path: root/lisp/hippie-exp.el

;; Expand a word trying various ways to find its expansion.
;; Copyright (C) 1992 Free Software Foundation, Inc.
;;
;; 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 2, 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; see the file COPYING.  If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
;; 
;;  Author: Anders Holst (aho@sans.kth.se)
;;
;;  Last change: 4 January 1993

;;  
;;  DESCRIPTION
;;  
;;  `hippie-expand' is a single function for a lot of different kinds
;;  of completions and expansions.  Called repeatedly it tries all
;;  possible completions in succession. 
;;  Which kinds of completions to try, and in which order, is
;;  determined by the contents of `hippie-expand-try-functions-list'.
;;  Much customization of `hippie-expand' can be made by changing the
;;  order of, removing, or inserting new functions in this list.
;;  Given a positive numeric argument, `hippie-expand' jumps directly
;;  ARG functions forward in this list.  Given some other argument
;;  (a negative argument or just Ctrl-U) it undoes the tried
;;  completion.
;;  If the variable `hippie-expand-verbose' is non-nil, `hippie-expand'
;;  outputs in a message which try-function in the list that is used
;;  currently (ie. was used currently and will be tried first the next
;;  time).
;;  See also the macro `make-hippie-expand-function' below.
;;  
;;  A short description of the current try-functions in this file:
;;    `try-complete-file-name' : very convenient to have in any buffer,
;;      and not just in the minibuffer or (some) shell-mode.  It goes
;;      through all possible completions instead of just completing as
;;      much as is unique.
;;    `try-complete-file-name-partially' : To insert in the list just
;;      before `try-complete-file-name' for those who want first to get
;;      a file name completed only as many characters as is unique.
;;      (NOTE: Not by default in `hippie-expand-try-functions-list'.)
;;    `try-expand-all-abbrevs' : can be removed if you don't use abbrevs.
;;      Otherwise it looks through all abbrev-tables, starting with
;;      the local followed by the global. 
;;    `try-expand-line' : Searches the buffer for an entire line that 
;;      begins exactly as the current line.  Convenient sometimes, for 
;;      example as a substitute for (or complement to) the history
;;      list in shell-like buffers.  Remove it if you find it confusing.
;;    `try-expand-line-all-buffers' : Like `try-expand-line' but searches
;;      in all buffers (except the current).  (This may be a little
;;      slow, don't use it unless you are really fond of `hippie-expand'.
;;      NOTE: Not by default in hippie-expand-try-functions-list.)
;;    `try-expand-dabbrev' : works exactly as dabbrev-expand (but of
;;      course in a way compatible with the other try-functions).
;;    `try-expand-dabbrev-all-buffers' : perhaps the most useful of them,
;;      like `dabbrev-expand' but searches all Emacs buffers (except the
;;      current) for matching words.  (No, I don't find this one
;;      particularly slow.) 
;;    `try-complete-lisp-symbol' : like `lisp-complete-symbol', but goes
;;      through all possibilities instead of completing what is unique.
;;      Might be tedious (usually a lot of possible completions) and
;;      since its function is much like `lisp-complete-symbol', which
;;      already has a key of its own, you might want to remove this.
;;    `try-complete-lisp-symbol-partially' : To insert in the list just
;;      before `try-complete-lisp-symbol' for those who first want to get
;;      completion of what is unique in the name.  (NOTE: Not by
;;      default in hippie-expand-try-functions-list.)
;;
;;  To write new try-functions, consider the following:
;;  Each try-function takes one argument OLD which is nil the first
;;  time the function is called and true in succeeding calls for the
;;  same string to complete.  The first time the function has to
;;  extract the string before point to complete, and substitute the
;;  first completion alternative for it.  On following calls it has to
;;  substitute the next possible completion for the last tried string.
;;  The try-function is to return t as long as it finds new
;;  possible completions.  When there are no more alternatives it has
;;  to restore the text before point to its original contents, and
;;  return nil (don't beep or message or anything).
;;  The try-function can (should) use the following functions:
;;    `he-init-string' : Initializes the text to substitute to the
;;      contents of the region BEGIN to END.  Also sets the variable
;;      `he-search-string' to the text to expand.
;;    `he-substitute-string' : substitutes STR into the region
;;      initialized with `he-init-string'.  (An optional second argument
;;      TRANS-CASE non-nil, means transfer of case from the abbreviation
;;      to the expansion is ok if that is enabled in the buffer.)
;;    `he-reset-string' : Resets the initialized region to its original
;;      contents.
;;  There is also a variable: `he-tried-table' which is meant to contain
;;  all tried expansions so far.  The try-function can check this 
;;  variable to see whether an expansion has already been tried
;;  (hint: `he-string-member'), and add its own tried expansions to it.
;;
;;
;;  KNOWN BUGS
;;
;;  It may happen that some completion suggestion occurs twice, in
;;  spite of the use of `he-tried-table' to prevent that.  This is 
;;  because different try-functions may try to complete different
;;  lengths of text, and thus put different amounts of the
;;  text in `he-try-table'.  Anyway this seems to occur seldom enough not
;;  to be too disturbing.  Also it should NOT bee possible for the
;;  opposite situation to occur, that `hippie-expand' misses some
;;  suggestion because it thinks it has already tried it.
;;
;;  
;;  ACKNOWLEDGEMENT
;;
;;  I want to thank Mikael Djurfeldt in discussions with whom the idea
;;  of this function took form.
;;  I am also grateful to all those who have given me suggestions on
;;  how to improve it.
;;


