unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
blob 820e8383d861c06fb24473607ada8bff5ef5dedd 40152 bytes (raw)
name: lisp/emacs-lisp/eieio.el 	 # note: path name is non-authoritative(*)

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
 
;;; eieio.el --- Enhanced Implementation of Emacs Interpreted Objects  -*- lexical-binding:t -*-
;;;              or maybe Eric's Implementation of Emacs Interpreted Objects

;; Copyright (C) 1995-1996, 1998-2022 Free Software Foundation, Inc.

;; Author: Eric M. Ludlam <zappo@gnu.org>
;; Version: 1.4
;; Keywords: OO, lisp

;; 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:
;;
;; EIEIO is a series of Lisp routines which implements a subset of
;; CLOS, the Common Lisp Object System.  In addition, EIEIO also adds
;; a few new features which help it integrate more strongly with the
;; Emacs running environment.
;;
;; See eieio.texi for complete documentation on using this package.
;;
;; Note: the implementation of the c3 algorithm is based on:
;;   Kim Barrett et al.: A Monotonic Superclass Linearization for Dylan
;;   Retrieved from:
;;   http://192.220.96.201/dylan/linearization-oopsla96.html

;; @TODO - fix :initform to be a form, not a quoted value
;; @TODO - Prefix non-clos functions with `eieio-'.

;; TODO: better integrate CL's defstructs and classes.  E.g. make it possible
;; to create a new class that inherits from a struct.

;;; Code:

(defvar eieio-version "1.4"
  "Current version of EIEIO.")

(defun eieio-version ()
  "Display the current version of EIEIO."
  (interactive)
  (message eieio-version))

(require 'eieio-core)
(eval-when-compile (require 'subr-x))

\f
;;; Defining a new class
;;
(defmacro defclass (name superclasses slots &rest options-and-doc)
  "Define NAME as a new class derived from SUPERCLASS with SLOTS.
OPTIONS-AND-DOC is used as the class' options and base documentation.
SUPERCLASSES is a list of superclasses to inherit from, with SLOTS
being the slots residing in that class definition.  Supported tags are:

  :initform   - Initializing form.
  :initarg    - Tag used during initialization.
  :accessor   - Tag used to create a function to access this slot.
  :allocation - Specify where the value is stored.
                Defaults to `:instance', but could also be `:class'.
  :writer     - A function symbol which will `write' an object's slot.
  :reader     - A function symbol which will `read' an object.
  :type       - The type of data allowed in this slot (see `typep').
  :documentation
              - A string documenting use of this slot.

The following are extensions on CLOS:
  :custom     - When customizing an object, the custom :type.  Public only.
  :label      - A text string label used for a slot when customizing.
  :group      - Name of a customization group this slot belongs in.
  :printer    - A function to call to print the value of a slot.
                See `eieio-override-prin1' as an example.

A class can also have optional options.  These options happen in place
of documentation (including a :documentation tag), in addition to
documentation, or not at all.  Supported options are:

  :documentation - The doc-string used for this class.

Options added to EIEIO:

  :allow-nil-initform - Non-nil to skip typechecking of null initforms.
  :custom-groups      - List of custom group names.  Organizes slots into
                        reasonable groups for customizations.
  :abstract           - Non-nil to prevent instances of this class.
                        If a string, use as an error string if someone does
                        try to make an instance.
  :method-invocation-order
                      - Control the method invocation order if there is
                        multiple inheritance.  Valid values are:
                         :breadth-first - The default.
                         :depth-first

Options in CLOS not supported in EIEIO:

  :metaclass - Class to use in place of `standard-class'
  :default-initargs - Initargs to use when initializing new objects of
                      this class.

Due to the way class options are set up, you can add any tags you wish,
and reference them using the function `class-option'."
  (declare (doc-string 4) (indent defun))
  (cl-check-type superclasses list)

  (cond ((and (stringp (car options-and-doc))
              (/= 1 (% (length options-and-doc) 2)))
         (error "Too many arguments to `defclass'"))
        ((and (symbolp (car options-and-doc))
              (/= 0 (% (length options-and-doc) 2)))
         (error "Too many arguments to `defclass'")))

  (if (stringp (car options-and-doc))
      (setq options-and-doc
            (cons :documentation options-and-doc)))

  ;; Make sure the method invocation order is a valid value.
  (let ((io (eieio--class-option-assoc options-and-doc
                                       :method-invocation-order)))
    (when (and io (not (member io '(:depth-first :breadth-first :c3))))
      (error "Method invocation order %s is not allowed" io)))

  (let ((testsym1 (intern (concat (symbol-name name) "-p")))
        (testsym2 (intern (format "%s--eieio-childp" name)))
        (warnings '())
        (accessors ()))

