Source

emacs / lisp / hilit-chg.el

Full commit
   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
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
;;; hilit-chg.el --- minor mode displaying buffer changes with special face

;; Copyright (C) 1998, 2000 Free Software Foundation, Inc.

;; Author: Richard Sharman <rsharman@pobox.com>
;; Keywords: faces

;; 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:

;; A minor mode: "Highlight Changes mode".
;;

;; Highlight Changes mode has 2 submodes: active and passive.
;; When active, changes to the buffer are displayed in a different face.
;; When passive, any existing displayed changes are saved and new ones
;; recorded but are not displayed differently.
;; Why active and passive?  Having the changes visible can be handy when you
;; want the information but very distracting otherwise.  So, you can keep
;; Highlight Changes mode in passive state while you make your changes, toggle
;; it on to active mode to see them, then toggle it back off to avoid
;; distraction.
;; 
;; When active, changes are displayed in `highlight-changes-face'.  When
;; text is deleted,  the following character is displayed in
;; `highlight-changes-delete-face' face.
;;
;;
;; You can "age" different sets of changes by using
;; `highlight-changes-rotate-faces'.  This rotates through a series
;; of different faces, so you can distinguish "new" changes from "older"
;; changes.  You can customize these "rotated" faces in two ways.  You can
;; either explicitly define each face by customizing
;; `highlight-changes-face-list'.  If, however, the faces differ from
;; `highlight-changes-face' only in the foreground color, you can simply set
;; `highlight-changes-colours'.  If `highlight-changes-face-list' is nil when
;; the faces are required they will be constructed from
;; `highlight-changes-colours'.
;;
;;
;; When a Highlight Changes mode is on (either active or passive) you can go
;; to the next or previous change with `highlight-changes-next-change' and
;; `highlight-changes-previous-change'.
;;
;;
;; You can also use the command highlight-compare-with-file to show changes
;; in this file compared with another file (typically the previous version
;; of the file).
;;
;;
;; There are currently three hooks run by `highlight-changes-mode':
;; `highlight-changes-enable-hook'  - is run when Highlight Changes mode
;;				    is initially enabled for a buffer.
;; `highlight-changes-disable-hook' - is run when Highlight Changes mode
;;				    is turned off.
;; `highlight-changes-toggle-hook'  - is run each time `highlight-changes-mode'
;;				    is called.  Typically this is when
;;				    toggling between active and passive
;;				    modes.  The variable
;;				    `highlight-changes-mode' contains the new
;;				    state (`active' or `passive'.)
;;				    
;;
;; 
;; Example usage:
;; (defun my-highlight-changes-enable-hook ()
;;   (add-hook 'local-write-file-hooks 'highlight-changes-rotate-faces)
;; )
;; 
;; (defun my-highlight-changes-disable-hook ()
;;   (remove-hook 'local-write-file-hooks 'highlight-changes-rotate-faces)
;; )
;; 
;; (add-hook 'highlight-changes-enable-hook 'my-highlight-changes-enable-hook)
;; (add-hook 'highlight-changes-disable-hook
;;		'my-highlight-changes-disable-hook)


;;           Explicit vs. Implicit
;;

;; Normally, Highlight Changes mode is turned on explicitly in a buffer.
;;
;; If you prefer to have it automatically invoked you can do it as
;; follows.
;; 
;; 1. Most modes have a major-hook, typically called MODE-hook.  You
;; can use `add-hook' to call `highlight-changes-mode'.  
;;
;;   Example:
;;	(add-hook 'c-mode-hook 'highlight-changes-mode)
;;
;;  If you want to make it start up in passive mode (regardless of the
;;  setting of highlight-changes-initial-state):
;;      (add-hook 'emacs-lisp-mode-hook 
;; 	    (lambda ()
;; 	      (highlight-changes-mode 'passive)))
;;
;; However, this cannot be done for Fundamental mode for there is no
;; such hook.
;;
;; 2. You can use the function `global-highlight-changes' 
;;
;; This function, which is fashioned after the way `global-font-lock' works,
;; toggles on or off global Highlight Changes mode.  When activated, it turns
;; on Highlight Changes mode in all "suitable" existing buffers and will turn
;; it on in new "suitable" buffers to be created.
;; 
;; A buffer's "suitability" is determined by variable
;; `highlight-changes-global-modes',  as follows.  If the variable is
;; * nil  -- then no buffers are suitable;
;; * a function -- this function is called and the result is used.  As
;;   an example,  if the value is `buffer-file-name' then all buffers
;;   who are visiting files are suitable, but others (like dired
;;   buffers) are not;
;; * a list -- then the buffer is suitable iff its mode is in the
;;   list,  except if the first element is `not', in which case the test
;;   is reversed (i.e. it is a list of unsuitable modes).
;; * Otherwise,  the buffer is suitable if its name does not begin with
;;   ` ' or `*' and if `buffer-file-name' returns true.
;;



;;     Possible bindings:
;; (global-set-key '[C-right] 'highlight-changes-next-change)
;; (global-set-key '[C-left]  'highlight-changes-previous-change)
;;
;;     Other interactive functions (which could be bound if desired):
;; highlight-changes-mode
;; highlight-changes-remove-highlight
;; highlight-changes-rotate-faces
;; highlight-compare-with-file

;; 
;; You can automatically rotate faces when the buffer is saved;
;; see function `highlight-changes-rotate-faces' for how to do this.
;;


;;; Bugs:

;; - the next-change and previous-change functions are too literal;
;;   they should find the next "real" change,  in other words treat
;;   consecutive changes as one.


