summaryrefslogtreecommitdiff
path: root/lisp/imenu.el
blob: e4af044db137cebcb2abba31e7e52bd1707ec0e0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
;;; imenu.el --- Framework for mode-specific buffer indexes.

;; Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc.

;; Author: Ake Stenhoff <etxaksf@aom.ericsson.se>
;;         Lars Lindberg <lli@sypro.cap.se>
;; Created: 8 Feb 1994
;; Keywords: tools

;; 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, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; Purpose of this package:
;;   To present a framework for mode-specific buffer indexes.
;;   A buffer index is an alist of names and buffer positions.
;;   For instance all functions in a C-file and their positions.
;;
;; How it works:

;;   A mode-specific function is called to generate the index.  It is
;;   then presented to the user, who can choose from this index.
;;
;;   The package comes with a set of example functions for how to
;;   utilize this package.

;;   There are *examples* for index gathering functions/regular
;;   expressions for C/C++ and Lisp/Emacs Lisp but it is easy to
;;   customize for other modes.  A function for jumping to the chosen
;;   index position is also supplied.

;;; Thanks goes to
;;  [simon] - Simon Leinen simon@lia.di.epfl.ch
;;  [dean] - Dean Andrews ada@unison.com
;;  [alon] - Alon Albert al@mercury.co.il 
;;  [greg] - Greg Thompson gregt@porsche.visix.COM
;;  [wolfgang] - Wolfgang Bangerth zcg51122@rpool1.rus.uni-stuttgart.de
;;  [kai] - Kai Grossjohann grossjoh@linus.informatik.uni-dortmund.de
;;  [david] - David M. Smith dsmith@stats.adelaide.edu.au
;;  [christian] - Christian Egli Christian.Egli@hcsd.hac.com
;;  [karl] - Karl Fogel kfogel@floss.life.uiuc.edu

;;; Code

(eval-when-compile (require 'cl))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; Customizable variables
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defvar imenu-use-keymap-menu nil
  "*Non-nil means use a keymap when making the mouse menu.")

(defvar imenu-auto-rescan nil
  "*Non-nil means Imenu should always rescan the buffers.")

(defvar imenu-auto-rescan-maxout 60000 
  "* auto-rescan is disabled in buffers larger than this.
This variable is buffer-local.")

(defvar imenu-always-use-completion-buffer-p nil
  "*Set this to non-nil for displaying the index in a completion buffer.

Non-nil means always display the index in a completion buffer.
Nil means display the index as a mouse menu when the mouse was
used to invoke `imenu'.
`never' means never automatically display a listing of any kind.")

(defvar imenu-sort-function nil
  "*The function to use for sorting the index mouse-menu.

Affects only the mouse index menu.

Set this to nil if you don't want any sorting (faster).
The items in the menu are then presented in the order they were found
in the buffer.

Set it to `imenu--sort-by-name' if you want alphabetic sorting.

The function should take two arguments and return T if the first
element should come before the second.  The arguments are cons cells;
\(NAME . POSITION).  Look at `imenu--sort-by-name' for an example.")

(defvar imenu-max-items 25
  "*Maximum number of elements in an mouse menu for Imenu.")

(defvar imenu-scanning-message "Scanning buffer for index (%3d%%)"
  "*Progress message during the index scanning of the buffer.
If non-nil, user gets a message during the scanning of the buffer

Relevant only if the mode-specific function that creates the buffer
index use `imenu-progress-message'.")

(defvar imenu-space-replacement "^"
  "*The replacement string for spaces in index names.
Used when presenting the index in a completion-buffer to make the
names work as tokens.")

(defvar imenu-level-separator ":"
  "*The separator between index names of different levels.
Used for making mouse-menu titles and for flattening nested indexes
with name concatenation.")

;;;###autoload
(defvar imenu-generic-expression nil
  "The regex pattern to use for creating a buffer index.

If non-nil this pattern is passed to `imenu-create-index-with-pattern'
to create a buffer index.

It is an alist with elements that look like this: (MENU-TITLE
REGEXP INDEX). 

MENU-TITLE is a string used as the title for the submenu or nil if the
entries are not nested.

REGEXP is a regexp that should match a construct in the buffer that is
to be displayed in the menu; i.e., function or variable definitions,
etc.  It contains a substring which is the name to appear in the
menu.  See the info section on Regexps for more information.

INDEX points to the substring in REGEXP that contains the name (of the
function, variable or type) that is to appear in the menu.