    ;; Collect the accessors we need to define.
    (pcase-dolist (`(,sname . ,soptions) slots)
      (let* ((acces   (plist-get soptions :accessor))
	     (initarg (plist-get soptions :initarg))
	     (reader  (plist-get soptions :reader))
	     (writer  (plist-get soptions :writer))
	     (alloc   (plist-get soptions :allocation))
	     (label   (plist-get soptions :label)))

        ;; Update eieio--known-slot-names already in case we compile code which
        ;; uses this before the class is loaded.
        (cl-pushnew sname eieio--known-slot-names)
        (when (eq alloc :class)
          (cl-pushnew sname eieio--known-class-slot-names))

	(if eieio-error-unsupported-class-tags
	    (let ((tmp soptions))
	      (while tmp
		(if (not (member (car tmp) '(:accessor
					     :initform
					     :initarg
					     :documentation
					     :protection
					     :reader
					     :writer
					     :allocation
					     :type
					     :custom
					     :label
					     :group
					     :printer
					     :allow-nil-initform
					     :custom-groups)))
		    (signal 'invalid-slot-type (list (car tmp))))
		(setq tmp (cdr (cdr tmp))))))

	;; Make sure the :allocation parameter has a valid value.
	(if (not (memq alloc '(nil :class :instance)))
	    (signal 'invalid-slot-type (list :allocation alloc)))

	;; Label is nil, or a string
	(if (not (or (null label) (stringp label)))
	    (signal 'invalid-slot-type (list :label label)))

	;; Is there an initarg, but allocation of class?
	(when (and initarg (eq alloc :class))
	  (push
           (cons sname
                 (format "Meaningless :initarg for class allocated slot '%S'"
	                 sname))
	   warnings))

        (let ((init (plist-get soptions :initform)))
          (unless (or (macroexp-const-p init)
                      (eieio--eval-default-p init))
            ;; FIXME: Historically, EIEIO used a heuristic to try and guess
            ;; whether the initform is a form to be evaluated or just
            ;; a constant.  We use `eieio--eval-default-p' to see what the
            ;; heuristic says and if it disagrees with normal evaluation
            ;; then tweak the initform to make it fit and emit
            ;; a warning accordingly.
            (push
             (cons init (format "Ambiguous initform needs quoting: %S" init))
             warnings)))

	;; Anyone can have an accessor function.  This creates a function
	;; of the specified name, and also performs a `defsetf' if applicable
	;; so that users can `setf' the space returned by this function.
	(when acces
          (push `(cl-defmethod (setf ,acces) (value (this ,name))
                   (eieio-oset this ',sname value))
                accessors)
          (push `(cl-defmethod ,acces ((this ,name))
                   ,(internal--format-docstring-line
                     "Retrieve the slot `%S' from an object of class `%S'."
                     sname name)
                   ;; FIXME: Why is this different from the :reader case?
                   (if (slot-boundp this ',sname) (eieio-oref this ',sname)))
                accessors)
          (when (and eieio-backward-compatibility (eq alloc :class))
            ;; FIXME: How could I declare this *method* as obsolete.
            (push `(cl-defmethod ,acces ((this (subclass ,name)))
                     ,(format
                       "Retrieve the class slot `%S' from a class `%S'.
This method is obsolete."
                       sname name)
                     (if (slot-boundp this ',sname)
                         (eieio-oref-default this ',sname)))
                  accessors)))

	;; If a writer is defined, then create a generic method of that
	;; name whose purpose is to set the value of the slot.
	(if writer
            (push `(cl-defmethod ,writer ((this ,name) value)
                     ,(format "Set the slot `%S' of an object of class `%S'."
                              sname name)
                     (setf (slot-value this ',sname) value))
                  accessors))
	;; If a reader is defined, then create a generic method
	;; of that name whose purpose is to access this slot value.
	(if reader
            (push `(cl-defmethod ,reader ((this ,name))
                     ,(format "Access the slot `%S' from object of class `%S'."
                              sname name)
                     (slot-value this ',sname))
                  accessors))
	))

    `(progn
       ,@(mapcar (lambda (w)
                   (macroexp-warn-and-return
                    (car w) (cdr w) `(progn ',(cdr w)) nil 'compile-only))
                 warnings)
       ;; This test must be created right away so we can have self-
       ;; referencing classes.  ei, a class whose slot can contain only
       ;; pointers to itself.

       ;; Create the test functions.
       (defalias ',testsym1 (eieio-make-class-predicate ',name))
       (defalias ',testsym2 (eieio-make-child-predicate ',name))

       ,@(when eieio-backward-compatibility
           (let ((f (intern (format "%s-child-p" name))))
             `((defalias ',f #',testsym2)
               (make-obsolete
                ',f ,(format "use (cl-typep ... \\='%s) instead" name)
                "25.1"))))

       ;; When using typep, (typep OBJ 'myclass) returns t for objects which
       ;; are subclasses of myclass.  For our predicates, however, it is
       ;; important for EIEIO to be backwards compatible, where
       ;; myobject-p, and myobject-child-p are different.
       ;; "cl" uses this technique to specify symbols with specific typep
       ;; test, so we can let typep have the CLOS documented behavior
       ;; while keeping our above predicate clean.

