summaryrefslogtreecommitdiff
path: root/lisp/emacs-lisp/cl-indent.el
blob: 73b91725cc8334594b59ebfff6654767446499e2 (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
878
879
880
881
882
883
884
885
886
887
888
;;; cl-indent.el --- Enhanced lisp-indent mode  -*- lexical-binding:t -*-

;; Copyright (C) 1987, 2000-2018 Free Software Foundation, Inc.

;; Author: Richard Mlynarik <mly@eddie.mit.edu>
;; Created: July 1987
;; Maintainer: emacs-devel@gnu.org
;; Keywords: lisp, tools
;; Package: emacs

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; This package supplies a single entry point, common-lisp-indent-function,
;; which performs indentation in the preferred style for Common Lisp code.
;; It is also a suitable function for indenting Emacs lisp code.
;;
;; To enable it:
;;
;; (setq lisp-indent-function 'common-lisp-indent-function)

;;; Code:

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

(defgroup lisp-indent nil
  "Indentation in Lisp."
  :group 'lisp)


(defcustom lisp-indent-maximum-backtracking 3
  "Maximum depth to backtrack out from a sublist for structured indentation.
If this variable is 0, no backtracking will occur and forms such as `flet'
may not be correctly indented."
  :type 'integer
  :group 'lisp-indent)

(defcustom lisp-tag-indentation 1
  "Indentation of tags relative to containing list.
This variable is used by the function `lisp-indent-tagbody'."
  :type 'integer
  :group 'lisp-indent)

(defcustom lisp-tag-body-indentation 3
  "Indentation of non-tagged lines relative to containing list.
This variable is used by the function `lisp-indent-tagbody' to indent normal
lines (lines without tags).
The indentation is relative to the indentation of the parenthesis enclosing
the special form.  If the value is t, the body of tags will be indented
as a block at the same indentation as the first s-expression following
the tag.  In this case, any forms before the first tag are indented
by `lisp-body-indent'."
  :type 'integer
  :group 'lisp-indent)

(defcustom lisp-backquote-indentation t
  "Whether or not to indent backquoted lists as code.
If nil, indent backquoted lists as data, i.e., like quoted lists."
  :type 'boolean
  :group 'lisp-indent)


(defcustom lisp-loop-keyword-indentation 3
  "Indentation of loop keywords in extended loop forms."
  :type 'integer
  :group 'lisp-indent)


(defcustom lisp-loop-forms-indentation 5
  "Indentation of forms in extended loop forms."
  :type 'integer
  :group 'lisp-indent)


(defcustom lisp-simple-loop-indentation 3
  "Indentation of forms in simple loop forms."
  :type 'integer
  :group 'lisp-indent)

(defcustom lisp-lambda-list-keyword-alignment nil
  "Whether to vertically align lambda-list keywords together.
If nil (the default), keyworded lambda-list parts are aligned
with the initial mandatory arguments, like this:

\(defun foo (arg1 arg2 &rest rest
            &key key1 key2)
  #|...|#)

If non-nil, alignment is done with the first keyword
\(or falls back to the previous case), as in:

\(defun foo (arg1 arg2 &rest rest
                      &key key1 key2)
  #|...|#)"
  :version "24.1"
  :type 'boolean
  :group 'lisp-indent)

(defcustom lisp-lambda-list-keyword-parameter-indentation 2
  "Indentation of lambda list keyword parameters.
See `lisp-lambda-list-keyword-parameter-alignment'
for more information."
  :version "24.1"
  :type 'integer
  :group 'lisp-indent)

(defcustom lisp-lambda-list-keyword-parameter-alignment nil
  "Whether to vertically align lambda-list keyword parameters together.
If nil (the default), the parameters are aligned
with their corresponding keyword, plus the value of
`lisp-lambda-list-keyword-parameter-indentation', like this:

\(defun foo (arg1 arg2 &key key1 key2
                        key3 key4)
  #|...|#)

If non-nil, alignment is done with the first parameter
\(or falls back to the previous case), as in:

\(defun foo (arg1 arg2 &key key1 key2
                            key3 key4)
  #|...|#)"
  :version "24.1"
  :type 'boolean
  :group 'lisp-indent)

(defcustom lisp-indent-backquote-substitution-mode t
  "How to indent substitutions in backquotes.
If t, the default, indent substituted forms normally.
If nil, do not apply special indentation rule to substituted
forms.  If `corrected', subtract the `,' or `,@' from the form
column, indenting as if this character sequence were not present.
In any case, do not backtrack beyond a backquote substitution.

