Factor isearch word description into new function
[emacs.git] / lisp / emacs-lisp / eieio.el
1 ;;; eieio.el --- Enhanced Implementation of Emacs Interpreted Objects -*- lexical-binding:t -*-
2 ;;; or maybe Eric's Implementation of Emacs Interpreted Objects
4 ;; Copyright (C) 1995-1996, 1998-2015 Free Software Foundation, Inc.
6 ;; Author: Eric M. Ludlam <zappo@gnu.org>
7 ;; Version: 1.4
8 ;; Keywords: OO, lisp
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software: you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation, either version 3 of the License, or
15 ;; (at your option) any later version.
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
25 ;;; Commentary:
26 ;;
27 ;; EIEIO is a series of Lisp routines which implements a subset of
28 ;; CLOS, the Common Lisp Object System. In addition, EIEIO also adds
29 ;; a few new features which help it integrate more strongly with the
30 ;; Emacs running environment.
31 ;;
32 ;; See eieio.texi for complete documentation on using this package.
33 ;;
34 ;; Note: the implementation of the c3 algorithm is based on:
35 ;; Kim Barrett et al.: A Monotonic Superclass Linearization for Dylan
36 ;; Retrieved from:
37 ;;
39 ;; @TODO - fix :initform to be a form, not a quoted value
40 ;; @TODO - Prefix non-clos functions with `eieio-'.
42 ;; TODO: better integrate CL's defstructs and classes. E.g. make it possible
43 ;; to create a new class that inherits from a struct.
45 ;;; Code:
47 (defvar eieio-version "1.4"
48 "Current version of EIEIO.")
50 (defun eieio-version ()
51 "Display the current version of EIEIO."
52 (interactive)
53 (message eieio-version))
55 (require 'eieio-core)
57 \f
58 ;;; Defining a new class
59 ;;
60 (defmacro defclass (name superclasses slots &rest options-and-doc)
61 "Define NAME as a new class derived from SUPERCLASS with SLOTS.
62 OPTIONS-AND-DOC is used as the class' options and base documentation.
63 SUPERCLASSES is a list of superclasses to inherit from, with SLOTS
64 being the slots residing in that class definition. Supported tags are:
66 :initform - Initializing form.
67 :initarg - Tag used during initialization.
68 :accessor - Tag used to create a function to access this slot.
69 :allocation - Specify where the value is stored.
70 Defaults to `:instance', but could also be `:class'.
71 :writer - A function symbol which will `write' an object's slot.
72 :reader - A function symbol which will `read' an object.
73 :type - The type of data allowed in this slot (see `typep').
74 :documentation
75 - A string documenting use of this slot.
77 The following are extensions on CLOS:
78 :custom - When customizing an object, the custom :type. Public only.
79 :label - A text string label used for a slot when customizing.
80 :group - Name of a customization group this slot belongs in.
81 :printer - A function to call to print the value of a slot.
82 See `eieio-override-prin1' as an example.
84 A class can also have optional options. These options happen in place
85 of documentation (including a :documentation tag), in addition to
86 documentation, or not at all. Supported options are:
88 :documentation - The doc-string used for this class.
90 Options added to EIEIO:
92 :allow-nil-initform - Non-nil to skip typechecking of null initforms.
93 :custom-groups - List of custom group names. Organizes slots into
94 reasonable groups for customizations.
95 :abstract - Non-nil to prevent instances of this class.
96 If a string, use as an error string if someone does
97 try to make an instance.
98 :method-invocation-order
99 - Control the method invocation order if there is
100 multiple inheritance. Valid values are:
101 :breadth-first - The default.
102 :depth-first
104 Options in CLOS not supported in EIEIO:
106 :metaclass - Class to use in place of `standard-class'
107 :default-initargs - Initargs to use when initializing new objects of
108 this class.
110 Due to the way class options are set up, you can add any tags you wish,
111 and reference them using the function `class-option'."
112 (declare (doc-string 4))
113 (cl-check-type superclasses list)
115 (cond ((and (stringp (car options-and-doc))
116 (/= 1 (% (length options-and-doc) 2)))
117 (error "Too many arguments to `defclass'"))
118 ((and (symbolp (car options-and-doc))
119 (/= 0 (% (length options-and-doc) 2)))
120 (error "Too many arguments to `defclass'")))
122 (if (stringp (car options-and-doc))
123 (setq options-and-doc
124 (cons :documentation options-and-doc)))
126 ;; Make sure the method invocation order is a valid value.
127 (let ((io (eieio--class-option-assoc options-and-doc
128 :method-invocation-order)))
129 (when (and io (not (member io '(:depth-first :breadth-first :c3))))
130 (error "Method invocation order %s is not allowed" io)))
132 (let ((testsym1 (intern (concat (symbol-name name) "-p")))
133 (testsym2 (intern (format "%s--eieio-childp" name)))
134 (accessors ()))
136 ;; Collect the accessors we need to define.