(defvar he-num -1)

(defvar he-string-beg ())

(defvar he-string-end ())

(defvar he-search-string ())

(defvar he-expand-list ())

(defvar he-tried-table ())

(defvar he-search-loc ())

(defvar he-search-bw ())

(defvar he-search-bufs ())

(defvar hippie-expand-try-functions-list '(try-complete-file-name
					   try-expand-all-abbrevs
					   try-expand-line
					   try-expand-dabbrev
					   try-expand-dabbrev-all-buffers
					   try-complete-lisp-symbol)
  "The list of expansion functions tried in order by `hippie-expand'.
To change the behavior of `hippie-expand', remove, change the order of,
or insert functions in this list.")

(defvar hippie-expand-verbose t
  "*Non-nil makes `hippie-expand' output which function it is trying.")

(defun hippie-expand (arg)
  "Try to expand text before point, using multiple methods.
The expansion functions in `hippie-expand-try-functions-list' are
tried in order, until a possible expansion is found.  Repeated
application of `hippie-expand' inserts successively possible
expansions.  
With a positive numeric argument, jumps directly to the ARG next
function in this list.  With a negative argument or just \\[universal-argument], 
undoes the expansion." 
  (interactive "P")
  (if (or (not arg) 
	  (and (integerp arg) (> arg 0)))
      (let ((first (or (= he-num -1)
		       (not (equal this-command last-command)))))
	(if first
	    (progn
	      (setq he-num -1)
	      (setq he-tried-table nil)))
	(if arg
	    (if (not first) (he-reset-string))
	    (setq arg 0))
	(let ((i (max (+ he-num arg) 0)))
	  (while (not (or (>= i (length hippie-expand-try-functions-list))
			  (apply (nth i hippie-expand-try-functions-list) 
				 (list (= he-num i)))))
	    (setq i (1+ i)))
	  (setq he-num i))
	(if (>= he-num (length hippie-expand-try-functions-list))
	    (progn
	      (setq he-num -1)
	      (if first
		  (message "No expansion found")
		  (message "No further expansions found"))
	      (ding))
	    (if hippie-expand-verbose
		(message (concat "Using "
				 (prin1-to-string (nth he-num 
				   hippie-expand-try-functions-list)))))))
      (if (>= he-num 0)
	  (progn
	    (setq he-num -1)
	    (he-reset-string)
	    (if hippie-expand-verbose
		(message "Undoing expansions"))))))
      