Until Emacs 25.1, the nil behavior was hard-wired."
  :version "25.1"
  :type '(choice (const corrected) (const nil) (const t))
  :group 'lisp-indent)


(defvar lisp-indent-defun-method '(4 &lambda &body)
  "Defun-like indentation method.
This applies when the value of the `common-lisp-indent-function' property
is set to `defun'.")


(defun lisp-extended-loop-p (loop-start)
  "True if an extended loop form starts at LOOP-START."
  (condition-case ()
      (save-excursion
	(goto-char loop-start)
	(forward-char 1)
	(forward-sexp 2)
	(backward-sexp 1)
	(looking-at "\\(:\\|\\sw\\)"))
    (error t)))

(defun lisp-indent-find-method (symbol &optional no-compat)
  "Find the lisp indentation function for SYMBOL.
If NO-COMPAT is non-nil, do not retrieve indenters intended for
the standard lisp indent package."
  (or (and (derived-mode-p 'emacs-lisp-mode)
           (get symbol 'common-lisp-indent-function-for-elisp))
      (get symbol 'common-lisp-indent-function)
      (and (not no-compat)
           (get symbol 'lisp-indent-function))))

(defun common-lisp-loop-part-indentation (indent-point state)
  "Compute the indentation of loop form constituents."
  (let* ((loop-indentation (save-excursion
			     (goto-char (elt state 1))
                             (current-column))))
    (when (and (eq lisp-indent-backquote-substitution-mode 'corrected))
      (save-excursion
        (goto-char (elt state 1))
        (cl-incf loop-indentation
                 (cond ((eq (char-before) ?,) -1)
                       ((and (eq (char-before) ?@)
                             (progn (backward-char)
                                    (eq (char-before) ?,)))
                        -2)
                       (t 0)))))

    (goto-char indent-point)
    (beginning-of-line)
    (list
     (cond ((not (lisp-extended-loop-p (elt state 1)))
	    (+ loop-indentation lisp-simple-loop-indentation))
	   ((looking-at "^\\s-*\\(:?\\sw+\\|;\\)")
	    (+ loop-indentation lisp-loop-keyword-indentation))
	   (t
	    (+ loop-indentation lisp-loop-forms-indentation)))
     ;; Tell the caller that the next line needs recomputation, even
     ;; though it doesn't start a sexp.
     loop-indentation)))


;; Cf (info "(elisp)Specification List")
;;;###autoload
(defun common-lisp-indent-function (indent-point state)
  "Function to indent the arguments of a Lisp function call.
This is suitable for use as the value of the variable
`lisp-indent-function'.  INDENT-POINT is the point at which the
indentation function is called, and STATE is the
`parse-partial-sexp' state at that position.  Browse the
`lisp-indent' customize group for options affecting the behavior
of this function.

If the indentation point is in a call to a Lisp function, that
function's `common-lisp-indent-function' property specifies how
this function should indent it.  Possible values for this
property are:

* defun, meaning indent according to `lisp-indent-defun-method';
  i.e., like (4 &lambda &body), as explained below.

* any other symbol, meaning a function to call.  The function should
  take the arguments: PATH STATE INDENT-POINT SEXP-COLUMN NORMAL-INDENT.
  PATH is a list of integers describing the position of point in terms of
  list-structure with respect to the containing lists.  For example, in
  ((a b c (d foo) f) g), foo has a path of (0 3 1).  In other words,
  to reach foo take the 0th element of the outermost list, then
  the 3rd element of the next list, and finally the 1st element.
  STATE and INDENT-POINT are as in the arguments to
  `common-lisp-indent-function'.  SEXP-COLUMN is the column of
  the open parenthesis of the innermost containing list.
  NORMAL-INDENT is the column the indentation point was
  originally in.  This function should behave like `lisp-indent-259'.

