goto-info "Starting up") t]
     ;; :help "Read about starting a new ESS process" :active t]
    )
   ["Switch Process"	ess-switch-process		t]
   "------"
   ["Describe"		describe-mode			t]
   ["About editing" (ess-goto-info "Editing")	t]
   ["Read ESS info" (ess-goto-info "") t]
   ["Send bug report"	ess-submit-bug-report		t]
   ))

(defun SAS-menu ()
  "Start SAS from the menu."
  (interactive)
  (if ess-microsoft-p
      ;; replace with other choices for starting SAS under XEmacs?
      (error "SAS cannot be started this way in ESS on Windows.")
    (SAS)))

(defun ess-mode-xemacs-menu ()
  "Hook to install `ess-mode' menu for XEmacs (w/ easymenu)."
  (if 'ess-mode
	(easy-menu-add ess-mode-menu)
    (easy-menu-remove ess-mode-menu)))

(if (featurep 'xemacs)
    (add-hook 'ess-mode-hook 'ess-mode-xemacs-menu))

(defun ess-mode (&optional alist proc-name)
  "Major mode for editing ESS source.
Optional arg ALIST describes how to customize the editing mode.
Optional arg PROC-NAME is name of associated inferior process.

\\{ess-mode-map}

Extra binding to note:	'ESC C-\\' indent-region.

Entry to this mode runs the hooks in ess-mode-hook.

You can send text to the inferior ESS process from other buffers containing
ESS source.
    `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 ESS 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-load-file' sources a file of commands to the ESS process.

\\[ess-indent-command] indents for ESS code.
\\[backward-delete-char-untabify] converts tabs to spaces as it moves back.
Comments are indented in a similar way to Emacs-lisp mode:
       `###'	 beginning of line
       `##'	 the same level of indentation as the code
       `#'	 the same column on the right, or to the right of such a
		 column if that is not possible.(default value 40).
		 \\[indent-for-comment] command automatically inserts such a
		 `#' in the right place, or aligns such a comment if it is
		 already inserted.
\\[ess-indent-exp] command indents each line of the ESS grouping following point.

Variables controlling indentation style:
 `ess-tab-always-indent'
    Non-nil means TAB in ESS mode should always reindent the current line,
    regardless of where in the line point is when the TAB command is used.
 `ess-auto-newline'
    Non-nil means automatically newline before and after braces inserted in S
    code.
 `ess-indent-level'
    Indentation of ESS statements within surrounding block.
    The surrounding block's indentation is the indentation of the line on
    which the open-brace appears.
 `ess-continued-statement-offset'
    Extra indentation given to a substatement, such as the then-clause of an
    if or body of a while.
 `ess-continued-brace-offset'
    Extra indentation given to a brace that starts a substatement.
    This is in addition to ess-continued-statement-offset.
 `ess-brace-offset'
    Extra indentation for line if it starts with an open brace.
 `ess-arg-function-offset'
    Extra indent for internal substatements of function `foo' that called
    in `arg=foo(...)' form.
   If not number, the statements are indented at open-parenthesis following
   `foo'.
 `ess-expression-offset'
    Extra indent for internal substatements of `expression' that specified
    in `obj <- expression(...)' form.
    If not number, the statements are indented at open-parenthesis following
    `expression'.
 `ess-brace-imaginary-offset'
    An open brace following other text is treated as if it were
    this far to the right of the start of its line.
 `ess-else-offset'
    Extra indentation for line if it starts with `else'.
 `ess-close-brace-offset'
    Extra indentation for closing braces.
 `ess-fancy-comments'
    Non-nil means distinguish between #, ##, and ### for indentation.

Furthermore, \\[ess-set-style] command enables you to set up predefined ess-mode
indentation style. At present, predefined style are `BSD', `GNU', `K&R', `C++',
`CLB' (quoted from C language style)."
  (kill-all-local-variables) ;; NOTICE THIS!
  (ess-setq-vars-local alist)
  ;; must happen here, since the mode map is set up too early:
;;this is bass-ackwards
;;  (define-key ess-mode-map "("  ;; allow to toggle after customization:
;;    (if ess-r-args-electric-paren 'ess-r-args-auto-show 'self-insert-command))
  (if ess-r-args-electric-paren (define-key ess-mode-map "(" 'ess-r-args-auto-show))
  (ess-write-to-dribble-buffer
   (format "(ess-mode-1): ess-language=%s, ess-dialect=%s buf=%s \n"
	   ess-language
	   ess-dialect
	   (current-buffer)))
  ;; (ess-write-to-dribble-buffer
  ;;  (format "(ess-mode-1.2): ess-process= %s \n"
  ;;   (ess-local-process-name ess-local-process-name "none")))
  (ess-write-to-dribble-buffer
   (format "(ess-mode-1.5): alist=%s \n" alist))
  (setq major-mode 'ess-mode)
  (setq mode-name (concat "ESS[" ess-language "]")) ; was ess-dialect
  ;; The following line does the next 20 or so :-).
  (ess-write-to-dribble-buffer
   (format "(ess-mode-1.6): editing-alist=%s \n"
	   ess-mode-editing-alist))
  (ess-setq-vars-local ess-mode-editing-alist)

  (ess-set-style ess-style t)
  (use-local-map ess-mode-map)
  (set-syntax-table ess-mode-syntax-table)

