| 1 | ;;;; goops.scm -- The Guile Object-Oriented Programming System |
| 2 | ;;;; |
| 3 | ;;;; Copyright (C) 1998-2003,2006,2009-2011,2013-2015 Free Software Foundation, Inc. |
| 4 | ;;;; Copyright (C) 1993-1998 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr> |
| 5 | ;;;; |
| 6 | ;;;; This library is free software; you can redistribute it and/or |
| 7 | ;;;; modify it under the terms of the GNU Lesser General Public |
| 8 | ;;;; License as published by the Free Software Foundation; either |
| 9 | ;;;; version 3 of the License, or (at your option) any later version. |
| 10 | ;;;; |
| 11 | ;;;; This library is distributed in the hope that it will be useful, |
| 12 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | ;;;; Lesser General Public License for more details. |
| 15 | ;;;; |
| 16 | ;;;; You should have received a copy of the GNU Lesser General Public |
| 17 | ;;;; License along with this library; if not, write to the Free Software |
| 18 | ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | ;;;; |
| 20 | \f |
| 21 | |
| 22 | ;;;; |
| 23 | ;;;; This file was based upon stklos.stk from the STk distribution |
| 24 | ;;;; version 4.0.1 by Erick Gallesio <eg@unice.fr>. |
| 25 | ;;;; |
| 26 | |
| 27 | (define-module (oop goops) |
| 28 | #:use-module (srfi srfi-1) |
| 29 | #:use-module (ice-9 match) |
| 30 | #:use-module ((language tree-il primitives) |
| 31 | :select (add-interesting-primitive!)) |
| 32 | #:export-syntax (define-class class standard-define-class |
| 33 | define-generic define-accessor define-method |
| 34 | define-extended-generic define-extended-generics |
| 35 | method) |
| 36 | #:export ( ;; The root of everything. |
| 37 | <top> |
| 38 | <class> <object> |
| 39 | |
| 40 | ;; Slot types. |
| 41 | <foreign-slot> <protected-slot> <hidden-slot> <opaque-slot> |
| 42 | <read-only-slot> <self-slot> <protected-opaque-slot> |
| 43 | <protected-hidden-slot> <protected-read-only-slot> |
| 44 | <scm-slot> <int-slot> <float-slot> <double-slot> |
| 45 | |
| 46 | ;; Methods are implementations of generic functions. |
| 47 | <method> <accessor-method> |
| 48 | |
| 49 | ;; Applicable objects, either procedures or applicable structs. |
| 50 | <procedure-class> <applicable> |
| 51 | <procedure> <primitive-generic> |
| 52 | |
| 53 | ;; Applicable structs. |
| 54 | <applicable-struct-class> <applicable-struct-with-setter-class> |
| 55 | <applicable-struct> <applicable-struct-with-setter> |
| 56 | <generic> <extended-generic> |
| 57 | <generic-with-setter> <extended-generic-with-setter> |
| 58 | <accessor> <extended-accessor> |
| 59 | |
| 60 | ;; Types with their own allocated typecodes. |
| 61 | <boolean> <char> <list> <pair> <null> <string> <symbol> |
| 62 | <vector> <bytevector> <uvec> <foreign> <hashtable> |
| 63 | <fluid> <dynamic-state> <frame> <vm> <vm-continuation> |
| 64 | <keyword> |
| 65 | |
| 66 | ;; Numbers. |
| 67 | <number> <complex> <real> <integer> <fraction> |
| 68 | |
| 69 | ;; Unknown. |
| 70 | <unknown> |
| 71 | |
| 72 | ;; Particular SMOB data types. All SMOB types have |
| 73 | ;; corresponding classes, which may be obtained via class-of, |
| 74 | ;; once you have an instance. Perhaps FIXME to provide a |
| 75 | ;; smob-type-name->class procedure. |
| 76 | <arbiter> <promise> <thread> <mutex> <condition-variable> |
| 77 | <regexp> <hook> <bitvector> <random-state> <async> |
| 78 | <directory> <array> <character-set> |
| 79 | <dynamic-object> <guardian> <macro> |
| 80 | |
| 81 | ;; Modules. |
| 82 | <module> |
| 83 | |
| 84 | ;; Ports. |
| 85 | <port> <input-port> <output-port> <input-output-port> |
| 86 | |
| 87 | ;; Like SMOB types, all port types have their own classes, |
| 88 | ;; which can be accessed via `class-of' once you have an |
