src/pcl/methods.lisp

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   2 ;;;; more information.
   3
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   8 ;;;; information.
   9
  10 ;;;; copyright information from original PCL sources:
  11 ;;;;
  12 ;;;; Copyright (c) 1985, 1986, 1987, 1988, 1989, 1990 Xerox Corporation.
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  16 ;;;; upon this software are permitted. Any distribution of this software or
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  21 ;;;; warranty about the software, its performance or its conformity to any
  22 ;;;; specification.
  23
  24 (in-package "SB-PCL")
  25 \f
  26 ;;; methods
  27 ;;;
  28 ;;; Methods themselves are simple inanimate objects. Most properties of
  29 ;;; methods are immutable, methods cannot be reinitialized. The following
  30 ;;; properties of methods can be changed:
  31 ;;;   METHOD-GENERIC-FUNCTION
  32 \f
  33 ;;; initialization
  34 ;;;
  35 ;;; Error checking is done in before methods. Because of the simplicity of
  36 ;;; standard method objects the standard primary method can fill the slots.
  37 ;;;
  38 ;;; Methods are not reinitializable.
  39
  40 (define-condition metaobject-initialization-violation
  41     (reference-condition simple-error)
  42   ())
  43
  44 (macrolet ((def (name args control)
  45                `(defmethod ,name ,args
  46                  (declare (ignore initargs))
  47                  (error 'metaobject-initialization-violation
  48                   :format-control ,(format nil "~@<~A~@:>" control)
  49                   :format-arguments (list ',name)
  50                   :references (list '(:amop :initialization method))))))
  51   (def reinitialize-instance ((method method) &rest initargs)
  52     "Method objects cannot be redefined by ~S.")
  53   (def change-class ((method method) new &rest initargs)
  54     "Method objects cannot be redefined by ~S.")
  55   ;; NEW being a subclass of method is dealt with in the general
  56   ;; method of CHANGE-CLASS
  57   (def update-instance-for-redefined-class ((method method) added discarded
  58                                             plist &rest initargs)
  59     "No behaviour specified for ~S on method objects.")
  60   (def update-instance-for-different-class (old (new method) &rest initargs)
  61     "No behaviour specified for ~S on method objects.")
  62   (def update-instance-for-different-class ((old method) new &rest initargs)
  63     "No behaviour specified for ~S on method objects."))
  64
  65 (define-condition invalid-method-initarg (simple-program-error)
  66   ((method :initarg :method :reader invalid-method-initarg-method))
  67   (:report
  68    (lambda (c s)
  69      (format s "~@<In initialization of ~S:~2I~_~?~@:>"
  70              (invalid-method-initarg-method c)
  71              (simple-condition-format-control c)
  72              (simple-condition-format-arguments c)))))
  73
  74 (defun invalid-method-initarg (method format-control &rest args)
  75   (error 'invalid-method-initarg :method method
  76          :format-control format-control :format-arguments args))
  77
  78 (defun check-documentation (method doc)
  79   (unless (or (null doc) (stringp doc))
  80     (invalid-method-initarg method "~@<~S of ~S is neither ~S nor a ~S.~@:>"
  81                             :documentation doc 'null 'string)))
  82 (defun check-lambda-list (method ll)
  83   nil)
  84
  85 (defun check-method-function (method fun)
  86   (unless (functionp fun)
  87     (invalid-method-initarg method "~@<~S of ~S is not a ~S.~@:>"
  88                             :function fun 'function)))
  89
  90 (defun check-qualifiers (method qualifiers)
  91   (flet ((improper-list ()
  92            (invalid-method-initarg method
  93                                    "~@<~S of ~S is an improper list.~@:>"
  94                                    :qualifiers qualifiers)))
  95     (dolist-carefully (q qualifiers improper-list)
  96       (unless (and q (atom q))
  97         (invalid-method-initarg method
  98                                 "~@<~S, in ~S ~S, is not a non-~S atom.~@:>"
  99                                 q :qualifiers qualifiers 'null)))))
 100
 101 (defun check-slot-name (method name)
 102   (unless (symbolp name)
 103     (invalid-method-initarg "~@<~S of ~S is not a ~S.~@:>"
 104                             :slot-name name 'symbol)))
 105
 106 (defun check-specializers (method specializers)
 107   (flet ((improper-list ()
 108            (invalid-method-initarg method
 109                                    "~@<~S of ~S is an improper list.~@:>"
 110                                    :specializers specializers)))
 111     (dolist-carefully (s specializers improper-list)
 112       (unless (specializerp s)
 113         (invalid-method-initarg method
 114                                 "~@<~S, in ~S ~S, is not a ~S.~@:>"
 115                                 s :specializers specializers 'specializer)))
 116     ;; KLUDGE: ANSI says that it's not valid to have methods
 117     ;; specializing on classes which are "not defined", leaving
 118     ;; unclear what the definedness of a class is; AMOP suggests that
 119     ;; forward-referenced-classes, since they have proper names and
 120     ;; all, are at least worthy of some level of definition.  We allow
 121     ;; methods specialized on forward-referenced-classes, but it's
 122     ;; non-portable and potentially dubious, so
 123     (let ((frcs (remove-if-not #'forward-referenced-class-p specializers)))
 124       (unless (null frcs)
 125         (style-warn "~@<Defining a method using ~
 126                      ~V[~;~1{~S~}~;~1{~S and ~S~}~:;~{~#[~;and ~]~S~^, ~}~] ~
 127                      as ~2:*~V[~;a specializer~:;specializers~].~@:>"
 128                     (length frcs) frcs)))))
 129
 130 (defmethod shared-initialize :before
 131     ((method standard-method) slot-names &key
 132      qualifiers lambda-list specializers function documentation)
 133   (declare (ignore slot-names))
 134   ;; FIXME: it's not clear to me (CSR, 2006-08-09) why methods get
 135   ;; this extra paranoia and nothing else does; either everything
 136   ;; should be aggressively checking initargs, or nothing much should.
 137   ;; In either case, it would probably be better to have :type
 138   ;; declarations in slots, which would then give a suitable type
 139   ;; error (if we implement type-checking for slots...) rather than
 140   ;; this hand-crafted thing.
 141   (check-qualifiers method qualifiers)
 142   (check-lambda-list method lambda-list)
 143   (check-specializers method specializers)
 144   (check-method-function method function)
 145   (check-documentation method documentation))
 146
 147 (defmethod shared-initialize :before
 148     ((method standard-accessor-method) slot-names &key
 149      slot-name slot-definition)
 150   (declare (ignore slot-names))
 151   (unless slot-definition
 152     (check-slot-name method slot-name)))
 153
 154 (defmethod shared-initialize :after ((method standard-method) slot-names
 155                                      &rest initargs &key ((method-cell method-cell)))
 156   (declare (ignore slot-names method-cell))
 157   (initialize-method-function initargs method))
 158 \f
 159 (defvar *the-class-generic-function*
 160   (find-class 'generic-function))
 161 (defvar *the-class-standard-generic-function*
 162   (find-class 'standard-generic-function))
 163 \f
 164 (defmethod shared-initialize :before
 165            ((generic-function standard-generic-function)
 166             slot-names
 167             &key (name nil namep)
 168                  (lambda-list () lambda-list-p)
 169                  argument-precedence-order
 170                  declarations
 171                  documentation
 172                  (method-class nil method-class-supplied-p)
 173                  (method-combination nil method-combination-supplied-p))
 174   (declare (ignore slot-names
 175                    declarations argument-precedence-order documentation
 176                    lambda-list lambda-list-p))
 177
 178   (when namep
 179     (set-fun-name generic-function name))
 180
 181   (flet ((initarg-error (initarg value string)
 182            (error "when initializing the generic function ~S:~%~
 183                    The ~S initialization argument was: ~A.~%~
 184                    It must be ~A."
 185                   generic-function initarg value string)))
 186     (cond (method-class-supplied-p
 187            (when (symbolp method-class)
 188              (setq method-class (find-class method-class)))
 189            (unless (and (classp method-class)
 190                         (*subtypep (class-eq-specializer method-class)
 191                                    *the-class-method*))
 192              (initarg-error :method-class
 193                             method-class
 194                             "a subclass of the class METHOD"))
 195            (setf (slot-value generic-function 'method-class) method-class))
 196           ((slot-boundp generic-function 'method-class))
 197           (t
 198            (initarg-error :method-class
 199                           "not supplied"
 200                           "a subclass of the class METHOD")))
 201     (cond (method-combination-supplied-p
 202            (unless (method-combination-p method-combination)
 203              (initarg-error :method-combination
 204                             method-combination
 205                             "a method combination object")))
 206           ((slot-boundp generic-function '%method-combination))
 207           (t
 208            (initarg-error :method-combination
 209                           "not supplied"
 210                           "a method combination object")))))
 211 \f
 212 (defun find-generic-function (name &optional (errorp t))
 213   (let ((fun (and (fboundp name) (fdefinition name))))
 214     (cond
 215       ((and fun (typep fun 'generic-function)) fun)
 216       (errorp (error "No generic function named ~S." name))
 217       (t nil))))
 218
 219 (defun real-add-named-method (generic-function-name qualifiers
 220                               specializers lambda-list &rest other-initargs)
 221   (unless (and (fboundp generic-function-name)
 222                (typep (fdefinition generic-function-name) 'generic-function))
 223     (warn 'implicit-generic-function-warning :name generic-function-name))
 224   (let* ((existing-gf (find-generic-function generic-function-name nil))
 225          (generic-function
 226           (if existing-gf
 227               (ensure-generic-function
 228                generic-function-name
 229                :generic-function-class (class-of existing-gf))
 230               (ensure-generic-function generic-function-name)))
 231          (proto (method-prototype-for-gf generic-function-name)))
 232     ;; FIXME: Destructive modification of &REST list.