For emacs-lisp-mode for example PATTERN would look like:

'((nil \"^\\\\s-*(def\\\\(un\\\\|subst\\\\|macro\\\\|advice\\\\)\\\\s-+\\\\([-A-Za-z0-9+]+\\\\)\" 2)
  (\"*Vars*\" \"^\\\\s-*(def\\\\(var\\\\|const\\\\)\\\\s-+\\\\([-A-Za-z0-9+]+\\\\)\" 2)
  (\"*Types*\" \"^\\\\s-*(def\\\\(type\\\\|struct\\\\|class\\\\|ine-condition\\\\)\\\\s-+\\\\([-A-Za-z0-9+]+\\\\)\" 2))

The variable is buffer-local.")

;;;###autoload
(make-variable-buffer-local 'imenu-generic-expression)

;;;; Hooks

(defvar imenu-create-index-function 'imenu-default-create-index-function
  "The function to use for creating a buffer index.

It should be a function that takes no arguments and returns an index
of the current buffer as an alist.  The elements in the alist look
like: (INDEX-NAME . INDEX-POSITION).  You may also nest index list like
\(INDEX-NAME . INDEX-ALIST).

This function is called within a `save-excursion'.

The variable is buffer-local.")
(make-variable-buffer-local 'imenu-create-index-function)

(defvar imenu-prev-index-position-function 'beginning-of-defun
  "Function for finding the next index position.

If `imenu-create-index-function' is set to
`imenu-default-create-index-function', then you must set this variable
to a function that will find the next index, looking backwards in the
file.

The function should leave point at the place to be connected to the
index and it should return nil when it doesn't find another index.")
(make-variable-buffer-local 'imenu-prev-index-position-function)

(defvar imenu-extract-index-name-function nil
  "Function for extracting the index name.

This function is called after the function pointed out by
`imenu-prev-index-position-function'.")
(make-variable-buffer-local 'imenu-extract-index-name-function)

;;;
;;; Macro to display a progress message.
;;; RELPOS is the relative position to display.
;;; If RELPOS is nil, then the relative position in the buffer
;;; is calculated.
;;; PREVPOS is the variable in which we store the last position displayed.
(defmacro imenu-progress-message (prevpos &optional relpos reverse)
  (` (and
      imenu-scanning-message
      (let ((pos (, (if relpos
			relpos
		      (` (imenu--relative-position (, reverse)))))))
	(if (, (if relpos t
		 (` (> pos (+ 5 (, prevpos))))))
	    (progn
	      (message imenu-scanning-message pos)
	      (setq (, prevpos) pos)))))))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;
;;;; Some examples of functions utilizing the framework of this
;;;; package.
;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Return the current/previous sexp and the location of the sexp (its
;; beginning) without moving the point.
(defun imenu-example--name-and-position ()
  (save-excursion
    (forward-sexp -1)
    (let ((beg (point))
	  (end (progn (forward-sexp) (point)))
	  (marker (make-marker)))
      (set-marker marker beg)
      (cons (buffer-substring beg end)
	    marker))))

;;;
;;; Lisp
;;; 

(defun imenu-example--lisp-extract-index-name ()
  ;; Example of a candidate for `imenu-extract-index-name-function'.
  ;; This will generate a flat index of definitions in a lisp file.
  (save-match-data
    (and (looking-at "(def")
	 (condition-case nil
	     (progn
	       (down-list 1)
	       (forward-sexp 2)
	       (let ((beg (point))
		     (end (progn (forward-sexp -1) (point))))
		 (buffer-substring beg end)))
	   (error nil)))))

