Commit | Line | Data |
---|---|---|
fd7fa35a | 1 | ;; cust-print.el -- handles print-level and print-circle. |
ecb4184d | 2 | |
e5167999 ER |
3 | ;; Author: Daniel LaLiberte <liberte@cs.uiuc.edu> |
4 | ;; Version: 1.0 | |
5 | ;; Last-Modified: 17 Mar 1992 | |
6 | ;; Adapted-By: ESR | |
fd7fa35a | 7 | ;; Keyword: extensions |
ecb4184d ER |
8 | |
9 | ;; Copyright (C) 1992 Free Software Foundation, Inc. | |
10 | ||
11 | ;; This file is part of GNU Emacs. | |
12 | ||
13 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
14 | ;; it under the terms of the GNU General Public License as published by | |
e5167999 | 15 | ;; the Free Software Foundation; either version 2, or (at your option) |
ecb4184d ER |
16 | ;; any later version. |
17 | ||
18 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
24 | ;; along with GNU Emacs; see the file COPYING. If not, write to | |
25 | ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. | |
26 | ||
e5167999 ER |
27 | ;;; Commentary: |
28 | ||
ecb4184d ER |
29 | ;; This package provides a general print handler for prin1 and princ |
30 | ;; that supports print-level and print-circle, and by the way, | |
31 | ;; print-length since the standard routines are being replaced. Also, | |
32 | ;; to print custom types constructed from lists and vectors, use | |
33 | ;; custom-print-list and custom-print-vector. See the documentation | |
34 | ;; strings of these variables for more details. | |
35 | ||
36 | ;; If the results of your expressions contain circular references to | |
37 | ;; other parts of the same structure, the standard Emacs print | |
38 | ;; subroutines may fail to print with an untrappable error, | |
39 | ;; "Apparently circular structure being printed". If you only use cdr | |
40 | ;; circular lists (where cdrs of lists point back; what is the right | |
41 | ;; term here?), you can limit the length of printing with | |
42 | ;; print-length. But car circular lists and circular vectors generate | |
43 | ;; the above mentioned untrappable error in Emacs version 18. Version | |
44 | ;; 19 will support print-level, but it is often useful to get a better | |
45 | ;; print representation of circular structures; the print-circle | |
46 | ;; option may be used to print more concise representations. | |
47 | ||
48 | ;; There are two main ways to use this package. First, you may | |
49 | ;; replace prin1, princ, and some subroutines that use them by calling | |
50 | ;; install-custom-print-funcs so that any use of these functions in | |
51 | ;; lisp code will be affected. Second, you could call the custom | |
52 | ;; routines directly, thus only affecting the printing that requires | |
53 | ;; them. | |
54 | ||
55 | ;; Note that subroutines which call print subroutines directly will not | |
56 | ;; use the custom print functions. In particular, the evaluation | |
57 | ;; functions like eval-region call the print subroutines directly. | |
58 | ;; Therefore, evaluating (aref circ-list 0), which calls error | |
59 | ;; directly (because circ-list is not an array), will jump to the top | |
60 | ;; level instead of printing the circular list. | |
61 | ||
62 | ;; Obviously the right way to implement this custom-print facility | |
63 | ;; is in C. Please volunteer since I don't have the time or need. | |
64 | ||
65 | ;; Implementation design: we want to use the same list and vector | |
66 | ;; processing algorithm for all versions of prin1 and princ, since how | |
67 | ;; the processing is done depends on print-length, print-level, and | |
68 | ;; print-circle. For circle printing, a preprocessing step is | |
69 | ;; required before the final printing. Thanks to Jamie Zawinski | |
70 | ;; for motivation and algorithms. | |
71 | ||
72 | ;;========================================================= | |
73 | ;; export list: | |
74 | ||
75 | ;; print-level | |