;; Initializes the region to expand (to between BEG and END).
(defun he-init-string (beg end)
  (setq he-string-beg beg)
  (setq he-string-end end)
  (setq he-search-string (buffer-substring beg end)))

;; Resets the expanded region to its original contents.
(defun he-reset-string ()
  (delete-region he-string-beg he-string-end)
  (insert he-search-string)
  (setq he-string-end (point)))

;; Substitutes an expansion STR into the correct region (the region
;; initialized with `he-init-string'). 
;; An optional argument TRANS-CASE means that it is ok to transfer case
;; from the abbreviation to the expansion if that is possible, and is
;; enabled in the buffer.
(defun he-substitute-string (str &optional trans-case)
  (let ((trans-case (and trans-case
			 case-replace
			 case-fold-search
			 (he-transfer-case-ok str he-search-string))))
    (he-reset-string)
    (goto-char he-string-beg)
    (search-forward he-search-string)
    (replace-match (if trans-case (downcase str) str)
		   (not trans-case)
		   'literal)
    (setq he-string-end (point))))

(defun he-ordinary-case-p (str)
  (or (string= str (downcase str))
      (string= str (upcase str))
      (string= str (capitalize str))))

(defun he-transfer-case-ok (to-str from-str)
  (and (not (string= from-str (substring to-str 0 (length from-str))))
         ;; otherwise transfer is not needed (and this also solves
	 ;; some obscure situations)
       (he-ordinary-case-p to-str)
         ;; otherwise case may be significant 
       (he-ordinary-case-p from-str)
         ;; otherwise replace-match wont know what to do
  ))

;; Check if STR is a member of LST.
;; Ignore case if `case-replace' and `case-fold-search' are both t.
(defun he-string-member (str lst)
  (while (and lst
	      (not
	       (if (and case-fold-search case-replace)
		   (string= (downcase (car lst)) (downcase str))
		   (string= (car lst) str))))
    (setq lst (cdr lst)))
  lst)

;;  For the real hippie-expand enthusiast: A macro that makes it
;;  possible to use many functions like hippie-expand, but with
;;  different try-functions-lists.
;;  Usage is for example:
;;    (fset 'my-complete-file (make-hippie-expand-function
;;                             '(try-complete-file-name-partially
;;                               try-complete-file-name)))
;;    (fset 'my-complete-line (make-hippie-expand-function
;;                             '(try-expand-line
;;                               try-expand-line-all-buffers)))
;;  
(defmacro make-hippie-expand-function (try-list &optional verbose)
  "Construct a function similar to `hippie-expand'.
Make it use the expansion functions in TRY-LIST.  An optional second
argument VERBOSE non-nil makes the function verbose."
  (` '(lambda (arg)
       (, (concat 
           "Try to expand text before point, using the following functions: \n"
	   (mapconcat 'prin1-to-string (eval try-list) ", ")))
       (interactive "P")
       (let ((hippie-expand-try-functions-list (, try-list))
	     (hippie-expand-verbose (, verbose)))
	 (hippie-expand arg)))))


;;;  Here follows the try-functions and their requisites:

(defun try-complete-file-name (old)
  "Try to complete text as a file name.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible completions of the same
string).  It returns t if a new completion is found, nil otherwise."
  (if (not old)
      (progn 
	(he-init-string (he-file-name-beg) (point))
	(let ((name-part (file-name-nondirectory he-search-string))
	      (dir-part (expand-file-name (or (file-name-directory
					       he-search-string) ""))))
	  (if (not (he-string-member name-part he-tried-table))
	      (setq he-tried-table (cons name-part he-tried-table)))
	  (if (and (not (equal he-search-string ""))
		   (file-directory-p dir-part))
	      (setq he-expand-list (sort (file-name-all-completions 
					  name-part
					  dir-part)
					 'string-lessp))
	      (setq he-expand-list ())))))

  (while (and he-expand-list
	      (he-string-member (car he-expand-list) he-tried-table))
    (setq he-expand-list (cdr he-expand-list)))
  (if (null he-expand-list)
      (progn
	(he-reset-string)
	())
      (let ((filename (concat (file-name-directory he-search-string)
			      (car he-expand-list))))
	(he-substitute-string filename)
	(setq he-tried-table (cons (car he-expand-list) he-tried-table))
	(setq he-expand-list (cdr he-expand-list))
	t)))

