;;; lisp-mode.el --- Lisp mode, and its idiosyncratic commands

;; Copyright (C) 1985-1986, 1999-2013 Free Software Foundation, Inc.

;; Maintainer: FSF
;; Keywords: lisp, languages
;; Package: emacs

;; This file is part of GNU Emacs.

;; GNU Emacs 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 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs 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.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; The base major mode for editing Lisp code (used also for Emacs Lisp).
;; This mode is documented in the Emacs manual.

;;; Code:

(defvar font-lock-comment-face)
(defvar font-lock-doc-face)
(defvar font-lock-keywords-case-fold-search)
(defvar font-lock-string-face)

(defvar lisp-mode-abbrev-table nil)
(define-abbrev-table 'lisp-mode-abbrev-table ()
  "Abbrev table for Lisp mode.")

(defvar emacs-lisp-mode-abbrev-table nil)
(define-abbrev-table 'emacs-lisp-mode-abbrev-table ()
  "Abbrev table for Emacs Lisp mode.
It has `lisp-mode-abbrev-table' as its parent."
  :parents (list lisp-mode-abbrev-table))

(defvar emacs-lisp-mode-syntax-table
  (let ((table (make-syntax-table))
        (i 0))
    (while (< i ?0)
      (modify-syntax-entry i "_   " table)
      (setq i (1+ i)))
    (setq i (1+ ?9))
    (while (< i ?A)
      (modify-syntax-entry i "_   " table)
      (setq i (1+ i)))
    (setq i (1+ ?Z))
    (while (< i ?a)
      (modify-syntax-entry i "_   " table)
      (setq i (1+ i)))
    (setq i (1+ ?z))
    (while (< i 128)
      (modify-syntax-entry i "_   " table)
      (setq i (1+ i)))
    (modify-syntax-entry ?\s "    " table)
    ;; Non-break space acts as whitespace.
    (modify-syntax-entry ?\x8a0 "    " table)
    (modify-syntax-entry ?\t "    " table)
    (modify-syntax-entry ?\f "    " table)
    (modify-syntax-entry ?\n ">   " table)
    ;; This is probably obsolete since nowadays such features use overlays.
    ;; ;; Give CR the same syntax as newline, for selective-display.
    ;; (modify-syntax-entry ?\^m ">   " table)
    (modify-syntax-entry ?\; "<   " table)
    (modify-syntax-entry ?` "'   " table)
    (modify-syntax-entry ?' "'   " table)
    (modify-syntax-entry ?, "'   " table)
    (modify-syntax-entry ?@ "'   " table)
    ;; Used to be singlequote; changed for flonums.
    (modify-syntax-entry ?. "_   " table)
    (modify-syntax-entry ?# "'   " table)
    (modify-syntax-entry ?\" "\"    " table)
    (modify-syntax-entry ?\\ "\\   " table)
    (modify-syntax-entry ?\( "()  " table)
    (modify-syntax-entry ?\) ")(  " table)
    (modify-syntax-entry ?\[ "(]  " table)
    (modify-syntax-entry ?\] ")[  " table)
    table)
  "Syntax table used in `emacs-lisp-mode'.")

(defvar lisp-mode-syntax-table
  (let ((table (copy-syntax-table emacs-lisp-mode-syntax-table)))
    (modify-syntax-entry ?\[ "_   " table)
    (modify-syntax-entry ?\] "_   " table)
    (modify-syntax-entry ?# "' 14" table)
    (modify-syntax-entry ?| "\" 23bn" table)
    table)
  "Syntax table used in `lisp-mode'.")

(defvar lisp-imenu-generic-expression
  (list
   (list nil
	 (purecopy (concat "^\\s-*("
			   (eval-when-compile
			     (regexp-opt
			      '("defun" "defun*" "defsubst" "defmacro"
				"defadvice" "define-skeleton"
				"define-minor-mode" "define-global-minor-mode"
				"define-globalized-minor-mode"
				"define-derived-mode" "define-generic-mode"
				"define-compiler-macro" "define-modify-macro"
				"defsetf" "define-setf-expander"
				"define-method-combination"
				"defgeneric" "defmethod") t))
			   "\\s-+\\(\\(\\sw\\|\\s_\\)+\\)"))
	 2)
   (list (purecopy "Variables")
	 (purecopy (concat "^\\s-*("
			   (eval-when-compile
			     (regexp-opt
			      '("defconst" "defconstant" "defcustom"
				"defparameter" "define-symbol-macro") t))
			   "\\s-+\\(\\(\\sw\\|\\s_\\)+\\)"))
	 2)
   ;; For `defvar', we ignore (defvar FOO) constructs.
   (list (purecopy "Variables")
	 (purecopy (concat "^\\s-*(defvar\\s-+\\(\\(\\sw\\|\\s_\\)+\\)"
			   "[[:space:]\n]+[^)]"))
	 1)
   (list (purecopy "Types")
	 (purecopy (concat "^\\s-*("
			   (eval-when-compile
			     (regexp-opt
			      '("defgroup" "deftheme" "deftype" "defstruct"
				"defclass" "define-condition" "define-widget"
				"defface" "defpackage") t))
			   "\\s-+'?\\(\\(\\sw\\|\\s_\\)+\\)"))
	 2))

  "Imenu generic expression for Lisp mode.  See `imenu-generic-expression'.")

;; This was originally in autoload.el and is still used there.
(put 'autoload 'doc-string-elt 3)
(put 'defmethod 'doc-string-elt 3)
(put 'defvar   'doc-string-elt 3)
(put 'defconst 'doc-string-elt 3)
(put 'defalias 'doc-string-elt 3)
(put 'defvaralias 'doc-string-elt 3)
(put 'define-category 'doc-string-elt 2)

(defvar lisp-doc-string-elt-property 'doc-string-elt
  "The symbol property that holds the docstring position info.")

(defun lisp-font-lock-syntactic-face-function (state)
  (if (nth 3 state)
      ;; This might be a (doc)string or a |...| symbol.
      (let ((startpos (nth 8 state)))
        (if (eq (char-after startpos) ?|)
            ;; This is not a string, but a |...| symbol.
            nil
          (let* ((listbeg (nth 1 state))
                 (firstsym (and listbeg
                                (save-excursion
                                  (goto-char listbeg)
                                  (and (looking-at "([ \t\n]*\\(\\(\\sw\\|\\s_\\)+\\)")
                                       (match-string 1)))))
                 (docelt (and firstsym
                              (function-get (intern-soft firstsym)
                                            lisp-doc-string-elt-property))))
            (if (and docelt
                     ;; It's a string in a form that can have a docstring.
                     ;; Check whether it's in docstring position.
                     (save-excursion
                       (when (functionp docelt)
                         (goto-char (match-end 1))
                         (setq docelt (funcall docelt)))
                       (goto-char listbeg)
                       (forward-char 1)
                       (condition-case nil
                           (while (and (> docelt 0) (< (point) startpos)
                                       (progn (forward-sexp 1) t))
                             (setq docelt (1- docelt)))
                         (error nil))
                       (and (zerop docelt) (<= (point) startpos)
                            (progn (forward-comment (point-max)) t)
                            (= (point) (nth 8 state)))))
                font-lock-doc-face
              font-lock-string-face))))
    font-lock-comment-face))