76 | ;; print-circle | |
77 | ||
78 | ;; custom-print-list | |
79 | ;; custom-print-vector | |
80 | ;; add-custom-print-list | |
81 | ;; add-custom-print-vector | |
82 | ||
83 | ;; install-custom-print-funcs | |
84 | ;; uninstall-custom-print-funcs | |
85 | ||
86 | ;; custom-prin1 | |
87 | ;; custom-princ | |
88 | ;; custom-prin1-to-string | |
89 | ;; custom-print | |
90 | ;; custom-format | |
91 | ;; custom-message | |
92 | ;; custom-error | |
93 | ||
e5167999 | 94 | ;;; Code: |
ecb4184d ER |
95 | |
96 | (provide 'custom-print) | |
97 | ;; Abbreviated package name: "CP" | |
98 | ||
99 | ;;(defvar print-length nil | |
100 | ;; "*Controls how many elements of a list, at each level, are printed. | |
101 | ;;This is defined by emacs.") | |
102 | ||
103 | (defvar print-level nil | |
104 | "*Controls how many levels deep a nested data object will print. | |
105 | ||
106 | If nil, printing proceeds recursively and may lead to | |
107 | max-lisp-eval-depth being exceeded or an untrappable error may occur: | |
108 | \"Apparently circular structure being printed.\" Also see | |
109 | print-length and print-circle. | |
110 | ||
111 | If non-nil, components at levels equal to or greater than print-level | |
112 | are printed simply as \"#\". The object to be printed is at level 0, | |
113 | and if the object is a list or vector, its top-level components are at | |
114 | level 1.") | |
115 | ||
116 | ||
117 | (defvar print-circle nil | |
118 | "*Controls the printing of recursive structures. | |
119 | ||
120 | If nil, printing proceeds recursively and may lead to | |
121 | max-lisp-eval-depth being exceeded or an untrappable error may occur: | |
122 | \"Apparently circular structure being printed.\" Also see | |
123 | print-length and print-level. | |
124 | ||
125 | If non-nil, shared substructures anywhere in the structure are printed | |
126 | with \"#n=\" before the first occurance (in the order of the print | |
127 | representation) and \"#n#\" in place of each subsequent occurance, | |
128 | where n is a positive decimal integer. | |
129 | ||
130 | Currently, there is no way to read this representation in Emacs.") | |
131 | ||
132 | ||
133 | (defconst custom-print-list | |
134 | nil | |
135 | ;; e.g. '((floatp . float-to-string)) | |
136 | "If non-nil, an alist for printing of custom list objects. | |
137 | Pairs are of the form (pred . converter). If the predicate is true | |
138 | for an object, the converter is called with the object and should | |
139 | return a string which will be printed with princ. | |
140 | Also see custom-print-vector.") | |
141 | ||
142 | (defconst custom-print-vector | |
143 | nil | |
144 | "If non-nil, an alist for printing of custom vector objects. | |
145 | Pairs are of the form (pred . converter). If the predicate is true | |
146 | for an object, the converter is called with the object and should | |
147 | return a string which will be printed with princ. | |
148 | Also see custom-print-list.") | |
149 | ||
150 | ||
151 | (defun add-custom-print-list (pred converter) | |
152 | "Add the pair, a PREDICATE and a CONVERTER, to custom-print-list. | |
153 | Any pair that has the same PREDICATE is first removed." | |
154 | (setq custom-print-list (cons (cons pred converter) | |
155 | (delq (assq pred custom-print-list) | |
156 | custom-print-list)))) | |
157 | ;; e.g. (add-custom-print-list 'floatp 'float-to-string) | |
158 | ||
159 | ||
160 | (defun add-custom-print-vector (pred converter) | |
161 | "Add the pair, a PREDICATE and a CONVERTER, to custom-print-vector. | |
162 | Any pair that has the same PREDICATE is first removed." | |
163 | (setq custom-print-vector (cons (cons pred converter) | |
164 | (delq (assq pred custom-print-vector) | |
165 | custom-print-vector)))) | |
166 | ||
167 | ||
168 | ;;==================================================== | |