       (define-symbol-prop ',name 'cl-deftype-satisfies #',testsym2)

       (eieio-defclass-internal ',name ',superclasses ',slots ',options-and-doc)

       ,@accessors

       ;; Create the constructor function
       ,(if (eieio--class-option-assoc options-and-doc :abstract)
            ;; Abstract classes cannot be instantiated.  Say so.
            (let ((abs (eieio--class-option-assoc options-and-doc :abstract)))
              (if (not (stringp abs))
                  (setq abs (format "Class %s is abstract" name)))
              `(defun ,name (&rest _)
                 ,(format "You cannot create a new object of type `%S'." name)
                 (error ,abs)))

          ;; Non-abstract classes need a constructor.
          `(defun ,name (&rest slots)
             ,(internal--format-docstring-line
               "Create a new object of class type `%S'." name)
             (declare (compiler-macro
                       (lambda (whole)
                         (if (not (stringp (car slots)))
                             whole
                           (macroexp-warn-and-return
                            (car slots)
                            (format "Obsolete name arg %S to constructor %S"
                                    (car slots) (car whole))
                            ;; Keep the name arg, for backward compatibility,
                            ;; but hide it so we don't trigger indefinitely.
                            `(,(car whole) (identity ,(car slots))
                              ,@(cdr slots)))))))
             (apply #'make-instance ',name slots))))))


;;; Get/Set slots in an object.
;;
(defmacro oref (obj slot)
  "Retrieve the value stored in OBJ in the slot named by SLOT."
  (declare (debug (form symbolp)))
  `(eieio-oref ,obj (quote ,slot)))

(defalias 'slot-value #'eieio-oref)
(defalias 'set-slot-value #'eieio-oset)
(make-obsolete 'set-slot-value "use (setf (slot-value ..) ..) instead" "25.1")

(defmacro oref-default (class slot)
  "Get the value of class allocated slot SLOT.
CLASS can also be an object, in which case we use the object's class."
  (declare (debug (form symbolp)))
  `(eieio-oref-default ,class (quote ,slot)))

;;; Handy CLOS macros
;;
(defmacro with-slots (spec-list object &rest body)
  "Bind SPEC-LIST lexically to slot values in OBJECT, and execute BODY.
This establishes a lexical environment for referring to the slots in
the instance named by the given slot-names as though they were
variables.  Within such a context the value of the slot can be
specified by using its slot name, as if it were a lexically bound
variable.  Both setf and setq can be used to set the value of the
slot.

SPEC-LIST is of a form similar to `let'.  For example:

  ((VAR1 SLOT1)
    SLOT2
    SLOTN
   (VARN+1 SLOTN+1))

Where each VAR is the local variable given to the associated
SLOT.  A slot specified without a variable name is given a
variable name of the same name as the slot."
  (declare (indent 2) (debug (sexp sexp def-body)))
  (require 'cl-lib)
  ;; Transform the spec-list into a cl-symbol-macrolet spec-list.
  (macroexp-let2 nil object object
    `(cl-symbol-macrolet
         ,(mapcar (lambda (entry)
                    (let ((var  (if (listp entry) (car entry) entry))
                          (slot (if (listp entry) (cadr entry) entry)))
                      (list var `(slot-value ,object ',slot))))
                  spec-list)
       ,@body)))

;; Keep it as a non-inlined function, so the internals of object don't get
;; hard-coded in random .elc files.
(defun eieio-pcase-slot-index-table (obj)
  "Return some data structure from which can be extracted the slot offset."
  (eieio--class-index-table (eieio--object-class obj)))

(defun eieio-pcase-slot-index-from-index-table (index-table slot)
  "Find the index to pass to `aref' to access SLOT."
  (gethash slot index-table))

(pcase-defmacro eieio (&rest fields)
  "Pcase patterns that match EIEIO object EXPVAL.
Elements of FIELDS can be of the form (NAME PAT) in which case the
contents of field NAME is matched against PAT, or they can be of
 the form NAME which is a shorthand for (NAME NAME)."
  (declare (debug (&rest [&or (sexp pcase-PAT) sexp])))
  ;; FIXME: This generates a horrendous mess of redundant let bindings.
  ;; `pcase' needs to be improved somehow to introduce let-bindings more
  ;; sparingly, or the byte-compiler needs to be taught to optimize
  ;; them away.
  ;; FIXME: `pcase' does not do a good job here of sharing tests&code among
  ;; various branches.
  `(and (pred eieio-object-p)
        ,@(mapcar (lambda (field)
                    (pcase-exhaustive field
                      (`(,name ,pat)
                       `(app (pcase--flip eieio-oref ',name) ,pat))
                      ((pred symbolp)
                       `(app (pcase--flip eieio-oref ',field) ,field))))
                  fields)))
\f
;;; Simple generators, and query functions.  None of these would do
;;  well embedded into an object.
;;