137 (pcase-dolist (`(,sname . ,soptions) slots)
138 (let* ((acces (plist-get soptions :accessor))
139 (initarg (plist-get soptions :initarg))
140 (reader (plist-get soptions :reader))
141 (writer (plist-get soptions :writer))
142 (alloc (plist-get soptions :allocation))
143 (label (plist-get soptions :label)))
145 (if eieio-error-unsupported-class-tags
146 (let ((tmp soptions))
147 (while tmp
148 (if (not (member (car tmp) '(:accessor
149 :initform
150 :initarg
151 :documentation
152 :protection
153 :reader
154 :writer
155 :allocation
156 :type
157 :custom
158 :label
159 :group
160 :printer
161 :allow-nil-initform
162 :custom-groups)))
163 (signal 'invalid-slot-type (list (car tmp))))
164 (setq tmp (cdr (cdr tmp))))))
166 ;; Make sure the :allocation parameter has a valid value.
167 (if (not (memq alloc '(nil :class :instance)))
168 (signal 'invalid-slot-type (list :allocation alloc)))
170 ;; Label is nil, or a string
171 (if (not (or (null label) (stringp label)))
172 (signal 'invalid-slot-type (list :label label)))
174 ;; Is there an initarg, but allocation of class?
175 (if (and initarg (eq alloc :class))
176 (message "Class allocated slots do not need :initarg"))
178 ;; Anyone can have an accessor function. This creates a function
179 ;; of the specified name, and also performs a `defsetf' if applicable
180 ;; so that users can `setf' the space returned by this function.
181 (when acces
182 (push `(cl-defmethod (setf ,acces) (value (this ,name))
183 (eieio-oset this ',sname value))
184 accessors)
185 (push `(cl-defmethod ,acces ((this ,name))
186 ,(format
187 "Retrieve the slot `%S' from an object of class `%S'."
188 sname name)
189 ;; FIXME: Why is this different from the :reader case?
190 (if (slot-boundp this ',sname) (eieio-oref this ',sname)))
191 accessors)
192 (when (and eieio-backward-compatibility (eq alloc :class))
193 ;; FIXME: How could I declare this *method* as obsolete.
194 (push `(cl-defmethod ,acces ((this (subclass ,name)))
195 ,(format
196 "Retrieve the class slot `%S' from a class `%S'.
197 This method is obsolete."
198 sname name)
199 (if (slot-boundp this ',sname)
200 (eieio-oref-default this ',sname)))
201 accessors)))
203 ;; If a writer is defined, then create a generic method of that
204 ;; name whose purpose is to set the value of the slot.
205 (if writer
206 (push `(cl-defmethod ,writer ((this ,name) value)
207 ,(format "Set the slot `%S' of an object of class `%S'."
208 sname name)
209 (setf (slot-value this ',sname) value))
210 accessors))
211 ;; If a reader is defined, then create a generic method
212 ;; of that name whose purpose is to access this slot value.
213 (if reader
214 (push `(cl-defmethod ,reader ((this ,name))
215 ,(format "Access the slot `%S' from object of class `%S'."
216 sname name)
217 (slot-value this ',sname))
218 accessors))
219 ))
221 `(progn
222 ;; This test must be created right away so we can have self-
223 ;; referencing classes. ei, a class whose slot can contain only
224 ;; pointers to itself.
226 ;; Create the test functions.
227 (defalias ',testsym1 (eieio-make-class-predicate ',name))
228 (defalias ',testsym2 (eieio-make-child-predicate ',name))
230 ,@(when eieio-backward-compatibility
231 (let ((f (intern (format "%s-child-p" name))))
232 `((defalias ',f ',testsym2)
233 (make-obsolete
234 ',f ,(format "use (cl-typep ... '%s) instead" name) "25.1"))))
236 ;; When using typep, (typep OBJ 'myclass) returns t for objects which
237 ;; are subclasses of myclass. For our predicates, however, it is
238 ;; important for EIEIO to be backwards compatible, where
239 ;; myobject-p, and myobject-child-p are different.
240 ;; "cl" uses this technique to specify symbols with specific typep
241 ;; test, so we can let typep have the CLOS documented behavior
242 ;; while keeping our above predicate clean.
244 (put ',name 'cl-deftype-satisfies #',testsym2)
246 (eieio-defclass-internal ',name ',superclasses ',slots ',options-and-doc)
248 ,@accessors
250 ;; Create the constructor function
251 ,(if (eieio--class-option-assoc options-and-doc :abstract)
252 ;; Abstract classes cannot be instantiated. Say so.
253 (let ((abs (eieio--class-option-assoc options-and-doc :abstract)))
254 (if (not (stringp abs))
255 (setq abs (format "Class %s is abstract" name)))
256 `(defun ,name (&rest _)
257 ,(format "You cannot create a new object of type %S." name)
258 (error ,abs)))
260 ;; Non-abstract classes need a constructor.
261 `(defun ,name (&rest slots)
262 ,(format "Create a new object with name NAME of class type %S."
263 name)
264 (declare (compiler-macro
265 (lambda (whole)
266 (if (not (stringp (car slots)))
267 whole
268 (macroexp--warn-and-return
269 (format "Obsolete name arg %S to constructor %S"
270 (car slots) (car whole))
271 ;; Keep the name arg, for backward compatibility,
272 ;; but hide it so we don't trigger indefinitely.
273 `(,(car whole) (identity ,(car slots))
274 ,@(cdr slots)))))))
275 (apply #'make-instance ',name slots))))))
278 ;;; Get/Set slots in an object.