169 | ;; Saving and restoring internal printing routines. | |
170 | ||
171 | (defun CP::set-function-cell (symbol-pair) | |
172 | (fset (car symbol-pair) | |
173 | (symbol-function (car (cdr symbol-pair))))) | |
174 | ||
175 | ||
176 | (if (not (fboundp 'CP::internal-prin1)) | |
177 | (mapcar 'CP::set-function-cell | |
178 | '((CP::internal-prin1 prin1) | |
179 | (CP::internal-princ princ) | |
180 | (CP::internal-print print) | |
181 | (CP::internal-prin1-to-string prin1-to-string) | |
182 | (CP::internal-format format) | |
183 | (CP::internal-message message) | |
184 | (CP::internal-error error)))) | |
185 | ||
186 | ||
187 | (defun install-custom-print-funcs () | |
188 | "Replace print functions with general, customizable, lisp versions. | |
189 | The internal subroutines are saved away and may be recovered with | |
190 | uninstall-custom-print-funcs." | |
191 | (interactive) | |
192 | (mapcar 'CP::set-function-cell | |
193 | '((prin1 custom-prin1) | |
194 | (princ custom-princ) | |
195 | (print custom-print) | |
196 | (prin1-to-string custom-prin1-to-string) | |
197 | (format custom-format) | |
198 | (message custom-message) | |
199 | (error custom-error) | |
200 | ))) | |
201 | ||
202 | (defun uninstall-custom-print-funcs () | |
203 | "Reset print functions to their internal subroutines." | |
204 | (interactive) | |
205 | (mapcar 'CP::set-function-cell | |
206 | '((prin1 CP::internal-prin1) | |
207 | (princ CP::internal-princ) | |
208 | (print CP::internal-print) | |
209 | (prin1-to-string CP::internal-prin1-to-string) | |
210 | (format CP::internal-format) | |
211 | (message CP::internal-message) | |
212 | (error CP::internal-error) | |
213 | ))) | |
214 | ||
215 | ||
216 | ;;=============================================================== | |
217 | ;; Lisp replacements for prin1 and princ and for subrs that use prin1 | |
218 | ;; (or princ) -- so far only the printing and formatting subrs. | |
219 | ||
220 | (defun custom-prin1 (object &optional stream) | |
221 | "Replacement for standard prin1 that uses the appropriate | |
222 | printer depending on the values of print-level and print-circle (which see). | |
223 | ||
224 | Output the printed representation of OBJECT, any Lisp object. | |
225 | Quoting characters are printed when needed to make output that `read' | |
226 | can handle, whenever this is possible. | |
227 | Output stream is STREAM, or value of `standard-output' (which see)." | |
228 | (CP::top-level object stream 'CP::internal-prin1)) | |
229 | ||
230 | ||
231 | (defun custom-princ (object &optional stream) | |
232 | "Same as custom-prin1 except no quoting." | |
233 | (CP::top-level object stream 'CP::internal-princ)) | |
234 | ||
235 | (defun custom-prin1-to-string-func (c) | |
236 | "Stream function for custom-prin1-to-string." | |
237 | (setq prin1-chars (cons c prin1-chars))) | |
238 | ||
239 | (defun custom-prin1-to-string (object) | |
240 | "Replacement for standard prin1-to-string." | |
241 | (let ((prin1-chars nil)) | |
242 | (custom-prin1 object 'custom-prin1-to-string-func) | |
243 | (concat (nreverse prin1-chars)))) | |
244 | ||
245 | ||
246 | (defun custom-print (object &optional stream) | |
247 | "Replacement for standard print." | |
248 | (CP::internal-princ "\n") | |
249 | (custom-prin1 object stream) | |
250 | (CP::internal-princ "\n")) | |
251 | ||
252 | ||
253 | (defun custom-format (fmt &rest args) | |
254 | "Replacement for standard format. | |
255 | ||
256 | Calls format after first making strings for list or vector args. | |
257 | The format specification for such args should be %s in any case, so a | |
258 | string argument will also work. The string is generated with | |
259 | custom-prin1-to-string, which quotes quotable characters." | |
260 | (apply 'CP::internal-format fmt | |
261 | (mapcar (function (lambda (arg) | |