(define-obsolete-function-alias
  'object-class-fast #'eieio-object-class "24.4")

;; In the past, every EIEIO object had a `name' field, so we had the
;; two methods `eieio-object-name-string' and
;; `eieio-object-set-name-string' "for free".  Since this field is
;; very rarely used, we got rid of it and instead we keep it in a weak
;; hash-tables, for those very rare objects that use it.
;; Really, those rare objects should inherit from `eieio-named' instead!
(defconst eieio--object-names (make-hash-table :test #'eq :weakness 'key))

(cl-defgeneric eieio-object-name-string (obj)
  "Return a string which is OBJ's name."
  (or (gethash obj eieio--object-names)
      (format "%s-%x" (eieio-object-class obj) (sxhash-eq obj))))

(define-obsolete-function-alias
  'object-name-string #'eieio-object-name-string "24.4")

(defun eieio-object-name (obj &optional extra)
  "Return a printed representation for object OBJ.
If EXTRA, include that in the string returned to represent the symbol."
  (cl-check-type obj eieio-object)
  (format "#<%s %s%s>" (eieio-object-class obj)
	  (eieio-object-name-string obj)
          (cond
           ((null extra)
            "")
           ((listp extra)
            (concat " " (mapconcat #'identity extra " ")))
           (t
            extra))))
(define-obsolete-function-alias 'object-name #'eieio-object-name "24.4")

(defun eieio-object-class (obj)
  "Return the class struct defining OBJ."
  ;; FIXME: We say we return a "struct" but we return a symbol instead!
  (cl-check-type obj eieio-object)
  (eieio--class-name (eieio--object-class obj)))
(define-obsolete-function-alias 'object-class #'eieio-object-class "24.4")
;; CLOS name, maybe?
(define-obsolete-function-alias 'class-of #'eieio-object-class "24.4")

(defun eieio-object-class-name (obj)
  "Return a Lisp like symbol name for OBJ's class."
  (cl-check-type obj eieio-object)
  (eieio-class-name (eieio--object-class obj)))
(define-obsolete-function-alias
  'object-class-name #'eieio-object-class-name "24.4")

(defun eieio-class-parents (class)
  ;; FIXME: What does "(overload of variable)" mean here?
  "Return parent classes to CLASS.  (overload of variable).

The CLOS function `class-direct-superclasses' is aliased to this function."
  (eieio--class-parents (eieio--full-class-object class)))

(define-obsolete-function-alias 'class-parents #'eieio-class-parents "24.4")

(defun eieio-class-children (class)
  "Return child classes to CLASS.
The CLOS function `class-direct-subclasses' is aliased to this function."
  (cl-check-type class class)
  (eieio--class-children (cl--find-class class)))
(define-obsolete-function-alias
  'class-children #'eieio-class-children "24.4")

;; Official CLOS functions.
(define-obsolete-function-alias
  'class-direct-superclasses #'eieio-class-parents "24.4")
(define-obsolete-function-alias
  'class-direct-subclasses #'eieio-class-children "24.4")

(defmacro eieio-class-parent (class)
  "Return first parent class to CLASS.  (overload of variable)."
  `(car (eieio-class-parents ,class)))
(define-obsolete-function-alias 'class-parent #'eieio-class-parent "24.4")

(defun same-class-p (obj class)
  "Return t if OBJ is of class-type CLASS."
  (setq class (eieio--class-object class))
  (cl-check-type class eieio--class)
  (cl-check-type obj eieio-object)
  (eq (eieio--object-class obj) class))

(defun object-of-class-p (obj class)
  "Return non-nil if OBJ is an instance of CLASS or CLASS' subclasses."
  (cl-check-type obj eieio-object)
  ;; class will be checked one layer down
  (child-of-class-p (eieio--object-class obj) class))
;; Backwards compatibility
(defalias 'obj-of-class-p #'object-of-class-p)

(defun child-of-class-p (child class)
  "Return non-nil if CHILD class is a subclass of CLASS."
  (setq child (eieio--full-class-object child))
  (cl-check-type child eieio--class)
  ;; `eieio-default-superclass' is never mentioned in eieio--class-parents,
  ;; so we have to special case it here.
  (or (eq class 'eieio-default-superclass)
      (let ((p nil))
        (setq class (eieio--class-object class))
        (cl-check-type class eieio--class)
        (while (and child (not (eq child class)))
          (setq p (append p (eieio--class-parents child))
                child (pop p)))
        (if child t))))

(defun eieio-slot-descriptor-name (slot)
  (cl--slot-descriptor-name slot))