| 89 | ;; instance. Here we export bindings just for file ports. |
| 90 | <file-port> |
| 91 | <file-input-port> <file-output-port> <file-input-output-port> |
| 92 | |
| 93 | is-a? class-of |
| 94 | ensure-metaclass ensure-metaclass-with-supers |
| 95 | make-class |
| 96 | make-generic ensure-generic |
| 97 | make-extended-generic |
| 98 | make-accessor ensure-accessor |
| 99 | add-method! |
| 100 | class-slot-ref class-slot-set! slot-unbound slot-missing |
| 101 | slot-definition-name slot-definition-options |
| 102 | slot-definition-allocation |
| 103 | |
| 104 | slot-definition-getter slot-definition-setter |
| 105 | slot-definition-accessor |
| 106 | slot-definition-init-value slot-definition-init-form |
| 107 | slot-definition-init-thunk slot-definition-init-keyword |
| 108 | slot-init-function class-slot-definition |
| 109 | method-source |
| 110 | compute-cpl compute-std-cpl compute-get-n-set compute-slots |
| 111 | compute-getter-method compute-setter-method |
| 112 | allocate-instance initialize make-instance make |
| 113 | no-next-method no-applicable-method no-method |
| 114 | change-class update-instance-for-different-class |
| 115 | shallow-clone deep-clone |
| 116 | class-redefinition |
| 117 | apply-generic apply-method apply-methods |
| 118 | compute-applicable-methods %compute-applicable-methods |
| 119 | method-more-specific? sort-applicable-methods |
| 120 | class-subclasses class-methods |
| 121 | goops-error |
| 122 | min-fixnum max-fixnum |
| 123 | |
| 124 | instance? |
| 125 | slot-ref slot-set! slot-bound? slot-exists? |
| 126 | class-name class-direct-supers class-direct-subclasses |
| 127 | class-direct-methods class-direct-slots class-precedence-list |
| 128 | class-slots |
| 129 | generic-function-name |
| 130 | generic-function-methods method-generic-function |
| 131 | method-specializers method-formals |
| 132 | primitive-generic-generic enable-primitive-generic! |
| 133 | method-procedure accessor-method-slot-definition |
| 134 | make find-method get-keyword)) |
| 135 | |
| 136 | |
| 137 | ;;; |
| 138 | ;;; Booting GOOPS is a tortuous process. We begin by loading a small |
| 139 | ;;; set of primitives from C. |
| 140 | ;;; |
| 141 | (eval-when (expand load eval) |
| 142 | (load-extension (string-append "libguile-" (effective-version)) |
| 143 | "scm_init_goops_builtins") |
| 144 | (add-interesting-primitive! 'class-of)) |
| 145 | |
| 146 | |
| 147 | \f |
| 148 | |
| 149 | ;;; |
| 150 | ;;; We then define the slots that must appear in all classes (<class> |
| 151 | ;;; objects) and slot definitions (<slot> objects). These slots must |
| 152 | ;;; appear in order. We'll use this list to statically compute offsets |
| 153 | ;;; for the various fields, to compute the struct layout for <class> |
| 154 | ;;; instances, and to compute the slot definition lists for <class>. |
| 155 | ;;; Because the list is needed at expansion-time, we define it as a |
| 156 | ;;; macro. |
| 157 | ;;; |
| 158 | (define-syntax macro-fold-left |
| 159 | (syntax-rules () |
| 160 | ((_ folder seed ()) seed) |
| 161 | ((_ folder seed (head . tail)) |
| 162 | (macro-fold-left folder (folder head seed) tail)))) |
| 163 | |
| 164 | (define-syntax macro-fold-right |
| 165 | (syntax-rules () |
| 166 | ((_ folder seed ()) seed) |
| 167 | ((_ folder seed (head . tail)) |
| 168 | (folder head (macro-fold-right folder seed tail))))) |
| 169 | |
| 170 | (define-syntax-rule (define-macro-folder macro-folder value ...) |
| 171 | (define-syntax macro-folder |
| 172 | (lambda (x) |
| 173 | (syntax-case x () |
| 174 | ((_ fold visit seed) |
| 175 | ;; The datum->syntax makes it as if each `value' were present |
| 176 | ;; in the initial form, which allows them to be used as |
| 177 | ;; (components of) introduced identifiers. |