 233     (setf (getf (getf other-initargs 'plist) :name)
 234           (make-method-spec generic-function qualifiers specializers))
 235     (let ((new (apply #'make-instance (class-of proto)
 236                       :qualifiers qualifiers :specializers specializers
 237                       :lambda-list lambda-list other-initargs)))
 238       (add-method generic-function new)
 239       new)))
 240
 241 (define-condition find-method-length-mismatch
 242     (reference-condition simple-error)
 243   ()
 244   (:default-initargs :references (list '(:ansi-cl :function find-method))))
 245
 246 (defun real-get-method (generic-function qualifiers specializers
 247                         &optional (errorp t)
 248                         always-check-specializers)
 249   (let ((lspec (length specializers))
 250         (methods (generic-function-methods generic-function)))
 251     (when (or methods always-check-specializers)
 252       (let ((nreq (length (arg-info-metatypes (gf-arg-info
 253                                                generic-function)))))
 254         ;; Since we internally bypass FIND-METHOD by using GET-METHOD
 255         ;; instead we need to to this here or users may get hit by a
 256         ;; failed AVER instead of a sensible error message.
 257         (when (/= lspec nreq)
 258           (error
 259            'find-method-length-mismatch
 260            :format-control
 261            "~@<The generic function ~S takes ~D required argument~:P; ~
 262             was asked to find a method with specializers ~S~@:>"
 263            :format-arguments (list generic-function nreq specializers)))))
 264     (let ((hit
 265            (dolist (method methods)
 266              (let ((mspecializers (method-specializers method)))
 267                (aver (= lspec (length mspecializers)))
 268                (when (and (equal qualifiers (method-qualifiers method))
 269                           (every #'same-specializer-p specializers
 270                                  (method-specializers method)))
 271                  (return method))))))
 272       (cond (hit hit)
 273             ((null errorp) nil)
 274             (t
 275              (error "~@<There is no method on ~S with ~
 276                     ~:[no qualifiers~;~:*qualifiers ~S~] ~
 277                     and specializers ~S.~@:>"
 278                     generic-function qualifiers specializers))))))
 279
 280 (defmethod find-method ((generic-function standard-generic-function)
 281                         qualifiers specializers &optional (errorp t))
 282   ;; ANSI about FIND-METHOD: "The specializers argument contains the
 283   ;; parameter specializers for the method. It must correspond in
 284   ;; length to the number of required arguments of the generic
 285   ;; function, or an error is signaled."
 286   ;;
 287   ;; This error checking is done by REAL-GET-METHOD.
 288   (real-get-method
 289    generic-function qualifiers
 290    ;; ANSI for FIND-METHOD seems to imply that in fact specializers
 291    ;; should always be passed in parsed form instead of being parsed
 292    ;; at this point.  Since there's no ANSI-blessed way of getting an
 293    ;; EQL specializer, that seems unnecessarily painful, so we are
 294    ;; nice to our users.  -- CSR, 2007-06-01
 295    (parse-specializers generic-function specializers) errorp t))
 296 \f
 297 ;;; Compute various information about a generic-function's arglist by looking
 298 ;;; at the argument lists of the methods. The hair for trying not to use
 299 ;;; &REST arguments lives here.
 300 ;;;  The values returned are:
 301 ;;;    number-of-required-arguments
 302 ;;;       the number of required arguments to this generic-function's
 303 ;;;       discriminating function
 304 ;;;    &rest-argument-p
 305 ;;;       whether or not this generic-function's discriminating
 306 ;;;       function takes an &rest argument.
 307 ;;;    specialized-argument-positions
 308 ;;;       a list of the positions of the arguments this generic-function
 309 ;;;       specializes (e.g. for a classical generic-function this is the
 310 ;;;       list: (1)).
 311 (defmethod compute-discriminating-function-arglist-info
 312            ((generic-function standard-generic-function))
 313   ;;(declare (values number-of-required-arguments &rest-argument-p
 314   ;;             specialized-argument-postions))
 315   (let ((number-required nil)
 316         (restp nil)
 317         (specialized-positions ())
 318         (methods (generic-function-methods generic-function)))
 319     (dolist (method methods)
 320       (multiple-value-setq (number-required restp specialized-positions)
 321         (compute-discriminating-function-arglist-info-internal
 322          generic-function method number-required restp specialized-positions)))
 323     (values number-required restp (sort specialized-positions #'<))))
 324
 325 (defun compute-discriminating-function-arglist-info-internal
 326        (generic-function method number-of-requireds restp
 327         specialized-argument-positions)
 328   (declare (ignore generic-function)
 329            (type (or null fixnum) number-of-requireds))
 330   (let ((requireds 0))
 331     (declare (fixnum requireds))
 332     ;; Go through this methods arguments seeing how many are required,
 333     ;; and whether there is an &rest argument.
 334     (dolist (arg (method-lambda-list method))
 335       (cond ((eq arg '&aux) (return))
 336             ((memq arg '(&optional &rest &key))
 337              (return (setq restp t)))
 338             ((memq arg lambda-list-keywords))
 339             (t (incf requireds))))
 340     ;; Now go through this method's type specifiers to see which
 341     ;; argument positions are type specified. Treat T specially
 342     ;; in the usual sort of way. For efficiency don't bother to
 343     ;; keep specialized-argument-positions sorted, rather depend
 344     ;; on our caller to do that.
 345     (let ((pos 0))
 346       (dolist (type-spec (method-specializers method))
 347         (unless (eq type-spec *the-class-t*)
 348           (pushnew pos specialized-argument-positions))
 349         (incf pos)))
 350     ;; Finally merge the values for this method into the values
 351     ;; for the exisiting methods and return them. Note that if
 352     ;; num-of-requireds is NIL it means this is the first method
 353     ;; and we depend on that.
 354     (values (min (or number-of-requireds requireds) requireds)
 355             (or restp
 356                 (and number-of-requireds (/= number-of-requireds requireds)))
 357             specialized-argument-positions)))
 358
 359 (defun make-discriminating-function-arglist (number-required-arguments restp)
 360   (nconc (let ((args nil))
 361            (dotimes (i number-required-arguments)
 362              (push (format-symbol *package* ;; ! is this right?
 363                                   "Discriminating Function Arg ~D"
 364                                   i)
 365                    args))
 366            (nreverse args))
 367          (when restp
 368                `(&rest ,(format-symbol *package*
 369                                        "Discriminating Function &rest Arg")))))
 370 \f
 371 (defmethod generic-function-argument-precedence-order
 372     ((gf standard-generic-function))
 373   (aver (eq *boot-state* 'complete))
 374   (loop with arg-info = (gf-arg-info gf)
 375         with lambda-list = (arg-info-lambda-list arg-info)
 376         for argument-position in (arg-info-precedence arg-info)
 377         collect (nth argument-position lambda-list)))
 378
 379 (defmethod generic-function-lambda-list ((gf generic-function))
 380   (gf-lambda-list gf))
 381
 382 (defmethod gf-fast-method-function-p ((gf standard-generic-function))
 383   (gf-info-fast-mf-p (slot-value gf 'arg-info)))
 384
 385 (defmethod initialize-instance :after ((gf standard-generic-function)
 386                                        &key (lambda-list nil lambda-list-p)
 387                                        argument-precedence-order)
 388   (with-slots (arg-info) gf
 389     (if lambda-list-p
 390         (set-arg-info gf
 391                       :lambda-list lambda-list
 392                       :argument-precedence-order argument-precedence-order)
 393         (set-arg-info gf))
 394     (when (arg-info-valid-p arg-info)
 395       (update-dfun gf))))
 396
 397 (defmethod reinitialize-instance :around
 398     ((gf standard-generic-function) &rest args &key
 399      (lambda-list nil lambda-list-p) (argument-precedence-order nil apo-p))
 400   (let ((old-mc (generic-function-method-combination gf)))
 401     (prog1 (call-next-method)
 402       ;; KLUDGE: EQ is too strong a test.