(defun lisp-mode-variables (&optional lisp-syntax keywords-case-insensitive)
  "Common initialization routine for lisp modes.
The LISP-SYNTAX argument is used by code in inf-lisp.el and is
\(uselessly) passed from pp.el, chistory.el, gnus-kill.el and
score-mode.el.  KEYWORDS-CASE-INSENSITIVE non-nil means that for
font-lock keywords will not be case sensitive."
  (when lisp-syntax
    (set-syntax-table lisp-mode-syntax-table))
  (setq-local paragraph-ignore-fill-prefix t)
  (setq-local fill-paragraph-function 'lisp-fill-paragraph)
  ;; Adaptive fill mode gets the fill wrong for a one-line paragraph made of
  ;; a single docstring.  Let's fix it here.
  (setq-local adaptive-fill-function
	      (lambda () (if (looking-at "\\s-+\"[^\n\"]+\"\\s-*$") "")))
  ;; Adaptive fill mode gets in the way of auto-fill,
  ;; and should make no difference for explicit fill
  ;; because lisp-fill-paragraph should do the job.
  ;;  I believe that newcomment's auto-fill code properly deals with it  -stef
  ;;(set (make-local-variable 'adaptive-fill-mode) nil)
  (setq-local indent-line-function 'lisp-indent-line)
  (setq-local outline-regexp ";;;\\(;* [^ \t\n]\\|###autoload\\)\\|(")
  (setq-local outline-level 'lisp-outline-level)
  (setq-local add-log-current-defun-function #'lisp-current-defun-name)
  (setq-local comment-start ";")
  ;; Look within the line for a ; following an even number of backslashes
  ;; after either a non-backslash or the line beginning.
  (setq-local comment-start-skip "\\(\\(^\\|[^\\\\\n]\\)\\(\\\\\\\\\\)*\\);+ *")
  ;; Font lock mode uses this only when it KNOWS a comment is starting.
  (setq-local font-lock-comment-start-skip ";+ *")
  (setq-local comment-add 1)		;default to `;;' in comment-region
  (setq-local comment-column 40)
  ;; Don't get confused by `;' in doc strings when paragraph-filling.
  (setq-local comment-use-global-state t)
  (setq-local imenu-generic-expression lisp-imenu-generic-expression)
  (setq-local multibyte-syntax-as-symbol t)
  (setq-local syntax-begin-function 'beginning-of-defun)
  (setq font-lock-defaults
	`((lisp-font-lock-keywords
	   lisp-font-lock-keywords-1 lisp-font-lock-keywords-2)
	  nil ,keywords-case-insensitive nil nil
	  (font-lock-mark-block-function . mark-defun)
	  (font-lock-syntactic-face-function
	   . lisp-font-lock-syntactic-face-function))))

(defun lisp-outline-level ()
  "Lisp mode `outline-level' function."
  (let ((len (- (match-end 0) (match-beginning 0))))
    (if (looking-at "(\\|;;;###autoload")
	1000
      len)))

(defun lisp-current-defun-name ()
  "Return the name of the defun at point, or nil."
  (save-excursion
    (let ((location (point)))
      ;; If we are now precisely at the beginning of a defun, make sure
      ;; beginning-of-defun finds that one rather than the previous one.
      (or (eobp) (forward-char 1))
      (beginning-of-defun)
      ;; Make sure we are really inside the defun found, not after it.
      (when (and (looking-at "\\s(")
		 (progn (end-of-defun)
			(< location (point)))
		 (progn (forward-sexp -1)
			(>= location (point))))
	(if (looking-at "\\s(")
	    (forward-char 1))
	;; Skip the defining construct name, typically "defun" or
	;; "defvar".
	(forward-sexp 1)
	;; The second element is usually a symbol being defined.  If it
	;; is not, use the first symbol in it.
	(skip-chars-forward " \t\n'(")
	(buffer-substring-no-properties (point)
					(progn (forward-sexp 1)
					       (point)))))))

(defvar lisp-mode-shared-map
  (let ((map (make-sparse-keymap)))
    (define-key map "\e\C-q" 'indent-sexp)
    (define-key map "\177" 'backward-delete-char-untabify)
    ;; This gets in the way when viewing a Lisp file in view-mode.  As
    ;; long as [backspace] is mapped into DEL via the
    ;; function-key-map, this should remain disabled!!
    ;;;(define-key map [backspace] 'backward-delete-char-untabify)
    map)
  "Keymap for commands shared by all sorts of Lisp modes.")

(defvar emacs-lisp-mode-map
  (let ((map (make-sparse-keymap "Emacs-Lisp"))
	(menu-map (make-sparse-keymap "Emacs-Lisp"))
	(lint-map (make-sparse-keymap))
	(prof-map (make-sparse-keymap))
	(tracing-map (make-sparse-keymap)))
    (set-keymap-parent map lisp-mode-shared-map)
    (define-key map "\e\t" 'completion-at-point)
    (define-key map "\e\C-x" 'eval-defun)
    (define-key map "\e\C-q" 'indent-pp-sexp)
    (bindings--define-key map [menu-bar emacs-lisp]
      (cons "Emacs-Lisp" menu-map))
    (bindings--define-key menu-map [eldoc]
      '(menu-item "Auto-Display Documentation Strings" eldoc-mode
		  :button (:toggle . (bound-and-true-p eldoc-mode))
		  :help "Display the documentation string for the item under cursor"))
    (bindings--define-key menu-map [checkdoc]
      '(menu-item "Check Documentation Strings" checkdoc
		  :help "Check documentation strings for style requirements"))
    (bindings--define-key menu-map [re-builder]
      '(menu-item "Construct Regexp" re-builder
		  :help "Construct a regexp interactively"))
    (bindings--define-key menu-map [tracing] (cons "Tracing" tracing-map))
    (bindings--define-key tracing-map [tr-a]
      '(menu-item "Untrace All" untrace-all
		  :help "Untrace all currently traced functions"))
    (bindings--define-key tracing-map [tr-uf]
      '(menu-item "Untrace Function..." untrace-function
		  :help "Untrace function, and possibly activate all remaining advice"))
    (bindings--define-key tracing-map [tr-sep] menu-bar-separator)
    (bindings--define-key tracing-map [tr-q]
      '(menu-item "Trace Function Quietly..." trace-function-background
		  :help "Trace the function with trace output going quietly to a buffer"))
    (bindings--define-key tracing-map [tr-f]
      '(menu-item "Trace Function..." trace-function
		  :help "Trace the function given as an argument"))
    (bindings--define-key menu-map [profiling] (cons "Profiling" prof-map))
    (bindings--define-key prof-map [prof-restall]
      '(menu-item "Remove Instrumentation for All Functions" elp-restore-all
		  :help "Restore the original definitions of all functions being profiled"))
    (bindings--define-key prof-map [prof-restfunc]
      '(menu-item "Remove Instrumentation for Function..." elp-restore-function
		  :help "Restore an instrumented function to its original definition"))

    (bindings--define-key prof-map [sep-rem] menu-bar-separator)
    (bindings--define-key prof-map [prof-resall]
      '(menu-item "Reset Counters for All Functions" elp-reset-all
		  :help "Reset the profiling information for all functions being profiled"))
    (bindings--define-key prof-map [prof-resfunc]
      '(menu-item "Reset Counters for Function..." elp-reset-function
		  :help "Reset the profiling information for a function"))
    (bindings--define-key prof-map [prof-res]
      '(menu-item "Show Profiling Results" elp-results
		  :help "Display current profiling results"))
    (bindings--define-key prof-map [prof-pack]
      '(menu-item "Instrument Package..." elp-instrument-package
		  :help "Instrument for profiling all function that start with a prefix"))
    (bindings--define-key prof-map [prof-func]
      '(menu-item "Instrument Function..." elp-instrument-function
		  :help "Instrument a function for profiling"))
    ;; Maybe this should be in a separate submenu from the ELP stuff?
    (bindings--define-key prof-map [sep-natprof] menu-bar-separator)
    (bindings--define-key prof-map [prof-natprof-stop]
      '(menu-item "Stop Native Profiler" profiler-stop
		  :help "Stop recording profiling information"
		  :enable (and (featurep 'profiler)
			       (profiler-running-p))))
    (bindings--define-key prof-map [prof-natprof-report]
      '(menu-item "Show Profiler Report" profiler-report
		  :help "Show the current profiler report"
		  :enable (and (featurep 'profiler)
			       (profiler-running-p))))
    (bindings--define-key prof-map [prof-natprof-start]
      '(menu-item "Start Native Profiler..." profiler-start
		  :help "Start recording profiling information"))