(defun try-complete-file-name-partially (old)
  "Try to complete text as a file name, as many characters as unique.
The argument OLD has to be nil the first call of this function.  It
returns t if a unique, possibly partial, completion is found, nil 
otherwise."
  (let ((expansion ()))
    (if (not old)
	(progn 
	  (he-init-string (he-file-name-beg) (point))
	  (let ((name-part (file-name-nondirectory he-search-string))
		(dir-part (expand-file-name (or (file-name-directory
						 he-search-string) ""))))
	    (if (and (not (equal he-search-string ""))
		     (file-directory-p dir-part))
		(setq expansion (file-name-completion name-part
						      dir-part)))
	    (if (or (eq expansion t)
		    (string= expansion name-part))
		(setq expansion ())))))

    (if (not expansion)
	(progn
	  (he-reset-string)
	  ())
	(let ((filename (concat (file-name-directory he-search-string)
				expansion)))
	  (he-substitute-string filename)
	  (setq he-tried-table (cons expansion he-tried-table))
	  t))))

(defun he-file-name-beg ()
  (let ((skips "-a-zA-Z0-9_./~^#$"))
    (save-excursion
      (skip-chars-backward skips)
      (point))))

(defun try-complete-lisp-symbol (old)
  "Try to complete word as an Emacs Lisp symbol.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible completions of the same
string).  It returns t if a new completion is found, nil otherwise."
  (if (not old)
      (progn 
	(he-init-string (he-lisp-symbol-beg) (point))
	(if (not (he-string-member he-search-string he-tried-table))
	    (setq he-tried-table (cons he-search-string he-tried-table)))
	(setq he-expand-list 
	      (and (not (equal he-search-string ""))
		   (sort (all-completions he-search-string obarray
					  (function (lambda (sym)
					    (or (boundp sym)
						(fboundp sym)
						(symbol-plist sym)))))
			 'string-lessp)))))
  (while (and he-expand-list
	      (he-string-member (car he-expand-list) he-tried-table))
    (setq he-expand-list (cdr he-expand-list)))
  (if (null he-expand-list)
      (progn
	(he-reset-string)
	())
      (progn
	(he-substitute-string (car he-expand-list))
	(setq he-tried-table (cons (car he-expand-list) he-tried-table))
	(setq he-expand-list (cdr he-expand-list))
	t)))

(defun try-complete-lisp-symbol-partially (old)
  "Try to complete as an Emacs Lisp symbol, as many characters as unique.
The argument OLD has to be nil the first call of this function.  It
returns t if a unique, possibly partial, completion is found, nil 
otherwise."
  (let ((expansion ()))
    (if (not old)
	(progn 
	  (he-init-string (he-lisp-symbol-beg) (point))
	  (if (not (string= he-search-string ""))
	      (setq expansion 
		    (try-completion he-search-string obarray
				    (function (lambda (sym)
				      (or (boundp sym)
					  (fboundp sym)
					  (symbol-plist sym)))))))
	  (if (or (eq expansion t)
		  (string= expansion he-search-string))
	      (setq expansion ()))))

  (if (not expansion)
      (progn
	(he-reset-string)
	())
      (progn
	(he-substitute-string expansion)
	(setq he-tried-table (cons expansion he-tried-table))
	t))))

(defun he-lisp-symbol-beg ()
  (let ((skips "-a-zA-Z0-9_."))
    (save-excursion
      (skip-chars-backward skips)
      (point))))

(defun try-expand-line (old)
  "Try to complete the current line to an entire line in the buffer.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible completions of the same
string).  It returns t if a new completion is found, nil otherwise."
  (let ((expansion ())
	(strip-prompt (and (get-buffer-process (current-buffer))
			   shell-prompt-pattern)))
    (if (not old)
	(progn
	  (he-init-string (he-line-beg strip-prompt) (point))
	  (setq he-search-loc he-string-beg)
	  (setq he-search-bw t)))