;;; To do (maybe),  notes, ...

;; - having different faces for deletion and non-deletion: is it
;;   really worth the hassle?
;; - should have better hooks:  when should they be run?
;; - highlight-compare-with-file should allow RCS files - e.g. nice to be
;;   able to say show changes compared with version 2.1.
;; - Maybe we should have compare-with-buffer as well.  (When I tried
;;   a while back I ran into a problem with ediff-buffers-internal.)


;;; History:

;; R Sharman (rsharman@magma.ca) Feb 1998:
;; - initial release as change-mode.
;; Jari Aalto <jari.aalto@ntc.nokia.com> Mar 1998
;; - fixes for byte compile errors 
;; - use eval-and-compile for autoload
;; Marijn Ros <J.M.Ros@fys.ruu.nl> Mar 98
;; - suggested turning it on by default
;; Eric Ludlam <zappo@gnu.org> Suggested using overlays.
;; July 98
;; - global mode and various stuff added
;; - Changed to use overlays
;; August 98
;; - renamed to Highlight Changes mode.


;;; Code:

(require 'wid-edit)

;; ====================== Customization =======================
(defgroup highlight-changes nil
  "Highlight Changes mode."
  :version "20.4"
  :group 'faces)


;; Face information: How the changes appear.

;; Defaults for face: red foreground, no change to background,
;; and underlined if a change is because of a deletion.
;; Note: underlining is helpful in that it shows up changes in white space.
;; However, having it set for non-delete changes can be annoying because all
;; indentation on inserts gets underlined (which can look pretty ugly!).

(defface highlight-changes-face
  '((((class color)) (:foreground "red" ))
    (t (:inverse-video t)))
  "Face used for highlighting changes."
  :group 'highlight-changes)

;; This looks pretty ugly, actually.  Maybe the underline should be removed.
(defface highlight-changes-delete-face
  '((((class color)) (:foreground "red" :underline t))
    (t (:inverse-video t)))
  "Face used for highlighting deletions."
  :group 'highlight-changes)



;; A (not very good) default list of colours to rotate through.
;;
(defcustom highlight-changes-colours 
  (if (eq (frame-parameter nil 'background-mode) 'light)
      ;; defaults for light background:
      '( "magenta" "blue" "darkgreen" "chocolate" "sienna4" "NavyBlue")
      ;; defaults for dark background:
    '("yellow" "magenta" "blue" "maroon" "firebrick" "green4" "DarkOrchid"))
  "*Colours used by `highlight-changes-rotate-faces'.
The newest rotated change will be displayed in the first element of this list, 
the next older will be in the second element etc.

This list is used if `highlight-changes-face-list' is nil,  otherwise that
variable overrides this list.   If you only care about foreground
colours then use this,  if you want fancier faces then set
`highlight-changes-face-list'."
  :type '(repeat color)
  :group 'highlight-changes)
 

;; If you invoke highlight-changes-mode with no argument,  should it start in
;; active or passive mode?
;;
(defcustom highlight-changes-initial-state 'active
  "*What state (active or passive) `highlight-changes' should start in.
This is used when `highlight-changes' is called with no argument.
This variable must be set to one of the symbols `active' or `passive'."
  :type '(choice (const :tag "Active" active)
		 (const :tag "Passive" passive))
  :group 'highlight-changes)

(defcustom highlight-changes-global-initial-state 'passive
  "*What state `global-highlight-changes' should start in.
This is used if `global-highlight-changes' is called with no argument.
This variable must be set to either `active' or `passive'"
  :type '(choice (const :tag "Active" active)
		 (const :tag "Passive" passive))
  :group 'highlight-changes)

;; The strings displayed in the mode-line for the minor mode:
(defcustom highlight-changes-active-string nil
  "*The string used when Highlight Changes mode is in the active state.
This should be set to nil if no indication is desired,  or to
a string with a leading space."
  :type '(choice string
		 (const :tag "None"  nil))
  :group 'highlight-changes)

(defcustom highlight-changes-passive-string " Chg"
  "*The string used when Highlight Changes mode is in the passive state.
This should be set to nil if no indication is desired,  or to
a string with a leading space."
  :type '(choice string
		 (const :tag "None"  nil))
  :group 'highlight-changes)

(defcustom highlight-changes-global-modes t
  "*Determine whether a buffer is suitable for global Highlight Changes mode.

A function means that function is called:  if it returns non-nil, the
buffer is suitable.

A list is a list of modes for which it is suitable,  or a list whose
first element is `not' followed by modes which are not suitable.

t means the buffer is suitable if its name does not begin with ` ' nor
`*' and the buffer has a filename.

A value of nil means no buffers are suitable for `global-highlight-changes'
(effectively disabling the mode).