 403       (unless (eq old-mc (generic-function-method-combination gf))
 404         (flush-effective-method-cache gf))
 405       (cond
 406         ((and lambda-list-p apo-p)
 407          (set-arg-info gf
 408                        :lambda-list lambda-list
 409                        :argument-precedence-order argument-precedence-order))
 410         (lambda-list-p (set-arg-info gf :lambda-list lambda-list))
 411         (t (set-arg-info gf)))
 412       (when (arg-info-valid-p (gf-arg-info gf))
 413         (update-dfun gf))
 414       (map-dependents gf (lambda (dependent)
 415                            (apply #'update-dependent gf dependent args))))))
 416
 417 (declaim (special *lazy-dfun-compute-p*))
 418
 419 (defun set-methods (gf methods)
 420   (setf (generic-function-methods gf) nil)
 421   (loop (when (null methods) (return gf))
 422         (real-add-method gf (pop methods) methods)))
 423
 424 (define-condition new-value-specialization (reference-condition error)
 425   ((%method :initarg :method :reader new-value-specialization-method))
 426   (:report
 427    (lambda (c s)
 428      (format s "~@<Cannot add method ~S to ~S, as it specializes the ~
 429                 new-value argument.~@:>"
 430              (new-value-specialization-method c)
 431              #'(setf slot-value-using-class))))
 432   (:default-initargs :references
 433       (list '(:sbcl :node "Metaobject Protocol")
 434             '(:amop :generic-function (setf slot-value-using-class)))))
 435
 436 (defun real-add-method (generic-function method &optional skip-dfun-update-p)
 437   (when (method-generic-function method)
 438     (error "~@<The method ~S is already part of the generic ~
 439             function ~S; it can't be added to another generic ~
 440             function until it is removed from the first one.~@:>"
 441            method (method-generic-function method)))
 442   (flet ((similar-lambda-lists-p (method-a method-b)
 443            (multiple-value-bind (a-nreq a-nopt a-keyp a-restp)
 444                (analyze-lambda-list (method-lambda-list method-a))
 445              (multiple-value-bind (b-nreq b-nopt b-keyp b-restp)
 446                  (analyze-lambda-list (method-lambda-list method-b))
 447                (and (= a-nreq b-nreq)
 448                     (= a-nopt b-nopt)
 449                     (eq (or a-keyp a-restp)
 450                         (or b-keyp b-restp)))))))
 451     (let ((lock (gf-lock generic-function)))
 452       ;; HANDLER-CASE takes care of releasing the lock and enabling
 453       ;; interrupts before going forth with the error.
 454       (handler-case
 455           ;; System lock because interrupts need to be disabled as
 456           ;; well: it would be bad to unwind and leave the gf in an
 457           ;; inconsistent state.
 458           (sb-thread::with-recursive-system-spinlock (lock)
 459             (let* ((qualifiers (method-qualifiers method))
 460                    (specializers (method-specializers method))
 461                    (existing (get-method generic-function
 462                                          qualifiers
 463                                          specializers
 464                                          nil)))
 465
 466               ;; If there is already a method like this one then we must get
 467               ;; rid of it before proceeding.  Note that we call the generic
 468               ;; function REMOVE-METHOD to remove it rather than doing it in
 469               ;; some internal way.
 470               (when (and existing (similar-lambda-lists-p existing method))
 471                 (remove-method generic-function existing))
 472
 473               ;; KLUDGE: We have a special case here, as we disallow
 474               ;; specializations of the NEW-VALUE argument to (SETF
 475               ;; SLOT-VALUE-USING-CLASS).  GET-ACCESSOR-METHOD-FUNCTION is
 476               ;; the optimizing function here: it precomputes the effective
 477               ;; method, assuming that there is no dispatch to be done on
 478               ;; the new-value argument.
 479               (when (and (eq generic-function #'(setf slot-value-using-class))
 480                          (not (eq *the-class-t* (first specializers))))
 481                 (error 'new-value-specialization :method  method))
 482
 483               (setf (method-generic-function method) generic-function)
 484               (pushnew method (generic-function-methods generic-function))
 485               (dolist (specializer specializers)
 486                 (add-direct-method specializer method))
 487
 488               ;; KLUDGE: SET-ARG-INFO contains the error-detecting logic for
 489               ;; detecting attempts to add methods with incongruent lambda
 490               ;; lists.  However, according to Gerd Moellmann on cmucl-imp,
 491               ;; it also depends on the new method already having been added
 492               ;; to the generic function.  Therefore, we need to remove it
 493               ;; again on error:
 494               (let ((remove-again-p t))
 495                 (unwind-protect
 496                      (progn
 497                        (set-arg-info generic-function :new-method method)
 498                        (setq remove-again-p nil))
 499                   (when remove-again-p
 500                     (remove-method generic-function method))))
 501
 502               ;; KLUDGE II: ANSI saith that it is not an error to add a
 503               ;; method with invalid qualifiers to a generic function of the
 504               ;; wrong kind; it's only an error at generic function
 505               ;; invocation time; I dunno what the rationale was, and it
 506               ;; sucks.  Nevertheless, it's probably a programmer error, so
 507               ;; let's warn anyway. -- CSR, 2003-08-20
 508               (let ((mc (generic-function-method-combination generic-functioN)))
 509                 (cond
 510                   ((eq mc *standard-method-combination*)
 511                    (when (and qualifiers
 512                               (or (cdr qualifiers)
 513                                   (not (memq (car qualifiers)
 514                                              '(:around :before :after)))))
 515                      (warn "~@<Invalid qualifiers for standard method ~
 516                             combination in method ~S:~2I~_~S.~@:>"
 517                            method qualifiers)))
 518                   ((short-method-combination-p mc)
 519                    (let ((mc-name (method-combination-type-name mc)))
 520                      (when (or (null qualifiers)
 521                                (cdr qualifiers)
 522                                (and (neq (car qualifiers) :around)
 523                                     (neq (car qualifiers) mc-name)))
 524                        (warn "~@<Invalid qualifiers for ~S method combination ~
 525                               in method ~S:~2I~_~S.~@:>"
 526                              mc-name method qualifiers))))))
 527
 528               (unless skip-dfun-update-p
 529                 (update-ctors 'add-method
 530                               :generic-function generic-function
 531                               :method method)
 532                 (update-dfun generic-function))
 533               (map-dependents generic-function
 534                               (lambda (dep)
 535                                 (update-dependent generic-function
 536                                                   dep 'add-method method)))))
 537         (serious-condition (c)
 538           (error c)))))
 539   generic-function)
 540
 541 (defun real-remove-method (generic-function method)
 542   (when (eq generic-function (method-generic-function method))
 543     (let ((lock (gf-lock generic-function)))
 544       ;; System lock because interrupts need to be disabled as well:
 545       ;; it would be bad to unwind and leave the gf in an inconsistent
 546       ;; state.
 547       (sb-thread::with-recursive-system-spinlock (lock)
 548         (let* ((specializers (method-specializers method))
 549                (methods (generic-function-methods generic-function))
 550                (new-methods (remove method methods)))
 551           (setf (method-generic-function method) nil
 552                 (generic-function-methods generic-function) new-methods)
 553           (dolist (specializer (method-specializers method))
 554             (remove-direct-method specializer method))
 555           (set-arg-info generic-function)
 556           (update-ctors 'remove-method
 557                         :generic-function generic-function
 558                         :method method)
 559           (update-dfun generic-function)
 560           (map-dependents generic-function
 561                           (lambda (dep)
 562                             (update-dependent generic-function
 563                                               dep 'remove-method method)))))))
 564   generic-function)
 565 \f
 566 (defun compute-applicable-methods-function (generic-function arguments)
 567   (values (compute-applicable-methods-using-types
 568            generic-function
 569            (types-from-args generic-function arguments 'eql))))
 570
 571 (defmethod compute-applicable-methods
 572     ((generic-function generic-function) arguments)
 573   (values (compute-applicable-methods-using-types
 574            generic-function
 575            (types-from-args generic-function arguments 'eql))))
 576
 577 (defmethod compute-applicable-methods-using-classes
 578     ((generic-function generic-function) classes)
 579   (compute-applicable-methods-using-types
 580    generic-function
 581    (types-from-args generic-function classes 'class-eq)))
 582
 583 (defun proclaim-incompatible-superclasses (classes)
 584   (setq classes (mapcar (lambda (class)
 585                           (if (symbolp class)
 586                               (find-class class)
 587                               class))
 588                         classes))
 589   (dolist (class classes)
 590     (dolist (other-class classes)