279 ;;
280 (defmacro oref (obj slot)
281 "Retrieve the value stored in OBJ in the slot named by SLOT.
282 Slot is the name of the slot when created by `defclass' or the label
283 created by the :initarg tag."
284 (declare (debug (form symbolp)))
285 `(eieio-oref ,obj (quote ,slot)))
287 (defalias 'slot-value 'eieio-oref)
288 (defalias 'set-slot-value 'eieio-oset)
289 (make-obsolete 'set-slot-value "use (setf (slot-value ..) ..) instead" "25.1")
291 (defmacro oref-default (obj slot)
292 "Get the default value of OBJ (maybe a class) for SLOT.
293 The default value is the value installed in a class with the :initform
294 tag. SLOT can be the slot name, or the tag specified by the :initarg
295 tag in the `defclass' call."
296 (declare (debug (form symbolp)))
297 `(eieio-oref-default ,obj (quote ,slot)))
299 ;;; Handy CLOS macros
300 ;;
301 (defmacro with-slots (spec-list object &rest body)
302 "Bind SPEC-LIST lexically to slot values in OBJECT, and execute BODY.
303 This establishes a lexical environment for referring to the slots in
304 the instance named by the given slot-names as though they were
305 variables. Within such a context the value of the slot can be
306 specified by using its slot name, as if it were a lexically bound
307 variable. Both setf and setq can be used to set the value of the
308 slot.
310 SPEC-LIST is of a form similar to `let'. For example:
312 ((VAR1 SLOT1)
313 SLOT2
315 (VARN+1 SLOTN+1))
317 Where each VAR is the local variable given to the associated
318 SLOT. A slot specified without a variable name is given a
319 variable name of the same name as the slot."
320 (declare (indent 2) (debug (sexp sexp def-body)))
321 (require 'cl-lib)
322 ;; Transform the spec-list into a cl-symbol-macrolet spec-list.
323 (macroexp-let2 nil object object
324 `(cl-symbol-macrolet
325 ,(mapcar (lambda (entry)
326 (let ((var (if (listp entry) (car entry) entry))
327 (slot (if (listp entry) (cadr entry) entry)))
328 (list var `(slot-value ,object ',slot))))
329 spec-list)
330 ,@body)))
332 ;; Keep it as a non-inlined function, so the internals of object don't get
333 ;; hard-coded in random .elc files.
334 (defun eieio-pcase-slot-index-table (obj)
335 "Return some data structure from which can be extracted the slot offset."
336 (eieio--class-index-table
337 (symbol-value (eieio--object-class-tag obj))))
339 (defun eieio-pcase-slot-index-from-index-table (index-table slot)
340 "Find the index to pass to `aref' to access SLOT."
341 (let ((index (gethash slot index-table)))
342 (if index (+ (eval-when-compile
343 (length (cl-struct-slot-info 'eieio--object)))
344 index))))
346 (pcase-defmacro eieio (&rest fields)
347 "Pcase patterns to match EIEIO objects.
348 Elements of FIELDS can be of the form (NAME UPAT) in which case the contents of
349 field NAME is matched against UPAT, or they can be of the form NAME which
350 is a shorthand for (NAME NAME)."
351 (declare (debug (&rest [&or (sexp pcase-UPAT) sexp])))
352 (let ((is (make-symbol "table")))
353 ;; FIXME: This generates a horrendous mess of redundant let bindings.
354 ;; `pcase' needs to be improved somehow to introduce let-bindings more
355 ;; sparingly, or the byte-compiler needs to be taught to optimize
356 ;; them away.
357 ;; FIXME: `pcase' does not do a good job here of sharing tests&code among
358 ;; various branches.
359 `(and (pred eieio-object-p)
360 (app eieio-pcase-slot-index-table ,is)
361 ,@(mapcar (lambda (field)
362 (let* ((name (if (consp field) (car field) field))
363 (pat (if (consp field) (cadr field) field))
364 (i (make-symbol "index")))
365 `(and (let (and ,i (pred natnump))
366 (eieio-pcase-slot-index-from-index-table
367 ,is ',name))
368 (app (pcase--flip aref ,i) ,pat))))
369 fields))))
370 \f
371 ;;; Simple generators, and query functions. None of these would do
372 ;; well embedded into an object.
373 ;;
375 (define-obsolete-function-alias
376 'object-class-fast #'eieio-object-class "24.4")
378 (cl-defgeneric eieio-object-name-string (obj)
379 "Return a string which is OBJ's name."
380 (declare (obsolete eieio-named "25.1")))
382 (defun eieio-object-name (obj &optional extra)
383 "Return a printed representation for object OBJ.
384 If EXTRA, include that in the string returned to represent the symbol."
385 (cl-check-type obj eieio-object)
386 (format "#<%s %s%s>" (eieio-object-class obj)
387 (eieio-object-name-string obj) (or extra "")))
388 (define-obsolete-function-alias 'object-name #'eieio-object-name "24.4")
390 (defconst eieio--object-names (make-hash-table :test #'eq :weakness 'key))
392 ;; In the past, every EIEIO object had a `name' field, so we had the two method
393 ;; below "for free". Since this field is very rarely used, we got rid of it
394 ;; and instead we keep it in a weak hash-tables, for those very rare objects
395 ;; that use it.