* an integer N, meaning indent the first N arguments like
  function arguments, and any further arguments like a body.
  This is equivalent to (4 4 ... &body).

* a list.  The list element in position M specifies how to indent the Mth
  function argument.  If there are fewer elements than function arguments,
  the last list element applies to all remaining arguments.  The accepted
  list elements are:

  * nil, meaning the default indentation.

  * an integer, specifying an explicit indentation.

  * &lambda.  Indent the argument (which may be a list) by 4.

  * &rest.  When used, this must be the penultimate element.  The
    element after this one applies to all remaining arguments.

  * &body.  This is equivalent to &rest lisp-body-indent, i.e., indent
    all remaining elements by `lisp-body-indent'.

  * &whole.  This must be followed by nil, an integer, or a
    function symbol.  This indentation is applied to the
    associated argument, and as a base indent for all remaining
    arguments.  For example, an integer P means indent this
    argument by P, and all remaining arguments by P, plus the
    value specified by their associated list element.

  * a symbol.  A function to call, with the 6 arguments specified above.

  * a list, with elements as described above.  This applies when the
    associated function argument is itself a list.  Each element of the list
    specifies how to indent the associated argument.

For example, the function `case' has an indent property
\(4 &rest (&whole 2 &rest 1)), meaning:
  * indent the first argument by 4.
  * arguments after the first should be lists, and there may be any number
    of them.  The first list element has an offset of 2, all the rest
    have an offset of 2+1=3.

If the current mode is actually `emacs-lisp-mode', look for a
`common-lisp-indent-function-for-elisp' property before looking
at `common-lisp-indent-function' and, if set, use its value
instead."
  ;; FIXME: why do we need to special-case loop?
  (if (save-excursion (goto-char (elt state 1))
                      (and (looking-at (if (derived-mode-p 'emacs-lisp-mode)
                                           "(\\(cl-\\)?loop"
                                         "([Ll][Oo][Oo][Pp]"))
                           (or lisp-indent-backquote-substitution-mode
                               (not
                                (or (and (eq (char-before) ?@)
                                         (progn (backward-char)
                                                (eq (char-before) ?,)))
                                    (eq (char-before) ?,))))))
      (common-lisp-loop-part-indentation indent-point state)
    (common-lisp-indent-function-1 indent-point state)))


(defun common-lisp-indent-function-1 (indent-point state)
  (let ((normal-indent (current-column)))
    ;; Walk up list levels until we see something
    ;;  which does special things with subforms.
    (let ((depth 0)
          ;; Path describes the position of point in terms of
          ;;  list-structure with respect to containing lists.
          ;; `foo' has a path of (0 3 1) in `((a b c (d foo) f) g)'.
          (path ())
          ;; set non-nil when somebody works out the indentation to use
          calculated
	  ;; If non-nil, this is an indentation to use
	  ;; if nothing else specifies it more firmly.
	  tentative-calculated
          ;; the position of the open-paren of the innermost containing list
          (containing-form-start (elt state 1))
          ;; the column of the above
          sexp-column)
      ;; Move to start of innermost containing list
      (goto-char containing-form-start)
      (setq sexp-column (current-column))