(defun eieio-class-slots (class)
  "Return list of slots available in instances of CLASS."
  ;; FIXME: This only gives the instance slots and ignores the
  ;; class-allocated slots.
  (setq class (eieio--class-object class))
  (cl-check-type class eieio--class)
  (mapcar #'identity (eieio--class-slots class)))

(defun object-slots (obj)
  "Return list of slot names available in OBJ."
  (declare (obsolete eieio-class-slots "25.1"))
  (cl-check-type obj eieio-object)
  (mapcar #'cl--slot-descriptor-name
	  (eieio-class-slots (eieio--object-class obj))))

(defun eieio--class-slot-initarg (class slot)
  "Fetch from CLASS, SLOT's :initarg."
  (cl-check-type class eieio--class)
  (let ((ia (eieio--class-initarg-tuples class))
	(f nil))
    (while (and ia (not f))
      (if (eq (cdr (car ia)) slot)
	  (setq f (car (car ia))))
      (setq ia (cdr ia)))
    f))

;;; Object Set macros
;;
(defmacro oset (obj slot value)
  "Set the value in OBJ for slot SLOT to VALUE.
SLOT is the slot name as specified in `defclass' or the tag created
with in the :initarg slot.  VALUE can be any Lisp object."
  (declare (debug (form symbolp form)))
  `(eieio-oset ,obj (quote ,slot) ,value))

(defmacro oset-default (class slot value)
  "Set the default slot in CLASS for SLOT to VALUE.
The default value is usually set with the :initform tag during class
creation.  This allows users to change the default behavior of classes
after they are created."
  (declare (debug (form symbolp form)))
  `(eieio-oset-default ,class (quote ,slot) ,value))

;;; CLOS queries into classes and slots
;;
(defun slot-boundp (object slot)
  "Return non-nil if OBJECT's SLOT is bound.
Setting a slot's value makes it bound.  Calling `slot-makeunbound' will
make a slot unbound.
OBJECT can be an instance or a class."
  ;; Skip typechecking while retrieving this value.
  (let ((eieio-skip-typecheck t))
    ;; Return nil if the magic symbol is in there.
    (not (eq (cond
	      ((eieio-object-p object) (eieio-oref object slot))
	      ((symbolp object)        (eieio-oref-default object slot))
	      (t (signal 'wrong-type-argument (list 'eieio-object-p object))))
	     eieio--unbound))))

(defun slot-makeunbound (object slot)
  "In OBJECT, make SLOT unbound."
  (eieio-oset object slot eieio--unbound))

(defun slot-exists-p (object-or-class slot)
  "Return non-nil if OBJECT-OR-CLASS has SLOT."
  (let ((cv (cond ((eieio-object-p object-or-class)
                   (eieio--object-class object-or-class))
                  ((eieio--class-p object-or-class) object-or-class)
                  (t (find-class object-or-class 'error)))))
    (or (gethash slot (eieio--class-index-table cv))
        ;; FIXME: We could speed this up by adding class slots into the
        ;; index-table (e.g. with a negative index?).
	(let ((cs (eieio--class-class-slots cv))
	      found)
	  (dotimes (i (length cs))
	    (if (eq slot (cl--slot-descriptor-name (aref cs i)))
		(setq found t)))
	  found))))

(defun find-class (symbol &optional errorp)
  "Return the class that SYMBOL represents.
If there is no class, nil is returned if ERRORP is nil.
If ERRORP is non-nil, `wrong-argument-type' is signaled."
  (let ((class (cl--find-class symbol)))
    (cond
     ((eieio--class-p class) class)
     (errorp (signal 'wrong-type-argument (list 'class-p symbol))))))

;;; Slightly more complex utility functions for objects
;;
(defun object-assoc (key slot list)
  "Return an object if KEY is `equal' to SLOT's value of an object in LIST.
LIST is a list of objects whose slots are searched.
Objects in LIST do not need to have a slot named SLOT, nor does
SLOT need to be bound.  If these errors occur, those objects will
be ignored."
  (cl-check-type list list)
  (while (and list (not (condition-case nil
			    ;; This prevents errors for missing slots.
			    (equal key (eieio-oref (car list) slot))
			  (error nil))))
    (setq list (cdr list)))
  (car list))

(defun object-assoc-list (slot list)
  "Return an association list with the contents of SLOT as the key element.
LIST must be a list of objects with SLOT in it.
This is useful when you need to do completing read on an object group."
  (cl-check-type list list)
  (let ((assoclist nil))
    (while list
      (setq assoclist (cons (cons (eieio-oref (car list) slot)
				  (car list))
			    assoclist))
      (setq list (cdr list)))
    (nreverse assoclist)))

(defun object-assoc-list-safe (slot list)
  "Return an association list with the contents of SLOT as the key element.
LIST must be a list of objects, but those objects do not need to have
SLOT in it.  If it does not, then that element is left out of the association
list."
  (cl-check-type list list)
  (let ((assoclist nil))
    (while list
      (if (slot-exists-p (car list) slot)
	  (setq assoclist (cons (cons (eieio-oref (car list) slot)
				      (car list))
				assoclist)))
      (setq list (cdr list)))
    (nreverse assoclist)))