| 178 | #`(fold visit seed #,(datum->syntax #'visit '(value ...)))))))) |
| 179 | |
| 180 | (define-macro-folder fold-class-slots |
| 181 | (layout #:class <protected-read-only-slot>) |
| 182 | (flags #:class <hidden-slot>) |
| 183 | (self #:class <self-slot>) |
| 184 | (instance-finalizer #:class <hidden-slot>) |
| 185 | (print) |
| 186 | (name #:class <protected-hidden-slot>) |
| 187 | (nfields #:class <hidden-slot>) |
| 188 | (%reserved #:class <hidden-slot>) |
| 189 | (redefined) |
| 190 | (direct-supers) |
| 191 | (direct-slots) |
| 192 | (direct-subclasses) |
| 193 | (direct-methods) |
| 194 | (cpl) |
| 195 | (slots)) |
| 196 | |
| 197 | (define-macro-folder fold-slot-slots |
| 198 | (name #:init-keyword #:name) |
| 199 | (allocation #:init-keyword #:allocation #:init-value #:instance) |
| 200 | (init-keyword #:init-keyword #:init-keyword #:init-value #f) |
| 201 | (init-form #:init-keyword #:init-form) |
| 202 | (init-value #:init-keyword #:init-value) |
| 203 | (init-thunk #:init-keyword #:init-thunk #:init-value #f) |
| 204 | (options) |
| 205 | (getter #:init-keyword #:getter #:init-value #f) |
| 206 | (setter #:init-keyword #:setter #:init-value #f) |
| 207 | (accessor #:init-keyword #:accessor #:init-value #f) |
| 208 | ;; These last don't have #:init-keyword because they are meant to be |
| 209 | ;; set by `allocate-slots', not in compute-effective-slot-definition. |
| 210 | (slot-ref #:init-value #f) |
| 211 | (slot-set! #:init-value #f) |
| 212 | (index #:init-value #f) |
| 213 | (size #:init-value #f)) |
| 214 | |
| 215 | ;;; |
| 216 | ;;; Statically define variables for slot offsets: `class-index-layout' |
| 217 | ;;; will be 0, `class-index-flags' will be 1, and so on, and the same |
| 218 | ;;; for `slot-index-name' and such for <slot>. |
| 219 | ;;; |
| 220 | (let-syntax ((define-slot-indexer |
| 221 | (syntax-rules () |
| 222 | ((_ define-index prefix) |
| 223 | (define-syntax define-index |
| 224 | (lambda (x) |
| 225 | (define (id-append ctx a b) |
| 226 | (datum->syntax ctx (symbol-append (syntax->datum a) |
| 227 | (syntax->datum b)))) |
| 228 | (define (tail-length tail) |
| 229 | (syntax-case tail () |
| 230 | ((begin) 0) |
| 231 | ((visit head tail) (1+ (tail-length #'tail))))) |
| 232 | (syntax-case x () |
| 233 | ((_ (name . _) tail) |
| 234 | #`(begin |
| 235 | (define-syntax #,(id-append #'name #'prefix #'name) |
| 236 | (identifier-syntax #,(tail-length #'tail))) |
| 237 | tail))))))))) |
| 238 | (define-slot-indexer define-class-index class-index-) |
| 239 | (define-slot-indexer define-slot-index slot-index-) |
| 240 | (fold-class-slots macro-fold-left define-class-index (begin)) |
| 241 | (fold-slot-slots macro-fold-left define-slot-index (begin))) |
| 242 | |
| 243 | ;;; |
| 244 | ;;; Structs that are vtables have a "flags" slot, which corresponds to |
| 245 | ;;; class-index-flags. `vtable-flag-vtable' indicates that instances of |
| 246 | ;;; a vtable are themselves vtables, and `vtable-flag-validated' |
| 247 | ;;; indicates that the struct's layout has been validated. goops.c |
| 248 | ;;; defines a few additional flags: one to indicate that a vtable is |
| 249 | ;;; actually a class, one to indicate that the class is "valid" (meaning |
| 250 | ;;; that it hasn't been redefined), and one to indicate that instances |
| 251 | ;;; of a class are slot definition objects (<slot> instances). |
| 252 | ;;; |
| 253 | (define vtable-flag-goops-metaclass |
| 254 | (logior vtable-flag-vtable vtable-flag-goops-class)) |
| 255 | |
| 256 | (define-inlinable (class-add-flags! class flags) |
| 257 | (struct-set! class class-index-flags |
| 258 | (logior flags (struct-ref class class-index-flags)))) |
| 259 | |