    (bindings--define-key menu-map [lint] (cons "Linting" lint-map))
    (bindings--define-key lint-map [lint-di]
      '(menu-item "Lint Directory..." elint-directory
		  :help "Lint a directory"))
    (bindings--define-key lint-map [lint-f]
      '(menu-item "Lint File..." elint-file
		  :help "Lint a file"))
    (bindings--define-key lint-map [lint-b]
      '(menu-item "Lint Buffer" elint-current-buffer
		  :help "Lint the current buffer"))
    (bindings--define-key lint-map [lint-d]
      '(menu-item "Lint Defun" elint-defun
		  :help "Lint the function at point"))
    (bindings--define-key menu-map [edebug-defun]
      '(menu-item "Instrument Function for Debugging" edebug-defun
		  :help "Evaluate the top level form point is in, stepping through with Edebug"
		  :keys "C-u C-M-x"))
    (bindings--define-key menu-map [separator-byte] menu-bar-separator)
    (bindings--define-key menu-map [disas]
      '(menu-item "Disassemble Byte Compiled Object..." disassemble
		  :help "Print disassembled code for OBJECT in a buffer"))
    (bindings--define-key menu-map [byte-recompile]
      '(menu-item "Byte-recompile Directory..." byte-recompile-directory
		  :help "Recompile every `.el' file in DIRECTORY that needs recompilation"))
    (bindings--define-key menu-map [emacs-byte-compile-and-load]
      '(menu-item "Byte-compile and Load" emacs-lisp-byte-compile-and-load
		  :help "Byte-compile the current file (if it has changed), then load compiled code"))
    (bindings--define-key menu-map [byte-compile]
      '(menu-item "Byte-compile This File" emacs-lisp-byte-compile
		  :help "Byte compile the file containing the current buffer"))
    (bindings--define-key menu-map [separator-eval] menu-bar-separator)
    (bindings--define-key menu-map [ielm]
      '(menu-item "Interactive Expression Evaluation" ielm
		  :help "Interactively evaluate Emacs Lisp expressions"))
    (bindings--define-key menu-map [eval-buffer]
      '(menu-item "Evaluate Buffer" eval-buffer
		  :help "Execute the current buffer as Lisp code"))
    (bindings--define-key menu-map [eval-region]
      '(menu-item "Evaluate Region" eval-region
		  :help "Execute the region as Lisp code"
		  :enable mark-active))
    (bindings--define-key menu-map [eval-sexp]
      '(menu-item "Evaluate Last S-expression" eval-last-sexp
		  :help "Evaluate sexp before point; print value in minibuffer"))
    (bindings--define-key menu-map [separator-format] menu-bar-separator)
    (bindings--define-key menu-map [comment-region]
      '(menu-item "Comment Out Region" comment-region
		  :help "Comment or uncomment each line in the region"
		  :enable mark-active))
    (bindings--define-key menu-map [indent-region]
      '(menu-item "Indent Region" indent-region
		  :help "Indent each nonblank line in the region"
		  :enable mark-active))
    (bindings--define-key menu-map [indent-line]
      '(menu-item "Indent Line" lisp-indent-line))
    map)
  "Keymap for Emacs Lisp mode.
All commands in `lisp-mode-shared-map' are inherited by this map.")

(defun emacs-lisp-byte-compile ()
  "Byte compile the file containing the current buffer."
  (interactive)
  (if buffer-file-name
      (byte-compile-file buffer-file-name)
    (error "The buffer must be saved in a file first")))

(defun emacs-lisp-byte-compile-and-load ()
  "Byte-compile the current file (if it has changed), then load compiled code."
  (interactive)
  (or buffer-file-name
      (error "The buffer must be saved in a file first"))
  (require 'bytecomp)
  ;; Recompile if file or buffer has changed since last compilation.
  (if (and (buffer-modified-p)
	   (y-or-n-p (format "Save buffer %s first? " (buffer-name))))
      (save-buffer))
  (byte-recompile-file buffer-file-name nil 0 t))

(defcustom emacs-lisp-mode-hook nil
  "Hook run when entering Emacs Lisp mode."
  :options '(turn-on-eldoc-mode imenu-add-menubar-index checkdoc-minor-mode)
  :type 'hook
  :group 'lisp)

(defcustom lisp-mode-hook nil
  "Hook run when entering Lisp mode."
  :options '(imenu-add-menubar-index)
  :type 'hook
  :group 'lisp)

(defcustom lisp-interaction-mode-hook nil
  "Hook run when entering Lisp Interaction mode."
  :options '(turn-on-eldoc-mode)
  :type 'hook
  :group 'lisp)

(define-derived-mode emacs-lisp-mode prog-mode "Emacs-Lisp"
  "Major mode for editing Lisp code to run in Emacs.
Commands:
Delete converts tabs to spaces as it moves back.
Blank lines separate paragraphs.  Semicolons start comments.

\\{emacs-lisp-mode-map}
Entry to this mode calls the value of `emacs-lisp-mode-hook'
if that value is non-nil."
  :group 'lisp
  (lisp-mode-variables)
  (setq imenu-case-fold-search nil)
  (add-hook 'completion-at-point-functions
            'lisp-completion-at-point nil 'local))

;;; Emacs Lisp Byte-Code mode

(eval-and-compile
  (defconst emacs-list-byte-code-comment-re
    (concat "\\(#\\)@\\([0-9]+\\) "
            ;; Make sure it's a docstring and not a lazy-loaded byte-code.
            "\\(?:[^(]\\|([^\"]\\)")))

(defun emacs-lisp-byte-code-comment (end &optional _point)
  "Try to syntactically mark the #@NNN ....^_ docstrings in byte-code files."
  (let ((ppss (syntax-ppss)))
    (when (and (nth 4 ppss)
               (eq (char-after (nth 8 ppss)) ?#))
      (let* ((n (save-excursion
                  (goto-char (nth 8 ppss))
                  (when (looking-at emacs-list-byte-code-comment-re)
                    (string-to-number (match-string 2)))))
             ;; `maxdiff' tries to make sure the loop below terminates.
             (maxdiff n))
        (when n
          (let* ((bchar (match-end 2))
                 (b (position-bytes bchar)))
            (goto-char (+ b n))
            (while (let ((diff (- (position-bytes (point)) b n)))
                     (unless (zerop diff)
                       (when (> diff maxdiff) (setq diff maxdiff))
                       (forward-char (- diff))
                       (setq maxdiff (if (> diff 0) diff
                                       (max (1- maxdiff) 1)))
                       t))))
          (if (<= (point) end)
              (put-text-property (1- (point)) (point)
                                 'syntax-table
                                 (string-to-syntax "> b"))
            (goto-char end)))))))

(defun emacs-lisp-byte-code-syntax-propertize (start end)
  (emacs-lisp-byte-code-comment end (point))
  (funcall
   (syntax-propertize-rules
    (emacs-list-byte-code-comment-re
     (1 (prog1 "< b" (emacs-lisp-byte-code-comment end (point))))))
   start end))

(add-to-list 'auto-mode-alist '("\\.elc\\'" . emacs-lisp-byte-code-mode))
(define-derived-mode emacs-lisp-byte-code-mode emacs-lisp-mode
  "Elisp-Byte-Code"
  "Major mode for *.elc files."
  ;; TODO: Add way to disassemble byte-code under point.
  (setq-local open-paren-in-column-0-is-defun-start nil)
  (setq-local syntax-propertize-function
              #'emacs-lisp-byte-code-syntax-propertize))

;;; Generic Lisp mode.

(defvar lisp-mode-map
  (let ((map (make-sparse-keymap))
	(menu-map (make-sparse-keymap "Lisp")))
    (set-keymap-parent map lisp-mode-shared-map)
    (define-key map "\e\C-x" 'lisp-eval-defun)
    (define-key map "\C-c\C-z" 'run-lisp)
    (bindings--define-key map [menu-bar lisp] (cons "Lisp" menu-map))
    (bindings--define-key menu-map [run-lisp]
      '(menu-item "Run inferior Lisp" run-lisp
		  :help "Run an inferior Lisp process, input and output via buffer `*inferior-lisp*'"))
    (bindings--define-key menu-map [ev-def]
      '(menu-item "Eval defun" lisp-eval-defun
		  :help "Send the current defun to the Lisp process made by M-x run-lisp"))
    (bindings--define-key menu-map [ind-sexp]
      '(menu-item "Indent sexp" indent-sexp
		  :help "Indent each line of the list starting just after point"))
    map)
  "Keymap for ordinary Lisp mode.
All commands in `lisp-mode-shared-map' are inherited by this map.")