396 (cl-defmethod eieio-object-name-string (obj)
397 (or (gethash obj eieio--object-names)
398 (symbol-name (eieio-object-class obj))))
399 (define-obsolete-function-alias
400 'object-name-string #'eieio-object-name-string "24.4")
402 (cl-defmethod eieio-object-set-name-string (obj name)
403 "Set the string which is OBJ's NAME."
404 (declare (obsolete eieio-named "25.1"))
405 (cl-check-type name string)
406 (setf (gethash obj eieio--object-names) name))
407 (define-obsolete-function-alias
408 'object-set-name-string 'eieio-object-set-name-string "24.4")
410 (defun eieio-object-class (obj)
411 "Return the class struct defining OBJ."
412 ;; FIXME: We say we return a "struct" but we return a symbol instead!
413 (cl-check-type obj eieio-object)
414 (eieio--class-name (eieio--object-class obj)))
415 (define-obsolete-function-alias 'object-class #'eieio-object-class "24.4")
416 ;; CLOS name, maybe?
417 (define-obsolete-function-alias 'class-of #'eieio-object-class "24.4")
419 (defun eieio-object-class-name (obj)
420 "Return a Lisp like symbol name for OBJ's class."
421 (cl-check-type obj eieio-object)
422 (eieio-class-name (eieio--object-class obj)))
423 (define-obsolete-function-alias
424 'object-class-name 'eieio-object-class-name "24.4")
426 (defun eieio-class-parents (class)
427 "Return parent classes to CLASS. (overload of variable).
429 The CLOS function `class-direct-superclasses' is aliased to this function."
430 (eieio--class-parents (eieio--class-object class)))
432 (define-obsolete-function-alias 'class-parents #'eieio-class-parents "24.4")
434 (defun eieio-class-children (class)
435 "Return child classes to CLASS.
436 The CLOS function `class-direct-subclasses' is aliased to this function."
437 (cl-check-type class class)
438 (eieio--class-children (cl--find-class class)))
439 (define-obsolete-function-alias
440 'class-children #'eieio-class-children "24.4")
442 ;; Official CLOS functions.
443 (define-obsolete-function-alias
444 'class-direct-superclasses #'eieio-class-parents "24.4")
445 (define-obsolete-function-alias
446 'class-direct-subclasses #'eieio-class-children "24.4")
448 (defmacro eieio-class-parent (class)
449 "Return first parent class to CLASS. (overload of variable)."
450 `(car (eieio-class-parents ,class)))
451 (define-obsolete-function-alias 'class-parent 'eieio-class-parent "24.4")
453 (defun same-class-p (obj class)
454 "Return t if OBJ is of class-type CLASS."
455 (setq class (eieio--class-object class))
456 (cl-check-type class eieio--class)
457 (cl-check-type obj eieio-object)
458 (eq (eieio--object-class obj) class))
460 (defun object-of-class-p (obj class)
461 "Return non-nil if OBJ is an instance of CLASS or CLASS' subclasses."
462 (cl-check-type obj eieio-object)
463 ;; class will be checked one layer down
464 (child-of-class-p (eieio--object-class obj) class))
465 ;; Backwards compatibility
466 (defalias 'obj-of-class-p 'object-of-class-p)
468 (defun child-of-class-p (child class)
469 "Return non-nil if CHILD class is a subclass of CLASS."
470 (setq child (eieio--class-object child))
471 (cl-check-type child eieio--class)
472 ;; `eieio-default-superclass' is never mentioned in eieio--class-parents,
473 ;; so we have to special case it here.
474 (or (eq class 'eieio-default-superclass)
475 (let ((p nil))
476 (setq class (eieio--class-object class))
477 (cl-check-type class eieio--class)
478 (while (and child (not (eq child class)))
479 (setq p (append p (eieio--class-parents child))
480 child (pop p)))
481 (if child t))))
483 (defun eieio-slot-descriptor-name (slot)
484 (cl--slot-descriptor-name slot))
486 (defun eieio-class-slots (class)
487 "Return list of slots available in instances of CLASS."
488 ;; FIXME: This only gives the instance slots and ignores the
489 ;; class-allocated slots.
490 (setq class (eieio--class-object class))
491 (cl-check-type class eieio--class)
492 (mapcar #'identity (eieio--class-slots class)))
494 (defun object-slots (obj)
495 "Return list of slot names available in OBJ."
496 (declare (obsolete eieio-class-slots "25.1"))
497 (cl-check-type obj eieio-object)
498 (mapcar #'cl--slot-descriptor-name
499 (eieio-class-slots (eieio--object-class obj))))
501 (defun eieio--class-slot-initarg (class slot)
502 "Fetch from CLASS, SLOT's :initarg."
503 (cl-check-type class eieio--class)
504 (let ((ia (eieio--class-initarg-tuples class))
505 (f nil))
506 (while (and ia (not f))
507 (if (eq (cdr (car ia)) slot)
508 (setq f (car (car ia))))
509 (setq ia (cdr ia)))
510 f))
512 ;;; Object Set macros
513 ;;
514 (defmacro oset (obj slot value)
515 "Set the value in OBJ for slot SLOT to VALUE.