      ;; Look over successively less-deep containing forms
      (while (and (not calculated)
                  (< depth lisp-indent-maximum-backtracking))
        (let ((containing-sexp (point)))
          (forward-char 1)
          (parse-partial-sexp (point) indent-point 1 t)
          ;; Move to the car of the relevant containing form
          (let (tem function method tentative-defun)
            (if (not (looking-at "\\sw\\|\\s_"))
                ;; This form doesn't seem to start with a symbol
                (setq function nil method nil)
              (setq tem (point))
              (forward-sexp 1)
              (setq function (downcase (buffer-substring-no-properties
                                        tem (point))))
              (goto-char tem)
              ;; Elisp generally provides CL functionality with a CL
              ;; prefix, so if we have a special indenter for the
              ;; unprefixed version, prefer it over whatever's defined
              ;; for the cl- version.  Users can override this
              ;; heuristic by defining a
              ;; common-lisp-indent-function-for-elisp property on the
              ;; cl- version.
              (when (and (derived-mode-p 'emacs-lisp-mode)
                         (not (lisp-indent-find-method
                               (intern-soft function) t))
                         (string-match "\\`cl-" function)
                         (setf tem (intern-soft
                                    (substring function (match-end 0))))
                         (lisp-indent-find-method tem t))
                (setf function (symbol-name tem)))
              (setq tem (intern-soft function)
                    method (lisp-indent-find-method tem))
              ;; The pleblisp package feature
              (when (and (null tem)
                         (string-match ":[^:]+" function))
                (setq function (substring function (1+ (match-beginning 0)))
                      tem (intern-soft function)
                      method (lisp-indent-find-method tem))))
            (let ((n 0))
              ;; How far into the containing form is the current form?
              (if (< (point) indent-point)
                  (while (condition-case ()
                             (progn
                               (forward-sexp 1)
                               (if (>= (point) indent-point)
                                   nil
                                 (parse-partial-sexp (point)
                                                     indent-point 1 t)
                                 (setq n (1+ n))
                                 t))
                           (error nil))))
              (setq path (cons n path)))

            ;; backwards compatibility.
            (cond ((null function))
                  ((null method)
                   (when (null (cdr path))
		     ;; (package prefix was stripped off above)
		     (cond ((string-match "\\`def"
					  function)
			    (setq tentative-defun t))
			   ((string-match
                             (eval-when-compile
                              (concat "\\`\\("
                                      (regexp-opt '("with" "without" "do"))
                                      "\\)-"))
                             function)
			    (setq method '(&lambda &body))))))
                  ;; backwards compatibility.  Bletch.
                  ((eq method 'defun)
                   (setq method lisp-indent-defun-method)))

            (cond ((and (or (eq (char-after (1- containing-sexp)) ?\')
			    (and (not lisp-backquote-indentation)
				 (eq (char-after (1- containing-sexp)) ?\`)))
                        (not (eq (char-after (- containing-sexp 2)) ?\#)))
                   ;; No indentation for "'(...)" elements
                   (setq calculated (1+ sexp-column)))
                  ((when
                       (or (eq (char-after (1- containing-sexp)) ?\,)
                           (and (eq (char-after (1- containing-sexp)) ?\@)
                                (eq (char-after (- containing-sexp 2)) ?\,)))
                     ;; ",(...)" or ",@(...)"
                     (when (eq lisp-indent-backquote-substitution-mode
                               'corrected)
                       (cl-incf sexp-column -1)
                       (when (eq (char-after (1- containing-sexp)) ?\@)
                         (cl-incf sexp-column -1)))
                     (cond (lisp-indent-backquote-substitution-mode
                            (setf tentative-calculated normal-indent)
                            (setq depth lisp-indent-maximum-backtracking)
                            nil)
                           (t (setq calculated normal-indent)))))
                  ((eq (char-after (1- containing-sexp)) ?\#)
                   ;; "#(...)"
                   (setq calculated (1+ sexp-column)))
                  ((null method)
		   ;; If this looks like a call to a `def...' form,
		   ;; think about indenting it as one, but do it
		   ;; tentatively for cases like
		   ;; (flet ((defunp ()
		   ;;          nil)))
		   ;; Set both normal-indent and tentative-calculated.
		   ;; The latter ensures this value gets used
		   ;; if there are no relevant containing constructs.
		   ;; The former ensures this value gets used
		   ;; if there is a relevant containing construct
		   ;; but we are nested within the structure levels
		   ;; that it specifies indentation for.
		   (if tentative-defun
		       (setq tentative-calculated
			     (common-lisp-indent-call-method
			      function lisp-indent-defun-method
			      path state indent-point
			      sexp-column normal-indent)
			     normal-indent tentative-calculated)))
                  ((integerp method)
                   ;; convenient top-level hack.
                   ;;  (also compatible with lisp-indent-function)
                   ;; The number specifies how many `distinguished'
                   ;;  forms there are before the body starts
                   ;; Equivalent to (4 4 ... &body)
                   (setq calculated (cond ((cdr path)
                                           normal-indent)
                                          ((<= (car path) method)
                                           ;; `distinguished' form
                                           (list (+ sexp-column 4)
                                                 containing-form-start))
                                          ((= (car path) (1+ method))
                                           ;; first body form.
                                           (+ sexp-column lisp-body-indent))
                                          (t
                                           ;; other body form
                                           normal-indent))))
		  (t
		   (setq calculated
			 (common-lisp-indent-call-method
			  function method path state indent-point
			  sexp-column normal-indent)))))
          (goto-char containing-sexp)
          (unless calculated
	    (condition-case ()
		(progn (backward-up-list 1)
		       (setq depth (1+ depth)))
	      (error (setq depth lisp-indent-maximum-backtracking))))))
      (or calculated tentative-calculated))))