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

  ;;  (make-local-variable 'paragraph-start)
  ;;  (setq paragraph-start (concat "^$\\|" page-delimiter))
  ;;  (make-local-variable 'paragraph-separate)
  ;;  (setq paragraph-separate paragraph-start)
  ;;  (make-local-variable 'paragraph-ignore-fill-prefix)
  ;;  (setq paragraph-ignore-fill-prefix t)
  ;;  (make-local-variable 'indent-line-function)
  ;;  (setq indent-line-function 'ess-indent-line)
  ;;  (make-local-variable 'require-final-newline)
  ;;  (setq require-final-newline t)
  ;;  (make-local-variable 'comment-start)
  ;;  (setq comment-start "#")
  ;;  (make-local-variable 'comment-start-skip)
  ;;  (setq comment-start-skip "#+ *")
  ;;  (make-local-variable 'comment-column)
  ;;  (setq comment-column 40)
  ;;  (make-local-variable 'comment-indent-function)
  ;;  (setq comment-indent-function 'ess-comment-indent)
  ;;  (make-local-variable 'parse-sexp-ignore-comments)
  ;;  (setq parse-sexp-ignore-comments t)
  ;;  (ess-set-style ess-default-style)
  ;;  (make-local-variable 'ess-local-process-name)
  ;;  (make-local-variable 'ess-keep-dump-files)
  (put 'ess-local-process-name 'permanent-local t) ; protect from RCS
  (setq mode-line-process ;; AJR: in future, XEmacs will use modeline-process.
	'(" [" (ess-local-process-name ess-local-process-name "none") "]"))
  ;; SJE Tue 28 Dec 2004: do not attempt to load object name db.
  ;; (ess-load-object-name-db-file)
  (if (> emacs-major-version 21)
      (run-mode-hooks 'ess-mode-hook)
    ;; old emacs 21.x
    (run-hooks 'ess-mode-hook))
  (ess-write-to-dribble-buffer "\nFinished setting up ESS-mode.\n"))

;;*;; User commands in ess-mode

;;;*;;; Handy commands

(defun ess-execute-in-tb ()
  "Like `ess-execute', but always evaluates in temp buffer."
  (interactive)
  (let ((ess-execute-in-process-buffer nil))
    (call-interactively 'ess-execute)))

;;;*;;; Buffer motion/manipulation commands

(defvar ess-set-function-start
  ;; setAs, setGeneric;  setMethod, setReplaceMethod, setGroupMethod
  "^set[MGAR][Ma-z]+\\s-?("
)

;; common R and S
(let*
    ((Q     "\\s\"")			; quote
     (repl "\\(<-\\)?")                 ; replacement (function)
     (Sym-0 "\\(\\sw\\|\\s_\\)")	; symbol
     (Symb  (concat Sym-0 "+"))
     (xSymb (concat "\\[?\\[?" Sym-0 "*")); symbol / [ / [[ / [symbol / [[symbol
     ;; FIXME: allow '%foo%' but only when quoted; don't allow [_0-9] at beg.
     (_or_  "\\)\\|\\(")		; OR
     (space "\\(\\s-\\|\n\\)*")         ; white space

     (part-1 (concat
	      "\\(" ;;--------outer Either-------
	      "\\(\\("		; EITHER
	      Q xSymb repl Sym-0 "*" Q  ; quote ([) (replacement) symbol quote
	      _or_
	      "\\(^\\|[ ]\\)" Symb 	; (beginning of name) + Symb
	      "\\)\\)"))	; END EITHER OR

     (set-S4-exp
      (concat
       "^set\\(As\\|Method\\|Generic\\|GroupMethod\\|ReplaceMethod\\)(" ; S4 ...
       Q xSymb Q "," space
       ;; and now often `` signature(......), : ''
       ".*" ;; <<< FIXME ???
       ))

     (part-2 (concat
	      "\\|" ;;--------outer Or ---------
	      set-S4-exp
	      "\\)" ;;--------end outer Either/Or-------

	      "\\(" space "\\s<.*\\s>\\)*"	; whitespace, comment
	      ;; FIXME: in principle we should skip 'definition *= *' here
	      space "function\\s-*(" ; whitespace, function keyword, parenthesis
	      ))
     )
  ;; SJE: 2007-07-16 add to quieten byte-compiler.
  (defvar ess-function-pattern nil
    "Regexp to match the beginning of a function in S buffers.")
  (defvar ess-R-function-pattern
    (concat part-1
	    "\\s-*\\(<-\\|=\\)"	; whitespace, assign
	    part-2)
    "The regular expression for matching the beginning of an R function.")

  (defvar ess-S-function-pattern
    (concat part-1
	    "\\s-*\\(<-\\|_\\|=\\)" ; whitespace, assign (incl. "_")
	    part-2)
    "The regular expression for matching the beginning of an S function.")