516 SLOT is the slot name as specified in `defclass' or the tag created
517 with in the :initarg slot. VALUE can be any Lisp object."
518 (declare (debug (form symbolp form)))
519 `(eieio-oset ,obj (quote ,slot) ,value))
521 (defmacro oset-default (class slot value)
522 "Set the default slot in CLASS for SLOT to VALUE.
523 The default value is usually set with the :initform tag during class
524 creation. This allows users to change the default behavior of classes
525 after they are created."
526 (declare (debug (form symbolp form)))
527 `(eieio-oset-default ,class (quote ,slot) ,value))
529 ;;; CLOS queries into classes and slots
530 ;;
531 (defun slot-boundp (object slot)
532 "Return non-nil if OBJECT's SLOT is bound.
533 Setting a slot's value makes it bound. Calling `slot-makeunbound' will
534 make a slot unbound.
535 OBJECT can be an instance or a class."
536 ;; Skip typechecking while retrieving this value.
537 (let ((eieio-skip-typecheck t))
538 ;; Return nil if the magic symbol is in there.
539 (not (eq (cond
540 ((eieio-object-p object) (eieio-oref object slot))
541 ((symbolp object) (eieio-oref-default object slot))
542 (t (signal 'wrong-type-argument (list 'eieio-object-p object))))
543 eieio-unbound))))
545 (defun slot-makeunbound (object slot)
546 "In OBJECT, make SLOT unbound."
547 (eieio-oset object slot eieio-unbound))
549 (defun slot-exists-p (object-or-class slot)
550 "Return non-nil if OBJECT-OR-CLASS has SLOT."
551 (let ((cv (cond ((eieio-object-p object-or-class)
552 (eieio--object-class object-or-class))
553 ((eieio--class-p object-or-class) object-or-class)
554 (t (find-class object-or-class 'error)))))
555 (or (gethash slot (eieio--class-index-table cv))
556 ;; FIXME: We could speed this up by adding class slots into the
557 ;; index-table (e.g. with a negative index?).
558 (let ((cs (eieio--class-class-slots cv))
559 found)
560 (dotimes (i (length cs))
561 (if (eq slot (cl--slot-descriptor-name (aref cs i)))
562 (setq found t)))
563 found))))
565 (defun find-class (symbol &optional errorp)
566 "Return the class that SYMBOL represents.
567 If there is no class, nil is returned if ERRORP is nil.
568 If ERRORP is non-nil, `wrong-argument-type' is signaled."
569 (let ((class (cl--find-class symbol)))
570 (cond
571 ((eieio--class-p class) class)
572 (errorp (signal 'wrong-type-argument (list 'class-p symbol))))))
574 ;;; Slightly more complex utility functions for objects
575 ;;
576 (defun object-assoc (key slot list)
577 "Return an object if KEY is `equal' to SLOT's value of an object in LIST.
578 LIST is a list of objects whose slots are searched.
579 Objects in LIST do not need to have a slot named SLOT, nor does
580 SLOT need to be bound. If these errors occur, those objects will
581 be ignored."
582 (cl-check-type list list)
583 (while (and list (not (condition-case nil
584 ;; This prevents errors for missing slots.
585 (equal key (eieio-oref (car list) slot))
586 (error nil))))
587 (setq list (cdr list)))
588 (car list))
590 (defun object-assoc-list (slot list)
591 "Return an association list with the contents of SLOT as the key element.
592 LIST must be a list of objects with SLOT in it.
593 This is useful when you need to do completing read on an object group."
594 (cl-check-type list list)
595 (let ((assoclist nil))
596 (while list
597 (setq assoclist (cons (cons (eieio-oref (car list) slot)
598 (car list))
599 assoclist))
600 (setq list (cdr list)))
601 (nreverse assoclist)))
603 (defun object-assoc-list-safe (slot list)
604 "Return an association list with the contents of SLOT as the key element.
605 LIST must be a list of objects, but those objects do not need to have
606 SLOT in it. If it does not, then that element is left out of the association
607 list."
608 (cl-check-type list list)
609 (let ((assoclist nil))
610 (while list
611 (if (slot-exists-p (car list) slot)
612 (setq assoclist (cons (cons (eieio-oref (car list) slot)
613 (car list))
614 assoclist)))
615 (setq list (cdr list)))
616 (nreverse assoclist)))
618 (defun object-add-to-list (object slot item &optional append)
619 "In OBJECT's SLOT, add ITEM to the list of elements.
620 Optional argument APPEND indicates we need to append to the list.
621 If ITEM already exists in the list in SLOT, then it is not added.
622 Comparison is done with `equal' through the `member' function call.
623 If SLOT is unbound, bind it to the list containing ITEM."
624 (let (ov)
625 ;; Find the originating list.
626 (if (not (slot-boundp object slot))
627 (setq ov (list item))
628 (setq ov (eieio-oref object slot))
629 ;; turn it into a list.
630 (unless (listp ov)
631 (setq ov (list ov)))
632 ;; Do the combination
633 (if (not (member item ov))
634 (setq ov
635 (if append
636 (append ov (list item))
637 (cons item ov)))))
638 ;; Set back into the slot.