(defun object-add-to-list (object slot item &optional append)
  "In OBJECT's SLOT, add ITEM to the list of elements.
Optional argument APPEND indicates we need to append to the list.
If ITEM already exists in the list in SLOT, then it is not added.
Comparison is done with `equal' through the `member' function call.
If SLOT is unbound, bind it to the list containing ITEM."
  (let (ov)
    ;; Find the originating list.
    (if (not (slot-boundp object slot))
	(setq ov (list item))
      (setq ov (eieio-oref object slot))
      ;; turn it into a list.
      (unless (listp ov)
	(setq ov (list ov)))
      ;; Do the combination
      (if (not (member item ov))
	  (setq ov
		(if append
		    (append ov (list item))
		  (cons item ov)))))
    ;; Set back into the slot.
    (eieio-oset object slot ov)))

(defun object-remove-from-list (object slot item)
  "In OBJECT's SLOT, remove occurrences of ITEM.
Deletion is done with `delete', which deletes by side effect,
and comparisons are done with `equal'.
If SLOT is unbound, do nothing."
  (if (not (slot-boundp object slot))
      nil
    (eieio-oset object slot (delete item (eieio-oref object slot)))))

\f
;;;
;; We want all objects created by EIEIO to have some default set of
;; behaviors so we can create object utilities, and allow various
;; types of error checking.  To do this, create the default EIEIO
;; class, and when no parent class is specified, use this as the
;; default.  (But don't store it in the other classes as the default,
;; allowing for transparent support.)
;;

(defclass eieio-default-superclass nil
  nil
  "Default parent class for classes with no specified parent class.
Its slots are automatically adopted by classes with no specified parents.
This class is not stored in the `parent' slot of a class vector."
  :abstract t)

(setq eieio-default-superclass (cl--find-class 'eieio-default-superclass))

(define-obsolete-function-alias 'standard-class
  #'eieio-default-superclass "26.1")

(cl-defgeneric make-instance (class &rest initargs)
  "Make a new instance of CLASS based on INITARGS.
For example:

  (make-instance \\='foo)

INITARGS is a property list with keywords based on the `:initarg'
for each slot.  For example:

  (make-instance \\='foo :slot1 value1 :slotN valueN)")

(define-obsolete-function-alias 'constructor #'make-instance "25.1")

(cl-defmethod make-instance
    ((class (subclass eieio-default-superclass)) &rest slots)
  "Default constructor for CLASS `eieio-default-superclass'.
SLOTS are the initialization slots used by `initialize-instance'.
This static method is called when an object is constructed.
It allocates the vector used to represent an EIEIO object, and then
calls `initialize-instance' on that object."
  (let* ((new-object (copy-sequence (eieio--class-default-object-cache
                                     (eieio--class-object class)))))
    (if (and slots
             (let ((x (car slots)))
               (or (stringp x) (null x))))
        (funcall (if eieio-backward-compatibility #'ignore #'message)
                 "Obsolete name %S passed to %S constructor"
                 (pop slots) class))
    ;; Call the initialize method on the new object with the slots
    ;; that were passed down to us.
    (initialize-instance new-object slots)
    (when eieio-backward-compatibility
      ;; Use symbol as type descriptor, for backwards compatibility.
      (aset new-object 0 class))
    ;; Return the created object.
    new-object))

;; FIXME: CLOS uses "&rest INITARGS" instead.
(cl-defgeneric shared-initialize (obj slots)
  "Set slots of OBJ with SLOTS which is a list of name/value pairs.
Called from the constructor routine.")

(cl-defmethod shared-initialize ((obj eieio-default-superclass) slots)
  "Set slots of OBJ with SLOTS which is a list of name/value pairs.
Called from the constructor routine."
  (while slots
    (let ((rn (eieio--initarg-to-attribute (eieio--object-class obj)
                                           (car slots))))
      (if (not rn)
          (slot-missing obj (car slots) 'oset (car (cdr slots)))
        (eieio-oset obj rn (car (cdr slots)))))
    (setq slots (cdr (cdr slots)))))

;; FIXME: CLOS uses "&rest INITARGS" instead.
(cl-defgeneric initialize-instance (this &optional slots)
  "Construct the new object THIS based on SLOTS.")