 591       (unless (eq class other-class)
 592         (pushnew other-class (class-incompatible-superclass-list class))))))
 593
 594 (defun superclasses-compatible-p (class1 class2)
 595   (let ((cpl1 (cpl-or-nil class1))
 596         (cpl2 (cpl-or-nil class2)))
 597     (dolist (sc1 cpl1 t)
 598       (dolist (ic (class-incompatible-superclass-list sc1))
 599         (when (memq ic cpl2)
 600           (return-from superclasses-compatible-p nil))))))
 601
 602 (mapc
 603  #'proclaim-incompatible-superclasses
 604  '(;; superclass class
 605    (built-in-class std-class structure-class) ; direct subclasses of pcl-class
 606    (standard-class funcallable-standard-class)
 607    ;; superclass metaobject
 608    (class eql-specializer class-eq-specializer method method-combination
 609     generic-function slot-definition)
 610    ;; metaclass built-in-class
 611    (number sequence character           ; direct subclasses of t, but not array
 612     standard-object structure-object)   ;                        or symbol
 613    (number array character symbol       ; direct subclasses of t, but not
 614     standard-object structure-object)   ;                        sequence
 615    (complex float rational)             ; direct subclasses of number
 616    (integer ratio)                      ; direct subclasses of rational
 617    (list vector)                        ; direct subclasses of sequence
 618    (cons null)                          ; direct subclasses of list
 619    (string bit-vector)                  ; direct subclasses of vector
 620    ))
 621 \f
 622 (defmethod same-specializer-p ((specl1 specializer) (specl2 specializer))
 623   (eql specl1 specl2))
 624
 625 (defmethod same-specializer-p ((specl1 class) (specl2 class))
 626   (eq specl1 specl2))
 627
 628 (defmethod specializer-class ((specializer class))
 629   specializer)
 630
 631 (defmethod same-specializer-p ((specl1 class-eq-specializer)
 632                                (specl2 class-eq-specializer))
 633   (eq (specializer-class specl1) (specializer-class specl2)))
 634
 635 (defmethod same-specializer-p ((specl1 eql-specializer)
 636                                (specl2 eql-specializer))
 637   (eq (specializer-object specl1) (specializer-object specl2)))
 638
 639 (defmethod specializer-class ((specializer eql-specializer))
 640   (class-of (slot-value specializer 'object)))
 641
 642 (defun specializer-class-or-nil (specializer)
 643   (and (standard-specializer-p specializer)
 644        (specializer-class specializer)))
 645
 646 (defun error-need-at-least-n-args (function n)
 647   (error 'simple-program-error
 648          :format-control "~@<The function ~2I~_~S ~I~_requires ~
 649                           at least ~W argument~:P.~:>"
 650          :format-arguments (list function n)))
 651
 652 (defun types-from-args (generic-function arguments &optional type-modifier)
 653   (multiple-value-bind (nreq applyp metatypes nkeys arg-info)
 654       (get-generic-fun-info generic-function)
 655     (declare (ignore applyp metatypes nkeys))
 656     (let ((types-rev nil))
 657       (dotimes-fixnum (i nreq)
 658         i
 659         (unless arguments
 660           (error-need-at-least-n-args (generic-function-name generic-function)
 661                                       nreq))
 662         (let ((arg (pop arguments)))
 663           (push (if type-modifier `(,type-modifier ,arg) arg) types-rev)))
 664       (values (nreverse types-rev) arg-info))))
 665
 666 (defun get-wrappers-from-classes (nkeys wrappers classes metatypes)
 667   (let* ((w wrappers) (w-tail w) (mt-tail metatypes))
 668     (dolist (class (if (listp classes) classes (list classes)))
 669       (unless (eq t (car mt-tail))
 670         (let ((c-w (class-wrapper class)))
 671           (unless c-w (return-from get-wrappers-from-classes nil))
 672           (if (eql nkeys 1)
 673               (setq w c-w)
 674               (setf (car w-tail) c-w
 675                     w-tail (cdr w-tail)))))
 676       (setq mt-tail (cdr mt-tail)))
 677     w))
 678
 679 (defun sdfun-for-caching (gf classes)
 680   (let ((types (mapcar #'class-eq-type classes)))
 681     (multiple-value-bind (methods all-applicable-and-sorted-p)
 682         (compute-applicable-methods-using-types gf types)
 683       (let ((generator (get-secondary-dispatch-function1
 684                         gf methods types nil t all-applicable-and-sorted-p)))
 685         (make-callable gf methods generator
 686                        nil (mapcar #'class-wrapper classes))))))
 687
 688 (defun value-for-caching (gf classes)
 689   (let ((methods (compute-applicable-methods-using-types
 690                    gf (mapcar #'class-eq-type classes))))
 691     (method-plist-value (car methods) :constant-value)))
 692
 693 (defun default-secondary-dispatch-function (generic-function)
 694   (lambda (&rest args)
 695     (let ((methods (compute-applicable-methods generic-function args)))
 696       (if methods
 697           (let ((emf (get-effective-method-function generic-function
 698                                                     methods)))
 699             (invoke-emf emf args))
 700           (apply #'no-applicable-method generic-function args)))))
 701
 702 (defun list-eq (x y)
 703   (loop (when (atom x) (return (eq x y)))
 704         (when (atom y) (return nil))
 705         (unless (eq (car x) (car y)) (return nil))
 706         (setq x (cdr x)
 707               y (cdr y))))
 708
 709 (defvar *std-cam-methods* nil)
 710
 711 (defun compute-applicable-methods-emf (generic-function)
 712   (if (eq *boot-state* 'complete)
 713       (let* ((cam (gdefinition 'compute-applicable-methods))
 714              (cam-methods (compute-applicable-methods-using-types
 715                            cam (list `(eql ,generic-function) t))))
 716         (values (get-effective-method-function cam cam-methods)
 717                 (list-eq cam-methods
 718                          (or *std-cam-methods*
 719                              (setq *std-cam-methods*
 720                                    (compute-applicable-methods-using-types
 721                                     cam (list `(eql ,cam) t)))))))
 722       (values #'compute-applicable-methods-function t)))
 723
 724 (defun compute-applicable-methods-emf-std-p (gf)
 725   (gf-info-c-a-m-emf-std-p (gf-arg-info gf)))
 726
 727 (defvar *old-c-a-m-gf-methods* nil)
 728
 729 (defun update-all-c-a-m-gf-info (c-a-m-gf)
 730   (let ((methods (generic-function-methods c-a-m-gf)))
 731     (if (and *old-c-a-m-gf-methods*
 732              (every (lambda (old-method)
 733                       (member old-method methods))
 734                     *old-c-a-m-gf-methods*))
 735         (let ((gfs-to-do nil)
 736               (gf-classes-to-do nil))
 737           (dolist (method methods)
 738             (unless (member method *old-c-a-m-gf-methods*)
 739               (let ((specl (car (method-specializers method))))
 740                 (if (eql-specializer-p specl)
 741                     (pushnew (specializer-object specl) gfs-to-do)
 742                     (pushnew (specializer-class specl) gf-classes-to-do)))))
 743           (map-all-generic-functions
 744            (lambda (gf)
 745              (when (or (member gf gfs-to-do)
 746                        (dolist (class gf-classes-to-do nil)
 747                          (member class
 748                                  (class-precedence-list (class-of gf)))))
 749                (update-c-a-m-gf-info gf)))))
 750         (map-all-generic-functions #'update-c-a-m-gf-info))
 751     (setq *old-c-a-m-gf-methods* methods)))
 752
 753 (defun update-gf-info (gf)
 754   (update-c-a-m-gf-info gf)
 755   (update-gf-simple-accessor-type gf))
 756
 757 (defun update-c-a-m-gf-info (gf)
 758   (unless (early-gf-p gf)
 759     (multiple-value-bind (c-a-m-emf std-p)
 760         (compute-applicable-methods-emf gf)
 761       (let ((arg-info (gf-arg-info gf)))
 762         (setf (gf-info-static-c-a-m-emf arg-info) c-a-m-emf)
 763         (setf (gf-info-c-a-m-emf-std-p arg-info) std-p)))))
 764
 765 (defun update-gf-simple-accessor-type (gf)
 766   (let ((arg-info (gf-arg-info gf)))
 767     (setf (gf-info-simple-accessor-type arg-info)
 768           (let* ((methods (generic-function-methods gf))
 769                  (class (and methods (class-of (car methods))))
 770                  (type
 771                   (and class
 772                        (cond ((or (eq class *the-class-standard-reader-method*)
 773                                   (eq class *the-class-global-reader-method*))
 774                               'reader)
 775                              ((or (eq class *the-class-standard-writer-method*)
 776                                   (eq class *the-class-global-writer-method*))
 777                               'writer)
 778                              ((or (eq class *the-class-standard-boundp-method*)
 779                                   (eq class *the-class-global-boundp-method*))
 780                               'boundp)))))
 781             (when (and (gf-info-c-a-m-emf-std-p arg-info)
 782                        type
 783                        (dolist (method (cdr methods) t)
 784                          (unless (eq class (class-of method)) (return nil)))
 785                        (eq (generic-function-method-combination gf)
 786                            *standard-method-combination*))
 787               type)))))
 788
 789
 790 ;;; CMUCL (Gerd's PCL, 2002-04-25) comment:
 791 ;;;
 792 ;;; Return two values.  First value is a function to be stored in
 793 ;;; effective slot definition SLOTD for reading it with
 794 ;;; SLOT-VALUE-USING-CLASS, setting it with (SETF
 795 ;;; SLOT-VALUE-USING-CLASS) or testing it with
 796 ;;; SLOT-BOUNDP-USING-CLASS.  GF is one of these generic functions,
 797 ;;; TYPE is one of the symbols READER, WRITER, BOUNDP.  CLASS is
 798 ;;; SLOTD's class.
 799 ;;;
 800 ;;; Second value is true if the function returned is one of the
 801 ;;; optimized standard functions for the purpose, which are used
 802 ;;; when only standard methods are applicable.
 803 ;;;
 804 ;;; FIXME: Change all these wacky function names to something sane.