); {end let}

(defun ess-beginning-of-function (&optional no-error)
  "Leave (and return) the point at the beginning of the current ESS function.
If the optional argument NO-ERROR is non-nil, the function returns nil when
it cannot find a function beginning."
  (interactive)
  (let ((init-point (point))
	(in-set-S4 nil)
	beg end done)


    ;; Note that we must be sure that we are past the 'function (' text,
    ;; such that ess-function-pattern is found in BACKwards later.
    ;; In case we're sitting in a function or setMethod() header,
    ;; we need to move further.
    ;; But not too far! {wrongly getting into next function}
    (if (search-forward "("
			(ess-line-end-position 2) t); at most end of next line
	(forward-char 1))

    (setq end (point)); = init-point when nothing found

    (ess-write-to-dribble-buffer
     (format "ess-BEG-of-fun after 'search-FWD (': Ini-pt %d, (p)-Ini-pt = %d\n"
	     init-point (- end init-point)))
    (if (and (> end 1)
	     (re-search-backward ;; in case of setMethod() etc ..
	      ess-set-function-start
	      ;; at most 1 line earlier {2 is too much: finds previous sometimes}
	      (+ 1 (ess-line-end-position -1)) t))

	(progn ;; yes we *have* an S4  setMethod(..)-like
	  (setq in-set-S4 t
		beg (point))
	  (ess-write-to-dribble-buffer
	   (format " set*() function start at position %d" beg))
	  ;; often need to move even further to have 'function(' to our left
;; 	  (if (search-forward "function" end t)
;; 	      (ess-write-to-dribble-buffer
;; 	       (format " -> 'function' already at pos %d\n" (point)))
;; 	    ;; else need to move further
	    (goto-char end)
	    ;; search 4 lines, we are pretty sure now:
	    (search-forward
	     "function" (ess-line-end-position 4) t)
;;        )
	  (search-forward "(" (ess-line-end-position) t)
	  )
      ;; else: regular function; no set*Method(..)
      (ess-write-to-dribble-buffer "ELSE  not in setMethod() header ...\n")
      )

    (while (not done)
      ;; Need this while loop to skip over local function definitions

      ;; In the case of non-success, it is inefficiently
      ;; going back in the buffer through all function definitions...
      (unless
	  (and (re-search-backward ess-function-pattern (point-min) t)
	       (not (ess-inside-string-or-comment-p (point))))
	(goto-char init-point)
	(if no-error
	    (setq  done t  beg nil)
	  ;; else [default]:
	  (error "Point is not in a function according to 'ess-function-pattern'.")
	  ))
      (unless done
	(setq beg (point))
	(ess-write-to-dribble-buffer
	 (format "\tMatch,Pt:(%d,%d),%d\n"
		 (match-beginning 0) (match-end 0) beg))
	(setq in-set-S4 (looking-at ess-set-function-start))
	(forward-list 1)		; get over arguments

	;; The following used to bomb  "Unbalanced parentheses", n1, n2
	;; when the above (search-forward "(" ..) wasn't delimited :
	(unless in-set-S4 (forward-sexp 1)) ; move over braces
	;;DBG (ess-write-to-dribble-buffer "|")
	(setq end (point))
	(goto-char beg)
	;; current function must begin and end around point
	(setq done (and (>= end init-point) (<= beg init-point)))))
    beg))

(defun ess-end-of-function (&optional beginning no-error)
  "Leave the point at the end of the current ESS function.
Optional argument for location of beginning.  Return '(beg end)."
  (interactive)
  (if beginning
      (goto-char beginning)
    (setq beginning (ess-beginning-of-function no-error)))
  (if beginning
      ;; *hack* only for S (R || S+): are we in setMethod(..) etc?
      (let ((in-set-S4 (looking-at ess-set-function-start))
	    (end-pos) (npos))
	(ess-write-to-dribble-buffer
	 (format "ess-END-of-fun: S4=%s, beginning = %d\n" in-set-S4 beginning))
	(forward-list 1)	; get over arguments || whole set*(..)
	(unless in-set-S4 (forward-sexp 1)) ; move over braces
	(ess-write-to-dribble-buffer
	 (format "ess-END-of-fun: found #1 : %d\n" (point)))

	;; For one-line functions withOUT '{ .. }' body  -- added 2008-07-23 --
	;; particularly helpful for C-c C-c (ess-eval-function-or-paragraph-and-step):
	(setq end-pos (ess-line-end-position))
	(while (< (point) end-pos) ; if not at end of line, move further forward
	  (goto-char ;; careful not to move too far; e.g. *not* over empty lines:
	   (min (save-excursion (forward-sexp 1) (point))
		(save-excursion (forward-paragraph 1) (point)))))
	(list beginning (point))
	)
    ;; else: 'no-error': we are not in a function
    nil))

;;; Kurt's version, suggested 1997-03-06.
(defun ess-mark-function ()
  "Put mark at end of ESS function, point at beginning."
  (interactive)
  (let ((beg (ess-beginning-of-function)))
    (push-mark (point))
    (ess-end-of-function beg)
    (exchange-point-and-mark)))

;; Donated by Stephen Eglen, 2001-08-29:
;; This command is analogous to `narrow-to-defun' (elisp)
;; and `py-narrow-to-defun' (python)."
(defun ess-narrow-to-defun ()
  "Make text outside current function invisible.
If text is already narrowed, this is removed before narrowing to the
current function."
  (interactive)
   ;; if point is not in a function, ess-end-of-function catches the error.
  (save-excursion
    (widen)
    (let* ((beg-end (ess-end-of-function)))
      (narrow-to-region (nth 0 beg-end) (nth 1 beg-end)))))