| 260 | (define-inlinable (class-clear-flags! class flags) |
| 261 | (struct-set! class class-index-flags |
| 262 | (logand (lognot flags) (struct-ref class class-index-flags)))) |
| 263 | |
| 264 | (define-inlinable (class-has-flags? class flags) |
| 265 | (eqv? flags |
| 266 | (logand (struct-ref class class-index-flags) flags))) |
| 267 | |
| 268 | (define-inlinable (class? obj) |
| 269 | (class-has-flags? (struct-vtable obj) vtable-flag-goops-metaclass)) |
| 270 | |
| 271 | (define-inlinable (slot? obj) |
| 272 | (and (struct? obj) |
| 273 | (class-has-flags? (struct-vtable obj) vtable-flag-goops-slot))) |
| 274 | |
| 275 | (define-inlinable (instance? obj) |
| 276 | (class-has-flags? (struct-vtable obj) vtable-flag-goops-class)) |
| 277 | |
| 278 | ;;; |
| 279 | ;;; Now that we know the slots that must be present in classes, and |
| 280 | ;;; their offsets, we can create the root of the class hierarchy. |
| 281 | ;;; |
| 282 | ;;; Note that the `direct-supers', `direct-slots', `cpl', and `slots' |
| 283 | ;;; fields will be updated later, once we can create slot definition |
| 284 | ;;; objects and once we have definitions for <top> and <object>. |
| 285 | ;;; |
| 286 | (define <class> |
| 287 | (let-syntax ((cons-layout |
| 288 | ;; A simple way to compute class layout for the concrete |
| 289 | ;; types used in <class>. |
| 290 | (syntax-rules (<protected-read-only-slot> |
| 291 | <self-slot> |
| 292 | <hidden-slot> |
| 293 | <protected-hidden-slot>) |
| 294 | ((_ (name) tail) |
| 295 | (string-append "pw" tail)) |
| 296 | ((_ (name #:class <protected-read-only-slot>) tail) |
| 297 | (string-append "pr" tail)) |
| 298 | ((_ (name #:class <self-slot>) tail) |
| 299 | (string-append "sr" tail)) |
| 300 | ((_ (name #:class <hidden-slot>) tail) |
| 301 | (string-append "uh" tail)) |
| 302 | ((_ (name #:class <protected-hidden-slot>) tail) |
| 303 | (string-append "ph" tail))))) |
| 304 | (let* ((layout (fold-class-slots macro-fold-right cons-layout "")) |
| 305 | (nfields (/ (string-length layout) 2)) |
| 306 | (<class> (%make-vtable-vtable layout))) |
| 307 | (class-add-flags! <class> (logior vtable-flag-goops-class |
| 308 | vtable-flag-goops-valid)) |
| 309 | (struct-set! <class> class-index-name '<class>) |
| 310 | (struct-set! <class> class-index-nfields nfields) |
| 311 | (struct-set! <class> class-index-direct-supers '()) |
| 312 | (struct-set! <class> class-index-direct-slots '()) |
| 313 | (struct-set! <class> class-index-direct-subclasses '()) |
| 314 | (struct-set! <class> class-index-direct-methods '()) |
| 315 | (struct-set! <class> class-index-cpl '()) |
| 316 | (struct-set! <class> class-index-slots '()) |
| 317 | (struct-set! <class> class-index-redefined #f) |
| 318 | <class>))) |
| 319 | |
| 320 | ;;; |
| 321 | ;;; Accessors to fields of <class>. |
| 322 | ;;; |
| 323 | (define-syntax-rule (define-class-accessor name docstring field) |
| 324 | (define (name obj) |
| 325 | docstring |
| 326 | (let ((val obj)) |
| 327 | (unless (class? val) |
| 328 | (scm-error 'wrong-type-arg #f "Not a class: ~S" |
| 329 | (list val) #f)) |
| 330 | (struct-ref val field)))) |
| 331 | |
| 332 | (define-class-accessor class-name |
| 333 | "Return the class name of @var{obj}." |
| 334 | class-index-name) |
| 335 | (define-class-accessor class-direct-supers |
| 336 | "Return the direct superclasses of the class @var{obj}." |
| 337 | class-index-direct-supers) |
| 338 | (define-class-accessor class-direct-slots |
| 339 | "Return the direct slots of the class @var{obj}." |
| 340 | class-index-direct-slots) |
| 341 | (define-class-accessor class-direct-subclasses |
| 342 | "Return the direct subclasses of the class @var{obj}." |
| 343 | class-index-direct-subclasses) |
| 344 | (define-class-accessor class-direct-methods |