;; Dynamically bound in common-lisp-indent-call-method.
(defvar lisp-indent-error-function)

(defun common-lisp-indent-call-method (function method path state indent-point
				       sexp-column normal-indent)
  (let ((lisp-indent-error-function function))
    (if (symbolp method)
	(funcall method
		 path state indent-point
		 sexp-column normal-indent)
      (lisp-indent-259 method path state indent-point
		       sexp-column normal-indent))))

(defun lisp-indent-report-bad-format (m)
  (error "%s has a badly-formed %s property: %s"
         ;; Love those free variable references!!
         lisp-indent-error-function 'common-lisp-indent-function m))


;; Lambda-list indentation is now done in LISP-INDENT-LAMBDA-LIST.
;; See also `lisp-lambda-list-keyword-alignment',
;; `lisp-lambda-list-keyword-parameter-alignment' and
;; `lisp-lambda-list-keyword-parameter-indentation' -- dvl

(defvar lisp-indent-lambda-list-keywords-regexp
  "&\\(\
optional\\|rest\\|key\\|allow-other-keys\\|aux\\|whole\\|body\\|environment\
\\)\\([ \t]\\|$\\)"
  "Regular expression matching lambda-list keywords.")

(defun lisp-indent-lambda-list
    (indent-point sexp-column containing-form-start)
  (let (limit)
    (cond ((save-excursion
	     (goto-char indent-point)
	     (beginning-of-line)
	     (skip-chars-forward " \t")
	     (setq limit (point))
	     (looking-at lisp-indent-lambda-list-keywords-regexp))
	   ;; We're facing a lambda-list keyword.
	   (if lisp-lambda-list-keyword-alignment
	       ;; Align to the first keyword if any, or to the beginning of
	       ;; the lambda-list.
	       (save-excursion
		 (goto-char containing-form-start)
		 (save-match-data
		   (if (re-search-forward
			lisp-indent-lambda-list-keywords-regexp
			limit t)
		       (progn
			 (goto-char (match-beginning 0))
			 (current-column))
		       (1+ sexp-column))))
	       ;; Align to the beginning of the lambda-list.
	       (1+ sexp-column)))
	  (t
	   ;; Otherwise, align to the first argument of the last lambda-list
	   ;; keyword, the keyword itself, or the beginning of the
	   ;; lambda-list.
	   (save-excursion
	     (goto-char indent-point)
	     (forward-line -1)
	     (end-of-line)
	     (save-match-data
	       (if (re-search-backward lisp-indent-lambda-list-keywords-regexp
				       containing-form-start t)
		   (let* ((keyword-posn
			   (progn
			     (goto-char (match-beginning 0))
			     (current-column)))
			  (indented-keyword-posn
			   (+ keyword-posn
			      lisp-lambda-list-keyword-parameter-indentation)))
		     (goto-char (match-end 0))
		     (skip-chars-forward " \t")
		     (if (eolp)
			 indented-keyword-posn
			 (if lisp-lambda-list-keyword-parameter-alignment
			     (current-column)
			     indented-keyword-posn)))
		   (1+ sexp-column))))))))