Examples:
        (c-mode c++-mode)
means that Highlight Changes mode is turned on for buffers in C and C++
modes only."
  :type '(choice 
	  (const :tag "all non-special buffers visiting files" t)
	  (set :menu-tag "specific modes" :tag "modes"
	       :value (not)
	       (const :tag "All except these" not)
	       (repeat :tag "Modes" :inline t (symbol :tag "mode")))
	  (function :menu-tag "determined by function"
			   :value buffer-file-name)
	  (const :tag "none" nil)
	  )
  :group 'highlight-changes)

(defvar global-highlight-changes nil)

(defcustom highlight-changes-global-changes-existing-buffers nil
  "*If non-nil, toggling global Highlight Changes mode affects existing buffers.
Normally, `global-highlight-changes' affects only new buffers (to be
created).  However, if `highlight-changes-global-changes-existing-buffers'
is non-nil, then turning on `global-highlight-changes' will turn on
Highlight Changes mode in suitable buffers, and turning the mode off will
remove it from existing buffers."
  :type 'boolean
  :group 'highlight-changes)

(defun hilit-chg-cust-fix-changes-face-list (w wc &optional event)
  ;; When customization function `highlight-changes-face-list' inserts a new
  ;; face it uses the default face.   We don't want the user to modify this
  ;; face,  so we rename the faces in the list on an insert.  The rename is
  ;; actually done by copying the faces so user-defined faces still remain
  ;; in the same order.
  ;; The notifying the parent is needed because without it changes to the
  ;; faces are saved but not to the actual list itself.
  (let ((old-list (widget-value w)))
    (if (member 'default old-list)
	(let
	    ((p (reverse old-list))
	     (n (length old-list))
	     new-name old-name
	     (new-list nil)
	     )
	  (while p
	    (setq old-name (car p))
	    (setq new-name (intern (format "highlight-changes-face-%d" n)))
	    (if (eq old-name new-name)
		nil
	      ;; A new face has been inserted: we don't want to modify the
	      ;; default face so copy it.   Better, though, (I think) is to
	      ;; make a new face have the same attributes as
	      ;; highlight-changes-face .
	      (if (eq old-name 'default)
		  (copy-face 'highlight-changes-face  new-name)
		(copy-face old-name new-name)
		))
	    (setq new-list (append  (list new-name) new-list))
	    (setq n (1- n))
	    (setq p (cdr p)))
	  (if (equal new-list (widget-value w))
	      nil ;; (message "notify: no change!")
	    (widget-value-set w new-list)
	    (widget-setup)
	    )
	  )
      ;; (message "notify: no default here!")
      ))
  (let ((parent (widget-get w :parent)))
    (when parent
      (widget-apply parent :notify w event))))


(defcustom highlight-changes-face-list nil
  "*A list of faces used when rotating changes.
Normally the variable is initialized to nil and the list is created from
`highlight-changes-colours' when needed.  However, you can set this variable
to any list of faces.  You will have to do this if you want faces which
don't just differ from `highlight-changes-face' by the foreground colour.
Otherwise, this list will be constructed when needed from
`highlight-changes-colours'."
  :type '(choice
	  (repeat 
	    :notify hilit-chg-cust-fix-changes-face-list
	    face  )
	  (const :tag "Derive from highlight-changes-colours"  nil)
	  )
  :group 'highlight-changes)

;; ========================================================================

;; These shouldn't be changed!

;; Autoload for the benefit of `make-mode-line-mouse-sensitive'.
;;;###autoload
(defvar highlight-changes-mode nil)
(defvar hilit-chg-list nil)
(defvar hilit-chg-string " ??")
(or (assq 'highlight-changes-mode minor-mode-alist)
    (setq minor-mode-alist
	  (cons '(highlight-changes-mode hilit-chg-string) minor-mode-alist)
	  ))
(make-variable-buffer-local 'highlight-changes-mode)
(make-variable-buffer-local 'hilit-chg-string)



(eval-and-compile
  ;;  For highlight-compare-with-file
  (defvar ediff-number-of-differences)
  (autoload 'ediff-setup		"ediff")
  (autoload 'ediff-with-current-buffer	"ediff")
  (autoload 'ediff-really-quit		"ediff")
  (autoload 'ediff-make-fine-diffs	"ediff")
  (autoload 'ediff-get-fine-diff-vector "ediff")
  (autoload 'ediff-get-difference	"ediff"))



;;; Functions...

(defun hilit-chg-map-changes  (func &optional start-position end-position)
  "Call function FUNC for each region used by Highlight Changes mode."
  ;; if start-position is nil, (point-min) is used
  ;; if end-position is nil, (point-max) is used
  ;; FUNC is called with 3 params: property start stop
  (let ((start (or start-position (point-min)))
	(limit (or end-position (point-max)))
	prop end)
    (while (and start (< start limit))
      (setq prop (get-text-property start 'hilit-chg))
      (setq end (text-property-not-all start limit 'hilit-chg prop))
      (if prop
	  (funcall func prop start (or end limit)))
      (setq start end))))


(defun hilit-chg-display-changes (&optional beg end)
  "Display face information for Highlight Changes mode.

An overlay containing a change face is added from the information
in the text property of type `hilit-chg'.