(cl-defmethod initialize-instance ((this eieio-default-superclass)
				   &optional args)
  "Construct the new object THIS based on ARGS.
ARGS is a property list where odd numbered elements are tags, and
even numbered elements are the values to store in the tagged slot.
If you overload the `initialize-instance', there you will need to
call `shared-initialize' yourself, or you can call `call-next-method'
to have this constructor called automatically.  If these steps are
not taken, then new objects of your class will not have their values
dynamically set from ARGS."
  (let* ((this-class (eieio--object-class this))
         (initargs args)
         (slots (eieio--class-slots this-class)))
    (dotimes (i (length slots))
      ;; For each slot, see if we need to evaluate its initform.
      (let* ((slot (aref slots i))
             (slot-name (eieio-slot-descriptor-name slot))
             (initform (cl--slot-descriptor-initform slot)))
        (unless (or (when-let ((initarg
                                (car (rassq slot-name
                                            (eieio--class-initarg-tuples
                                             this-class)))))
                      (plist-get initargs initarg))
                    ;; Those slots whose initform is constant already have
                    ;; the right value set in the default-object.
                    (macroexp-const-p initform))
          ;; FIXME: Use `aset' instead of `eieio-oset', relying on that
          ;; vector returned by `eieio--class-slots'
          ;; should be congruent with the object itself.
          (eieio-oset this slot-name (eval initform t))))))
  ;; Shared initialize will parse our args for us.
  (shared-initialize this args))

(cl-defgeneric slot-missing (object slot-name _operation &optional _new-value)
  "Method invoked when an attempt to access a slot in OBJECT fails.
SLOT-NAME is the name of the failed slot, OPERATION is the type of access
that was requested, and optional NEW-VALUE is the value that was desired
to be set.

This method is called from `oref', `oset', and other functions which
directly reference slots in EIEIO objects."
  (signal 'invalid-slot-name
          (list (if (eieio-object-p object) (eieio-object-name object) object)
                slot-name)))

(cl-defgeneric slot-unbound (object class slot-name fn)
  "Slot unbound is invoked during an attempt to reference an unbound slot.")

(cl-defmethod slot-unbound ((object eieio-default-superclass)
			 class slot-name fn)
  "Slot unbound is invoked during an attempt to reference an unbound slot.
OBJECT is the instance of the object being reference.  CLASS is the
class of OBJECT, and SLOT-NAME is the offending slot.  This function
throws the signal `unbound-slot'.  You can overload this function and
return the value to use in place of the unbound value.
Argument FN is the function signaling this error.
Use `slot-boundp' to determine if a slot is bound or not.

In CLOS, the argument list is (CLASS OBJECT SLOT-NAME), but
EIEIO can only dispatch on the first argument, so the first two are swapped."
  (signal 'unbound-slot (list (eieio-class-name class)
                              (eieio-object-name object)
			      slot-name fn)))

(cl-defgeneric clone (obj &rest params)
  "Make a copy of OBJ, and then supply PARAMS.
PARAMS is a parameter list of the same form used by `initialize-instance'.

When overloading `clone', be sure to call `call-next-method'
first and modify the returned object.")

(cl-defmethod clone ((obj eieio-default-superclass) &rest params)
  "Make a copy of OBJ, and then apply PARAMS."
  (let ((nobj (copy-sequence obj)))
    (if (stringp (car params))
        (funcall (if eieio-backward-compatibility #'ignore #'message)
                 "Obsolete name %S passed to clone" (pop params)))
    (if params (shared-initialize nobj params))
    nobj))

(cl-defgeneric destructor (_this &rest _params)
  "Destructor for cleaning up any dynamic links to our object."
  (declare (obsolete nil "26.1"))
  ;; No cleanup... yet.
  nil)

(cl-defgeneric object-print (this &rest _strings)
  "Pretty printer for object THIS.

It is sometimes useful to put a summary of the object into the
default #<notation> string when using EIEIO browsing tools.
Implement this method to customize the summary."
  (declare (obsolete cl-print-object "26.1"))
  (format "%S" this))

(with-suppressed-warnings ((obsolete object-print))
  (cl-defmethod object-print ((this eieio-default-superclass) &rest strings)
    "Pretty printer for object THIS.  Call function `object-name' with STRINGS.
The default method for printing object THIS is to use the
function `object-name'.

It is sometimes useful to put a summary of the object into the
default #<notation> string when using EIEIO browsing tools.

Implement this function and specify STRINGS in a call to
`call-next-method' to provide additional summary information.
When passing in extra strings from child classes, always remember
to prepend a space."
    (eieio-object-name this (apply #'concat strings))))

(with-suppressed-warnings ((obsolete object-print))
  (cl-defmethod cl-print-object ((object eieio-default-superclass) stream)
    "Default printer for EIEIO objects."
    ;; Fallback to the old `object-print'.  There should be no
    ;; `object-print' methods in the Emacs tree, but there may be some
    ;; out-of-tree.
    (princ (object-print object) stream)))


(defvar eieio-print-depth 0
  "The current indentation depth while printing.
Ignored if `eieio-print-indentation' is nil.")

(defvar eieio-print-indentation t
  "When non-nil, indent contents of printed objects.")

(defvar eieio-print-object-name t
  "When non-nil write the object name in `object-write'.
Does not affect objects subclassing `eieio-named'.  Note that
Emacs<26 requires that object names be present.")