 805 (defun get-accessor-method-function (gf type class slotd)
 806   (let* ((std-method (standard-svuc-method type))
 807          (str-method (structure-svuc-method type))
 808          (types1 `((eql ,class) (class-eq ,class) (eql ,slotd)))
 809          (types (if (eq type 'writer) `(t ,@types1) types1))
 810          (methods (compute-applicable-methods-using-types gf types))
 811          (std-p (null (cdr methods))))
 812     (values
 813      (if std-p
 814          (get-optimized-std-accessor-method-function class slotd type)
 815          (let* ((optimized-std-fun
 816                  (get-optimized-std-slot-value-using-class-method-function
 817                   class slotd type))
 818                 (method-alist
 819                  `((,(car (or (member std-method methods)
 820                               (member str-method methods)
 821                               (bug "error in ~S"
 822                                    'get-accessor-method-function)))
 823                     ,optimized-std-fun)))
 824                 (wrappers
 825                  (let ((wrappers (list (wrapper-of class)
 826                                        (class-wrapper class)
 827                                        (wrapper-of slotd))))
 828                    (if (eq type 'writer)
 829                        (cons (class-wrapper *the-class-t*) wrappers)
 830                        wrappers)))
 831                 (sdfun (get-secondary-dispatch-function
 832                         gf methods types method-alist wrappers)))
 833            (get-accessor-from-svuc-method-function class slotd sdfun type)))
 834      std-p)))
 835
 836 ;;; used by OPTIMIZE-SLOT-VALUE-BY-CLASS-P (vector.lisp)
 837 (defun update-slot-value-gf-info (gf type)
 838   (unless *new-class*
 839     (update-std-or-str-methods gf type))
 840   (when (and (standard-svuc-method type) (structure-svuc-method type))
 841     (flet ((update-accessor-info (class)
 842              (when (class-finalized-p class)
 843                (dolist (slotd (class-slots class))
 844                  (compute-slot-accessor-info slotd type gf)))))
 845       (if *new-class*
 846           (update-accessor-info *new-class*)
 847           (map-all-classes #'update-accessor-info 'slot-object)))))
 848
 849 (defvar *standard-slot-value-using-class-method* nil)
 850 (defvar *standard-setf-slot-value-using-class-method* nil)
 851 (defvar *standard-slot-boundp-using-class-method* nil)
 852 (defvar *condition-slot-value-using-class-method* nil)
 853 (defvar *condition-setf-slot-value-using-class-method* nil)
 854 (defvar *condition-slot-boundp-using-class-method* nil)
 855 (defvar *structure-slot-value-using-class-method* nil)
 856 (defvar *structure-setf-slot-value-using-class-method* nil)
 857 (defvar *structure-slot-boundp-using-class-method* nil)
 858
 859 (defun standard-svuc-method (type)
 860   (case type
 861     (reader *standard-slot-value-using-class-method*)
 862     (writer *standard-setf-slot-value-using-class-method*)
 863     (boundp *standard-slot-boundp-using-class-method*)))
 864
 865 (defun set-standard-svuc-method (type method)
 866   (case type
 867     (reader (setq *standard-slot-value-using-class-method* method))
 868     (writer (setq *standard-setf-slot-value-using-class-method* method))
 869     (boundp (setq *standard-slot-boundp-using-class-method* method))))
 870
 871 (defun condition-svuc-method (type)
 872   (case type
 873     (reader *condition-slot-value-using-class-method*)
 874     (writer *condition-setf-slot-value-using-class-method*)
 875     (boundp *condition-slot-boundp-using-class-method*)))
 876
 877 (defun set-condition-svuc-method (type method)
 878   (case type
 879     (reader (setq *condition-slot-value-using-class-method* method))
 880     (writer (setq *condition-setf-slot-value-using-class-method* method))
 881     (boundp (setq *condition-slot-boundp-using-class-method* method))))
 882
 883 (defun structure-svuc-method (type)
 884   (case type
 885     (reader *structure-slot-value-using-class-method*)
 886     (writer *structure-setf-slot-value-using-class-method*)
 887     (boundp *structure-slot-boundp-using-class-method*)))
 888
 889 (defun set-structure-svuc-method (type method)
 890   (case type
 891     (reader (setq *structure-slot-value-using-class-method* method))
 892     (writer (setq *structure-setf-slot-value-using-class-method* method))
 893     (boundp (setq *structure-slot-boundp-using-class-method* method))))
 894
 895 (defun update-std-or-str-methods (gf type)
 896   (dolist (method (generic-function-methods gf))
 897     (let ((specls (method-specializers method)))
 898       (when (and (or (not (eq type 'writer))
 899                      (eq (pop specls) *the-class-t*))
 900                  (every #'classp specls))
 901         (cond ((and (eq (class-name (car specls)) 'std-class)
 902                     (eq (class-name (cadr specls)) 'standard-object)
 903                     (eq (class-name (caddr specls))
 904                         'standard-effective-slot-definition))
 905                (set-standard-svuc-method type method))
 906               ((and (eq (class-name (car specls)) 'condition-class)
 907                     (eq (class-name (cadr specls)) 'condition)
 908                     (eq (class-name (caddr specls))
 909                         'condition-effective-slot-definition))
 910                (set-condition-svuc-method type method))
 911               ((and (eq (class-name (car specls)) 'structure-class)
 912                     (eq (class-name (cadr specls)) 'structure-object)
 913                     (eq (class-name (caddr specls))
 914                         'structure-effective-slot-definition))
 915                (set-structure-svuc-method type method)))))))
 916
 917 (defun mec-all-classes-internal (spec precompute-p)
 918   (let ((wrapper (class-wrapper (specializer-class spec))))
 919     (unless (or (not wrapper) (invalid-wrapper-p wrapper))
 920       (cons (specializer-class spec)
 921             (and (classp spec)
 922                  precompute-p
 923                  (not (or (eq spec *the-class-t*)
 924                           (eq spec *the-class-slot-object*)
 925                           (eq spec *the-class-standard-object*)
 926                           (eq spec *the-class-structure-object*)))
 927                  (let ((sc (class-direct-subclasses spec)))
 928                    (when sc
 929                      (mapcan (lambda (class)
 930                                (mec-all-classes-internal class precompute-p))
 931                              sc))))))))
 932
 933 (defun mec-all-classes (spec precompute-p)
 934   (let ((classes (mec-all-classes-internal spec precompute-p)))
 935     (if (null (cdr classes))
 936         classes
 937         (let* ((a-classes (cons nil classes))
 938                (tail classes))
 939           (loop (when (null (cdr tail))
 940                   (return (cdr a-classes)))
 941                 (let ((class (cadr tail))
 942                       (ttail (cddr tail)))
 943                   (if (dolist (c ttail nil)
 944                         (when (eq class c) (return t)))
 945                       (setf (cdr tail) (cddr tail))
 946                       (setf tail (cdr tail)))))))))
 947
 948 (defun mec-all-class-lists (spec-list precompute-p)
 949   (if (null spec-list)
 950       (list nil)
 951       (let* ((car-all-classes (mec-all-classes (car spec-list)
 952                                                precompute-p))
 953              (all-class-lists (mec-all-class-lists (cdr spec-list)
 954                                                    precompute-p)))
 955         (mapcan (lambda (list)
 956                   (mapcar (lambda (c) (cons c list)) car-all-classes))
 957                 all-class-lists))))
 958
 959 (defun make-emf-cache (generic-function valuep cache classes-list new-class)
 960   (let* ((arg-info (gf-arg-info generic-function))
 961          (nkeys (arg-info-nkeys arg-info))
 962          (metatypes (arg-info-metatypes arg-info))
 963          (wrappers (unless (eq nkeys 1) (make-list nkeys)))
 964          (precompute-p (gf-precompute-dfun-and-emf-p arg-info)))
 965     (flet ((add-class-list (classes)
 966              (when (or (null new-class) (memq new-class classes))
 967                (let ((%wrappers (get-wrappers-from-classes
 968                                  nkeys wrappers classes metatypes)))
 969                  (when (and %wrappers (not (probe-cache cache %wrappers)))
 970                    (let ((value (cond ((eq valuep t)
 971                                        (sdfun-for-caching generic-function
 972                                                           classes))
 973                                       ((eq valuep :constant-value)
 974                                        (value-for-caching generic-function
 975                                                           classes)))))
 976                      ;; need to get them again, as finalization might
 977                      ;; have happened in between, which would
 978                      ;; invalidate wrappers.