;;*;; Loading files

(defun ess-check-modifications nil
  "Check whether loading this file would overwrite some ESS objects
which have been modified more recently than this file, and confirm
if this is the case."
  ;; FIXME: this should really cycle through all top-level assignments in
  ;; the buffer
  (and (buffer-file-name) ess-filenames-map
       (let ((sourcemod (nth 5 (file-attributes (buffer-file-name))))
	     (objname))
	 (save-excursion
	   (goto-char (point-min))
	   ;; Get name of assigned object, if we can find it
	   (setq objname
		 (and
		  (re-search-forward
		   "^\\s *\"?\\(\\(\\sw\\|\\s_\\)+\\)\"?\\s *[<_]"
		   nil
		   t)
		  (buffer-substring (match-beginning 1)
				    (match-end 1)))))
	 (and
	  sourcemod			; the file may have been deleted
	  objname			; may not have been able to
					; find name
	  (ess-modtime-gt (ess-object-modtime objname) sourcemod)
	  (not (y-or-n-p

		(format
		 "The ESS object %s is newer than this file. Continue?"
		 objname)))
	  (error "Aborted")))))

(defun ess-check-source (fname)
  "If file FNAME has an unsaved buffer, offer to save it.
Returns t if the buffer existed and was modified, but was not saved."
  (let ((buff (get-file-buffer fname)))
    ;; RMH: Corrections noted below are needed for C-c C-l to work
    ;; correctly when issued from *S* buffer.
    ;; The following barfs since
    ;; 1. `if' does not accept a buffer argument, `not' does.
    ;; 2. (buffer-file-name) is not necessarily defined for *S*
    ;;(if buff
    ;; (let ((deleted (not (file-exists-p (buffer-file-name)))))
    ;; Next 2 lines are RMH's solution:
    (if (not(not buff))
	(let ((deleted (not (file-exists-p fname))))
	  (if (and deleted (not (buffer-modified-p buff)))
	      ;; Buffer has been silently deleted, so silently save
	      (save-excursion
		(set-buffer buff)
		(set-buffer-modified-p t)
		(save-buffer))
	    (if (and (buffer-modified-p buff)
		     (or ess-mode-silently-save
			 (y-or-n-p
			  (format "Save buffer %s first? "
				  (buffer-name buff)))))
		(save-excursion
		  (set-buffer buff)
		  (save-buffer))))
	  (buffer-modified-p buff)))))

(defun ess-parse-errors (showerr)
  "Jump to error in last loaded ESS source file.
With prefix argument, only shows the errors ESS reported."
  (interactive "P")
  (ess-make-buffer-current)
  (let ((errbuff (get-buffer ess-error-buffer-name)))
    (if (not errbuff)
	(error "You need to do a load first!")
      (set-buffer errbuff)
      (goto-char (point-max))
      (if
	  (re-search-backward
	   ;; FIXME: R does not give "useful" error messages -
	   ;; -----  by default: We (ESS) could try to use a more useful one, via
	   ;;   options(error = essErrorHandler)
	   "^\\(Syntax error: .*\\) at line \\([0-9]*\\), file \\(.*\\)$"
	   nil
	   t)
	  (let* ((filename (buffer-substring (match-beginning 3) (match-end 3)))
		 (fbuffer (get-file-buffer filename))
		 (linenum
		  (string-to-number
		   (buffer-substring (match-beginning 2) (match-end 2))))
		 (errmess (buffer-substring (match-beginning 1) (match-end 1))))
	    (if showerr
		  (ess-display-temp-buffer errbuff)
	      (if fbuffer nil
		(setq fbuffer (find-file-noselect filename))
		(save-excursion
		  (set-buffer fbuffer)
		  (ess-mode)))
	      (pop-to-buffer fbuffer)
	      ;;(goto-line linenum) gives warning: is said to be replaced by
	      (goto-char (point-min)) (forward-line (1- linenum)))
	    (princ errmess t))
	(message "Not a syntax error.")
	(ess-display-temp-buffer errbuff)))))

;;*;; ESS code formatting/indentation

;;;*;;; User commands

(defun ess-electric-brace (arg)
  "Insert character and correct line's indentation."
  (interactive "P")
  ;; skeleton-pair takes precedence
  (if (and (boundp 'skeleton-pair) skeleton-pair (featurep 'skeleton))
      (skeleton-pair-insert-maybe "{")
    ;; else
    (let (insertpos)
      (if (and (not arg)
	       (eolp)
	       (or (save-excursion
		     (skip-chars-backward " \t")
		     (bolp))
		   (if ess-auto-newline (progn (ess-indent-line) (newline) t) nil)))
	  (progn
	    (insert (if (featurep 'xemacs) (event-to-character last-command-event) last-command-event))
	    (ess-indent-line)
	    (if ess-auto-newline
		(progn
		  (newline)
		  ;; (newline) may have done auto-fill
		  (setq insertpos (- (point) 2))
		  (ess-indent-line)))
	    (save-excursion
	      (if insertpos (goto-char (1+ insertpos)))
	      (delete-char -1))))
      (if insertpos
	  (save-excursion
	    (goto-char insertpos)
	    (self-insert-command (prefix-numeric-value arg)))
	(self-insert-command (prefix-numeric-value arg))))))