    (if (not (equal he-search-string ""))
	(save-excursion
	  ;; Try looking backward unless inhibited.
	  (if he-search-bw
	      (progn 
		(goto-char he-search-loc)
		(setq expansion (he-line-search he-search-string
						strip-prompt t))
		(setq he-search-loc (point-marker))
		(if (not expansion)
		    (progn
		      (setq he-search-loc he-string-end)
		      (setq he-search-bw ())))))
	  
	  (if (not expansion) ; Then look forward.
	      (progn 
		(goto-char he-search-loc)
		(setq expansion (he-line-search he-search-string 
						strip-prompt nil))
		(setq he-search-loc (point-marker))))))

    (if (not expansion)
	(progn
	  (he-reset-string)
	  ())
	(progn
	  (he-substitute-string expansion t)
	  (setq he-tried-table (cons expansion he-tried-table))
	  t))))

(defun try-expand-line-all-buffers (old)
  "Try to complete the current line, searching all other buffers.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible completions of the same
string).  It returns t if a new completion is found, nil otherwise."
  (let ((expansion ())
	(strip-prompt (and (get-buffer-process (current-buffer))
			   shell-prompt-pattern))
	(buf (current-buffer)))
    (if (not old)
	(progn
	  (he-init-string (he-line-beg strip-prompt) (point))
	  (setq he-search-loc 0)
	  (setq he-search-bufs (buffer-list))))

    (if (not (equal he-search-string ""))
	(while (and he-search-bufs (not expansion))
	  (set-buffer (car he-search-bufs))
	  (if (and (not (eq (current-buffer) buf))
		   (not (eq major-mode 'dired-mode)))
		   ;; dont search dired buffers
	      (save-excursion
		(goto-char he-search-loc)
		(setq expansion (he-line-search he-search-string
						strip-prompt nil))
		(setq he-search-loc (point-marker))))
	  (if expansion
	      (setq he-tried-table (cons expansion he-tried-table))
	      (progn
		(setq he-search-loc 0)
		(setq he-search-bufs (cdr he-search-bufs))))))

    (set-buffer buf)
    (if (not expansion)
	(progn
	  (he-reset-string)
	  ())
	(progn
	  (he-substitute-string expansion t)
	  t))))

(defun he-line-search (str strip-prompt reverse) 
  (let ((result ()))
    (while (and (not result)
		(if reverse
		    (re-search-backward 
		     (he-line-search-regexp str strip-prompt)
		     nil t)
		    (re-search-forward
		     (he-line-search-regexp str strip-prompt)
		     nil t)))
      (setq result (buffer-substring (match-beginning 2) (match-end 2)))
      (if (he-string-member result he-tried-table)
	  (setq result nil)))	            ; if already in table, ignore
    result))

(defun he-line-beg (strip-prompt)
  (save-excursion
    (end-of-line)
    (if (re-search-backward (he-line-search-regexp "" strip-prompt) 
			    (save-excursion (beginning-of-line)
					    (point)) t)
	(match-beginning 2)
      (beginning-of-line)
      (point))))

(defun he-line-search-regexp (pat strip-prompt)
  (if strip-prompt
      (concat "\\(" shell-prompt-pattern "\\|^\\s-*\\)\\("
	      (regexp-quote pat)
	      "[^\n]*[^ \t\n]\\)")
      (concat "^\\(\\s-*\\)\\(" 
	      (regexp-quote pat)
	      "[^\n]*[^ \t\n]\\)")))