(define-derived-mode lisp-mode prog-mode "Lisp"
  "Major mode for editing Lisp code for Lisps other than GNU Emacs Lisp.
Commands:
Delete converts tabs to spaces as it moves back.
Blank lines separate paragraphs.  Semicolons start comments.

\\{lisp-mode-map}
Note that `run-lisp' may be used either to start an inferior Lisp job
or to switch back to an existing one.

Entry to this mode calls the value of `lisp-mode-hook'
if that value is non-nil."
  (lisp-mode-variables nil t)
  (setq-local find-tag-default-function 'lisp-find-tag-default)
  (setq-local comment-start-skip
	      "\\(\\(^\\|[^\\\\\n]\\)\\(\\\\\\\\\\)*\\)\\(;+\\|#|\\) *")
  (setq imenu-case-fold-search t))

(defun lisp-find-tag-default ()
  (let ((default (find-tag-default)))
    (when (stringp default)
      (if (string-match ":+" default)
          (substring default (match-end 0))
	default))))

;; Used in old LispM code.
(defalias 'common-lisp-mode 'lisp-mode)

;; This will do unless inf-lisp.el is loaded.
(defun lisp-eval-defun (&optional and-go)
  "Send the current defun to the Lisp process made by \\[run-lisp]."
  (interactive)
  (error "Process lisp does not exist"))

(defvar lisp-interaction-mode-map
  (let ((map (make-sparse-keymap))
	(menu-map (make-sparse-keymap "Lisp-Interaction")))
    (set-keymap-parent map lisp-mode-shared-map)
    (define-key map "\e\C-x" 'eval-defun)
    (define-key map "\e\C-q" 'indent-pp-sexp)
    (define-key map "\e\t" 'completion-at-point)
    (define-key map "\n" 'eval-print-last-sexp)
    (bindings--define-key map [menu-bar lisp-interaction]
      (cons "Lisp-Interaction" menu-map))
    (bindings--define-key menu-map [eval-defun]
      '(menu-item "Evaluate Defun" eval-defun
		  :help "Evaluate the top-level form containing point, or after point"))
    (bindings--define-key menu-map [eval-print-last-sexp]
      '(menu-item "Evaluate and Print" eval-print-last-sexp
		  :help "Evaluate sexp before point; print value into current buffer"))
    (bindings--define-key menu-map [edebug-defun-lisp-interaction]
      '(menu-item "Instrument Function for Debugging" edebug-defun
		  :help "Evaluate the top level form point is in, stepping through with Edebug"
		  :keys "C-u C-M-x"))
    (bindings--define-key menu-map [indent-pp-sexp]
      '(menu-item "Indent or Pretty-Print" indent-pp-sexp
		  :help "Indent each line of the list starting just after point, or prettyprint it"))
    (bindings--define-key menu-map [complete-symbol]
      '(menu-item "Complete Lisp Symbol" completion-at-point
		  :help "Perform completion on Lisp symbol preceding point"))
    map)
  "Keymap for Lisp Interaction mode.
All commands in `lisp-mode-shared-map' are inherited by this map.")

(define-derived-mode lisp-interaction-mode emacs-lisp-mode "Lisp Interaction"
  "Major mode for typing and evaluating Lisp forms.
Like Lisp mode except that \\[eval-print-last-sexp] evals the Lisp expression
before point, and prints its value into the buffer, advancing point.
Note that printing is controlled by `eval-expression-print-length'
and `eval-expression-print-level'.

Commands:
Delete converts tabs to spaces as it moves back.
Paragraphs are separated only by blank lines.
Semicolons start comments.

\\{lisp-interaction-mode-map}
Entry to this mode calls the value of `lisp-interaction-mode-hook'
if that value is non-nil."
  :abbrev-table nil)

(defun eval-print-last-sexp ()
  "Evaluate sexp before point; print value into current buffer.

If `eval-expression-debug-on-error' is non-nil, which is the default,
this command arranges for all errors to enter the debugger.

Note that printing the result is controlled by the variables
`eval-expression-print-length' and `eval-expression-print-level',
which see."
  (interactive)
  (let ((standard-output (current-buffer)))
    (terpri)
    (eval-last-sexp t)
    (terpri)))


(defun last-sexp-setup-props (beg end value alt1 alt2)
  "Set up text properties for the output of `eval-last-sexp-1'.
BEG and END are the start and end of the output in current-buffer.
VALUE is the Lisp value printed, ALT1 and ALT2 are strings for the
alternative printed representations that can be displayed."
  (let ((map (make-sparse-keymap)))
    (define-key map "\C-m" 'last-sexp-toggle-display)
    (define-key map [down-mouse-2] 'mouse-set-point)
    (define-key map [mouse-2] 'last-sexp-toggle-display)
    (add-text-properties
     beg end
     `(printed-value (,value ,alt1 ,alt2)
		     mouse-face highlight
		     keymap ,map
		     help-echo "RET, mouse-2: toggle abbreviated display"
		     rear-nonsticky (mouse-face keymap help-echo
						printed-value)))))


(defun last-sexp-toggle-display (&optional arg)
  "Toggle between abbreviated and unabbreviated printed representations."
  (interactive "P")
  (save-restriction
    (widen)
    (let ((value (get-text-property (point) 'printed-value)))
      (when value
	(let ((beg (or (previous-single-property-change (min (point-max) (1+ (point)))
							'printed-value)
		       (point)))
	      (end (or (next-single-char-property-change (point) 'printed-value) (point)))
	      (standard-output (current-buffer))
	      (point (point)))
	  (delete-region beg end)
	  (insert (nth 1 value))
	  (or (= beg point)
	      (setq point (1- (point))))
	  (last-sexp-setup-props beg (point)
				 (nth 0 value)
				 (nth 2 value)
				 (nth 1 value))
	  (goto-char (min (point-max) point)))))))

(defun prin1-char (char)
  "Return a string representing CHAR as a character rather than as an integer.
If CHAR is not a character, return nil."
  (and (integerp char)
       (eventp char)
       (let ((c (event-basic-type char))
	     (mods (event-modifiers char))
	     string)
	 ;; Prevent ?A from turning into ?\S-a.
	 (if (and (memq 'shift mods)
		  (zerop (logand char ?\S-\^@))
		  (not (let ((case-fold-search nil))
			 (char-equal c (upcase c)))))
	     (setq c (upcase c) mods nil))
	 ;; What string are we considering using?
	 (condition-case nil
	     (setq string
		   (concat
		    "?"
		    (mapconcat
		     (lambda (modif)
		       (cond ((eq modif 'super) "\\s-")
			     (t (string ?\\ (upcase (aref (symbol-name modif) 0)) ?-))))
		     mods "")
		    (cond
		     ((memq c '(?\; ?\( ?\) ?\{ ?\} ?\[ ?\] ?\" ?\' ?\\)) (string ?\\ c))
		     ((eq c 127) "\\C-?")
		     (t
		      (string c)))))
	   (error nil))
	 ;; Verify the string reads a CHAR, not to some other character.
	 ;; If it doesn't, return nil instead.
	 (and string
	      (= (car (read-from-string string)) char)
	      string))))


(defun preceding-sexp ()
  "Return sexp before the point."
  (let ((opoint (point))
	ignore-quotes
	expr)
    (save-excursion
      (with-syntax-table emacs-lisp-mode-syntax-table
	;; If this sexp appears to be enclosed in `...'
	;; then ignore the surrounding quotes.
	(setq ignore-quotes
	      (or (eq (following-char) ?\')
		  (eq (preceding-char) ?\')))
	(forward-sexp -1)
	;; If we were after `?\e' (or similar case),
	;; use the whole thing, not just the `e'.
	(when (eq (preceding-char) ?\\)
	  (forward-char -1)
	  (when (eq (preceding-char) ??)
	    (forward-char -1)))