(defun ess-indent-command (&optional whole-exp)
  "Indent current line as ESS code, or in some cases insert a tab character.
If `ess-tab-always-indent' is non-nil (the default), always indent
current line.  Otherwise, indent the current line only if point is at
the left margin or in the line's indentation; otherwise insert a tab.
A numeric argument, regardless of its value, means indent rigidly all
the lines of the expression starting after point so that this line
becomes properly indented.  The relative indentation among the lines
of the expression are preserved."
  (interactive "P")
  (if whole-exp
      ;; If arg, always indent this line as S
      ;; and shift remaining lines of expression the same amount.
      (let ((shift-amt (ess-indent-line))
	    beg end)
	(save-excursion
	  (if ess-tab-always-indent
	      (beginning-of-line))
	  (setq beg (point))
	  (backward-up-list 1)
	  (forward-list 1)
	  (setq end (point))
	  (goto-char beg)
	  (forward-line 1)
	  (setq beg (point)))
	(if (> end beg)
	    (indent-code-rigidly beg end shift-amt)))
    (if (and (not ess-tab-always-indent)
	     (save-excursion
	       (skip-chars-backward " \t")
	       (not (bolp))))
	(insert-tab)
      (ess-indent-line))))

(defun ess-indent-exp ()
  "Indent each line of the ESS grouping following point."
  (interactive)
  (let ((indent-stack (list nil))
	(contain-stack (list (point)))
	(case-fold-search nil)
	;; restart
	outer-loop-done	innerloop-done state ostate
	this-indent
	last-sexp
	last-depth
	at-else at-brace
	(opoint (point))
	(next-depth 0))
    (save-excursion
      (forward-sexp 1))
    (save-excursion
      (setq outer-loop-done nil)
      (while (and (not (eobp)) (not outer-loop-done))
	(setq last-depth next-depth)
	;; Compute how depth changes over this line
	;; plus enough other lines to get to one that
	;; does not end inside a comment or string.
	;; Meanwhile, do appropriate indentation on comment lines.
	(setq innerloop-done nil)
	(while (and (not innerloop-done)
		    (not (and (eobp) (setq outer-loop-done t))))
	  (setq ostate state)
	  (setq state (parse-partial-sexp (point) (progn (end-of-line) (point))
					  nil nil state))
	  (setq next-depth (car state))
	  (if (and (car (cdr (cdr state)))
		   (>= (car (cdr (cdr state))) 0))
	      (setq last-sexp (car (cdr (cdr state)))))
	  (if (or (nth 4 ostate))
	      (ess-indent-line))
	  (if (nth 4 state)
	      (and (ess-indent-line)
		   (setcar (nthcdr 4 state) nil)))
	  (if (or (nth 3 state))
	      (forward-line 1)
	    (setq innerloop-done t)))
	(if (<= next-depth 0)
	    (setq outer-loop-done t))
	(if outer-loop-done
	    nil
	  ;; If this line had ..))) (((.. in it, pop out of the levels
	  ;; that ended anywhere in this line, even if the final depth
	  ;; doesn't indicate that they ended.
	  (while (> last-depth (nth 6 state))
	    (setq indent-stack (cdr indent-stack)
		  contain-stack (cdr contain-stack)
		  last-depth (1- last-depth)))
	  (if (/= last-depth next-depth)
	      (setq last-sexp nil))
	  ;; Add levels for any parens that were started in this line.
	  (while (< last-depth next-depth)
	    (setq indent-stack (cons nil indent-stack)
		  contain-stack (cons nil contain-stack)
		  last-depth (1+ last-depth)))
	  (if (null (car contain-stack))
	      (setcar contain-stack (or (car (cdr state))
					(save-excursion (forward-sexp -1)
							(point)))))
	  (forward-line 1)
	  (skip-chars-forward " \t")
	  (if (eolp)
	      nil
	    (if (and (car indent-stack)
		     (>= (car indent-stack) 0))
		;; Line is on an existing nesting level.
		;; Lines inside parens are handled specially.
		(if (/= (char-after (car contain-stack)) ?{)
		    (setq this-indent (car indent-stack))
		  ;; Line is at statement level.
		  ;; Is it a new statement?  Is it an else?
		  ;; Find last non-comment character before this line
		  (save-excursion
		    (setq at-else (looking-at "else\\W"))
		    (setq at-brace (= (following-char) ?{))
		    (ess-backward-to-noncomment opoint)
		    (if (ess-continued-statement-p)
			;; Preceding line did not end in comma or semi;
			;; indent this line  ess-continued-statement-offset
			;; more than previous.
			(progn
			  (ess-backward-to-start-of-continued-exp (car contain-stack))
			  (setq this-indent
				(+ ess-continued-statement-offset (current-column)
				   (if at-brace ess-continued-brace-offset 0))))
		      ;; Preceding line ended in comma or semi;
		      ;; use the standard indent for this level.
		      (if at-else
			  (progn (ess-backward-to-start-of-if opoint)
				 (setq this-indent (+ ess-else-offset
						      (current-indentation))))
			(setq this-indent (car indent-stack))))))
	      ;; Just started a new nesting level.
	      ;; Compute the standard indent for this level.
	      (let ((val (ess-calculate-indent
			   (if (car indent-stack)
			       (- (car indent-stack))))))
		(setcar indent-stack
			(setq this-indent val))))
	    ;; Adjust line indentation according to its contents
	    (if (= (following-char) ?})
		;;(setq this-indent (- this-indent ess-indent-level)))
		(setq this-indent (+ this-indent
				     (- ess-close-brace-offset ess-indent-level))))
	    (if (= (following-char) ?{)
		(setq this-indent (+ this-indent ess-brace-offset)))
	    ;; Put chosen indentation into effect.
	    (or (= (current-column) this-indent)
		(= (following-char) ?\#)
		(progn
		  (delete-region (point) (progn (beginning-of-line) (point)))
		  (indent-to this-indent)))
	    ;; Indent any comment following the text.
	    (or (looking-at comment-start-skip)
		(if (re-search-forward comment-start-skip
				       (save-excursion (end-of-line)
						       (point)) t)
		    (progn (indent-for-comment) (beginning-of-line))))))))))
;; (message "Indenting ESS expression...done")