This is the opposite of `hilit-chg-hide-changes'."
  (hilit-chg-map-changes 'hilit-chg-make-ov beg end))


(defun hilit-chg-make-ov (prop start end)
  ;; for the region make change overlays corresponding to
  ;; the text property 'hilit-chg
  (let ((ov (make-overlay start end))
	face)
    (or prop
	(error "hilit-chg-make-ov: prop is nil"))
    (if (eq prop 'hilit-chg-delete)
	(setq face 'highlight-changes-delete-face)
      (setq face (nth 1 (member prop hilit-chg-list))))
    (if face
	(progn
	  ;; We must mark the face,  that is the purpose of the overlay
	  (overlay-put ov 'face face)
	  ;; I don't think we need to set evaporate since we should
	  ;; be controlling them!
	  (overlay-put ov 'evaporate t)
	  ;; We set the change property so we can tell this is one
	  ;; of our overlays (so we don't delete someone else's).
	  (overlay-put ov 'hilit-chg t)
	  )
      (error "hilit-chg-make-ov: no face for prop: %s" prop))))

(defun hilit-chg-hide-changes (&optional beg end)
  "Remove face information for Highlight Changes mode.

The overlay containing the face is removed,  but the text property
containing the change information is retained.

This is the opposite of `hilit-chg-display-changes'."
  (let ((start (or beg (point-min)))
	(limit (or end (point-max)))
	p ov)
    (setq p (overlays-in start limit))
    (while p
      ;; don't delete the overlay if it isn't ours!
      (if (overlay-get (car p) 'hilit-chg)
	  (delete-overlay (car p)))
      (setq p (cdr p)))))

(defun hilit-chg-fixup (beg end)
  "Fix change overlays in region between BEG and END.

Ensure the overlays agree with the changes as determined from
the text properties of type `hilit-chg' ."
  ;; Remove or alter overlays in region beg..end
  (let (p ov ov-start ov-end
	 props q)
    (setq p (overlays-in beg end))
    ;; temp for debugging:
    ;; (or (eq highlight-changes-mode 'active)
    ;;	 (error "hilit-chg-fixup called but Highlight Changes mode not active"))
    (while p
      (setq ov (car p))
      (setq ov-start (overlay-start ov))
      (setq ov-end (overlay-end ov))
      (if (< ov-start beg)
	  (progn
	    (move-overlay ov ov-start beg)
	    (if (> ov-end end)
		(progn
		  (setq props (overlay-properties ov))
		  (setq ov (make-overlay end ov-end))
		  (while props
		    (overlay-put ov (car props)(car (cdr props)))
		    (setq props (cdr (cdr props)))))))
	(if (> ov-end end)
	    (move-overlay ov end ov-end)
	  (delete-overlay ov)))
      (setq p (cdr p)))
    (hilit-chg-display-changes beg end)))

;;;###autoload
(defun highlight-changes-remove-highlight (beg end) 
  "Remove the change face from the region between BEG and END.  
This allows you to manually remove highlighting from uninteresting changes."
  (interactive "r")
  (let ((after-change-functions nil))
    (remove-text-properties beg end  '(hilit-chg nil))
    (hilit-chg-fixup beg end)))

(defun hilit-chg-set-face-on-change (beg end leng-before 
	&optional no-proerty-change)
  "Record changes and optionally display them in a distinctive face.
`hilit-chg-set' adds this function to the `after-change-functions' hook."
  ;;
  ;; This function is called by the `after-change-functions' hook, which
  ;; is how we are notified when text is changed.
  ;; It is also called from `highlight-compare-with-file'.
  ;;
  ;; We do NOT want to simply do this if this is an undo command, because
  ;; otherwise an undone change shows up as changed.  While the properties
  ;; are automatically restored by undo,  we must fix up the overlay.
  (save-match-data
    (let ((beg-decr 1) (end-incr 1)
	  (type 'hilit-chg)
	  old)
      (if undo-in-progress
	  (if (eq highlight-changes-mode 'active)
	      (hilit-chg-fixup beg end))
	(if (and (= beg end) (> leng-before 0))
	    ;; deletion
	    (progn
	      ;; The eolp and bolp tests are a kludge!  But they prevent
	      ;; rather nasty looking displays when deleting text at the end 
	      ;; of line,  such as normal corrections as one is typing and
	      ;; immediately makes a correction,  and when deleting first
	      ;; character of a line.
;;;	      (if (= leng-before 1)
;;;		  (if (eolp)
;;;		      (setq beg-decr 0 end-incr 0)
;;;		    (if (bolp)
;;;			(setq beg-decr 0))))
;;;	      (setq beg (max (- beg beg-decr) (point-min)))
	      (setq end (min (+ end end-incr) (point-max)))
	      (setq type 'hilit-chg-delete))
	  ;; Not a deletion.
	  ;; Most of the time the following is not necessary,  but
	  ;; if the current text was marked as a deletion then
	  ;; the old overlay is still in effect, so if we add some
	  ;; text then remove the deletion marking,  but set it to
	  ;; changed otherwise its highlighting disappears.
	  (if (eq (get-text-property end 'hilit-chg) 'hilit-chg-delete)
	      (progn
		(remove-text-properties end (+ end 1) '(hilit-chg nil))
		(put-text-property end (+ end 1) 'hilit-chg 'hilit-chg)
		(if (eq highlight-changes-mode 'active)
		    (hilit-chg-fixup beg (+ end 1))))))
	(unless no-proerty-change
		(put-text-property beg end 'hilit-chg type))
	(if (or (eq highlight-changes-mode 'active) no-proerty-change)
	    (hilit-chg-make-ov type beg end))))))