	;; Skip over hash table read syntax.
	(and (> (point) (1+ (point-min)))
	     (looking-back "#s" (- (point) 2))
	     (forward-char -2))

	;; Skip over `#N='s.
	(when (eq (preceding-char) ?=)
	  (let (labeled-p)
	    (save-excursion
	      (skip-chars-backward "0-9#=")
	      (setq labeled-p (looking-at "\\(#[0-9]+=\\)+")))
	    (when labeled-p
	      (forward-sexp -1))))

	(save-restriction
	  ;; vladimir@cs.ualberta.ca 30-Jul-1997: skip ` in
	  ;; `variable' so that the value is returned, not the
	  ;; name
	  (if (and ignore-quotes
		   (eq (following-char) ?`))
	      (forward-char))
	  (narrow-to-region (point-min) opoint)
	  (setq expr (read (current-buffer)))
	  ;; If it's an (interactive ...) form, it's more
	  ;; useful to show how an interactive call would
	  ;; use it.
	  (and (consp expr)
	       (eq (car expr) 'interactive)
	       (setq expr
		     (list 'call-interactively
			   (list 'quote
				 (list 'lambda
				       '(&rest args)
				       expr
				       'args)))))
	  expr)))))


(defun eval-last-sexp-1 (eval-last-sexp-arg-internal)
  "Evaluate sexp before point; print value in minibuffer.
With argument, print output into current buffer."
  (let ((standard-output (if eval-last-sexp-arg-internal (current-buffer) t)))
    ;; Setup the lexical environment if lexical-binding is enabled.
    (eval-last-sexp-print-value
     (eval (eval-sexp-add-defvars (preceding-sexp)) lexical-binding))))


(defun eval-last-sexp-print-value (value)
  (let ((unabbreviated (let ((print-length nil) (print-level nil))
			 (prin1-to-string value)))
	(print-length eval-expression-print-length)
	(print-level eval-expression-print-level)
	(beg (point))
	end)
    (prog1
	(prin1 value)
      (let ((str (eval-expression-print-format value)))
	(if str (princ str)))
      (setq end (point))
      (when (and (bufferp standard-output)
		 (or (not (null print-length))
		     (not (null print-level)))
		 (not (string= unabbreviated
			       (buffer-substring-no-properties beg end))))
	(last-sexp-setup-props beg end value
			       unabbreviated
			       (buffer-substring-no-properties beg end))
	))))


(defvar eval-last-sexp-fake-value (make-symbol "t"))

(defun eval-sexp-add-defvars (exp &optional pos)
  "Prepend EXP with all the `defvar's that precede it in the buffer.
POS specifies the starting position where EXP was found and defaults to point."
  (if (not lexical-binding)
      exp
    (save-excursion
      (unless pos (setq pos (point)))
      (let ((vars ()))
        (goto-char (point-min))
        (while (re-search-forward
                "(def\\(?:var\\|const\\|custom\\)[ \t\n]+\\([^; '()\n\t]+\\)"
                pos t)
          (let ((var (intern (match-string 1))))
            (and (not (special-variable-p var))
                 (save-excursion
                   (zerop (car (syntax-ppss (match-beginning 0)))))
              (push var vars))))
        `(progn ,@(mapcar (lambda (v) `(defvar ,v)) vars) ,exp)))))

(defun eval-last-sexp (eval-last-sexp-arg-internal)
  "Evaluate sexp before point; print value in minibuffer.
Interactively, with prefix argument, print output into current buffer.
Truncates long output according to the value of the variables
`eval-expression-print-length' and `eval-expression-print-level'.

If `eval-expression-debug-on-error' is non-nil, which is the default,
this command arranges for all errors to enter the debugger."
  (interactive "P")
  (if (null eval-expression-debug-on-error)
      (eval-last-sexp-1 eval-last-sexp-arg-internal)
    (let ((value
	   (let ((debug-on-error eval-last-sexp-fake-value))
	     (cons (eval-last-sexp-1 eval-last-sexp-arg-internal)
		   debug-on-error))))
      (unless (eq (cdr value) eval-last-sexp-fake-value)
	(setq debug-on-error (cdr value)))
      (car value))))

(defun eval-defun-1 (form)
  "Treat some expressions specially.
Reset the `defvar' and `defcustom' variables to the initial value.
\(For `defcustom', use the :set function if there is one.)
Reinitialize the face according to the `defface' specification."
  ;; The code in edebug-defun should be consistent with this, but not
  ;; the same, since this gets a macroexpanded form.
  (cond ((not (listp form))
	 form)
	((and (eq (car form) 'defvar)
	      (cdr-safe (cdr-safe form))
	      (boundp (cadr form)))
	 ;; Force variable to be re-set.
	 `(progn (defvar ,(nth 1 form) nil ,@(nthcdr 3 form))
		 (setq-default ,(nth 1 form) ,(nth 2 form))))
	;; `defcustom' is now macroexpanded to
	;; `custom-declare-variable' with a quoted value arg.
	((and (eq (car form) 'custom-declare-variable)
	      (default-boundp (eval (nth 1 form) lexical-binding)))
	 ;; Force variable to be bound, using :set function if specified.
	 (let ((setfunc (memq :set form)))
	   (when setfunc
	     (setq setfunc (car-safe (cdr-safe setfunc)))
	     (or (functionp setfunc) (setq setfunc nil)))
	   (funcall (or setfunc 'set-default)
		    (eval (nth 1 form) lexical-binding)
		    ;; The second arg is an expression that evaluates to
		    ;; an expression.  The second evaluation is the one
		    ;; normally performed not by normal execution but by
		    ;; custom-initialize-set (for example), which does not
		    ;; use lexical-binding.
		    (eval (eval (nth 2 form) lexical-binding))))
	 form)
	;; `defface' is macroexpanded to `custom-declare-face'.
	((eq (car form) 'custom-declare-face)
	 ;; Reset the face.
	 (let ((face-symbol (eval (nth 1 form) lexical-binding)))
	   (setq face-new-frame-defaults
		 (assq-delete-all face-symbol face-new-frame-defaults))
	   (put face-symbol 'face-defface-spec nil)
	   (put face-symbol 'face-override-spec nil))
	 form)
	((eq (car form) 'progn)
	 (cons 'progn (mapcar 'eval-defun-1 (cdr form))))
	(t form)))

(defun eval-defun-2 ()
  "Evaluate defun that point is in or before.
The value is displayed in the minibuffer.
If the current defun is actually a call to `defvar',
then reset the variable using the initial value expression
even if the variable already has some other value.
\(Normally `defvar' does not change the variable's value
if it already has a value.\)

With argument, insert value in current buffer after the defun.
Return the result of evaluation."
  ;; FIXME: the print-length/level bindings should only be applied while
  ;; printing, not while evaluating.
  (let ((debug-on-error eval-expression-debug-on-error)
	(print-length eval-expression-print-length)
	(print-level eval-expression-print-level))
    (save-excursion
      ;; Arrange for eval-region to "read" the (possibly) altered form.
      ;; eval-region handles recording which file defines a function or
      ;; variable.  Re-written using `apply' to avoid capturing
      ;; variables like `end'.
      (apply
       #'eval-region
       (let ((standard-output t)
	     beg end form)
	 ;; Read the form from the buffer, and record where it ends.
	 (save-excursion
	   (end-of-defun)
	   (beginning-of-defun)
	   (setq beg (point))
	   (setq form (read (current-buffer)))
	   (setq end (point)))
	 ;; Alter the form if necessary.
	 (setq form (eval-sexp-add-defvars (eval-defun-1 (macroexpand form))))
	 (list beg end standard-output
	       `(lambda (ignore)
		 ;; Skipping to the end of the specified region
		 ;; will make eval-region return.
		 (goto-char ,end)
		 ',form))))))
  ;; The result of evaluation has been put onto VALUES.  So return it.
  (car values))

(defun eval-defun (edebug-it)
  "Evaluate the top-level form containing point, or after point.