639 (eieio-oset object slot ov)))
641 (defun object-remove-from-list (object slot item)
642 "In OBJECT's SLOT, remove occurrences of ITEM.
643 Deletion is done with `delete', which deletes by side effect,
644 and comparisons are done with `equal'.
645 If SLOT is unbound, do nothing."
646 (if (not (slot-boundp object slot))
647 nil
648 (eieio-oset object slot (delete item (eieio-oref object slot)))))
650 ;;; Here are some CLOS items that need the CL package
651 ;;
653 ;; FIXME: Shouldn't this be a more complex gv-expander which extracts the
654 ;; common code between oref and oset, so as to reduce the redundant work done
655 ;; in (push foo (oref bar baz)), like we do for the `nth' expander?
656 (gv-define-simple-setter eieio-oref eieio-oset)
658 \f
659 ;;;
660 ;; We want all objects created by EIEIO to have some default set of
661 ;; behaviors so we can create object utilities, and allow various
662 ;; types of error checking. To do this, create the default EIEIO
663 ;; class, and when no parent class is specified, use this as the
664 ;; default. (But don't store it in the other classes as the default,
665 ;; allowing for transparent support.)
666 ;;
668 (defclass eieio-default-superclass nil
669 nil
670 "Default parent class for classes with no specified parent class.
671 Its slots are automatically adopted by classes with no specified parents.
672 This class is not stored in the `parent' slot of a class vector."
673 :abstract t)
675 (setq eieio-default-superclass (cl--find-class 'eieio-default-superclass))
677 (defalias 'standard-class 'eieio-default-superclass)
679 (cl-defgeneric make-instance (class &rest initargs)
680 "Make a new instance of CLASS based on INITARGS.
681 For example:
683 (make-instance 'foo)
685 INITARGS is a property list with keywords based on the `:initarg'
686 for each slot. For example:
688 (make-instance 'foo :slot1 value1 :slotN valueN)")
690 (define-obsolete-function-alias 'constructor #'make-instance "25.1")
692 (cl-defmethod make-instance
693 ((class (subclass eieio-default-superclass)) &rest slots)
694 "Default constructor for CLASS `eieio-default-superclass'.
695 SLOTS are the initialization slots used by `initialize-instance'.
696 This static method is called when an object is constructed.
697 It allocates the vector used to represent an EIEIO object, and then
698 calls `initialize-instance' on that object."
699 (let* ((new-object (copy-sequence (eieio--class-default-object-cache
700 (eieio--class-object class)))))
701 (if (and slots
702 (let ((x (car slots)))
703 (or (stringp x) (null x))))
704 (funcall (if eieio-backward-compatibility #'ignore #'message)
705 "Obsolete name %S passed to %S constructor"
706 (pop slots) class))
707 ;; Call the initialize method on the new object with the slots
708 ;; that were passed down to us.
709 (initialize-instance new-object slots)
710 ;; Return the created object.
711 new-object))
713 ;; FIXME: CLOS uses "&rest INITARGS" instead.
714 (cl-defgeneric shared-initialize (obj slots)
715 "Set slots of OBJ with SLOTS which is a list of name/value pairs.
716 Called from the constructor routine.")
718 (cl-defmethod shared-initialize ((obj eieio-default-superclass) slots)
719 "Set slots of OBJ with SLOTS which is a list of name/value pairs.
720 Called from the constructor routine."
721 (while slots
722 (let ((rn (eieio--initarg-to-attribute (eieio--object-class obj)
723 (car slots))))
724 (if (not rn)
725 (slot-missing obj (car slots) 'oset (car (cdr slots)))
726 (eieio-oset obj rn (car (cdr slots)))))
727 (setq slots (cdr (cdr slots)))))
729 ;; FIXME: CLOS uses "&rest INITARGS" instead.
730 (cl-defgeneric initialize-instance (this &optional slots)
731 "Construct the new object THIS based on SLOTS.")
733 (cl-defmethod initialize-instance ((this eieio-default-superclass)
734 &optional slots)
735 "Construct the new object THIS based on SLOTS.
736 SLOTS is a tagged list where odd numbered elements are tags, and
737 even numbered elements are the values to store in the tagged slot.
738 If you overload the `initialize-instance', there you will need to
739 call `shared-initialize' yourself, or you can call `call-next-method'
740 to have this constructor called automatically. If these steps are
741 not taken, then new objects of your class will not have their values
742 dynamically set from SLOTS."
743 ;; First, see if any of our defaults are `lambda', and
744 ;; re-evaluate them and apply the value to our slots.
745 (let* ((this-class (eieio--object-class this))
746 (slots (eieio--class-slots this-class)))
747 (dotimes (i (length slots))
748 ;; For each slot, see if we need to evaluate it.
749 ;;
750 ;; Paul Landes said in an email:
751 ;; > CL evaluates it if it can, and otherwise, leaves it as
752 ;; > the quoted thing as you already have. This is by the
753 ;; > Sonya E. Keene book and other things I've look at on the
754 ;; > web.
755 (let* ((slot (aref slots i))
756 (initform (cl--slot-descriptor-initform slot))
757 (dflt (eieio-default-eval-maybe initform)))
758 (when (not (eq dflt initform))
759 ;; FIXME: We should be able to just do (aset this (+ i <cst>) dflt)!