(defun imenu-example--create-lisp-index ()
  ;; Example of a candidate for `imenu-create-index-function'.
  ;; It will generate a nested index of definitions.
  (let ((index-alist '())
	(index-var-alist '())
	(index-type-alist '())
	(index-unknown-alist '())
	prev-pos)
    (goto-char (point-max))
    (imenu-progress-message prev-pos 0)
    ;; Search for the function
    (while (beginning-of-defun)
      (imenu-progress-message prev-pos nil t)
      (save-match-data
	(and (looking-at "(def")
	     (save-excursion
	       (down-list 1)
	       (cond
		((looking-at "def\\(var\\|const\\)")
		 (forward-sexp 2)
		 (push (imenu-example--name-and-position)
		       index-var-alist))
		((looking-at "def\\(un\\|subst\\|macro\\|advice\\)")
		 (forward-sexp 2)
		 (push (imenu-example--name-and-position)
		       index-alist))
		((looking-at "def\\(type\\|struct\\|class\\|ine-condition\\)")
 		 (forward-sexp 2)
 		 (if (= (char-after (1- (point))) ?\))
 		     (progn
 		       (forward-sexp -1)
 		       (down-list 1)
 		       (forward-sexp 1)))
 		 (push (imenu-example--name-and-position)
 		       index-type-alist))
		(t
		 (forward-sexp 2)
		 (push (imenu-example--name-and-position)
		       index-unknown-alist)))))))
    (imenu-progress-message prev-pos 100)
    (and index-var-alist
	 (push (cons "Variables" index-var-alist)
	       index-alist))
    (and index-type-alist
 	 (push (cons "Types" index-type-alist)
  	       index-alist))
    (and index-unknown-alist
	 (push (cons "Syntax-unknown" index-unknown-alist)
	       index-alist))
    index-alist))

;; Regular expression to find C functions
(defvar imenu-example--function-name-regexp-c
  (concat 
   "^[a-zA-Z0-9]+[ \t]?"		; type specs; there can be no
   "\\([a-zA-Z0-9_*]+[ \t]+\\)?"	; more than 3 tokens, right?
   "\\([a-zA-Z0-9_*]+[ \t]+\\)?"
   "\\([*&]+[ \t]*\\)?"			; pointer
   "\\([a-zA-Z0-9_*]+\\)[ \t]*("	; name
   ))

(defun imenu-example--create-c-index (&optional regexp)
  (let ((index-alist '())
	prev-pos char)
    (goto-char (point-min))
    (imenu-progress-message prev-pos 0)
    ;; Search for the function
    (save-match-data
      (while (re-search-forward
	      (or regexp imenu-example--function-name-regexp-c)
	      nil t)
	(imenu-progress-message prev-pos)
	(backward-up-list 1)
	(save-excursion
	  (goto-char (scan-sexps (point) 1))
	  (setq char (following-char)))
	;; Skip this function name if it is a prototype declaration.
	(if (not (eq char ?\;))
	    (push (imenu-example--name-and-position) index-alist))))
    (imenu-progress-message prev-pos 100)
    (nreverse index-alist)))


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; Internal variables
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; The item to use in the index for rescanning the buffer.
(defconst imenu--rescan-item '("*Rescan*" . -99))

;; The latest buffer index.
;; Buffer local.
(defvar imenu--index-alist nil)
(make-variable-buffer-local 'imenu--index-alist)

;; The latest buffer index used to update the menu bar menu.
(defvar imenu--last-menubar-index-alist nil)
(make-variable-buffer-local 'imenu--last-menubar-index-alist)

;; History list for 'jump-to-function-in-buffer'.
;; Making this buffer local caused it not to work!
(defvar imenu--history-list nil)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; Internal support functions
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;;
;;; Sort function
;;; Sorts the items depending on their index name.
;;; An item look like (NAME . POSITION).
;;;
(defun imenu--sort-by-name (item1 item2)
  (string-lessp (car item1) (car item2)))

(defun imenu--relative-position (&optional reverse)
  ;; Support function to calculate relative position in buffer
  ;; Beginning of buffer is 0 and end of buffer is 100
  ;; If REVERSE is non-nil then the beginning is 100 and the end is 0.
  (let ((pos (point))
	(total (buffer-size)))
    (and reverse (setq pos (- total pos)))
    (if (> total 50000)
	;; Avoid overflow from multiplying by 100!
	(/ (1- pos) (max (/ total 100) 1))
      (/ (* 100 (1- pos)) (max total 1)))))

;; Split LIST into sublists of max length N.
;; Example (imenu--split '(1 2 3 4 5 6 7 8) 3)-> '((1 2 3) (4 5 6) (7 8))
(defun imenu--split (list n)
  (let ((remain list)
	(result '())
	(sublist '())
	(i 0))
    (while remain
      (push (pop remain) sublist)
      (incf i)
      (and (= i n)
	   ;; We have finished a sublist
	   (progn (push (nreverse sublist) result)
		  (setq i 0)
		  (setq sublist '()))))
    ;; There might be a sublist (if the length of LIST mod n is != 0)
    ;; that has to be added to the result list.
    (and sublist
	 (push (nreverse sublist) result))
    (nreverse result)))