(defun hilit-chg-set (value)
  "Turn on Highlight Changes mode for this buffer."
  (setq highlight-changes-mode value)
  (remove-hook 'after-change-functions 'hilit-chg-set-face-on-change t)
  (hilit-chg-make-list)
  (if (eq highlight-changes-mode 'active)
      (progn
	(setq hilit-chg-string highlight-changes-active-string)
	(or buffer-read-only
	    (hilit-chg-display-changes)))
    ;; mode is passive
    (setq hilit-chg-string highlight-changes-passive-string)
    (or buffer-read-only
	(hilit-chg-hide-changes)))
  (force-mode-line-update)
  (make-local-hook 'after-change-functions)
  (add-hook 'after-change-functions 'hilit-chg-set-face-on-change nil t))

(defun hilit-chg-clear ()
  "Remove Highlight Changes mode for this buffer.
This removes all saved change information."
  (if buffer-read-only
      ;; We print the buffer name because this function could be called
      ;; on many buffers from `global-highlight-changes'.
      (message "Cannot remove highlighting from read-only mode buffer %s"
	       (buffer-name))
    (remove-hook 'after-change-functions 'hilit-chg-set-face-on-change t)
    (let ((after-change-functions nil))
      (hilit-chg-hide-changes)
      (hilit-chg-map-changes 
       '(lambda (prop start stop)
	  (remove-text-properties start stop '(hilit-chg nil))))
      )
    (setq highlight-changes-mode nil)
    (force-mode-line-update)
    ;; If we type:  C-u -1 M-x highlight-changes-mode
    ;; we want to turn it off,  but hilit-chg-post-command-hook
    ;; runs and that turns it back on!
    (remove-hook 'post-command-hook 'hilit-chg-post-command-hook)))

;;;###autoload
(defun highlight-changes-mode (&optional arg)
  "Toggle (or initially set) Highlight Changes mode.

Without an argument: 
  If Highlight Changes mode is not enabled, then enable it (in either active
  or passive state as determined by the variable
  `highlight-changes-initial-state'); otherwise, toggle between active
  and passive state.

With an argument ARG:
  If ARG is positive, set state to active;
  If ARG is zero, set state to passive;
  If ARG is negative, disable Highlight Changes mode completely.

Active state  - means changes are shown in a distinctive face.
Passive state - means changes are kept and new ones recorded but are
		not displayed in a different face.

Functions:
\\[highlight-changes-next-change] - move point to beginning of next change
\\[highlight-changes-previous-change] - move to beginning of previous change 
\\[highlight-compare-with-file] - mark text as changed by comparing this
	buffer with the contents of a file
\\[highlight-changes-remove-highlight] - remove the change face from the region
\\[highlight-changes-rotate-faces] - rotate different \"ages\" of changes \
through 
	various faces.

Hook variables:
`highlight-changes-enable-hook'  - when enabling Highlight Changes mode.
`highlight-changes-toggle-hook'  - when entering active or passive state
`highlight-changes-disable-hook' - when turning off Highlight Changes mode."
  (interactive "P")
  (if (or (display-color-p)
	  (and (fboundp 'x-display-grayscale-p) (x-display-grayscale-p)))
      (let ((was-on highlight-changes-mode)
	    (new-highlight-changes-mode
	     (cond
	      ((null arg)
	       ;; no arg => toggle (or set to active initially)
	       (if highlight-changes-mode
		   (if (eq highlight-changes-mode 'active) 'passive 'active)
		 highlight-changes-initial-state))
	      ;; an argument is given
	      ((eq arg 'active)
	       'active)
	      ((eq arg  'passive)
	       'passive)
	      ((> (prefix-numeric-value arg) 0)
	       'active)
	      ((< (prefix-numeric-value arg) 0)
	       nil)
	      (t
	       'passive))))
	(if new-highlight-changes-mode
	    ;; mode is turned on -- but may be passive
	    (progn
	      (hilit-chg-set new-highlight-changes-mode)
	      (or was-on
		  ;; run highlight-changes-enable-hook once
		  (run-hooks 'highlight-changes-enable-hook))
	      (run-hooks 'highlight-changes-toggle-hook))
	  ;; mode is turned off
	  (run-hooks 'highlight-changes-disable-hook)
	  (hilit-chg-clear)))
    (message "Highlight Changes mode requires color or grayscale display")))

;;;###autoload
(defun highlight-changes-next-change ()
  "Move to the beginning of the next change, if in Highlight Changes mode."
  (interactive)
  (if highlight-changes-mode
      (let ((start (point))
	    prop)
	(setq prop (get-text-property (point) 'hilit-chg))
	(if prop
	    ;; we are in a change
	    (setq start (next-single-property-change (point) 'hilit-chg)))
	(if start
	    (setq start (next-single-property-change start 'hilit-chg)))
	(if start
	    (goto-char start)
	  (message "no next change")))
    (message "This buffer is not in Highlight Changes mode.")))


;;;###autoload
(defun highlight-changes-previous-change ()
  "Move to the beginning of the previous change, if in Highlight Changes mode."
  (interactive)
  (if highlight-changes-mode
      (let ( (start (point)) (prop nil) )
	(or (bobp)
	    (setq prop (get-text-property (1- (point)) 'hilit-chg)))
	(if prop
	    ;; we are in a change
	    (setq start (previous-single-property-change (point) 'hilit-chg)))
	(if start
	    (setq start (previous-single-property-change start 'hilit-chg)))
	;; special handling for the case where (point-min) is a change
	(if start
	    (setq start (or (previous-single-property-change start 'hilit-chg)
			    (if (get-text-property (point-min) 'hilit-chg)
				(point-min)))))
	(if start
	    (goto-char start)
	  (message "no previous change")))
    (message "This buffer is not in Highlight Changes mode.")))