;;;*;;; Support functions for indentation

(defun ess-comment-indent ()
  (if (or (looking-at "###")
      (and (looking-at "#!") (= 1 (line-number-at-pos))))
      (current-column)
    (if (looking-at "##")
	(let ((tem (ess-calculate-indent)))
	  (if (listp tem) (car tem) tem))
      (skip-chars-backward " \t")
      (max (if (bolp) 0 (1+ (current-column)))
	   comment-column))))

(defun ess-indent-line ()
  "Indent current line as ESS code.
Return the amount the indentation changed by."
  (let ((indent (ess-calculate-indent nil))
	beg shift-amt
	(case-fold-search nil)
	(pos (- (point-max) (point))))
    (beginning-of-line)
    (setq beg (point))
    (cond ((eq indent nil)
	   (setq indent (current-indentation)))
	  (t
	   (skip-chars-forward " \t")
	   (cond ((and ess-fancy-comments ;; ### or #!
		       (or (looking-at "###")
			   (and (looking-at "#!") (= 1 (line-number-at-pos)))))
		  (setq indent 0))
		 ;; Single # comment
		 ((and ess-fancy-comments
		       (looking-at "#") (not (looking-at "##")))
		  (setq indent comment-column))
		 (t
		  (if (eq indent t) (setq indent 0))
		  (if (listp indent) (setq indent (car indent)))
		  (cond ((and (looking-at "else\\b")
			      (not (looking-at "else\\s_")))
			 (setq indent (save-excursion
					(ess-backward-to-start-of-if)
					(+ ess-else-offset (current-indentation)))))
			((= (following-char) ?})
			 (setq indent
			       (+ indent
				  (- ess-close-brace-offset ess-indent-level))))
			((= (following-char) ?{)
			 (setq indent (+ indent ess-brace-offset))))))))
    (skip-chars-forward " \t")
    (setq shift-amt (- indent (current-column)))
    (if (zerop shift-amt)
	(if (> (- (point-max) pos) (point))
	    (goto-char (- (point-max) pos)))
      (delete-region beg (point))
      (indent-to indent)
      ;; If initial point was within line's indentation,
      ;; position after the indentation.
      ;; Else stay at same point in text.
      (if (> (- (point-max) pos) (point))
	  (goto-char (- (point-max) pos))))
    shift-amt))

(defun ess-calculate-indent (&optional parse-start)
  "Return appropriate indentation for current line as ESS code.
In usual case returns an integer: the column to indent to.
Returns nil if line starts inside a string, t if in a comment."
  (save-excursion
    (beginning-of-line)
    (let ((indent-point (point))
	  (case-fold-search nil)
	  state
	  containing-sexp)
      (if parse-start
	  (goto-char parse-start)
	(beginning-of-defun))
      (while (< (point) indent-point)
	(setq parse-start (point))
	(setq state (parse-partial-sexp (point) indent-point 0))
	(setq containing-sexp (car (cdr state))))
      (cond ((or (nth 3 state) (nth 4 state))
	     ;; return nil or t if should not change this line
	     (nth 4 state))
	    ((null containing-sexp)
	     ;; Line is at top level.  May be data or function definition,
	     (beginning-of-line)
	     (if (and (/= (following-char) ?\{)
		      (save-excursion
			(ess-backward-to-noncomment (point-min))
			(ess-continued-statement-p)))
		 ess-continued-statement-offset
	       0))   ; Unless it starts a function body
	    ((/= (char-after containing-sexp) ?{)
	     ;; line is expression, not statement:
	     ;; indent to just after the surrounding open.
	     (goto-char containing-sexp)
	     (let ((bol (save-excursion (beginning-of-line) (point))))