;; Blame the crufty control structure on dynamic scoping
;;  -- not on me!
(defun lisp-indent-259
    (method path state indent-point sexp-column normal-indent)
  (catch 'exit
    (let ((p path)
          (containing-form-start (elt state 1))
          n tem tail)
      ;; Isn't tail-recursion wonderful?
      (while p
        ;; This while loop is for destructuring.
        ;; p is set to (cdr p) each iteration.
        (if (not (consp method)) (lisp-indent-report-bad-format method))
        (setq n (1- (car p))
              p (cdr p)
              tail nil)
        (while n
          ;; This while loop is for advancing along a method
          ;; until the relevant (possibly &rest/&body) pattern
          ;; is reached.
          ;; n is set to (1- n) and method to (cdr method)
          ;; each iteration.
          (setq tem (car method))

          (or (eq tem 'nil)             ;default indentation
              (eq tem '&lambda)         ;lambda list
              (and (eq tem '&body) (null (cdr method)))
              (and (eq tem '&rest)
                   (consp (cdr method))
                   (null (cddr method)))
              (integerp tem)            ;explicit indentation specified
              (and (consp tem)          ;destructuring
                   (eq (car tem) '&whole)
                   (or (symbolp (cadr tem))
                       (integerp (cadr tem))))
              (and (symbolp tem)        ;a function to call to do the work.
                   (null (cdr method)))
              (lisp-indent-report-bad-format method))

          (cond ((and tail (not (consp tem)))
                 ;; indent tail of &rest in same way as first elt of rest
                 (throw 'exit normal-indent))
                ((eq tem '&body)
                 ;; &body means (&rest <lisp-body-indent>)
                 (throw 'exit
                   (if (and (= n 0)     ;first body form
                            (null p))   ;not in subforms
                       (+ sexp-column
                          lisp-body-indent)
                       normal-indent)))
                ((eq tem '&rest)
                 ;; this pattern holds for all remaining forms
                 (setq tail (> n 0)
                       n 0
                       method (cdr method)))
                ((> n 0)
                 ;; try next element of pattern
                 (setq n (1- n)
                       method (cdr method))
                 (if (< n 0)
                     ;; Too few elements in pattern.
                     (throw 'exit normal-indent)))
                ((eq tem 'nil)
		 (throw 'exit (if (consp normal-indent)
				  normal-indent
				(list normal-indent containing-form-start))))
		((eq tem '&lambda)
		 (throw 'exit
			(cond ((null p)
			       (list (+ sexp-column 4) containing-form-start))
			      ((null (cdr p))
                               ;; Indentation within a lambda-list. -- dvl
                               (list (lisp-indent-lambda-list
                                      indent-point
                                      sexp-column
                                      containing-form-start)
                                     containing-form-start))
                              (t
                               normal-indent))))
                ((integerp tem)
                 (throw 'exit
                   (if (null p)         ;not in subforms
                       (list (+ sexp-column tem) containing-form-start)
                       normal-indent)))
                ((symbolp tem)          ;a function to call
                 (throw 'exit
                   (funcall tem path state indent-point
                            sexp-column normal-indent)))
                (t
                 ;; must be a destructing frob
                 (if (not (null p))
                     ;; descend
               (setq method (cddr tem)
                           n nil)
               (setq tem (cadr tem))
                   (throw 'exit
                     (cond (tail
                            normal-indent)
                           ((eq tem 'nil)
                            (list normal-indent
                                  containing-form-start))
                           ((integerp tem)
                            (list (+ sexp-column tem)
                                  containing-form-start))
                           (t
                            (funcall tem path state indent-point
                                     sexp-column normal-indent))))))))))))

(defun lisp-indent-tagbody (path state indent-point sexp-column normal-indent)
  (if (not (null (cdr path)))
      normal-indent
    (save-excursion
      (goto-char indent-point)
      (beginning-of-line)
      (skip-chars-forward " \t")
      (list (cond ((looking-at "\\sw\\|\\s_")
                   ;; a tagbody tag
                   (+ sexp-column lisp-tag-indentation))
                  ((integerp lisp-tag-body-indentation)
                   (+ sexp-column lisp-tag-body-indentation))
                  ((eq lisp-tag-body-indentation 't)
                   (condition-case ()
                       (progn (backward-sexp 1) (current-column))
                     (error (1+ sexp-column))))
                  (t (+ sexp-column lisp-body-indent)))
;            (cond ((integerp lisp-tag-body-indentation)
;                   (+ sexp-column lisp-tag-body-indentation))
;                  ((eq lisp-tag-body-indentation 't)
;                   normal-indent)
;                  (t
;                   (+ sexp-column lisp-body-indent)))
            (elt state 1)
            ))))