;;; Split the alist MENULIST into a nested alist, if it is long enough.
;;; In any case, add TITLE to the front of the alist.
(defun imenu--split-menu (menulist title)
  (if (> (length menulist) imenu-max-items)
      (let ((count 0))
	(cons title
	      (mapcar
	       (function
		(lambda (menu)
		  (cons (format "(%s-%d)" title (setq count (1+ count)))
			menu)))
	       (imenu--split menulist imenu-max-items))))
    (cons title menulist)))

;;; Split up each long alist that are nested within ALIST
;;; into nested alists.
(defun imenu--split-submenus (alist)
  (mapcar (function (lambda (elt)
		      (if (and (consp elt)
			       (stringp (car elt))
			       (listp (cdr elt)))
			  (imenu--split-menu (cdr elt) (car elt))
			elt)))
	  alist))

;;;
;;; Find all items in this buffer that should be in the index.
;;; Returns an alist on the form
;;; ((NAME . POSITION) (NAME . POSITION) ...)
;;;

(defun imenu--make-index-alist (&optional noerror)
  ;; Create a list for this buffer only when needed.
  (or (and imenu--index-alist
	   (or (not imenu-auto-rescan)
	       (and imenu-auto-rescan
		    (> (buffer-size)  imenu-auto-rescan-maxout))))
      ;; Get the index
      (setq imenu--index-alist
	    (save-excursion
	      (funcall imenu-create-index-function))))
  (or imenu--index-alist noerror
      (error "No items suitable for an index found in this buffer"))
  (or imenu--index-alist
      (setq imenu--index-alist (list nil)))
  ;; Add a rescan option to the index.
  (cons imenu--rescan-item imenu--index-alist))
;;;
;;; Find all markers in alist and makes
;;; them point nowhere.
;;;
(defun imenu--cleanup (&optional alist)
  ;; Sets the markers in imenu--index-alist 
  ;; point nowhere.
  ;; if alist is provided use that list.
  (or alist
      (setq alist imenu--index-alist))
  (and alist
       (mapcar
	(function
	 (lambda (item)
	   (cond
	    ((markerp (cdr item))
	     (set-marker (cdr item) nil))
	    ((consp (cdr item))
	     (imenu--cleanup (cdr item))))))
	alist)
       t))

(defun imenu--create-keymap-2 (alist counter &optional commands)
  (let ((map nil))
    (mapcar
     (function
      (lambda (item)
	(cond
	 ((listp (cdr item))
	  (append (list (setq counter (1+ counter))
			(car item) 'keymap (car item))
		  (imenu--create-keymap-2 (cdr item) (+ counter 10) commands)))
	 (t
	  (let ((end (if commands `(lambda () (interactive)
				     (imenu--menubar-select ',item))
		       (cons '(nil) t))))
	    (cons (car item)
		  (cons (car item) end))))
	 )))
     alist)))

;; If COMMANDS is non-nil, make a real keymap
;; with a real command used as the definition.
;; If it is nil, make something suitable for x-popup-menu.
(defun imenu--create-keymap-1 (title alist &optional commands)
  (append (list 'keymap title) (imenu--create-keymap-2 alist 0 commands)))


(defun imenu--in-alist (str alist)
  "Check whether the string STR is contained in multi-level ALIST."
  (let (elt head tail res)
    (setq res nil)
    (while alist
      (setq elt (car alist) 
	    tail (cdr elt)
	    alist (cdr alist) 
	    head (car elt)) 
      (if (string= str head)
	  (setq alist nil res elt)
	(if (and (listp tail)
		 (setq res (imenu--in-alist str tail)))
	    (setq alist nil))))
    res))

(defun imenu-default-create-index-function ()
  "*Wrapper for index searching functions.