;; ========================================================================

(defun hilit-chg-make-list (&optional force)
  "Construct `hilit-chg-list' and `highlight-changes-face-list'."
  ;; Constructs highlight-changes-face-list if necessary,  
  ;; and hilit-chg-list always:
  ;; Maybe this should always be called when rotating a face
  ;; so we pick up any changes?
  (if (or (null highlight-changes-face-list)  ; Don't do it if it
	  force) ; already exists unless FORCE non-nil.
      (let ((p highlight-changes-colours) 
	    (n 1) name)
	(setq highlight-changes-face-list nil)
	(while p
	  (setq name (intern (format "highlight-changes-face-%d" n)))
	  (copy-face 'highlight-changes-face name)
	  (set-face-foreground name (car p))
	  (setq highlight-changes-face-list 
		(append highlight-changes-face-list (list name)))
	  (setq p (cdr p))
	  (setq n (1+ n)))))
  (setq hilit-chg-list (list 'hilit-chg 'highlight-changes-face))
  (let ((p highlight-changes-face-list)
	(n 1) 
	last-category last-face)
    (while p
      (setq last-category (intern (format "change-%d" n)))
      ;; (setq last-face (intern (format "highlight-changes-face-%d" n)))
      (setq last-face (car p))
      (setq hilit-chg-list
	    (append hilit-chg-list
		    (list last-category last-face)))
      (setq p (cdr p))
      (setq n (1+ n)))
    (setq hilit-chg-list
	  (append hilit-chg-list
		  (list last-category last-face)))))

(defun hilit-chg-bump-change (prop start end)
  "Increment (age) the Highlight Changes mode text property."
  (let ( new-prop )
    (if (eq prop 'hilit-chg-delete)
	(setq new-prop (nth 2 hilit-chg-list))
      (setq new-prop (nth 2 (member prop hilit-chg-list))))
    (if prop
	(put-text-property start end 'hilit-chg new-prop)
      (message "%d-%d unknown property %s not changed" start end prop))))

;;;###autoload
(defun highlight-changes-rotate-faces ()
  "Rotate the faces used by Highlight Changes mode.

Current changes are displayed in the face described by the first element
of `highlight-changes-face-list', one level older changes are shown in
face described by the second element, and so on.  Very old changes remain
shown in the last face in the list.

You can automatically rotate colours when the buffer is saved
by adding the following to `local-write-file-hooks',  by evaling it in the
buffer to be saved):

  \(add-hook 'local-write-file-hooks 'highlight-changes-rotate-faces)"
  (interactive)
  ;; If not in active mode do nothing but don't complain because this
  ;; may be bound to a hook.
  (if (eq highlight-changes-mode 'active)
      (let ((after-change-functions nil))
	;; ensure hilit-chg-list is made and up to date
	(hilit-chg-make-list)
	;; remove our existing overlays
	(hilit-chg-hide-changes)
	;; for each change text property, increment it
	(hilit-chg-map-changes 'hilit-chg-bump-change)
	;; and display them all if active
	(if (eq highlight-changes-mode 'active)
	    (hilit-chg-display-changes))))
  ;; This always returns nil so it is safe to use in
  ;; local-write-file-hook
  nil)

;; ========================================================================
;; Comparing with an existing file.   
;; This uses ediff to find the differences.

;;;###autoload
(defun highlight-compare-with-file (file-b)
  "Compare this buffer with a file, and highlight differences.

The current buffer must be an unmodified buffer visiting a file,
and must not be read-only.

If the buffer has a backup filename, it is used as the default when
this function is called interactively.

If the current buffer is visiting the file being compared against, it
also will have its differences highlighted.  Otherwise, the file is
read in temporarily but the buffer is deleted.

If the buffer is read-only, differences will be highlighted but no property
changes are made, so \\[highlight-changes-next-change] and
\\[highlight-changes-previous-change] will not work."
  (interactive (list
	      (read-file-name
	       "File to compare with? " ;; prompt
	       ""			;; directory
	       nil			;; default
	       'yes			;; must exist
	       (let ((f (make-backup-file-name 
			 (or (buffer-file-name (current-buffer))
			     (error "no file for this buffer")))))
		 (if (file-exists-p f) f "")))))

  (let* ((buf-a (current-buffer))
	 (buf-a-read-only buffer-read-only)
	 (orig-pos (point))
	 (file-a (buffer-file-name))
	 (existing-buf (get-file-buffer file-b))
	 (buf-b (or existing-buf
		    (find-file-noselect file-b)))
	 (buf-b-read-only (with-current-buffer buf-b buffer-read-only))
	 xy  xx yy p q
	 a-start a-end len-a
	 b-start b-end len-b)