262 | (if (or (listp arg) (vectorp arg)) | |
263 | (custom-prin1-to-string arg) | |
264 | arg))) | |
265 | args))) | |
266 | ||
267 | ||
268 | ||
269 | (defun custom-message (fmt &rest args) | |
270 | "Replacement for standard message that works like custom-format." | |
271 | ;; It doesnt work to princ the result of custom-format | |
272 | ;; because the echo area requires special handling | |
273 | ;; to avoid duplicating the output. CP::internal-message does it right. | |
274 | ;; (CP::internal-princ (apply 'custom-format fmt args)) | |
275 | (apply 'CP::internal-message fmt | |
276 | (mapcar (function (lambda (arg) | |
277 | (if (or (listp arg) (vectorp arg)) | |
278 | (custom-prin1-to-string arg) | |
279 | arg))) | |
280 | args))) | |
281 | ||
282 | ||
283 | (defun custom-error (fmt &rest args) | |
284 | "Replacement for standard error that uses custom-format" | |
285 | (signal 'error (list (apply 'custom-format fmt args)))) | |
286 | ||
287 | ||
288 | ;;========================================= | |
289 | ;; Support for custom prin1 and princ | |
290 | ||
291 | (defun CP::top-level (object stream internal-printer) | |
292 | "Set up for printing." | |
293 | (let ((standard-output (or stream standard-output)) | |
294 | (circle-table (and print-circle (CP::preprocess-circle-tree object))) | |
295 | (level (or print-level -1)) | |
296 | ) | |
297 | ||
298 | (fset 'CP::internal-printer internal-printer) | |
299 | (fset 'CP::low-level-prin | |
300 | (cond | |
301 | ((or custom-print-list | |
302 | custom-print-vector | |
303 | print-level ; comment out for version 19 | |
304 | ) | |
305 | 'CP::custom-object) | |
306 | (circle-table | |
307 | 'CP::object) | |
308 | (t 'CP::internal-printer))) | |
309 | (fset 'CP::prin (if circle-table 'CP::circular 'CP::low-level-prin)) | |
310 | ||
311 | (CP::prin object) | |
312 | object)) | |
313 | ||
314 | ||
315 | (defun CP::object (object) | |
316 | "Test object type and print accordingly." | |
317 | ;; Could be called as either CP::low-level-prin or CP::prin. | |
318 | (cond | |
319 | ((null object) (CP::internal-printer object)) | |
320 | ((consp object) (CP::list object)) | |
321 | ((vectorp object) (CP::vector object)) | |
322 | ;; All other types, just print. | |
323 | (t (CP::internal-printer object)))) | |
324 | ||
325 | ||
326 | (defun CP::custom-object (object) | |
327 | "Test object type and print accordingly." | |
328 | ;; Could be called as either CP::low-level-prin or CP::prin. | |
329 | (cond | |
330 | ((null object) (CP::internal-printer object)) | |
331 | ||
332 | ((consp object) | |
333 | (or (and custom-print-list | |
334 | (CP::custom-object1 object custom-print-list)) | |
335 | (CP::list object))) | |
336 | ||
337 | ((vectorp object) | |
338 | (or (and custom-print-vector | |
339 | (CP::custom-object1 object custom-print-vector)) | |
340 | (CP::vector object))) | |
341 | ||
342 | ;; All other types, just print. | |
343 | (t (CP::internal-printer object)))) | |
344 | ||
345 | ||
346 | (defun CP::custom-object1 (object alist) | |
347 | "Helper for CP::custom-object. | |
348 | Print the custom OBJECT using the custom type ALIST. | |
349 | For the first predicate that matches the object, the corresponding | |
350 | converter is evaluated with the object and the string that results is | |
351 | printed with princ. Return nil if no predicte matches the object." | |
352 | (while (and alist (not (funcall (car (car alist)) object))) | |
353 | (setq alist (cdr alist))) | |
354 | ;; If alist is not null, then something matched. | |
355 | (if alist | |
356 | (CP::internal-princ | |
357 | (funcall (cdr (car alist)) object) ; returns string | |
358 | ))) | |
359 | ||
360 | ||
361 | (defun CP::circular (object) | |
362 | "Printer for prin1 and princ that handles circular structures. | |
363 | If OBJECT appears multiply, and has not yet been printed, | |