Moves point to end of buffer and then repeatedly calls
`imenu-prev-index-position-function' and `imenu-extract-index-name-function'.
Their results are gathered into an index alist."
  ;; These should really be done by setting imenu-create-index-function
  ;; in these major modes.  But save that change for later.
  (cond ((and (fboundp imenu-prev-index-position-function)
	      (fboundp imenu-extract-index-name-function))
	 (let ((index-alist '())
	       prev-pos name)
	   (goto-char (point-max))
	   (imenu-progress-message prev-pos 0 t)
	   ;; Search for the function
	   (while (funcall imenu-prev-index-position-function) 
	     (imenu-progress-message prev-pos nil t)
	     (save-excursion
	       (setq name (funcall imenu-extract-index-name-function)))
	     (and (stringp name)
		  (push (cons name (point)) index-alist)))
	   (imenu-progress-message prev-pos 100 t)
	   index-alist))
	;; Use generic expression if possible.
	((and imenu-generic-expression)
	 (imenu--generic-function imenu-generic-expression)) 
	(t
	 (error "The mode \"%s\" does not take full advantage of imenu.el yet."
		mode-name))))      

(defun imenu--replace-spaces (name replacement)
  ;; Replace all spaces in NAME with REPLACEMENT.
  ;; That second argument should be a string.
  (mapconcat
   (function
    (lambda (ch)
      (if (char-equal ch ?\ )
	  replacement
	(char-to-string ch))))
   name
   ""))

(defun imenu--flatten-index-alist (index-alist &optional concat-names prefix)
  ;; Takes a nested INDEX-ALIST and returns a flat index alist.
  ;; If optional CONCAT-NAMES is non-nil, then a nested index has its
  ;; name and a space concatenated to the names of the children.
  ;; Third argument PREFIX is for internal use only.
  (mapcan
   (function
    (lambda (item)
      (let* ((name (car item))
	     (pos (cdr item))
	     (new-prefix (and concat-names
			      (if prefix
				  (concat prefix imenu-level-separator name)
				name))))
	(cond
	 ((or (markerp pos) (numberp pos))
	  (list (cons new-prefix pos)))
	 (t
	  (imenu--flatten-index-alist pos new-prefix))))))
   index-alist))

;;;
;;; Generic index gathering function.
;;;

(defun imenu--generic-function (patterns)
;; Built on some ideas that Erik Naggum <erik@naggum.no> once posted
;; to comp.emacs
  "Return an index of the current buffer as an alist.

PATTERN is an alist with elements that look like this: (MENU-TITLE
REGEXP INDEX).

MENU-TITLE is a string used as the title for the submenu or nil if the
entries are not nested.

REGEXP is a regexp that should match a construct in the buffer that is
to be displayed in the menu; i.e., function or variable definitions,
etc.  It contains a substring which is the name to appear in the
menu.  See the info section on Regexps for more information.

INDEX points to the substring in REGEXP that contains the name (of the
function, variable or type) that is to appear in the menu.

For emacs-lisp-mode for example PATTERN would look like:

'((nil \"^\\\\s-*(def\\\\(un\\\\|subst\\\\|macro\\\\|advice\\\\)\\\\s-+\\\\([-A-Za-z0-9]+\\\\)\" 2)
  (\"*Vars*\" \"^\\\\s-*(def\\\\(var\\\\|const\\\\)\\\\s-+\\\\([-A-Za-z0-9]+\\\\)\" 2)
  (\"*Types*\" \"^\\\\s-*(def\\\\(type\\\\|struct\\\\|class\\\\|ine-condition\\\\)\\\\s-+\\\\([-A-Za-z0-9]+\\\\)\" 2))'

Returns an index of the current buffer as an alist.  The elements in
the alist look like: (INDEX-NAME . INDEX-POSITION).  They may also be
nested index lists like (INDEX-NAME . INDEX-ALIST) depending on
pattern.

\(imenu--generic-function PATTERN\)."

  (let ((index-alist (list 'dummy))
        (found nil)
	(global-regexp 
	 (concat "\\(" 
		 (mapconcat
		  (function (lambda (pattern) (identity (cadr pattern)))) 
		  patterns "\\)\\|\\(") 
		 "\\)"))
	prev-pos)

    (goto-char (point-max))
    (imenu-progress-message prev-pos 0 t)
    (save-match-data
      (while (re-search-backward global-regexp nil t)
	(imenu-progress-message prev-pos nil t)
        (setq found nil)
	(save-excursion
	  (goto-char (match-beginning 0))
	  (mapcar 
	   (function 
	    (lambda (pat) 
	      (let ((menu-title (car pat))
		    (regexp (cadr pat))
		    (index (caddr pat)))
		    (if (and (not found) ; Only allow one entry;
			     (looking-at regexp))
			(let ((beg (match-beginning index))
			      (end (match-end index)))
			  (setq found t)
			  (push 
			   (cons (buffer-substring-no-properties beg end) beg)
			   (cdr 
			    (or (assoc menu-title index-alist)
				(car (push 
				      (cons menu-title '()) 
				      index-alist))))))))))
	   patterns))))
    (imenu-progress-message prev-pos 100 t)
    (let ((main-element (assq nil index-alist)))
      (nconc (delq main-element (delq 'dummy index-alist)) main-element))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;
;;; The main functions for this package!
;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun imenu--completion-buffer (index-alist &optional prompt)
  "Let the user select from INDEX-ALIST in a completion buffer with PROMPT.