    ;; We use the fact that the buffer is not marked modified at the
    ;; end where we clear its modified status
    (if (buffer-modified-p buf-a)
	(if (y-or-n-p (format "OK to save %s?  " file-a))
		       (save-buffer buf-a)
	  (error "Buffer must be saved before comparing with a file")))
    (if (and existing-buf (buffer-modified-p buf-b))
	(if (y-or-n-p (format "OK to save %s?  " file-b))
		       (save-buffer buf-b)
	  (error "Cannot compare with a file in an unsaved buffer")))
    (highlight-changes-mode 'active)
    (if existing-buf (with-current-buffer buf-b
		       (highlight-changes-mode 'active)))
    (save-window-excursion
      (setq xy (hilit-chg-get-diff-info buf-a file-a buf-b file-b)))
    (setq xx (car xy))
    (setq p xx)
    (setq yy (car (cdr xy)))
    (setq q yy)
    (hilit-chg-make-list)
    (while p
      (setq a-start (nth 0 (car p)))
      (setq a-end (nth 1 (car p)))
      (setq b-start (nth 0 (car q)))
      (setq b-end (nth 1 (car q)))
      (setq len-a (- a-end a-start))
      (setq len-b (- b-end b-start))
      (set-buffer buf-a)
      (hilit-chg-set-face-on-change a-start a-end len-b buf-a-read-only)
      (set-buffer-modified-p nil)
      (goto-char orig-pos)
      (if existing-buf
	  (with-current-buffer buf-b
	    (hilit-chg-set-face-on-change b-start b-end len-a
					  buf-b-read-only )
	    ))
      (setq p (cdr p))
      (setq q (cdr q)))
    (if existing-buf
	(set-buffer-modified-p nil) 
      (kill-buffer buf-b))))


(defun hilit-chg-get-diff-info (buf-a file-a buf-b file-b)
  (let ((e nil) x y)   ;; e is set by function hilit-chg-get-diff-list-hk
    (ediff-setup buf-a file-a buf-b file-b
	       nil nil   ; buf-c file-C
	       'hilit-chg-get-diff-list-hk
	       (list (cons 'ediff-job-name 'something))
	       )
    (ediff-with-current-buffer e (ediff-really-quit nil))
    (list x y)))


(defun hilit-chg-get-diff-list-hk ()
  ;; x and y are dynamically bound by hilit-chg-get-diff-info 
  ;; which calls this function as a hook
  (defvar x)  ;; placate the byte-compiler
  (defvar y)
  (setq  e (current-buffer))
  (let ((n 0) extent p va vb a b)
    (setq  x nil  y nil)    ;; x and y are bound by hilit-chg-get-diff-info
    (while (< n ediff-number-of-differences)
      (ediff-make-fine-diffs n)
      (setq va (ediff-get-fine-diff-vector n 'A))
      ;; va is a vector if there are fine differences
      (if va
	  (setq a (append va nil))
	;; if not,  get the unrefined difference
	(setq va (ediff-get-difference n 'A))
	(setq a (list (elt va 0))))
      ;; a list a list
      (setq p a)
      (while p
	(setq extent (list (overlay-start (car p))
			   (overlay-end (car p))))
	(setq p (cdr p))
	(setq x (append x (list extent) )));; while p
      ;;
      (setq vb (ediff-get-fine-diff-vector n 'B))
      ;; vb is a vector
      (if vb
	  (setq b (append vb nil))
	;; if not,  get the unrefined difference
	(setq vb (ediff-get-difference n 'B))
	(setq b (list (elt vb 0))))
      ;; b list a list
      (setq p b)
      (while p
	(setq extent (list (overlay-start (car p))
			   (overlay-end (car p))))
	(setq p (cdr p))
	(setq y (append y (list extent) )))
      (setq n (1+ n)));; while
    ;; ediff-quit doesn't work here.
    ;; No point in returning a value, since this is a hook function.
    ))

;; ======================= automatic stuff ==============

;; Global Highlight Changes mode is modeled after Global Font-lock mode.
;; Three hooks are used to gain control.  When Global Changes Mode is
;; enabled, `find-file-hooks' and `change-major-mode-hook' are set.
;; `find-file-hooks' is called when visiting a file,  the new mode is
;; known at this time.
;; `change-major-mode-hook' is called when a buffer is changing mode.
;; This could be because of finding a file in which case
;; `find-file-hooks' has already been called and has done its work.
;; However, it also catches the case where a new mode is being set by
;; the user.  However, it is called from `kill-all-variables' and at
;; this time the mode is the old mode,  which is not what we want.
;; So,  our function temporarily sets `post-command-hook' which will
;; be called after the buffer has been completely set up (with the new
;; mode).  It then removes the `post-command-hook'.
;; One other wrinkle - every M-x command runs the `change-major-mode-hook'
;; so we ignore this by examining the buffer name.


(defun hilit-chg-major-mode-hook ()
  (add-hook 'post-command-hook 'hilit-chg-post-command-hook))

(defun hilit-chg-post-command-hook ()
  ;; This is called after changing a major mode, but also after each
  ;; M-x command,  in which case the current buffer is a minibuffer.
  ;; In that case, do not act on it here,  but don't turn it off
  ;; either,  we will get called here again soon-after. 
  ;; Also,  don't enable it for other special buffers.
  (if (string-match "^[ *]"  (buffer-name))
      nil ;; (message "ignoring this post-command-hook")
    (remove-hook 'post-command-hook 'hilit-chg-post-command-hook)
    ;; The following check isn't necessary,  since 
    ;; hilit-chg-turn-on-maybe makes this check too.
    (or highlight-changes-mode	;; don't turn it on if it already is
	(hilit-chg-turn-on-maybe highlight-changes-global-initial-state))))

(defun hilit-chg-check-global ()
  ;; This is called from the find file hook.
  (hilit-chg-turn-on-maybe highlight-changes-global-initial-state))


;;;###autoload
(defun global-highlight-changes (&optional arg)
  "Turn on or off global Highlight Changes mode.