(cl-defgeneric object-write (this &optional comment)
  "Write out object THIS to the current stream.
Optional COMMENT will add comments to the beginning of the output.")

(cl-defmethod object-write ((this eieio-default-superclass) &optional comment)
  "Write object THIS out to the current stream.
This writes out the vector version of this object.  Complex and recursive
object are discouraged from being written.
  If optional COMMENT is non-nil, include comments when outputting
this object."
  (when (and comment eieio-print-object-name)
    (princ ";; Object ")
    (princ (eieio-object-name-string this))
    (princ "\n"))
  (when comment
    (princ comment)
    (princ "\n"))
  (let* ((cl (eieio-object-class this))
	 (cv (cl--find-class cl)))
    ;; Now output readable lisp to recreate this object
    ;; It should look like this:
    ;; (<constructor> <name> <slot> <slot> ... )
    ;; Each slot's slot is written using its :writer.
    (when eieio-print-indentation
      (princ (make-string (* eieio-print-depth 2) ? )))
    (princ "(")
    (princ (symbol-name (eieio--class-constructor (eieio-object-class this))))
    (when eieio-print-object-name
      (princ " ")
      (prin1 (eieio-object-name-string this))
      (princ "\n"))
    ;; Loop over all the public slots
    (let ((slots (eieio--class-slots cv))
	  (eieio-print-depth (1+ eieio-print-depth)))
      (dotimes (i (length slots))
        (let ((slot (aref slots i)))
          (when (slot-boundp this (cl--slot-descriptor-name slot))
            (let ((i (eieio--class-slot-initarg
                      cv (cl--slot-descriptor-name slot)))
                  (v (eieio-oref this (cl--slot-descriptor-name slot))))
              (unless (or (not i) (equal v (cl--slot-descriptor-initform slot)))
                (unless (bolp)
                  (princ "\n"))
                (when eieio-print-indentation
                  (princ (make-string (* eieio-print-depth 2) ? )))
                (princ (symbol-name i))
                (if (alist-get :printer (cl--slot-descriptor-props slot))
                    ;; Use our public printer
                    (progn
                      (princ " ")
                      (funcall (alist-get :printer
                                          (cl--slot-descriptor-props slot))
                               v))
                  ;; Use our generic override prin1 function.
                  (princ (if (or (eieio-object-p v)
                                 (eieio-object-p (car-safe v)))
                             "\n" " "))
                  (eieio-override-prin1 v))))))))
    (princ ")")
    (when (zerop eieio-print-depth)
      (princ "\n"))))

(defun eieio-override-prin1 (thing)
  "Perform a `prin1' on THING taking advantage of object knowledge."
  (cond ((eieio-object-p thing)
	 (object-write thing))
	((consp thing)
	 (eieio-list-prin1 thing))
	((hash-table-p thing)
         (let ((copy (copy-hash-table thing)))
	   (maphash
	    (lambda (key val)
	      (setf (gethash key copy)
		    (read
		     (with-output-to-string
		       (eieio-override-prin1 val)))))
	    copy)
	   (prin1 copy)))
	((vectorp thing)
         (let ((copy (copy-sequence thing)))
	  (dotimes (i (length copy))
	    (aset copy i
		  (read
		   (with-output-to-string
		     (eieio-override-prin1
		      (aref copy i))))))
	  (prin1 copy)))
	((eieio--class-p thing)
	 (princ (eieio--class-print-name thing)))
	(t (prin1 thing))))

(defun eieio-list-prin1 (list)
  "Display LIST where list may contain objects."
  (if (not (eieio-object-p (car list)))
      (progn
	(princ "'")
	(prin1 list))
    (when eieio-print-indentation
      (princ (make-string (* eieio-print-depth 2) ? )))
    (princ "(list")
    (let ((eieio-print-depth (1+ eieio-print-depth)))
      (while list
	(princ "\n")
	(if (eieio-object-p (car list))
	    (object-write (car list))
          (when eieio-print-indentation
	   (princ (make-string (* eieio-print-depth) ? )))
	  (eieio-override-prin1 (car list)))
	(setq list (cdr list))))
    (princ ")")))

\f
;;; Unimplemented functions from CLOS
;;
(defun eieio-change-class (_obj _class)
  "Change the class of OBJ to type CLASS.
This may create or delete slots, but does not affect the return value
of `eq'."
  (error "EIEIO: `change-class' is unimplemented"))
(define-obsolete-function-alias 'change-class #'eieio-change-class "26.1")

(provide 'eieio)

;;; eieio.el ends here

debug log:

solving 820e8383d8 ...
found 820e8383d8 in https://git.savannah.gnu.org/cgit/emacs.git

(*) Git path names are given by the tree(s) the blob belongs to.
    Blobs themselves have no identifier aside from the hash of its contents.^

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).