 979                      (let ((wrappers (get-wrappers-from-classes
 980                                       nkeys wrappers classes metatypes)))
 981                        (when (if (atom wrappers)
 982                                  (not (invalid-wrapper-p wrappers))
 983                                  (every (complement #'invalid-wrapper-p)
 984                                         wrappers))
 985                          (setq cache (fill-cache cache wrappers value))))))))))
 986       (if classes-list
 987           (mapc #'add-class-list classes-list)
 988           (dolist (method (generic-function-methods generic-function))
 989             (mapc #'add-class-list
 990                   (mec-all-class-lists (method-specializers method)
 991                                        precompute-p))))
 992       cache)))
 993
 994 (defmacro class-test (arg class)
 995   (cond
 996     ((eq class *the-class-t*) t)
 997     ((eq class *the-class-slot-object*)
 998      `(not (typep (classoid-of ,arg) 'built-in-classoid)))
 999     ((eq class *the-class-standard-object*)
1000      `(or (std-instance-p ,arg) (fsc-instance-p ,arg)))
1001     ((eq class *the-class-funcallable-standard-object*)
1002      `(fsc-instance-p ,arg))
1003     (t
1004      `(typep ,arg ',(class-name class)))))
1005
1006 (defmacro class-eq-test (arg class)
1007   `(eq (class-of ,arg) ',class))
1008
1009 (defmacro eql-test (arg object)
1010   `(eql ,arg ',object))
1011
1012 (defun dnet-methods-p (form)
1013   (and (consp form)
1014        (or (eq (car form) 'methods)
1015            (eq (car form) 'unordered-methods))))
1016
1017 ;;; This is CASE, but without gensyms.
1018 (defmacro scase (arg &rest clauses)
1019   `(let ((.case-arg. ,arg))
1020      (cond ,@(mapcar (lambda (clause)
1021                        (list* (cond ((null (car clause))
1022                                      nil)
1023                                     ((consp (car clause))
1024                                      (if (null (cdar clause))
1025                                          `(eql .case-arg.
1026                                                ',(caar clause))
1027                                          `(member .case-arg.
1028                                                   ',(car clause))))
1029                                     ((member (car clause) '(t otherwise))
1030                                      `t)
1031                                     (t
1032                                      `(eql .case-arg. ',(car clause))))
1033                               nil
1034                               (cdr clause)))
1035                      clauses))))
1036
1037 (defmacro mcase (arg &rest clauses) `(scase ,arg ,@clauses))
1038
1039 (defun generate-discrimination-net (generic-function methods types sorted-p)
1040   (let* ((arg-info (gf-arg-info generic-function))
1041          (c-a-m-emf-std-p (gf-info-c-a-m-emf-std-p arg-info))
1042          (precedence (arg-info-precedence arg-info)))
1043     (generate-discrimination-net-internal
1044      generic-function methods types
1045      (lambda (methods known-types)
1046        (if (or sorted-p
1047                (and c-a-m-emf-std-p
1048                     (block one-order-p
1049                       (let ((sorted-methods nil))
1050                         (map-all-orders
1051                          (copy-list methods) precedence
1052                          (lambda (methods)
1053                            (when sorted-methods (return-from one-order-p nil))
1054                            (setq sorted-methods methods)))
1055                         (setq methods sorted-methods))
1056                       t)))
1057            `(methods ,methods ,known-types)
1058            `(unordered-methods ,methods ,known-types)))
1059      (lambda (position type true-value false-value)
1060        (let ((arg (dfun-arg-symbol position)))
1061          (if (eq (car type) 'eql)
1062              (let* ((false-case-p (and (consp false-value)
1063                                        (or (eq (car false-value) 'scase)
1064                                            (eq (car false-value) 'mcase))
1065                                        (eq arg (cadr false-value))))
1066                     (false-clauses (if false-case-p
1067                                        (cddr false-value)
1068                                        `((t ,false-value))))
1069                     (case-sym (if (and (dnet-methods-p true-value)
1070                                        (if false-case-p
1071                                            (eq (car false-value) 'mcase)
1072                                            (dnet-methods-p false-value)))
1073                                   'mcase
1074                                   'scase))
1075                     (type-sym `(,(cadr type))))
1076                `(,case-sym ,arg
1077                            (,type-sym ,true-value)
1078                            ,@false-clauses))
1079              `(if ,(let ((arg (dfun-arg-symbol position)))
1080                      (case (car type)
1081                        (class    `(class-test    ,arg ,(cadr type)))
1082                        (class-eq `(class-eq-test ,arg ,(cadr type)))))
1083                   ,true-value
1084                   ,false-value))))
1085      #'identity)))
1086
1087 (defun class-from-type (type)
1088   (if (or (atom type) (eq (car type) t))
1089       *the-class-t*
1090       (case (car type)
1091         (and (dolist (type (cdr type) *the-class-t*)
1092                (when (and (consp type) (not (eq (car type) 'not)))
1093                  (return (class-from-type type)))))
1094         (not *the-class-t*)
1095         (eql (class-of (cadr type)))
1096         (class-eq (cadr type))
1097         (class (cadr type)))))
1098
1099 (defun precompute-effective-methods (gf caching-p &optional classes-list-p)
1100   (let* ((arg-info (gf-arg-info gf))
1101          (methods (generic-function-methods gf))
1102          (precedence (arg-info-precedence arg-info))
1103          (*in-precompute-effective-methods-p* t)
1104          (classes-list nil))
1105     (generate-discrimination-net-internal
1106      gf methods nil
1107      (lambda (methods known-types)
1108        (when methods
1109          (when classes-list-p
1110            (push (mapcar #'class-from-type known-types) classes-list))
1111          (let ((no-eql-specls-p (not (methods-contain-eql-specializer-p
1112                                       methods))))
1113            (map-all-orders
1114             methods precedence
1115             (lambda (methods)
1116               (get-secondary-dispatch-function1
1117                gf methods known-types
1118                nil caching-p no-eql-specls-p))))))
1119      (lambda (position type true-value false-value)
1120        (declare (ignore position type true-value false-value))
1121        nil)
1122      (lambda (type)
1123        (if (and (consp type) (eq (car type) 'eql))
1124            `(class-eq ,(class-of (cadr type)))
1125            type)))
1126     classes-list))
1127
1128 ;;; We know that known-type implies neither new-type nor `(not ,new-type).
1129 (defun augment-type (new-type known-type)
1130   (if (or (eq known-type t)
1131           (eq (car new-type) 'eql))
1132       new-type
1133       (let ((so-far (if (and (consp known-type) (eq (car known-type) 'and))
1134                         (cdr known-type)
1135                         (list known-type))))
1136         (unless (eq (car new-type) 'not)
1137           (setq so-far
1138                 (mapcan (lambda (type)
1139                           (unless (*subtypep new-type type)
1140                             (list type)))
1141                         so-far)))
1142         (if (null so-far)
1143             new-type
1144             `(and ,new-type ,@so-far)))))
1145
1146 (defun generate-discrimination-net-internal
1147     (gf methods types methods-function test-fun type-function)
1148   (let* ((arg-info (gf-arg-info gf))
1149          (precedence (arg-info-precedence arg-info))
1150          (nreq (arg-info-number-required arg-info))
1151          (metatypes (arg-info-metatypes arg-info)))
1152     (labels ((do-column (p-tail contenders known-types)
1153                (if p-tail
1154                    (let* ((position (car p-tail))
1155                           (known-type (or (nth position types) t)))
1156                      (if (eq (nth position metatypes) t)
1157                          (do-column (cdr p-tail) contenders
1158                                     (cons (cons position known-type)
1159                                           known-types))
1160                          (do-methods p-tail contenders
1161                                      known-type () known-types)))
1162                    (funcall methods-function contenders
1163                             (let ((k-t (make-list nreq)))
1164                               (dolist (index+type known-types)
1165                                 (setf (nth (car index+type) k-t)
1166                                       (cdr index+type)))
1167                               k-t))))
1168              (do-methods (p-tail contenders known-type winners known-types)
1169                ;; CONTENDERS
1170                ;;   is a (sorted) list of methods that must be discriminated.
1171                ;; KNOWN-TYPE
1172                ;;   is the type of this argument, constructed from tests
1173                ;;   already made.
1174                ;; WINNERS
1175                ;;   is a (sorted) list of methods that are potentially
1176                ;;   applicable after the discrimination has been made.