When called interactively:
- if no prefix, toggle global Highlight Changes mode on or off
- if called with a positive prefix (or just C-u) turn it on in active mode
- if called with a zero prefix  turn it on in passive mode
- if called with a negative prefix turn it off

When called from a program:
- if ARG is nil or omitted, turn it off
- if ARG is `active',  turn it on in active mode
- if ARG is `passive', turn it on in passive mode
- otherwise just turn it on 

When global Highlight Changes mode is enabled, Highlight Changes mode is turned
on for future \"suitable\" buffers (and for \"suitable\" existing buffers if
variable `highlight-changes-global-changes-existing-buffers' is non-nil).
\"Suitability\" is determined by variable `highlight-changes-global-modes'."

  (interactive 
   (list
    (cond
     ((null current-prefix-arg)
      ;; no arg => toggle it on/off
      (setq global-highlight-changes (not global-highlight-changes)))
     ;; positive interactive arg - turn it on as active
     ((> (prefix-numeric-value current-prefix-arg) 0)
      (setq global-highlight-changes t)
      'active)
     ;; zero interactive arg - turn it on as passive
     ((= (prefix-numeric-value current-prefix-arg) 0)
      (setq global-highlight-changes t)
      'passive)
     ;; negative interactive arg - turn it off
     (t
      (setq global-highlight-changes nil)      
      nil))))

  (if arg
      (progn
	(if (eq arg 'active)
	    (setq highlight-changes-global-initial-state 'active)
	  (if (eq arg  'passive)
	      (setq highlight-changes-global-initial-state 'passive)))
	(setq global-highlight-changes t)
	(message "turning ON Global Highlight Changes mode in %s state"
		 highlight-changes-global-initial-state)
	(add-hook 'hilit-chg-major-mode-hook 'hilit-chg-major-mode-hook)
	(add-hook 'find-file-hooks 'hilit-chg-check-global)
	(if highlight-changes-global-changes-existing-buffers
	    (hilit-chg-update-all-buffers 
	     highlight-changes-global-initial-state)))
    
    (message "turning OFF global Highlight Changes mode")
    (remove-hook 'hilit-chg-major-mode-hook 'hilit-chg-major-mode-hook)
    (remove-hook 'find-file-hooks 'hilit-chg-check-global)
    (remove-hook 'post-command-hook
		 'hilit-chg-post-command-hook)
    (remove-hook 'find-file-hooks 'hilit-chg-check-global)
    (if highlight-changes-global-changes-existing-buffers
	(hilit-chg-update-all-buffers nil))))


(defun hilit-chg-turn-on-maybe (value)
  "Turn on Highlight Changes mode if it is appropriate for this buffer.

A buffer is appropriate for Highlight Changes mode if all these are true:
- the buffer is not a special buffer (one whose name begins with 
  `*' or ` ')
- the buffer's mode is suitable as per variable
  `highlight-changes-global-modes'
- Highlight Changes mode is not already on for this buffer.

This function is called from `hilit-chg-update-all-buffers' or 
from `global-highlight-changes' when turning on global Highlight Changes mode."
  (or highlight-changes-mode			; do nothing if already on
      (if
	  (cond
	   ((null highlight-changes-global-modes)
	    nil)
	   ((functionp highlight-changes-global-modes)
	    (funcall highlight-changes-global-modes))
	    ((listp highlight-changes-global-modes)
	     (if (eq (car-safe highlight-changes-global-modes) 'not)
		 (not (memq major-mode (cdr highlight-changes-global-modes)))
	       (memq major-mode highlight-changes-global-modes)))
	    (t
	     (and 
	      (not (string-match "^[ *]"  (buffer-name)))
	      (buffer-file-name))))
	  (progn
	    (hilit-chg-set value)
	    (run-hooks 'highlight-changes-enable-hook)))))
    

(defun hilit-chg-turn-off-maybe ()
  (if highlight-changes-mode
      (progn
	(run-hooks 'highlight-changes-disable-hook)
	(hilit-chg-clear))))


(defun hilit-chg-update-all-buffers (value)
  (mapcar
   (function (lambda (buffer)
	       (with-current-buffer buffer
		 (if value
		     (hilit-chg-turn-on-maybe value)
		   (hilit-chg-turn-off-maybe))
		 )))
   (buffer-list)))

;; ===================== debug ==================
;; For debug & test use:
;;
;; (defun hilit-chg-debug-show (&optional beg end)
;;   (interactive)
;;   (message "--- hilit-chg-debug-show ---")
;;   (hilit-chg-map-changes '(lambda (prop start end)
;; 			      (message "%d-%d: %s" start end prop)
;; 			      )
;; 			   beg end
;; 			   ))
;; 
;; ================== end of debug ===============

(provide 'hilit-chg)

;;; hilit-chg.el ends here