If the current defun is actually a call to `defvar' or `defcustom',
evaluating it this way resets the variable using its initial value
expression (using the defcustom's :set function if there is one), even
if the variable already has some other value.  \(Normally `defvar' and
`defcustom' do not alter the value if there already is one.)  In an
analogous way, evaluating a `defface' overrides any customizations of
the face, so that it becomes defined exactly as the `defface' expression
says.

If `eval-expression-debug-on-error' is non-nil, which is the default,
this command arranges for all errors to enter the debugger.

With a prefix argument, instrument the code for Edebug.

If acting on a `defun' for FUNCTION, and the function was
instrumented, `Edebug: FUNCTION' is printed in the minibuffer.  If not
instrumented, just FUNCTION is printed.

If not acting on a `defun', the result of evaluation is displayed in
the minibuffer.  This display is controlled by the variables
`eval-expression-print-length' and `eval-expression-print-level',
which see."
  (interactive "P")
  (cond (edebug-it
	 (require 'edebug)
	 (eval-defun (not edebug-all-defs)))
	(t
	 (if (null eval-expression-debug-on-error)
	     (eval-defun-2)
	   (let ((old-value (make-symbol "t")) new-value value)
	     (let ((debug-on-error old-value))
	       (setq value (eval-defun-2))
	       (setq new-value debug-on-error))
	     (unless (eq old-value new-value)
	       (setq debug-on-error new-value))
	     value)))))

;; May still be used by some external Lisp-mode variant.
(define-obsolete-function-alias 'lisp-comment-indent
    'comment-indent-default "22.1")
(define-obsolete-function-alias 'lisp-mode-auto-fill 'do-auto-fill "23.1")

(defcustom lisp-indent-offset nil
  "If non-nil, indent second line of expressions that many more columns."
  :group 'lisp
  :type '(choice (const nil) integer))
(put 'lisp-indent-offset 'safe-local-variable
     (lambda (x) (or (null x) (integerp x))))

(defcustom lisp-indent-function 'lisp-indent-function
  "A function to be called by `calculate-lisp-indent'.
It indents the arguments of a Lisp function call.  This function
should accept two arguments: the indent-point, and the
`parse-partial-sexp' state at that position.  One option for this
function is `common-lisp-indent-function'."
  :type 'function
  :group 'lisp)

(defun lisp-indent-line (&optional whole-exp)
  "Indent current line as Lisp code.
With argument, indent any additional lines of the same expression
rigidly along with this one."
  (interactive "P")
  (let ((indent (calculate-lisp-indent)) shift-amt end
	(pos (- (point-max) (point)))
	(beg (progn (beginning-of-line) (point))))
    (skip-chars-forward " \t")
    (if (or (null indent) (looking-at "\\s<\\s<\\s<"))
	;; Don't alter indentation of a ;;; comment line
	;; or a line that starts in a string.
        ;; FIXME: inconsistency: comment-indent moves ;;; to column 0.
	(goto-char (- (point-max) pos))
      (if (and (looking-at "\\s<") (not (looking-at "\\s<\\s<")))
	  ;; Single-semicolon comment lines should be indented
	  ;; as comment lines, not as code.
	  (progn (indent-for-comment) (forward-char -1))
	(if (listp indent) (setq indent (car indent)))
	(setq shift-amt (- indent (current-column)))
	(if (zerop shift-amt)
	    nil
	  (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))))))

(defvar calculate-lisp-indent-last-sexp)

(defun calculate-lisp-indent (&optional parse-start)
  "Return appropriate indentation for current line as Lisp code.
In usual case returns an integer: the column to indent to.
If the value is nil, that means don't change the indentation
because the line starts inside a string.

The value can also be a list of the form (COLUMN CONTAINING-SEXP-START).
This means that following lines at the same level of indentation
should not necessarily be indented the same as this line.
Then COLUMN is the column to indent to, and CONTAINING-SEXP-START
is the buffer position of the start of the containing expression."
  (save-excursion
    (beginning-of-line)
    (let ((indent-point (point))
          state paren-depth
          ;; setting this to a number inhibits calling hook
          (desired-indent nil)
          (retry t)
          calculate-lisp-indent-last-sexp containing-sexp)
      (if parse-start
          (goto-char parse-start)
          (beginning-of-defun))
      ;; Find outermost containing sexp
      (while (< (point) indent-point)
        (setq state (parse-partial-sexp (point) indent-point 0)))
      ;; Find innermost containing sexp
      (while (and retry
		  state
                  (> (setq paren-depth (elt state 0)) 0))
        (setq retry nil)
        (setq calculate-lisp-indent-last-sexp (elt state 2))
        (setq containing-sexp (elt state 1))
        ;; Position following last unclosed open.
        (goto-char (1+ containing-sexp))
        ;; Is there a complete sexp since then?
        (if (and calculate-lisp-indent-last-sexp
		 (> calculate-lisp-indent-last-sexp (point)))
            ;; Yes, but is there a containing sexp after that?
            (let ((peek (parse-partial-sexp calculate-lisp-indent-last-sexp
					    indent-point 0)))
              (if (setq retry (car (cdr peek))) (setq state peek)))))
      (if retry
          nil
        ;; Innermost containing sexp found
        (goto-char (1+ containing-sexp))
        (if (not calculate-lisp-indent-last-sexp)
	    ;; indent-point immediately follows open paren.
	    ;; Don't call hook.
            (setq desired-indent (current-column))
	  ;; Find the start of first element of containing sexp.
	  (parse-partial-sexp (point) calculate-lisp-indent-last-sexp 0 t)
	  (cond ((looking-at "\\s(")
		 ;; First element of containing sexp is a list.
		 ;; Indent under that list.
		 )
		((> (save-excursion (forward-line 1) (point))
		    calculate-lisp-indent-last-sexp)
		 ;; This is the first line to start within the containing sexp.
		 ;; It's almost certainly a function call.
		 (if (= (point) calculate-lisp-indent-last-sexp)
		     ;; Containing sexp has nothing before this line
		     ;; except the first element.  Indent under that element.
		     nil
		   ;; Skip the first element, find start of second (the first
		   ;; argument of the function call) and indent under.
		   (progn (forward-sexp 1)
			  (parse-partial-sexp (point)
					      calculate-lisp-indent-last-sexp
					      0 t)))
		 (backward-prefix-chars))
		(t
		 ;; Indent beneath first sexp on same line as
		 ;; `calculate-lisp-indent-last-sexp'.  Again, it's
		 ;; almost certainly a function call.
		 (goto-char calculate-lisp-indent-last-sexp)
		 (beginning-of-line)
		 (parse-partial-sexp (point) calculate-lisp-indent-last-sexp
				     0 t)
		 (backward-prefix-chars)))))
      ;; Point is at the point to indent under unless we are inside a string.
      ;; Call indentation hook except when overridden by lisp-indent-offset
      ;; or if the desired indentation has already been computed.
      (let ((normal-indent (current-column)))
        (cond ((elt state 3)
               ;; Inside a string, don't change indentation.
	       nil)
              ((and (integerp lisp-indent-offset) containing-sexp)
               ;; Indent by constant offset
               (goto-char containing-sexp)
               (+ (current-column) lisp-indent-offset))
              ;; in this case calculate-lisp-indent-last-sexp is not nil
              (calculate-lisp-indent-last-sexp
               (or
                ;; try to align the parameters of a known function
                (and lisp-indent-function
                     (not retry)
                     (funcall lisp-indent-function indent-point state))
                ;; If the function has no special alignment
		;; or it does not apply to this argument,
		;; try to align a constant-symbol under the last
                ;; preceding constant symbol, if there is such one of
                ;; the last 2 preceding symbols, in the previous
                ;; uncommented line.
                (and (save-excursion
                       (goto-char indent-point)
                       (skip-chars-forward " \t")
                       (looking-at ":"))
                     ;; The last sexp may not be at the indentation
                     ;; where it begins, so find that one, instead.
                     (save-excursion
                       (goto-char calculate-lisp-indent-last-sexp)
		       ;; Handle prefix characters and whitespace
		       ;; following an open paren.  (Bug#1012)
                       (backward-prefix-chars)
                       (while (and (not (looking-back "^[ \t]*\\|([ \t]+"))
                                   (or (not containing-sexp)
                                       (< (1+ containing-sexp) (point))))
                         (forward-sexp -1)
                         (backward-prefix-chars))
                       (setq calculate-lisp-indent-last-sexp (point)))
                     (> calculate-lisp-indent-last-sexp
                        (save-excursion
                          (goto-char (1+ containing-sexp))
                          (parse-partial-sexp (point) calculate-lisp-indent-last-sexp 0 t)
                          (point)))
                     (let ((parse-sexp-ignore-comments t)
                           indent)
                       (goto-char calculate-lisp-indent-last-sexp)
                       (or (and (looking-at ":")
                                (setq indent (current-column)))
                           (and (< (line-beginning-position)
                                   (prog2 (backward-sexp) (point)))
                                (looking-at ":")
                                (setq indent (current-column))))
                       indent))
                ;; another symbols or constants not preceded by a constant
                ;; as defined above.
                normal-indent))
              ;; in this case calculate-lisp-indent-last-sexp is nil
              (desired-indent)
              (t
               normal-indent))))))