(defun lisp-indent-do (path state indent-point sexp-column normal-indent)
  (if (>= (car path) 3)
      (let ((lisp-tag-body-indentation lisp-body-indent))
        (funcall (function lisp-indent-tagbody)
                 path state indent-point sexp-column normal-indent))
    (funcall (function lisp-indent-259)
             '((&whole nil &rest
                ;; the following causes weird indentation
                ;;(&whole 1 1 2 nil)
                )
               (&whole nil &rest 1))
             path state indent-point sexp-column normal-indent)))


;; LISP-INDENT-DEFMETHOD now supports the presence of more than one method
;; qualifier and indents the method's lambda list properly. -- dvl
(defun lisp-indent-defmethod
    (path state indent-point sexp-column normal-indent)
  (lisp-indent-259
   (let ((nqual 0))
     (if (and (>= (car path) 3)
	      (save-excursion
		(beginning-of-defun)
		(forward-char 1)
		(forward-sexp 2)
		(skip-chars-forward " \t\n")
		(while (looking-at "\\sw\\|\\s_")
		  (cl-incf nqual)
		  (forward-sexp)
		  (skip-chars-forward " \t\n"))
		(> nqual 0)))
         (append '(4) (make-list nqual 4) '(&lambda &body))
	 (get 'defun 'common-lisp-indent-function)))
   path state indent-point sexp-column normal-indent))


(defun lisp-indent-function-lambda-hack (path _state _indent-point
                                         sexp-column normal-indent)
  ;; indent (function (lambda () <newline> <body-forms>)) kludgily.
  (if (or (cdr path) ; wtf?
          (> (car path) 3))
      ;; line up under previous body form
      normal-indent
    ;; line up under function rather than under lambda in order to
    ;;  conserve horizontal space.  (Which is what #' is for.)
    (condition-case ()
        (save-excursion
          (backward-up-list 2)
          (forward-char 1)
          (if (looking-at "\\(lisp:+\\)?function\\(\\Sw\\|\\S_\\)")
              (+ lisp-body-indent -1 (current-column))
              (+ sexp-column lisp-body-indent)))
       (error (+ sexp-column lisp-body-indent)))))