760 (eieio-oset this (cl--slot-descriptor-name slot) dflt)))))
761 ;; Shared initialize will parse our slots for us.
762 (shared-initialize this slots))
764 (cl-defgeneric slot-missing (object slot-name operation &optional new-value)
765 "Method invoked when an attempt to access a slot in OBJECT fails.")
767 (cl-defmethod slot-missing ((object eieio-default-superclass) slot-name
768 _operation &optional _new-value)
769 "Method invoked when an attempt to access a slot in OBJECT fails.
770 SLOT-NAME is the name of the failed slot, OPERATION is the type of access
771 that was requested, and optional NEW-VALUE is the value that was desired
772 to be set.
774 This method is called from `oref', `oset', and other functions which
775 directly reference slots in EIEIO objects."
776 (signal 'invalid-slot-name (list (eieio-object-name object)
777 slot-name)))
779 (cl-defgeneric slot-unbound (object class slot-name fn)
780 "Slot unbound is invoked during an attempt to reference an unbound slot.")
782 (cl-defmethod slot-unbound ((object eieio-default-superclass)
783 class slot-name fn)
784 "Slot unbound is invoked during an attempt to reference an unbound slot.
785 OBJECT is the instance of the object being reference. CLASS is the
786 class of OBJECT, and SLOT-NAME is the offending slot. This function
787 throws the signal `unbound-slot'. You can overload this function and
788 return the value to use in place of the unbound value.
789 Argument FN is the function signaling this error.
790 Use `slot-boundp' to determine if a slot is bound or not.
792 In CLOS, the argument list is (CLASS OBJECT SLOT-NAME), but
793 EIEIO can only dispatch on the first argument, so the first two are swapped."
794 (signal 'unbound-slot (list (eieio-class-name class)
795 (eieio-object-name object)
796 slot-name fn)))
798 (cl-defgeneric clone (obj &rest params)
799 "Make a copy of OBJ, and then supply PARAMS.
800 PARAMS is a parameter list of the same form used by `initialize-instance'.
802 When overloading `clone', be sure to call `call-next-method'
803 first and modify the returned object.")
805 (cl-defmethod clone ((obj eieio-default-superclass) &rest params)
806 "Make a copy of OBJ, and then apply PARAMS."
807 (let ((nobj (copy-sequence obj)))
808 (if (stringp (car params))
809 (funcall (if eieio-backward-compatibility #'ignore #'message)
810 "Obsolete name %S passed to clone" (pop params)))
811 (if params (shared-initialize nobj params))
812 nobj))
814 (cl-defgeneric destructor (this &rest params)
815 "Destructor for cleaning up any dynamic links to our object.")
817 (cl-defmethod destructor ((_this eieio-default-superclass) &rest _params)
818 "Destructor for cleaning up any dynamic links to our object.
819 Argument THIS is the object being destroyed. PARAMS are additional
820 ignored parameters."
821 ;; No cleanup... yet.
824 (cl-defgeneric object-print (this &rest strings)
825 "Pretty printer for object THIS. Call function `object-name' with STRINGS.
827 It is sometimes useful to put a summary of the object into the
828 default #<notation> string when using EIEIO browsing tools.
829 Implement this method to customize the summary.")
831 (cl-defmethod object-print ((this eieio-default-superclass) &rest strings)
832 "Pretty printer for object THIS. Call function `object-name' with STRINGS.
833 The default method for printing object THIS is to use the
834 function `object-name'.
836 It is sometimes useful to put a summary of the object into the
837 default #<notation> string when using EIEIO browsing tools.
839 Implement this function and specify STRINGS in a call to
840 `call-next-method' to provide additional summary information.
841 When passing in extra strings from child classes, always remember
842 to prepend a space."
843 (eieio-object-name this (apply #'concat strings)))
845 (defvar eieio-print-depth 0
846 "When printing, keep track of the current indentation depth.")
848 (cl-defgeneric object-write (this &optional comment)
849 "Write out object THIS to the current stream.
850 Optional COMMENT will add comments to the beginning of the output.")
852 (cl-defmethod object-write ((this eieio-default-superclass) &optional comment)
853 "Write object THIS out to the current stream.
854 This writes out the vector version of this object. Complex and recursive
855 object are discouraged from being written.
856 If optional COMMENT is non-nil, include comments when outputting
857 this object."
858 (when comment
859 (princ ";; Object ")
860 (princ (eieio-object-name-string this))
861 (princ "\n")
862 (princ comment)
863 (princ "\n"))
864 (let* ((cl (eieio-object-class this))
865 (cv (cl--find-class cl)))
866 ;; Now output readable lisp to recreate this object
867 ;; It should look like this:
868 ;; (<constructor> <name> <slot> <slot> ... )
869 ;; Each slot's slot is writen using its :writer.