Returns t for rescan and otherwise a position number."
  ;; Create a list for this buffer only when needed.
  (let (name choice
	     (prepared-index-alist
	      (mapcar
	       (function
		(lambda (item)
		  (cons (imenu--replace-spaces (car item) imenu-space-replacement)
			(cdr item))))
	       index-alist)))
    (if (eq imenu-always-use-completion-buffer-p 'never)
  	(setq name (completing-read (or prompt "Index item: ")
  				    prepared-index-alist
 				    nil t nil 'imenu--history-list))
      (save-window-excursion
	;; Display the completion buffer
	(with-output-to-temp-buffer "*Completions*"
	  (display-completion-list
	   (all-completions "" prepared-index-alist )))
	(let ((minibuffer-setup-hook
	       (function (lambda ()
			   (let ((buffer (current-buffer)))
			     (save-excursion
			       (set-buffer "*Completions*")
			       (setq completion-reference-buffer buffer)))))))
	  ;; Make a completion question
	  (setq name (completing-read (or prompt "Index item: ")
				      prepared-index-alist
				      nil t nil 'imenu--history-list)))))
    (cond ((not (stringp name))
	   nil)
	  ((string= name (car imenu--rescan-item))
	   t)
	  (t
	   (setq choice (assoc name prepared-index-alist))
	   (if (listp (cdr choice))
	       (imenu--completion-buffer (cdr choice) prompt)
	     choice)))))

(defun imenu--mouse-menu (index-alist event &optional title)
  "Let the user select from a buffer index from a mouse menu.

INDEX-ALIST is the buffer index and EVENT is a mouse event.

Returns t for rescan and otherwise a position number."
  (setq index-alist (imenu--split-submenus index-alist))
  (let* ((menu 	(imenu--split-menu
		 (if imenu-sort-function
		     (sort
		      (let ((res nil)
			    (oldlist index-alist))
			;; Copy list method from the cl package `copy-list'
			(while (consp oldlist) (push (pop oldlist) res))
			(prog1 (nreverse res) (setcdr res oldlist)))
		      imenu-sort-function)
		   index-alist)
		 (or title (buffer-name))))
	 position)
    (and imenu-use-keymap-menu
	 (setq menu (imenu--create-keymap-1 (car menu) 
					    (if (< 1 (length (cdr menu)))
						(cdr menu)
					      (cdr (cadr menu))))))

    (or imenu-use-keymap-menu
	(setq menu (list "Imenu" (delq nil menu))))
    (setq position (x-popup-menu event menu))
    (if imenu-use-keymap-menu
	(progn
	  (cond 
	   ((and (listp position)
		 (numberp (car position))
		 (stringp (nth (1- (length position)) position)))
	    (setq position (nth (1- (length position)) position)))
	   ((and (stringp (car position))
		 (null (cdr position)))
	    (setq position (car position))))))
    (cond
     ((eq position nil)
      position)
     ((listp position)
      (imenu--mouse-menu position event
			 (if title
			     (concat title imenu-level-separator
				     (car (rassq position index-alist)))
			   (car (rassq position index-alist)))))
     ((stringp position)
      (or (string= position (car imenu--rescan-item))
	  (imenu--in-alist position index-alist)))
     ((or (= position (cdr imenu--rescan-item))
	  (and (stringp position)
	       (string= position (car imenu--rescan-item))))
      t)
     (t
      (rassq position index-alist)))))

(defun imenu-choose-buffer-index (&optional prompt alist)
  "Let the user select from a buffer index and return the chosen index.

If the user originally activated this function with the mouse, a mouse
menu is used.  Otherwise a completion buffer is used and the user is
prompted with PROMPT.

If you call this function with index alist ALIST, then it lets the user
select from ALIST.

With no index alist ALIST, it calls `imenu--make-index-alist' to
create the index alist.

If `imenu-always-use-completion-buffer-p' is non-nil, then the
completion buffer is always used, no matter if the mouse was used or
not.