	       ;; modified by shiba@isac 7.3.1992
	       (cond ((and (numberp ess-expression-offset)
		   (re-search-backward "[ \t]*expression[ \t]*" bol t))
		      ;; This regexp match every "expression".
		      ;; modified by shiba
		      ;;(forward-sexp -1)
		      (beginning-of-line)
		      (skip-chars-forward " \t")
		      ;; End
		      (+ (current-column) ess-expression-offset))
		     ((and (numberp ess-arg-function-offset)
			   (re-search-backward
			    "=[ \t]*\\s\"*\\(\\w\\|\\s_\\)+\\s\"*[ \t]*"
			    bol t))
		      (forward-sexp -1)
		      (+ (current-column) ess-arg-function-offset))
		     ;; "expression" is searched before "=".
		     ;; End
		     (t
		      (progn (goto-char (1+ containing-sexp))
			     (current-column))))))
	    (t
	     ;; Statement level.  Is it a continuation or a new statement?
	     ;; Find previous non-comment character.
	     (goto-char indent-point)
	     (ess-backward-to-noncomment containing-sexp)
	     ;; Back up over label lines, since they don't
	     ;; affect whether our line is a continuation.
	     (while (eq (preceding-char) ?\,)
	       (ess-backward-to-start-of-continued-exp containing-sexp)
	       (beginning-of-line)
	       (ess-backward-to-noncomment containing-sexp))
	     ;; Now we get the answer.
	     (if (ess-continued-statement-p)
		 ;; This line is continuation of preceding line's statement;
		 ;; indent  ess-continued-statement-offset  more than the
		 ;; previous line of the statement.
		 (progn
		   (ess-backward-to-start-of-continued-exp containing-sexp)
		   (+ ess-continued-statement-offset (current-column)
		      (if (save-excursion (goto-char indent-point)
					  (skip-chars-forward " \t")
					  (eq (following-char) ?{))
			  ess-continued-brace-offset 0)))
	       ;; This line starts a new statement.
	       ;; Position following last unclosed open.
	       (goto-char containing-sexp)
	       ;; Is line first statement after an open-brace?
	       (or
		 ;; If no, find that first statement and indent like it.
		 (save-excursion
		   (forward-char 1)
		   (while (progn (skip-chars-forward " \t\n")
				 (looking-at "#"))
		     ;; Skip over comments following openbrace.
		     (forward-line 1))
		   ;; The first following code counts
		   ;; if it is before the line we want to indent.
		   (and (< (point) indent-point)
			(current-column)))
		 ;; If no previous statement,
		 ;; indent it relative to line brace is on.
		 ;; For open brace in column zero, don't let statement
		 ;; start there too.  If ess-indent-level is zero,
		 ;; use ess-brace-offset +
		 ;; ess-continued-statement-offset instead.
		 ;; For open-braces not the first thing in a line,
		 ;; add in ess-brace-imaginary-offset.
		 (+ (if (and (bolp) (zerop ess-indent-level))
			(+ ess-brace-offset ess-continued-statement-offset)
		      ess-indent-level)
		    ;; Move back over whitespace before the openbrace.
		    ;; If openbrace is not first nonwhite thing on the line,
		    ;; add the ess-brace-imaginary-offset.
		    (progn (skip-chars-backward " \t")
			   (if (bolp) 0 ess-brace-imaginary-offset))
		    ;; If the openbrace is preceded by a parenthesized exp,
		    ;; move to the beginning of that;
		    ;; possibly a different line
		    (progn
		      (if (eq (preceding-char) ?\))
			  (forward-sexp -1))
		      ;; Get initial indentation of the line we are on.
		      (current-indentation))))))))))

(defun ess-continued-statement-p ()
  (let ((eol (point)))
    (save-excursion
      (cond ((memq (preceding-char) '(nil ?\, ?\; ?\} ?\{ ?\]))
	     nil)
	    ;; ((bolp))
	    ((= (preceding-char) ?\))
	     (forward-sexp -2)
	     (looking-at "if\\b[ \t]*(\\|function\\b[ \t]*(\\|for\\b[ \t]*(\\|while\\b[ \t]*("))
	    ((progn (forward-sexp -1)
		    (and (looking-at "else\\b\\|repeat\\b")
			 (not (looking-at "else\\s_\\|repeat\\s_"))))
	     (skip-chars-backward " \t")
	     (or (bolp)
		 (= (preceding-char) ?\;)))
	    (t
	     (progn (goto-char eol)
		    (skip-chars-backward " \t")
		    (or (and (> (current-column) 1)
			     (save-excursion (backward-char 1)
					     (looking-at "[-:+*/><=]")))
			(and (> (current-column) 3)
			     (progn (backward-char 3)
				    (looking-at "%[^ \t]%"))))))))))

(defun ess-backward-to-noncomment (lim)
  (let (opoint stop)
    (while (not stop)
      (skip-chars-backward " \t\n\f" lim)
      (setq opoint (point))
      (beginning-of-line)
      (search-forward "#" opoint 'move)
      (skip-chars-backward " \t#")
      (setq stop (or (/= (preceding-char) ?\n) (<= (point) lim)))
	(if stop (point)
	  (beginning-of-line)))))

(defun ess-backward-to-start-of-continued-exp (lim)
  (if (= (preceding-char) ?\))
      (forward-sexp -1))
  (beginning-of-line)
  (if (<= (point) lim)
      (goto-char (1+ lim)))
  (skip-chars-forward " \t"))

(defun ess-backward-to-start-of-if (&optional limit)
  "Move to the start of the last ``unbalanced'' if."
  (or limit (setq limit (save-excursion (beginning-of-defun) (point))))
  (let ((if-level 1)
	(case-fold-search nil))
    (while (not (zerop if-level))
      (backward-sexp 1)
      (cond ((looking-at "else\\b")
	     (setq if-level (1+ if-level)))
	    ((looking-at "if\\b")
	     (setq if-level (1- if-level)))
	    ((< (point) limit)
	     (setq if-level 0)
	     (goto-char limit))))))

;;;*;;; Predefined indentation styles

(defun ess-set-style (&optional style quiet)
  "Set up the `ess-mode' style variables from the `ess-style' variable
or if STYLE argument is given, use that.  It makes the ESS indentation
style variables buffer local."