870 (princ (make-string (* eieio-print-depth 2) ? ))
871 (princ "(")
872 (princ (symbol-name (eieio--class-constructor (eieio-object-class this))))
873 (princ " ")
874 (prin1 (eieio-object-name-string this))
875 (princ "\n")
876 ;; Loop over all the public slots
877 (let ((slots (eieio--class-slots cv))
878 (eieio-print-depth (1+ eieio-print-depth)))
879 (dotimes (i (length slots))
880 (let ((slot (aref slots i)))
881 (when (slot-boundp this (cl--slot-descriptor-name slot))
882 (let ((i (eieio--class-slot-initarg
883 cv (cl--slot-descriptor-name slot)))
884 (v (eieio-oref this (cl--slot-descriptor-name slot))))
885 (unless (or (not i) (equal v (cl--slot-descriptor-initform slot)))
886 (unless (bolp)
887 (princ "\n"))
888 (princ (make-string (* eieio-print-depth 2) ? ))
889 (princ (symbol-name i))
890 (if (alist-get :printer (cl--slot-descriptor-props slot))
891 ;; Use our public printer
892 (progn
893 (princ " ")
894 (funcall (alist-get :printer
895 (cl--slot-descriptor-props slot))
896 v))
897 ;; Use our generic override prin1 function.
898 (princ (if (or (eieio-object-p v)
899 (eieio-object-p (car-safe v)))
900 "\n" " "))
901 (eieio-override-prin1 v))))))))
902 (princ ")")
903 (when (= eieio-print-depth 0)
904 (princ "\n"))))
906 (defun eieio-override-prin1 (thing)
907 "Perform a `prin1' on THING taking advantage of object knowledge."
908 (cond ((eieio-object-p thing)
909 (object-write thing))
910 ((consp thing)
911 (eieio-list-prin1 thing))
912 ((eieio--class-p thing)
913 (princ (eieio--class-print-name thing)))
914 (t (prin1 thing))))
916 (defun eieio-list-prin1 (list)
917 "Display LIST where list may contain objects."
918 (if (not (eieio-object-p (car list)))
919 (progn
920 (princ "'")
921 (prin1 list))
922 (princ (make-string (* eieio-print-depth 2) ? ))
923 (princ "(list")
924 (let ((eieio-print-depth (1+ eieio-print-depth)))
925 (while list
926 (princ "\n")
927 (if (eieio-object-p (car list))
928 (object-write (car list))
929 (princ (make-string (* eieio-print-depth 2) ? ))
930 (eieio-override-prin1 (car list)))
931 (setq list (cdr list))))
932 (princ ")")))
934 \f
935 ;;; Unimplemented functions from CLOS
936 ;;
937 (defun change-class (_obj _class)
938 "Change the class of OBJ to type CLASS.
939 This may create or delete slots, but does not affect the return value
940 of `eq'."
941 (error "EIEIO: `change-class' is unimplemented"))
943 ;; Hook ourselves into help system for describing classes and methods.
944 (add-hook 'help-fns-describe-function-functions 'eieio-help-constructor)
946 ;;; Interfacing with edebug
947 ;;
948 (defun eieio-edebug-prin1-to-string (print-function object &optional noescape)
949 "Display EIEIO OBJECT in fancy format.
951 Used as advice around `edebug-prin1-to-string', held in the
952 variable PRINT-FUNCTION. Optional argument NOESCAPE is passed to
953 `prin1-to-string' when appropriate."
954 (cond ((eieio--class-p object) (eieio--class-print-name object))
955 ((eieio-object-p object) (object-print object))
956 ((and (listp object) (or (eieio--class-p (car object))
957 (eieio-object-p (car object))))
958 (concat "(" (mapconcat
959 (lambda (x) (eieio-edebug-prin1-to-string print-function x))
960 object " ")
961 ")"))
962 (t (funcall print-function object noescape))))
964 (advice-add 'edebug-prin1-to-string
965 :around #'eieio-edebug-prin1-to-string)
967 \f
968 ;;; Start of automatically extracted autoloads.
969 \f
970 ;;;### (autoloads nil "eieio-custom" "eieio-custom.el" "916f54b818479a77a02f3ecccda84a11")
971 ;;; Generated autoloads from eieio-custom.el
973 (autoload 'customize-object "eieio-custom" "\
974 Customize OBJ in a custom buffer.
975 Optional argument GROUP is the sub-group of slots to display.
977 \(fn OBJ &optional GROUP)" nil nil)
979 ;;;***
980 \f
981 ;;;### (autoloads nil "eieio-opt" "eieio-opt.el" "b7995d9076e4dd4b9358b2aa66835619")
982 ;;; Generated autoloads from eieio-opt.el
984 (autoload 'eieio-browse "eieio-opt" "\
985 Create an object browser window to show all objects.
986 If optional ROOT-CLASS, then start with that, otherwise start with
987 variable `eieio-default-superclass'.
989 \(fn &optional ROOT-CLASS)" t nil)
991 (autoload 'eieio-help-class "eieio-opt" "\
992 Print help description for CLASS.
993 If CLASS is actually an object, then also display current values of that object.
995 \(fn CLASS)" nil nil)
997 (autoload 'eieio-help-constructor "eieio-opt" "\
998 Describe CTR if it is a class constructor.
1000 \(fn CTR)" nil nil)
1002 ;;;***
1003 \f
1004 ;;; End of automatically extracted autoloads.
1006 (provide 'eieio)
1008 ;;; eieio ends here