(defun lisp-indent-function (indent-point state)
  "This function is the normal value of the variable `lisp-indent-function'.
The function `calculate-lisp-indent' calls this to determine
if the arguments of a Lisp function call should be indented specially.

INDENT-POINT is the position at which the line being indented begins.
Point is located at the point to indent under (for default indentation);
STATE is the `parse-partial-sexp' state for that position.

If the current line is in a call to a Lisp function that has a non-nil
property `lisp-indent-function' (or the deprecated `lisp-indent-hook'),
it specifies how to indent.  The property value can be:

* `defun', meaning indent `defun'-style
  \(this is also the case if there is no property and the function
  has a name that begins with \"def\", and three or more arguments);

* an integer N, meaning indent the first N arguments specially
  (like ordinary function arguments), and then indent any further
  arguments like a body;

* a function to call that returns the indentation (or nil).
  `lisp-indent-function' calls this function with the same two arguments
  that it itself received.

This function returns either the indentation to use, or nil if the
Lisp function does not specify a special indentation."
  (let ((normal-indent (current-column)))
    (goto-char (1+ (elt state 1)))
    (parse-partial-sexp (point) calculate-lisp-indent-last-sexp 0 t)
    (if (and (elt state 2)
             (not (looking-at "\\sw\\|\\s_")))
        ;; car of form doesn't seem to be a symbol
        (progn
          (if (not (> (save-excursion (forward-line 1) (point))
                      calculate-lisp-indent-last-sexp))
		(progn (goto-char calculate-lisp-indent-last-sexp)
		       (beginning-of-line)
		       (parse-partial-sexp (point)
					   calculate-lisp-indent-last-sexp 0 t)))
	    ;; Indent under the list or under the first sexp on the same
	    ;; line as calculate-lisp-indent-last-sexp.  Note that first
	    ;; thing on that line has to be complete sexp since we are
          ;; inside the innermost containing sexp.
          (backward-prefix-chars)
          (current-column))
      (let ((function (buffer-substring (point)
					(progn (forward-sexp 1) (point))))
	    method)
	(setq method (or (function-get (intern-soft function)
                                       'lisp-indent-function)
			 (get (intern-soft function) 'lisp-indent-hook)))
	(cond ((or (eq method 'defun)
		   (and (null method)
			(> (length function) 3)
			(string-match "\\`def" function)))
	       (lisp-indent-defform state indent-point))
	      ((integerp method)
	       (lisp-indent-specform method state
				     indent-point normal-indent))
	      (method
		(funcall method indent-point state)))))))

(defcustom lisp-body-indent 2
  "Number of columns to indent the second line of a `(def...)' form."
  :group 'lisp
  :type 'integer)
(put 'lisp-body-indent 'safe-local-variable 'integerp)

(defun lisp-indent-specform (count state indent-point normal-indent)
  (let ((containing-form-start (elt state 1))
        (i count)
        body-indent containing-form-column)
    ;; Move to the start of containing form, calculate indentation
    ;; to use for non-distinguished forms (> count), and move past the
    ;; function symbol.  lisp-indent-function guarantees that there is at
    ;; least one word or symbol character following open paren of containing
    ;; form.
    (goto-char containing-form-start)
    (setq containing-form-column (current-column))
    (setq body-indent (+ lisp-body-indent containing-form-column))
    (forward-char 1)
    (forward-sexp 1)
    ;; Now find the start of the last form.
    (parse-partial-sexp (point) indent-point 1 t)
    (while (and (< (point) indent-point)
                (condition-case ()
                    (progn
                      (setq count (1- count))
                      (forward-sexp 1)
                      (parse-partial-sexp (point) indent-point 1 t))
                  (error nil))))
    ;; Point is sitting on first character of last (or count) sexp.
    (if (> count 0)
        ;; A distinguished form.  If it is the first or second form use double
        ;; lisp-body-indent, else normal indent.  With lisp-body-indent bound
        ;; to 2 (the default), this just happens to work the same with if as
        ;; the older code, but it makes unwind-protect, condition-case,
        ;; with-output-to-temp-buffer, et. al. much more tasteful.  The older,
        ;; less hacked, behavior can be obtained by replacing below with
        ;; (list normal-indent containing-form-start).
        (if (<= (- i count) 1)
            (list (+ containing-form-column (* 2 lisp-body-indent))
                  containing-form-start)
            (list normal-indent containing-form-start))
      ;; A non-distinguished form.  Use body-indent if there are no
      ;; distinguished forms and this is the first undistinguished form,
      ;; or if this is the first undistinguished form and the preceding
      ;; distinguished form has indentation at least as great as body-indent.
      (if (or (and (= i 0) (= count 0))
              (and (= count 0) (<= body-indent normal-indent)))
          body-indent
          normal-indent))))

(defun lisp-indent-defform (state indent-point)
  (goto-char (car (cdr state)))
  (forward-line 1)
  (if (> (point) (car (cdr (cdr state))))
      (progn
	(goto-char (car (cdr state)))
	(+ lisp-body-indent (current-column)))))


;; (put 'progn 'lisp-indent-function 0), say, causes progn to be indented
;; like defun if the first form is placed on the next line, otherwise
;; it is indented like any other form (i.e. forms line up under first).

(put 'autoload 'lisp-indent-function 'defun)
(put 'progn 'lisp-indent-function 0)
(put 'prog1 'lisp-indent-function 1)
(put 'prog2 'lisp-indent-function 2)
(put 'save-excursion 'lisp-indent-function 0)
(put 'save-restriction 'lisp-indent-function 0)
(put 'save-current-buffer 'lisp-indent-function 0)
(put 'let 'lisp-indent-function 1)
(put 'let* 'lisp-indent-function 1)
(put 'while 'lisp-indent-function 1)
(put 'if 'lisp-indent-function 2)
(put 'catch 'lisp-indent-function 1)
(put 'condition-case 'lisp-indent-function 2)
(put 'unwind-protect 'lisp-indent-function 1)
(put 'with-output-to-temp-buffer 'lisp-indent-function 1)