  (interactive)
  (let ((ess-styles (mapcar 'car ess-style-alist)))
    (if (interactive-p)
	(setq style
	      (let ((style-string ; get style name with completion
		     (completing-read
		      (format
		       "Set ESS mode indentation style (default %s): "
		       ess-default-style)
		      (vconcat ess-styles)
		      (function (lambda (arg) (memq arg ess-styles))))))
		(if (string-equal "" style-string)
		    ess-default-style
		  (intern style-string)))))
    (setq style (or style ess-style)) ; use ess-style if style is nil
    (make-local-variable 'ess-style)
    (if (memq style ess-styles)
	(setq ess-style style)
      (error (concat "Bad ESS style: " style)))
    (if (not quiet)
	(message "ESS-style: %s" ess-style))
    ; finally, set the indentation style variables making each one local
    (mapc (function (lambda (ess-style-pair)
		      (make-local-variable (car ess-style-pair))
		      (set (car ess-style-pair)
			   (cdr ess-style-pair))))
	  (cdr (assq ess-style ess-style-alist)))
    ess-style))

;;*;; Creating and manipulating dump buffers

;;;*;;; The user command

(defun ess-dump-object-into-edit-buffer (object)
  "Edit an ESS object in its own buffer.

Without a prefix argument, this simply finds the file pointed to by
`ess-source-directory'. If this file does not exist, or if a
prefix argument is given, a dump() command is sent to the ESS process to
generate the source buffer."
  (interactive
   (progn
     (ess-force-buffer-current "Process to dump from: ")
     (if (ess-ddeclient-p)
	 (list (read-string "Object to edit: "))
       (ess-read-object-name "Object to edit: "))))

  (let* ((dirname (file-name-as-directory
		   (if (stringp ess-source-directory)
		       ess-source-directory
		     (save-excursion
		       (set-buffer
			(process-buffer (get-ess-process
					 ess-local-process-name)))
		       (ess-setq-vars-local ess-customize-alist)
		       (apply ess-source-directory nil)))))
	 (filename (concat dirname (format ess-dump-filename-template object)))
	 (old-buff (get-file-buffer filename)))

    ;; If the directory doesn't exist, offer to create it
    (if (file-exists-p (directory-file-name dirname)) nil
      (if (y-or-n-p			; Approved
	   (format "Directory %s does not exist. Create it? " dirname))
	  (make-directory (directory-file-name dirname))
	(error "Directory %s does not exist." dirname)))

    ;; Three options:
    ;;	(1) Pop to an existing buffer containing the file in question
    ;;	(2) Find an existing file
    ;;	(3) Create a new file by issuing a dump() command to S
    ;; Force option (3) if there is a prefix arg

    (if current-prefix-arg
	(ess-dump-object object filename)
      (if old-buff
	  (progn
	    (pop-to-buffer old-buff)
	    (message "Popped to edit buffer."))
	;; No current buffer containing desired file
	(if (file-exists-p filename)
	    (progn
	      (ess-find-dump-file-other-window filename)
	      (message "Read %s" filename))
	  ;; No buffer and no file
	  (ess-dump-object object filename))))))

(defun ess-dump-object (object filename)
  "Dump the ESS object OBJECT into file FILENAME."
  (let ((complete-dump-command (format inferior-ess-dump-command
				       object filename)))
    (if (file-writable-p filename) nil
      (error "Can't dump %s as %f is not writeable." object filename))

    (if (ess-ddeclient-p)
	;; ddeclient version
	(ess-dump-object-ddeclient object filename)

      ;; else: "normal", non-DDE behavior:

      ;; Make sure we start fresh
      (if (get-file-buffer filename)
	  (kill-buffer (get-file-buffer filename)))

      (ess-command complete-dump-command)
      (message "Dumped in %s" filename)

      (ess-find-dump-file-other-window filename)

      ;; PD, 1Apr97
      ;;This ensures that the object gets indented according to ess-mode,
      ;;not as the R/S deparser does it. At the same time, it gets rid
      ;;of the mess generated by sending TAB characters to the readline
      ;;functions in R when you eval-buffer-*.
      (indent-region (point-min-marker) (point-max-marker) nil)
      (set-buffer-modified-p nil) ; no need to safe just because of indenting

      ;; Don't make backups for temporary files; it only causes clutter.
      ;; The ESS object itself is a kind of backup, anyway.
      (unless ess-keep-dump-files
	(make-local-variable 'make-backup-files)
	(setq make-backup-files nil))

      ;; Don't get confirmation to delete dumped files when loading
      (if (eq ess-keep-dump-files 'check)
	  (setq ess-keep-dump-files nil))

      ;; Delete the file if necessary
      (if ess-delete-dump-files
	  (delete-file (buffer-file-name))))))

(defun ess-find-dump-file-other-window (filename)
  "Find ESS source file FILENAME in another window."

  (if (file-exists-p filename) nil
    (ess-write-to-dribble-buffer
     (format "%s does not exist. Bad dump, starting fresh." filename)))

  ;; Generate a buffer with the dumped data
  (find-file-other-window filename)
  (ess-mode ess-customize-alist)

  (auto-save-mode 1)		; Auto save in this buffer
  (setq ess-local-process-name ess-current-process-name)

  (if ess-function-template
      (progn
	(goto-char (point-max))
	(if (re-search-backward ess-dumped-missing-re nil t)
	    (progn
	      (replace-match ess-function-template t t)
	      (set-buffer-modified-p nil) ; Don't offer to save if killed now
	      (goto-char (point-min))
	      (condition-case nil
		  ;; This may fail if there are no opens
		  (down-list 1)
		(error nil)))))))

;; AJR: XEmacs, makes sense to dump into "other frame".
(defun ess-dump-object-into-edit-buffer-other-frame (object)
  "Edit an ESS object in its own frame."
  (switch-to-buffer-other-frame (ess-dump-object-into-edit-buffer object)))

(provide 'ess-mode)

 ; 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-mode.el ends here