364 | prefix with label; if it has been printed, use #n# instead. | |
365 | Otherwise, print normally." | |
366 | (let ((tag (assq object circle-table))) | |
367 | (if tag | |
368 | (let ((id (cdr tag))) | |
369 | (if (> id 0) | |
370 | (progn | |
371 | ;; Already printed, so just print id. | |
372 | (CP::internal-princ "#") | |
373 | (CP::internal-princ id) | |
374 | (CP::internal-princ "#")) | |
375 | ;; Not printed yet, so label with id and print object. | |
376 | (setcdr tag (- id)) ; mark it as printed | |
377 | (CP::internal-princ "#") | |
378 | (CP::internal-princ (- id)) | |
379 | (CP::internal-princ "=") | |
380 | (CP::low-level-prin object) | |
381 | )) | |
382 | ;; Not repeated in structure. | |
383 | (CP::low-level-prin object)))) | |
384 | ||
385 | ||
386 | ;;================================================ | |
387 | ;; List and vector processing for print functions. | |
388 | ||
389 | (defun CP::list (list) | |
390 | "Print a list using print-length, print-level, and print-circle." | |
391 | (if (= level 0) | |
392 | (CP::internal-princ "#") | |
393 | (let ((level (1- level))) | |
394 | (CP::internal-princ "(") | |
395 | (let ((length (or print-length 0))) | |
396 | ||
397 | ;; Print the first element always (even if length = 0). | |
398 | (CP::prin (car list)) | |
399 | (setq list (cdr list)) | |
400 | (if list (CP::internal-princ " ")) | |
401 | (setq length (1- length)) | |
402 | ||
403 | ;; Print the rest of the elements. | |
404 | (while (and list (/= 0 length)) | |
405 | (if (and (listp list) | |
406 | (not (assq list circle-table))) | |
407 | (progn | |
408 | (CP::prin (car list)) | |
409 | (setq list (cdr list))) | |
410 | ||
411 | ;; cdr is not a list, or it is in circle-table. | |
412 | (CP::internal-princ ". ") | |
413 | (CP::prin list) | |
414 | (setq list nil)) | |
415 | ||
416 | (setq length (1- length)) | |
417 | (if list (CP::internal-princ " "))) | |
418 | ||
419 | (if (and list (= length 0)) (CP::internal-princ "...")) | |
420 | (CP::internal-princ ")")))) | |
421 | list) | |
422 | ||
423 | ||
424 | (defun CP::vector (vector) | |
425 | "Print a vector using print-length, print-level, and print-circle." | |
426 | (if (= level 0) | |
427 | (CP::internal-princ "#") | |
428 | (let ((level (1- level)) | |
429 | (i 0) | |
430 | (len (length vector))) | |
431 | (CP::internal-princ "[") | |
432 | ||
433 | (if print-length | |
434 | (setq len (min print-length len))) | |
435 | ;; Print the elements | |
436 | (while (< i len) | |
437 | (CP::prin (aref vector i)) | |
438 | (setq i (1+ i)) | |
439 | (if (< i (length vector)) (CP::internal-princ " "))) | |
440 | ||
441 | (if (< i (length vector)) (CP::internal-princ "...")) | |
442 | (CP::internal-princ "]") | |
443 | )) | |
444 | vector) | |
445 | ||
446 | ||
447 | ;;================================== | |
448 | ;; Circular structure preprocessing | |
449 | ||
450 | (defun CP::preprocess-circle-tree (object) | |
451 | ;; Fill up the table. | |
452 | (let (;; Table of tags for each object in an object to be printed. | |
453 | ;; A tag is of the form: | |
454 | ;; ( <object> <nil-t-or-id-number> ) | |
455 | ;; The id-number is generated after the entire table has been computed. | |
456 | ;; During walk through, the real circle-table lives in the cdr so we | |
457 | ;; can use setcdr to add new elements instead of having to setq the | |
458 | ;; variable sometimes (poor man's locf). | |
459 | (circle-table (list nil))) | |
460 | (CP::walk-circle-tree object) | |
461 | ||
462 | ;; Reverse table so it is in the order that the objects will be printed. | |
463 | ;; This pass could be avoided if we always added to the end of the | |
464 | ;; table with setcdr in walk-circle-tree. | |
465 | (setcdr circle-table (nreverse (cdr circle-table))) | |
466 | ||
467 | ;; Walk through the table, assigning id-numbers to those | |