(defun indent-sexp (&optional endpos)
  "Indent each line of the list starting just after point.
If optional arg ENDPOS is given, indent each line, stopping when
ENDPOS is encountered."
  (interactive)
  (let ((indent-stack (list nil))
	(next-depth 0)
	;; If ENDPOS is non-nil, use nil as STARTING-POINT
	;; so that calculate-lisp-indent will find the beginning of
	;; the defun we are in.
	;; If ENDPOS is nil, it is safe not to scan before point
	;; since every line we indent is more deeply nested than point is.
	(starting-point (if endpos nil (point)))
	(last-point (point))
	last-depth bol outer-loop-done inner-loop-done state this-indent)
    (or endpos
	;; Get error now if we don't have a complete sexp after point.
	(save-excursion (forward-sexp 1)))
    (save-excursion
      (setq outer-loop-done nil)
      (while (if endpos (< (point) endpos)
	       (not outer-loop-done))
	(setq last-depth next-depth
	      inner-loop-done nil)
	;; Parse this line so we can learn the state
	;; to indent the next line.
	;; This inner loop goes through only once
	;; unless a line ends inside a string.
	(while (and (not inner-loop-done)
		    (not (setq outer-loop-done (eobp))))
	  (setq state (parse-partial-sexp (point) (progn (end-of-line) (point))
					  nil nil state))
	  (setq next-depth (car state))
	  ;; If the line contains a comment other than the sort
	  ;; that is indented like code,
	  ;; indent it now with indent-for-comment.
	  ;; Comments indented like code are right already.
	  ;; In any case clear the in-comment flag in the state
	  ;; because parse-partial-sexp never sees the newlines.
	  (if (car (nthcdr 4 state))
	      (progn (indent-for-comment)
		     (end-of-line)
		     (setcar (nthcdr 4 state) nil)))
	  ;; If this line ends inside a string,
	  ;; go straight to next line, remaining within the inner loop,
	  ;; and turn off the \-flag.
	  (if (car (nthcdr 3 state))
	      (progn
		(forward-line 1)
		(setcar (nthcdr 5 state) nil))
	    (setq inner-loop-done t)))
	(and endpos
	     (<= next-depth 0)
	     (progn
	       (setq indent-stack (nconc indent-stack
					 (make-list (- next-depth) nil))
		     last-depth (- last-depth next-depth)
		     next-depth 0)))
	(forward-line 1)
	;; Decide whether to exit.
	(if endpos
	    ;; If we have already reached the specified end,
	    ;; give up and do not reindent this line.
	    (if (<= endpos (point))
		(setq outer-loop-done t))
	  ;; If no specified end, we are done if we have finished one sexp.
	  (if (<= next-depth 0)
	      (setq outer-loop-done t)))
	(unless outer-loop-done
	  (while (> last-depth next-depth)
	    (setq indent-stack (cdr indent-stack)
		  last-depth (1- last-depth)))
	  (while (< last-depth next-depth)
	    (setq indent-stack (cons nil indent-stack)
		  last-depth (1+ last-depth)))
	  ;; Now indent the next line according
	  ;; to what we learned from parsing the previous one.
	  (setq bol (point))
	  (skip-chars-forward " \t")
	  ;; But not if the line is blank, or just a comment
	  ;; (except for double-semi comments; indent them as usual).
	  (if (or (eobp) (looking-at "\\s<\\|\n"))
	      nil
	    (if (and (car indent-stack)
		     (>= (car indent-stack) 0))
		(setq this-indent (car indent-stack))
	      (let ((val (calculate-lisp-indent
			  (if (car indent-stack) (- (car indent-stack))
			    starting-point))))
		(if (null val)
		    (setq this-indent val)
		  (if (integerp val)
		      (setcar indent-stack
			      (setq this-indent val))
		    (setcar indent-stack (- (car (cdr val))))
		    (setq this-indent (car val))))))
	    (if (and this-indent (/= (current-column) this-indent))
		(progn (delete-region bol (point))
		       (indent-to this-indent)))))
	(or outer-loop-done
	    (setq outer-loop-done (= (point) last-point))
	    (setq last-point (point)))))))

(defun indent-pp-sexp (&optional arg)
  "Indent each line of the list starting just after point, or prettyprint it.
A prefix argument specifies pretty-printing."
  (interactive "P")
  (if arg
      (save-excursion
        (save-restriction
          (narrow-to-region (point) (progn (forward-sexp 1) (point)))
          (pp-buffer)
          (goto-char (point-max))
          (if (eq (char-before) ?\n)
              (delete-char -1)))))
  (indent-sexp))

;;;; Lisp paragraph filling commands.

(defcustom emacs-lisp-docstring-fill-column 65
  "Value of `fill-column' to use when filling a docstring.
Any non-integer value means do not use a different value of
`fill-column' when filling docstrings."
  :type '(choice (integer)
                 (const :tag "Use the current `fill-column'" t))
  :group 'lisp)
(put 'emacs-lisp-docstring-fill-column 'safe-local-variable
     (lambda (x) (or (eq x t) (integerp x))))

(defun lisp-fill-paragraph (&optional justify)
  "Like \\[fill-paragraph], but handle Emacs Lisp comments and docstrings.
If any of the current line is a comment, fill the comment or the
paragraph of it that point is in, preserving the comment's indentation
and initial semicolons."
  (interactive "P")
  (or (fill-comment-paragraph justify)
      ;; Since fill-comment-paragraph returned nil, that means we're not in
      ;; a comment: Point is on a program line; we are interested
      ;; particularly in docstring lines.
      ;;
      ;; We bind `paragraph-start' and `paragraph-separate' temporarily.  They
      ;; are buffer-local, but we avoid changing them so that they can be set
      ;; to make `forward-paragraph' and friends do something the user wants.
      ;;
      ;; `paragraph-start': The `(' in the character alternative and the
      ;; left-singlequote plus `(' sequence after the \\| alternative prevent
      ;; sexps and backquoted sexps that follow a docstring from being filled
      ;; with the docstring.  This setting has the consequence of inhibiting
      ;; filling many program lines that are not docstrings, which is sensible,
      ;; because the user probably asked to fill program lines by accident, or
      ;; expecting indentation (perhaps we should try to do indenting in that
      ;; case).  The `;' and `:' stop the paragraph being filled at following
      ;; comment lines and at keywords (e.g., in `defcustom').  Left parens are
      ;; escaped to keep font-locking, filling, & paren matching in the source
      ;; file happy.
      ;;
      ;; `paragraph-separate': A clever regexp distinguishes the first line of
      ;; a docstring and identifies it as a paragraph separator, so that it
      ;; won't be filled.  (Since the first line of documentation stands alone
      ;; in some contexts, filling should not alter the contents the author has
      ;; chosen.)  Only the first line of a docstring begins with whitespace
      ;; and a quotation mark and ends with a period or (rarely) a comma.
      ;;
      ;; The `fill-column' is temporarily bound to
      ;; `emacs-lisp-docstring-fill-column' if that value is an integer.
      (let ((paragraph-start (concat paragraph-start
				     "\\|\\s-*\\([(;:\"]\\|`(\\|#'(\\)"))
	    (paragraph-separate
	     (concat paragraph-separate "\\|\\s-*\".*[,\\.]$"))
            (fill-column (if (and (integerp emacs-lisp-docstring-fill-column)
                                  (derived-mode-p 'emacs-lisp-mode))
                             emacs-lisp-docstring-fill-column
                           fill-column)))
	(fill-paragraph justify))
      ;; Never return nil.
      t))

(defun indent-code-rigidly (start end arg &optional nochange-regexp)
  "Indent all lines of code, starting in the region, sideways by ARG columns.
Does not affect lines starting inside comments or strings, assuming that
the start of the region is not inside them.

Called from a program, takes args START, END, COLUMNS and NOCHANGE-REGEXP.
The last is a regexp which, if matched at the beginning of a line,
means don't indent that line."
  (interactive "r\np")
  (let (state)
    (save-excursion
      (goto-char end)
      (setq end (point-marker))
      (goto-char start)
      (or (bolp)
	  (setq state (parse-partial-sexp (point)
					  (progn
					    (forward-line 1) (point))
					  nil nil state)))
      (while (< (point) end)
	(or (car (nthcdr 3 state))
	    (and nochange-regexp
		 (looking-at nochange-regexp))
	    ;; If line does not start in string, indent it
	    (let ((indent (current-indentation)))
	      (delete-region (point) (progn (skip-chars-forward " \t") (point)))
	      (or (eolp)
		  (indent-to (max 0 (+ indent arg)) 0))))
	(setq state (parse-partial-sexp (point)
					(progn
					  (forward-line 1) (point))
					nil nil state))))))

(provide 'lisp-mode)

;;; lisp-mode.el ends here