1177                (if (null contenders)
1178                    (do-column (cdr p-tail)
1179                               winners
1180                               (cons (cons (car p-tail) known-type)
1181                                     known-types))
1182                    (let* ((position (car p-tail))
1183                           (method (car contenders))
1184                           (specl (nth position (method-specializers method)))
1185                           (type (funcall type-function
1186                                          (type-from-specializer specl))))
1187                      (multiple-value-bind (app-p maybe-app-p)
1188                          (specializer-applicable-using-type-p type known-type)
1189                        (flet ((determined-to-be (truth-value)
1190                                 (if truth-value app-p (not maybe-app-p)))
1191                               (do-if (truth &optional implied)
1192                                 (let ((ntype (if truth type `(not ,type))))
1193                                   (do-methods p-tail
1194                                     (cdr contenders)
1195                                     (if implied
1196                                         known-type
1197                                         (augment-type ntype known-type))
1198                                     (if truth
1199                                         (append winners `(,method))
1200                                         winners)
1201                                     known-types))))
1202                          (cond ((determined-to-be nil) (do-if nil t))
1203                                ((determined-to-be t)   (do-if t   t))
1204                                (t (funcall test-fun position type
1205                                            (do-if t) (do-if nil))))))))))
1206       (do-column precedence methods ()))))
1207
1208 (defun compute-secondary-dispatch-function (generic-function net &optional
1209                                             method-alist wrappers)
1210   (function-funcall (compute-secondary-dispatch-function1 generic-function net)
1211                     method-alist wrappers))
1212
1213 (defvar *eq-case-table-limit* 15)
1214 (defvar *case-table-limit* 10)
1215
1216 (defun compute-mcase-parameters (case-list)
1217   (unless (eq t (caar (last case-list)))
1218     (error "The key for the last case arg to mcase was not T"))
1219   (let* ((eq-p (dolist (case case-list t)
1220                  (unless (or (eq (car case) t)
1221                              (symbolp (caar case)))
1222                    (return nil))))
1223          (len (1- (length case-list)))
1224          (type (cond ((= len 1)
1225                       :simple)
1226                      ((<= len
1227                           (if eq-p
1228                               *eq-case-table-limit*
1229                               *case-table-limit*))
1230                       :assoc)
1231                      (t
1232                       :hash-table))))
1233     (list eq-p type)))
1234
1235 (defmacro mlookup (key info default &optional eq-p type)
1236   (unless (or (eq eq-p t) (null eq-p))
1237     (bug "Invalid eq-p argument: ~S" eq-p))
1238   (ecase type
1239     (:simple
1240      `(if (locally
1241             (declare (optimize (inhibit-warnings 3)))
1242             (,(if eq-p 'eq 'eql) ,key (car ,info)))
1243           (cdr ,info)
1244           ,default))
1245     (:assoc
1246      `(dolist (e ,info ,default)
1247         (when (locally
1248                 (declare (optimize (inhibit-warnings 3)))
1249                 (,(if eq-p 'eq 'eql) (car e) ,key))
1250           (return (cdr e)))))
1251     (:hash-table
1252      `(gethash ,key ,info ,default))))
1253
1254 (defun net-test-converter (form)
1255   (if (atom form)
1256       (default-test-converter form)
1257       (case (car form)
1258         ((invoke-effective-method-function invoke-fast-method-call
1259           invoke-effective-narrow-method-function)
1260          '.call.)
1261         (methods
1262          '.methods.)
1263         (unordered-methods
1264          '.umethods.)
1265         (mcase
1266          `(mlookup ,(cadr form)
1267                    nil
1268                    nil
1269                    ,@(compute-mcase-parameters (cddr form))))
1270         (t (default-test-converter form)))))
1271
1272 (defun net-code-converter (form)
1273   (if (atom form)
1274       (default-code-converter form)
1275       (case (car form)
1276         ((methods unordered-methods)
1277          (let ((gensym (gensym)))
1278            (values gensym
1279                    (list gensym))))
1280         (mcase
1281          (let ((mp (compute-mcase-parameters (cddr form)))
1282                (gensym (gensym)) (default (gensym)))
1283            (values `(mlookup ,(cadr form) ,gensym ,default ,@mp)
1284                    (list gensym default))))
1285         (t
1286          (default-code-converter form)))))
1287
1288 (defun net-constant-converter (form generic-function)
1289   (or (let ((c (methods-converter form generic-function)))
1290         (when c (list c)))
1291       (if (atom form)
1292           (default-constant-converter form)
1293           (case (car form)
1294             (mcase
1295              (let* ((mp (compute-mcase-parameters (cddr form)))
1296                     (list (mapcar (lambda (clause)
1297                                     (let ((key (car clause))
1298                                           (meth (cadr clause)))
1299                                       (cons (if (consp key) (car key) key)
1300                                             (methods-converter
1301                                              meth generic-function))))
1302                                   (cddr form)))
1303                     (default (car (last list))))
1304                (list (list* :mcase mp (nbutlast list))
1305                      (cdr default))))
1306             (t
1307              (default-constant-converter form))))))
1308
1309 (defun methods-converter (form generic-function)
1310   (cond ((and (consp form) (eq (car form) 'methods))
1311          (cons '.methods.
1312                (get-effective-method-function1 generic-function (cadr form))))
1313         ((and (consp form) (eq (car form) 'unordered-methods))
1314          (default-secondary-dispatch-function generic-function))))
1315
1316 (defun convert-methods (constant method-alist wrappers)
1317   (if (and (consp constant)
1318            (eq (car constant) '.methods.))
1319       (funcall (cdr constant) method-alist wrappers)
1320       constant))
1321
1322 (defun convert-table (constant method-alist wrappers)
1323   (cond ((and (consp constant)
1324               (eq (car constant) :mcase))
1325          (let ((alist (mapcar (lambda (k+m)
1326                                 (cons (car k+m)
1327                                       (convert-methods (cdr k+m)
1328                                                        method-alist
1329                                                        wrappers)))
1330                               (cddr constant)))
1331                (mp (cadr constant)))
1332            (ecase (cadr mp)
1333              (:simple
1334               (car alist))
1335              (:assoc
1336               alist)
1337              (:hash-table
1338               (let ((table (make-hash-table :test (if (car mp) 'eq 'eql))))
1339                 (dolist (k+m alist)
1340                   (setf (gethash (car k+m) table) (cdr k+m)))
1341                 table)))))))
1342
1343 (defun compute-secondary-dispatch-function1 (generic-function net
1344                                              &optional function-p)
1345   (cond
1346    ((and (eq (car net) 'methods) (not function-p))
1347     (get-effective-method-function1 generic-function (cadr net)))
1348    (t
1349     (let* ((name (generic-function-name generic-function))
1350            (arg-info (gf-arg-info generic-function))
1351            (metatypes (arg-info-metatypes arg-info))
1352            (nargs (length metatypes))
1353            (applyp (arg-info-applyp arg-info))
1354            (fmc-arg-info (cons nargs applyp))
1355            (arglist (if function-p
1356                         (make-dfun-lambda-list nargs applyp)
1357                         (make-fast-method-call-lambda-list nargs applyp))))
1358       (multiple-value-bind (cfunction constants)
1359           (get-fun1 `(lambda
1360                       ,arglist
1361                       ,@(unless function-p
1362                           `((declare (ignore .pv. .next-method-call.))))
1363                       (locally (declare #.*optimize-speed*)
1364                                (let ((emf ,net))
1365                                  ,(make-emf-call nargs applyp 'emf))))
1366                     #'net-test-converter
1367                     #'net-code-converter
1368                     (lambda (form)
1369                       (net-constant-converter form generic-function)))
1370         (lambda (method-alist wrappers)
1371           (let* ((alist (list nil))
1372                  (alist-tail alist))
1373             (dolist (constant constants)
1374               (let* ((a (or (dolist (a alist nil)
1375                               (when (eq (car a) constant)
1376                                 (return a)))
1377                             (cons constant
1378                                   (or (convert-table
1379                                        constant method-alist wrappers)
1380                                       (convert-methods
1381                                        constant method-alist wrappers)))))
1382                      (new (list a)))
1383                 (setf (cdr alist-tail) new)
1384                 (setf alist-tail new)))
1385             (let ((function (apply cfunction (mapcar #'cdr (cdr alist)))))
1386               (if function-p
1387                   function
1388                   (make-fast-method-call
1389                    :function (set-fun-name function `(sdfun-method ,name))
1390                    :arg-info fmc-arg-info))))))))))
1391
1392 (defvar *show-make-unordered-methods-emf-calls* nil)
1393
1394 (defun make-unordered-methods-emf (generic-function methods)
1395   (when *show-make-unordered-methods-emf-calls*
1396     (format t "~&make-unordered-methods-emf ~S~%"
1397             (generic-function-name generic-function)))
1398   (lambda (&rest args)
1399     (let* ((types (types-from-args generic-function args 'eql))
1400            (smethods (sort-applicable-methods generic-function
1401                                               methods
1402                                               types))
1403            (emf (get-effective-method-function generic-function smethods)))
1404       (invoke-emf emf args))))
1405 \f
1406 ;;; The value returned by compute-discriminating-function is a function
1407 ;;; object. It is called a discriminating function because it is called
1408 ;;; when the generic function is called and its role is to discriminate
1409 ;;; on the arguments to the generic function and then call appropriate
1410 ;;; method functions.
1411 ;;;
1412 ;;; A discriminating function can only be called when it is installed as
1413 ;;; the funcallable instance function of the generic function for which
1414 ;;; it was computed.
1415 ;;;
1416 ;;; More precisely, if compute-discriminating-function is called with
1417 ;;; an argument <gf1>, and returns a result <df1>, that result must
1418 ;;; not be passed to apply or funcall directly. Rather, <df1> must be
1419 ;;; stored as the funcallable instance function of the same generic
1420 ;;; function <gf1> (using SET-FUNCALLABLE-INSTANCE-FUNCTION). Then the
1421 ;;; generic function can be passed to funcall or apply.
1422 ;;;
1423 ;;; An important exception is that methods on this generic function are
1424 ;;; permitted to return a function which itself ends up calling the value
1425 ;;; returned by a more specific method. This kind of `encapsulation' of
1426 ;;; discriminating function is critical to many uses of the MOP.
1427 ;;;
1428 ;;; As an example, the following canonical case is legal:
1429 ;;;
1430 ;;;   (defmethod compute-discriminating-function ((gf my-generic-function))
1431 ;;;     (let ((std (call-next-method)))
1432 ;;;       (lambda (arg)
1433 ;;;         (print (list 'call-to-gf gf arg))
1434 ;;;         (funcall std arg))))
1435 ;;;
1436 ;;; Because many discriminating functions would like to use a dynamic
1437 ;;; strategy in which the precise discriminating function changes with
1438 ;;; time it is important to specify how a discriminating function is
1439 ;;; permitted itself to change the funcallable instance function of the
1440 ;;; generic function.