The returned value is on the form (INDEX-NAME . INDEX-POSITION)."
  (let (index-alist
	(mouse-triggered (listp last-nonmenu-event))
	(result t) )
    ;; If selected by mouse, see to that the window where the mouse is
    ;; really is selected.
    (and mouse-triggered
	 (not (equal last-nonmenu-event '(menu-bar)))
	 (let ((window (posn-window (event-start last-nonmenu-event))))
	   (or (framep window) (null window) (select-window window))))
    ;; Create a list for this buffer only when needed.
    (while (eq result t)
      (setq index-alist (if alist alist (imenu--make-index-alist)))
      (setq result
	    (if (and mouse-triggered
		     (not imenu-always-use-completion-buffer-p))
		(imenu--mouse-menu index-alist last-nonmenu-event)
	      (imenu--completion-buffer index-alist prompt)))
      (and (eq result t)
	   (imenu--cleanup)
	   (setq imenu--index-alist nil)))
    result))

;;;###autoload
(defun imenu-add-to-menubar (name)
  "Adds an `imenu' entry to the menu bar for the current buffer.
NAME is a string used to name the menu bar item.
See the command `imenu' for more information."
  (interactive "sImenu menu item name: ")
  (let ((newmap (make-sparse-keymap))
	(menu-bar (lookup-key (current-local-map) [menu-bar])))
    (define-key newmap [menu-bar]
      (append (make-sparse-keymap) menu-bar))
    (define-key newmap [menu-bar index]
      (cons name (nconc (make-sparse-keymap "Imenu")
			(make-sparse-keymap))))
    (use-local-map (append newmap (current-local-map))))
  (add-hook 'menu-bar-update-hook 'imenu-update-menubar))

(defvar imenu-buffer-menubar nil)

(defun imenu-update-menubar ()
  (and (current-local-map)
       (keymapp (lookup-key (current-local-map) [menu-bar index]))
       (let ((index-alist (imenu--make-index-alist t)))
	 ;; Don't bother updating if the index-alist has not changed
	 ;; since the last time we did it.
	 (or (equal index-alist imenu--last-menubar-index-alist)
	     (let (menu menu1 old)
	       (setq imenu--last-menubar-index-alist index-alist)
	       (setq index-alist (imenu--split-submenus index-alist))
	       (setq menu (imenu--split-menu
			   (if imenu-sort-function
			       (sort
				(let ((res nil)
				      (oldlist index-alist))
				  ;; Copy list method from the cl package `copy-list'
				  (while (consp oldlist) (push (pop oldlist) res))
				  (prog1 (nreverse res) (setcdr res oldlist)))
				imenu-sort-function)
			     index-alist)
			   (buffer-name)))
	       (setq menu1 (imenu--create-keymap-1 (car menu) 
						   (if (< 1 (length (cdr menu)))
						       (cdr menu)
						     (cdr (car (cdr menu))))
						   t))
	       (setq old (lookup-key (current-local-map) [menu-bar index]))
	       (if (keymapp old)
		   (setcdr (nthcdr 2 old) menu1)))))))

(defun imenu--menubar-select (item)
  "Use Imenu to select the function or variable named in this menu item."
  (if (equal item '("*Rescan*" . -99))
      (progn
	(imenu--cleanup)
	(setq imenu--index-alist nil)
	(imenu-update-menubar))
    (imenu item)))

;;;###autoload
(defun imenu (index-item)
  "Jump to a place in the buffer chosen using a buffer menu or mouse menu.
See `imenu-choose-buffer-index' for more information."
  (interactive
   (list (save-restriction 
	   (widen)
	   (imenu-choose-buffer-index))))
  ;; Convert a string to an alist element.
  (if (stringp index-item)
      (setq index-item (assoc index-item (imenu--make-index-alist))))
  (and index-item
       (progn
	 (push-mark)
	 (cond
	  ((markerp (cdr index-item))
	   (if (or ( > (marker-position (cdr index-item)) (point-min))
		   ( < (marker-position (cdr index-item)) (point-max)))
	       ;; widen if outside narrowing
	       (widen))
	   (goto-char (marker-position (cdr index-item))))
	  (t
	   (if (or ( > (cdr index-item) (point-min))
		   ( < (cdr index-item) (point-max)))
	       ;; widen if outside narrowing
	       (widen))
	   (goto-char (cdr index-item)))))))

(provide 'imenu)

;;; imenu.el ends here