468 | ;; objects which will be printed using #N= syntax. Delete those | |
469 | ;; objects which will be printed only once (to speed up assq later). | |
470 | (let ((rest circle-table) | |
471 | (id -1)) | |
472 | (while (cdr rest) | |
473 | (let ((tag (car (cdr rest)))) | |
474 | (cond ((cdr tag) | |
475 | (setcdr tag id) | |
476 | (setq id (1- id)) | |
477 | (setq rest (cdr rest))) | |
478 | ;; Else delete this object. | |
479 | (t (setcdr rest (cdr (cdr rest)))))) | |
480 | )) | |
481 | ;; Drop the car. | |
482 | (cdr circle-table) | |
483 | )) | |
484 | ||
485 | ||
486 | ||
487 | (defun CP::walk-circle-tree (object) | |
488 | (let (read-equivalent-p tag) | |
489 | (while object | |
490 | (setq read-equivalent-p (or (numberp object) (symbolp object)) | |
491 | tag (and (not read-equivalent-p) | |
492 | (assq object (cdr circle-table)))) | |
493 | (cond (tag | |
494 | ;; Seen this object already, so note that. | |
495 | (setcdr tag t)) | |
496 | ||
497 | ((not read-equivalent-p) | |
498 | ;; Add a tag for this object. | |
499 | (setcdr circle-table | |
500 | (cons (list object) | |
501 | (cdr circle-table))))) | |
502 | (setq object | |
503 | (cond | |
504 | (tag ;; No need to descend since we have already. | |
505 | nil) | |
506 | ||
507 | ((consp object) | |
508 | ;; Walk the car of the list recursively. | |
509 | (CP::walk-circle-tree (car object)) | |
510 | ;; But walk the cdr with the above while loop | |
511 | ;; to avoid problems with max-lisp-eval-depth. | |
512 | ;; And it should be faster than recursion. | |
513 | (cdr object)) | |
514 | ||
515 | ((vectorp object) | |
516 | ;; Walk the vector. | |
517 | (let ((i (length object)) | |
518 | (j 0)) | |
519 | (while (< j i) | |
520 | (CP::walk-circle-tree (aref object j)) | |
521 | (setq j (1+ j)))))))))) | |
522 | ||
523 | ||
524 | ||
525 | ;;======================================= | |
526 | ||
527 | (quote | |
528 | examples | |
529 | ||
530 | (progn | |
531 | ;; Create some circular structures. | |
532 | (setq circ-sym (let ((x (make-symbol "FOO"))) (list x x))) | |
533 | (setq circ-list (list 'a 'b (vector 1 2 3 4) 'd 'e 'f)) | |
534 | (setcar (nthcdr 3 circ-list) circ-list) | |
535 | (aset (nth 2 circ-list) 2 circ-list) | |
536 | (setq dotted-circ-list (list 'a 'b 'c)) | |
537 | (setcdr (cdr (cdr dotted-circ-list)) dotted-circ-list) | |
538 | (setq circ-vector (vector 1 2 3 4 (list 'a 'b 'c 'd) 6 7)) | |
539 | (aset circ-vector 5 (make-symbol "-gensym-")) | |
540 | (setcar (cdr (aref circ-vector 4)) (aref circ-vector 5)) | |
541 | nil) | |
542 | ||
543 | (install-custom-print-funcs) | |
544 | ;; (setq print-circle t) | |
545 | ||
546 | (let ((print-circle t)) | |
547 | (or (equal (prin1-to-string circ-list) "#1=(a b [1 2 #1# 4] #1# e f)") | |
548 | (error "circular object with array printing"))) | |
549 | ||
550 | (let ((print-circle t)) | |
551 | (or (equal (prin1-to-string dotted-circ-list) "#1=(a b c . #1#)") | |
552 | (error "circular object with array printing"))) | |
553 | ||
554 | (let* ((print-circle t) | |
555 | (x (list 'p 'q)) | |
556 | (y (list (list 'a 'b) x 'foo x))) | |
557 | (setcdr (cdr (cdr (cdr y))) (cdr y)) | |
558 | (or (equal (prin1-to-string y) "((a b) . #1=(#2=(p q) foo #2# . #1#))" | |
559 | ) | |
560 | (error "circular list example from CL manual"))) | |
561 | ||
562 | ;; There's no special handling of uninterned symbols in custom-print. | |
563 | (let ((print-circle nil)) | |
564 | (or (equal (prin1-to-string circ-sym) "(#:FOO #:FOO)") | |
565 | (error "uninterned symbols in list"))) | |
566 | (let ((print-circle t)) | |
567 | (or (equal (prin1-to-string circ-sym) "(#1=FOO #1#)") | |
568 | (error "circular uninterned symbols in list"))) | |
569 | ||
570 | (uninstall-custom-print-funcs) | |
571 | ) | |
572 | ||
fd7fa35a | 573 | ;;; cust-print.el ends here |