(let ((l '((block 1)
           (case        (4 &rest (&whole 2 &rest 1)))
           (ccase . case)
           (ecase . case)
           (typecase . case)
           (etypecase . case)
           (ctypecase . case)
           (catch 1)
           (cond        (&rest (&whole 2 &rest 1)))
           (defvar      (4 2 2))
           (defclass    (6 4 (&whole 2 &rest 1) (&whole 2 &rest 1)))
           (defconstant . defvar)
           (defcustom   (4 2 2 2))
           (defparameter . defvar)
           (defconst     . defcustom)
           (define-condition  . defclass)
           (define-modify-macro (4 &lambda &body))
           (defsetf     (4 &lambda 4 &body))
           (defun       (4 &lambda &body))
	   (defgeneric  (4 &lambda &body))
           (define-setf-method . defun)
           (define-setf-expander . defun)
           (defmacro . defun)
           (defsubst . defun)
           (deftype . defun)
	   (defmethod	lisp-indent-defmethod)
           (defpackage  (4 2))
           (defstruct   ((&whole 4 &rest (&whole 2 &rest 1))
                         &rest (&whole 2 &rest 1)))
           (destructuring-bind
                        ((&whole 6 &rest 1) 4 &body))
           (do          lisp-indent-do)
           (do* . do)
           (dolist      ((&whole 4 2 1) &body))
           (dotimes . dolist)
           (eval-when   1)
           (flet        ((&whole 4 &rest (&whole 1 &lambda &body)) &body))
           (labels . flet)
           (macrolet . flet)
           (generic-flet . flet)
           (generic-labels . flet)
           (handler-case (4 &rest (&whole 2 &lambda &body)))
           (restart-case . handler-case)
           ;; `else-body' style
           (if          (nil nil &body))
           ;; single-else style (then and else equally indented)
           (if          (&rest nil))
           (lambda      (&lambda &rest lisp-indent-function-lambda-hack))
           (let         ((&whole 4 &rest (&whole 1 1 2)) &body))
           (let* . let)
           (compiler-let . let) ;barf
           (handler-bind . let)
           (restart-bind . let)
           (locally 1)
           ;(loop         lisp-indent-loop)
           (:method (&lambda &body)) ; in `defgeneric'
           (multiple-value-bind ((&whole 6 &rest 1) 4 &body))
           (multiple-value-call (4 &body))
           (multiple-value-prog1 1)
           (multiple-value-setq (4 2))
           (multiple-value-setf . multiple-value-setq)
           (pprint-logical-block (4 2))
           (print-unreadable-object ((&whole 4 1 &rest 1) &body))
           ;; Combines the worst features of BLOCK, LET and TAGBODY
           (prog        (&lambda &rest lisp-indent-tagbody))
           (prog* . prog)
           (prog1 1)
           (prog2 2)
           (progn 0)
           (progv       (4 4 &body))
           (return 0)
           (return-from (nil &body))
           (symbol-macrolet . let)
           (tagbody     lisp-indent-tagbody)
           (throw 1)
           (unless 1)
           (unwind-protect (5 &body))
           (when 1)
           (with-accessors . multiple-value-bind)
           (with-condition-restarts . multiple-value-bind)
	   (with-compilation-unit (&lambda &body))
           (with-output-to-string (4 2))
           (with-slots . multiple-value-bind)
           (with-standard-io-syntax (2)))))
  (dolist (el l)
    (put (car el) 'common-lisp-indent-function
         (if (symbolp (cdr el))
             (get (cdr el) 'common-lisp-indent-function)
           (car (cdr el))))))

;; In elisp, the else part of `if' is in an implicit progn, so indent
;; it more.
(put 'if 'common-lisp-indent-function-for-elisp 2)
(put 'with-output-to-string 'common-lisp-indent-function-for-elisp 0)


;(defun foo (x)
;  (tagbody
;   foo
;     (bar)
;   baz
;     (when (losing)
;       (with-big-loser
;           (yow)
;         ((lambda ()
;            foo)
;          big)))
;     (flet ((foo (bar baz zap)
;              (zip))
;            (zot ()
;              quux))
;       (do ()
;           ((lose)
;            (foo 1))
;         (quux)
;        foo
;         (lose))
;       (cond ((x)
;              (win 1 2
;                   (foo)))
;             (t
;              (lose
;                3))))))


;(put 'while    'common-lisp-indent-function 1)
;(put 'defwrapper'common-lisp-indent-function ...)
;(put 'def 'common-lisp-indent-function ...)
;(put 'defflavor        'common-lisp-indent-function ...)
;(put 'defsubst 'common-lisp-indent-function ...)

;(put 'with-restart 'common-lisp-indent-function '((1 4 ((* 1))) (2 &body)))
;(put 'restart-case 'common-lisp-indent-function '((1 4) (* 2 ((0 1) (* 1)))))
;(put 'define-condition 'common-lisp-indent-function '((1 6) (2 6 ((&whole 1))) (3 4 ((&whole 1))) (4 &body)))
;(put 'with-condition-handler 'common-lisp-indent-function '((1 4 ((* 1))) (2 &body)))
;(put 'condition-case 'common-lisp-indent-function '((1 4) (* 2 ((0 1) (1 3) (2 &body)))))
;(put 'defclass 'common-lisp-indent-function '((&whole 2 &rest (&whole 2 &rest 1) &rest (&whole 2 &rest 1)))
;(put 'defgeneric 'common-lisp-indent-function 'defun)

(provide 'cl-indent)

;;; cl-indent.el ends here