1441 ;;;
1442 ;;; Discriminating functions may set the funcallable instance function
1443 ;;; of the generic function, but the new value must be generated by making
1444 ;;; a call to COMPUTE-DISCRIMINATING-FUNCTION. This is to ensure that any
1445 ;;; more specific methods which may have encapsulated the discriminating
1446 ;;; function will get a chance to encapsulate the new, inner discriminating
1447 ;;; function.
1448 ;;;
1449 ;;; This implies that if a discriminating function wants to modify itself
1450 ;;; it should first store some information in the generic function proper,
1451 ;;; and then call compute-discriminating-function. The appropriate method
1452 ;;; on compute-discriminating-function will see the information stored in
1453 ;;; the generic function and generate a discriminating function accordingly.
1454 ;;;
1455 ;;; The following is an example of a discriminating function which modifies
1456 ;;; itself in accordance with this protocol:
1457 ;;;
1458 ;;;   (defmethod compute-discriminating-function ((gf my-generic-function))
1459 ;;;     (lambda (arg)
1460 ;;;      (cond (<some condition>
1461 ;;;             <store some info in the generic function>
1462 ;;;             (set-funcallable-instance-function
1463 ;;;               gf
1464 ;;;               (compute-discriminating-function gf))
1465 ;;;             (funcall gf arg))
1466 ;;;            (t
1467 ;;;             <call-a-method-of-gf>))))
1468 ;;;
1469 ;;; Whereas this code would not be legal:
1470 ;;;
1471 ;;;   (defmethod compute-discriminating-function ((gf my-generic-function))
1472 ;;;     (lambda (arg)
1473 ;;;      (cond (<some condition>
1474 ;;;             (set-funcallable-instance-function
1475 ;;;               gf
1476 ;;;               (lambda (a) ..))
1477 ;;;             (funcall gf arg))
1478 ;;;            (t
1479 ;;;             <call-a-method-of-gf>))))
1480 ;;;
1481 ;;; NOTE:  All the examples above assume that all instances of the class
1482 ;;;     my-generic-function accept only one argument.
1483
1484 (defun slot-value-using-class-dfun (class object slotd)
1485   (declare (ignore class))
1486   (function-funcall (slot-definition-reader-function slotd) object))
1487
1488 (defun setf-slot-value-using-class-dfun (new-value class object slotd)
1489   (declare (ignore class))
1490   (function-funcall (slot-definition-writer-function slotd) new-value object))
1491
1492 (defun slot-boundp-using-class-dfun (class object slotd)
1493   (declare (ignore class))
1494   (function-funcall (slot-definition-boundp-function slotd) object))
1495
1496 (defun special-case-for-compute-discriminating-function-p (gf)
1497   (or (eq gf #'slot-value-using-class)
1498       (eq gf #'(setf slot-value-using-class))
1499       (eq gf #'slot-boundp-using-class)))
1500
1501 (defmethod compute-discriminating-function ((gf standard-generic-function))
1502   (let ((dfun-state (slot-value gf 'dfun-state)))
1503     (when (special-case-for-compute-discriminating-function-p gf)
1504       ;; if we have a special case for
1505       ;; COMPUTE-DISCRIMINATING-FUNCTION, then (at least for the
1506       ;; special cases implemented as of 2006-05-09) any information
1507       ;; in the cache is misplaced.
1508       (aver (null dfun-state)))
1509     (typecase dfun-state
1510       (null
1511        (when (eq gf #'compute-applicable-methods)
1512          (update-all-c-a-m-gf-info gf))
1513        (cond
1514          ((eq gf #'slot-value-using-class)
1515           (update-slot-value-gf-info gf 'reader)
1516           #'slot-value-using-class-dfun)
1517          ((eq gf #'(setf slot-value-using-class))
1518           (update-slot-value-gf-info gf 'writer)
1519           #'setf-slot-value-using-class-dfun)
1520          ((eq gf #'slot-boundp-using-class)
1521           (update-slot-value-gf-info gf 'boundp)
1522           #'slot-boundp-using-class-dfun)
1523          ((gf-precompute-dfun-and-emf-p (slot-value gf 'arg-info))
1524           (make-final-dfun gf))
1525          (t
1526           (make-initial-dfun gf))))
1527       (function dfun-state)
1528       (cons (car dfun-state)))))
1529
1530 (defmethod update-gf-dfun ((class std-class) gf)
1531   (let ((*new-class* class)
1532         (arg-info (gf-arg-info gf)))
1533     (cond
1534       ((special-case-for-compute-discriminating-function-p gf))
1535       ((gf-precompute-dfun-and-emf-p arg-info)
1536        (multiple-value-bind (dfun cache info)
1537            (make-final-dfun-internal gf)
1538          (update-dfun gf dfun cache info))))))
1539 \f
1540 (defmethod (setf class-name) (new-value class)
1541   (let ((classoid (wrapper-classoid (class-wrapper class))))
1542     (if (and new-value (symbolp new-value))
1543         (setf (classoid-name classoid) new-value)
1544         (setf (classoid-name classoid) nil)))
1545   (reinitialize-instance class :name new-value)
1546   new-value)
1547
1548 (defmethod (setf generic-function-name) (new-value generic-function)
1549   (reinitialize-instance generic-function :name new-value)
1550   new-value)
1551 \f
1552 (defmethod function-keyword-parameters ((method standard-method))
1553   (multiple-value-bind (nreq nopt keysp restp allow-other-keys-p
1554                         keywords keyword-parameters)
1555       (analyze-lambda-list (if (consp method)
1556                                (early-method-lambda-list method)
1557                                (method-lambda-list method)))
1558     (declare (ignore nreq nopt keysp restp keywords))
1559     (values keyword-parameters allow-other-keys-p)))
1560
1561 (defun method-ll->generic-function-ll (ll)
1562   (multiple-value-bind
1563       (nreq nopt keysp restp allow-other-keys-p keywords keyword-parameters)
1564       (analyze-lambda-list ll)
1565     (declare (ignore nreq nopt keysp restp allow-other-keys-p keywords))
1566     (remove-if (lambda (s)
1567                  (or (memq s keyword-parameters)
1568                      (eq s '&allow-other-keys)))
1569                ll)))
1570 \f
1571 ;;; This is based on the rules of method lambda list congruency
1572 ;;; defined in the spec. The lambda list it constructs is the pretty
1573 ;;; union of the lambda lists of the generic function and of all its
1574 ;;; methods.  It doesn't take method applicability into account at all
1575 ;;; yet.
1576
1577 ;;; (Notice that we ignore &AUX variables as they're not part of the
1578 ;;; "public interface" of a function.)
1579
1580 (defmethod generic-function-pretty-arglist
1581            ((generic-function standard-generic-function))
1582   (let ((gf-lambda-list (generic-function-lambda-list generic-function))
1583         (methods (generic-function-methods generic-function)))
1584     (if (null methods)
1585         gf-lambda-list
1586         (multiple-value-bind (gf.required gf.optional gf.rest gf.keys gf.allowp)
1587             (%split-arglist gf-lambda-list)
1588           ;; Possibly extend the keyword parameters of the gf by
1589           ;; additional key parameters of its methods:
1590           (let ((methods.keys nil) (methods.allowp nil))
1591             (dolist (m methods)
1592               (multiple-value-bind (m.keyparams m.allow-other-keys)
1593                   (function-keyword-parameters m)
1594                 (setq methods.keys (union methods.keys m.keyparams :key #'maybe-car))
1595                 (setq methods.allowp (or methods.allowp m.allow-other-keys))))
1596             (let ((arglist '()))
1597               (when (or gf.allowp methods.allowp)
1598                 (push '&allow-other-keys arglist))
1599               (when (or gf.keys methods.keys)
1600                 ;; We make sure that the keys of the gf appear before
1601                 ;; those of its methods, since they're probably more
1602                 ;; generally appliable.
1603                 (setq arglist (nconc (list '&key) gf.keys
1604                                      (nset-difference methods.keys gf.keys)
1605                                      arglist)))
1606               (when gf.rest
1607                 (setq arglist (nconc (list '&rest gf.rest) arglist)))
1608               (when gf.optional
1609                 (setq arglist (nconc (list '&optional) gf.optional arglist)))
1610               (nconc gf.required arglist)))))))
1611
1612 (defun maybe-car (thing)
1613   (if (listp thing)
1614       (car thing)
1615       thing))
1616
1617
1618 (defun %split-arglist (lambda-list)
1619   ;; This function serves to shrink the number of returned values of
1620   ;; PARSE-LAMBDA-LIST to something handier.
1621   (multiple-value-bind (required optional restp rest keyp keys allowp
1622                         auxp aux morep more-context more-count)
1623       (parse-lambda-list lambda-list)
1624     (declare (ignore restp keyp auxp aux morep))
1625     (declare (ignore more-context more-count))
1626     (values required optional rest keys allowp)))