(defun try-expand-all-abbrevs (old)
  "Try to expand word before point according to all abbrev tables.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible expansions of the same
string).  It returns t if a new expansion is found, nil otherwise."
  (if (not old)
      (progn
	(he-init-string (he-dabbrev-beg) (point))
	(setq he-expand-list 
	      (and (not (equal he-search-string ""))
		   (mapcar (function (lambda (sym)
			     (abbrev-expansion he-search-string 
					       (eval sym))))
			   (append '(local-abbrev-table 
				     global-abbrev-table)
				   abbrev-table-name-list))))))
  (while (and he-expand-list
	      (or (not (car he-expand-list))
		  (he-string-member (car he-expand-list) he-tried-table)))
    (setq he-expand-list (cdr he-expand-list)))
  (if (null he-expand-list)
      (progn
	(he-reset-string)
	())
      (progn
	(he-substitute-string (car he-expand-list))
	(setq he-tried-table (cons (car he-expand-list) he-tried-table))
	(setq he-expand-list (cdr he-expand-list))
	t)))

(defun try-expand-dabbrev (old)
  "Try to expand word \"dynamically\", searching the current buffer.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible expansions of the same
string).  It returns t if a new expansion is found, nil otherwise."
  (let ((expansion ()))
    (if (not old)
	(progn
	  (he-init-string (he-dabbrev-beg) (point))
	  (setq he-search-loc he-string-beg)
	  (setq he-search-bw t)))

    (if (not (equal he-search-string ""))
	(save-excursion
	  ;; Try looking backward unless inhibited.
	  (if he-search-bw
	      (progn 
		(goto-char he-search-loc)
		(setq expansion (he-dab-search he-search-string t))
		(setq he-search-loc (point-marker))
		(if (not expansion)
		    (progn
		      (setq he-search-loc he-string-end)
		      (setq he-search-bw ())))))
	  
	  (if (not expansion) ; Then look forward.
	      (progn 
		(goto-char he-search-loc)
		(setq expansion (he-dab-search he-search-string nil))
		(setq he-search-loc (point-marker))))))
	
    (if (not expansion)
	(progn
	  (he-reset-string)
	  ())
	(progn
	  (he-substitute-string expansion t)
	  (setq he-tried-table (cons expansion he-tried-table))
	  t))))

(defun try-expand-dabbrev-all-buffers (old)
  "Tries to expand word \"dynamically\", searching all other buffers.
The argument OLD has to be nil the first call of this function, and t
for subsequent calls (for further possible expansions of the same
string).  It returns t if a new expansion is found, nil otherwise."
  (let ((expansion ())
	(buf (current-buffer)))
    (if (not old)
	(progn
	  (he-init-string (he-dabbrev-beg) (point))
	  (setq he-search-loc 0)
	  (setq he-search-bufs (buffer-list))))

    (if (not (equal he-search-string ""))
	(while (and he-search-bufs (not expansion))
	  (set-buffer (car he-search-bufs))
	  (if (and (not (eq (current-buffer) buf))
		   (not (eq major-mode 'dired-mode))) 
		   ;; dont search dired buffers
	      (save-excursion
		(goto-char he-search-loc)
		(setq expansion (he-dab-search he-search-string nil))
		(setq he-search-loc (point-marker))))
	  (if expansion
	      (setq he-tried-table (cons expansion he-tried-table))
	      (progn
		(setq he-search-loc 0)
		(setq he-search-bufs (cdr he-search-bufs))))))

    (set-buffer buf)
    (if (not expansion)
	(progn
	  (he-reset-string)
	  ())
	(progn
	  (he-substitute-string expansion t)
	  t))))

(defun he-dab-search-regexp (pat)
  (concat "\\b" (regexp-quote pat) 
	  "\\(\\sw\\|\\s_\\)+"))

(defun he-dab-search (pattern reverse)
  (let ((result ()))
    (while (and (not result) 
		(if reverse
		     (re-search-backward (he-dab-search-regexp pattern)
					 nil t)
		     (re-search-forward (he-dab-search-regexp pattern)
					nil t)))
      (setq result (buffer-substring (match-beginning 0) (match-end 0)))
      (if (he-string-member result he-tried-table)
	  (setq result nil)))	            ; if already in table, ignore
    result))

(defun he-dabbrev-beg ()
  (let ((skips "-a-zA-Z0-9_."))
    (save-excursion
      (skip-chars-backward skips)
      (skip-chars-forward "-_.")
      (point))))