| 345 | "Return the direct methods of the class @var{obj}." |
| 346 | class-index-direct-methods) |
| 347 | (define-class-accessor class-precedence-list |
| 348 | "Return the class precedence list of the class @var{obj}." |
| 349 | class-index-cpl) |
| 350 | (define-class-accessor class-slots |
| 351 | "Return the slot list of the class @var{obj}." |
| 352 | class-index-slots) |
| 353 | |
| 354 | (define (class-subclasses c) |
| 355 | "Compute a list of all subclasses of @var{c}, direct and indirect." |
| 356 | (define (all-subclasses c) |
| 357 | (cons c (append-map all-subclasses |
| 358 | (class-direct-subclasses c)))) |
| 359 | (delete-duplicates (cdr (all-subclasses c)) eq?)) |
| 360 | |
| 361 | (define (class-methods c) |
| 362 | "Compute a list of all methods that specialize on @var{c} or |
| 363 | subclasses of @var{c}." |
| 364 | (delete-duplicates (append-map class-direct-methods |
| 365 | (cons c (class-subclasses c))) |
| 366 | eq?)) |
| 367 | |
| 368 | (define (is-a? obj class) |
| 369 | "Return @code{#t} if @var{obj} is an instance of @var{class}, or |
| 370 | @code{#f} otherwise." |
| 371 | (and (memq class (class-precedence-list (class-of obj))) #t)) |
| 372 | |
| 373 | |
| 374 | \f |
| 375 | |
| 376 | ;;; |
| 377 | ;;; At this point, <class> is missing slot definitions, but we can't |
| 378 | ;;; create slot definitions until we have a slot definition class. |
| 379 | ;;; Continue with manual object creation until we're able to bootstrap |
| 380 | ;;; more of the protocol. Again, the CPL and class hierarchy slots |
| 381 | ;;; remain uninitialized. |
| 382 | ;;; |
| 383 | (define* (get-keyword key l #:optional default) |
| 384 | "Determine an associated value for the keyword @var{key} from the list |
| 385 | @var{l}. The list @var{l} has to consist of an even number of elements, |
| 386 | where, starting with the first, every second element is a keyword, |
| 387 | followed by its associated value. If @var{l} does not hold a value for |
| 388 | @var{key}, the value @var{default} is returned." |
| 389 | (unless (keyword? key) |
| 390 | (scm-error 'wrong-type-arg #f "Not a keyword: ~S" (list key) #f)) |
| 391 | (let lp ((l l)) |
| 392 | (match l |
| 393 | (() default) |
| 394 | ((kw arg . l) |
| 395 | (unless (keyword? kw) |
| 396 | (scm-error 'wrong-type-arg #f "Not a keyword: ~S" (list kw) #f)) |
| 397 | (if (eq? kw key) arg (lp l)))))) |
| 398 | |
| 399 | (define *unbound* (list 'unbound)) |
| 400 | |
| 401 | (define-inlinable (unbound? x) |
| 402 | (eq? x *unbound*)) |
| 403 | |
| 404 | (define (%allocate-instance class) |
| 405 | (let ((obj (allocate-struct class (struct-ref class class-index-nfields)))) |
| 406 | (%clear-fields! obj *unbound*) |
| 407 | obj)) |
| 408 | |
| 409 | (define <slot> |
| 410 | (let-syntax ((cons-layout |
| 411 | ;; All slots are "pw" in <slot>. |
| 412 | (syntax-rules () |
| 413 | ((_ _ tail) (string-append "pw" tail))))) |
| 414 | (let* ((layout (fold-slot-slots macro-fold-right cons-layout "")) |
| 415 | (nfields (/ (string-length layout) 2)) |
| 416 | (<slot> (make-struct/no-tail <class> (make-struct-layout layout)))) |
| 417 | (class-add-flags! <slot> (logior vtable-flag-goops-class |
| 418 | vtable-flag-goops-slot |
| 419 | vtable-flag-goops-valid)) |
| 420 | (struct-set! <slot> class-index-name '<slot>) |
| 421 | (struct-set! <slot> class-index-nfields nfields) |
| 422 | (struct-set! <slot> class-index-direct-supers '()) |
| 423 | (struct-set! <slot> class-index-direct-slots '()) |
| 424 | (struct-set! <slot> class-index-direct-subclasses '()) |
| 425 | (struct-set! <slot> class-index-direct-methods '()) |
| 426 | (struct-set! <slot> class-index-cpl (list <slot>)) |
| 427 | (struct-set! <slot> class-index-slots '()) |
| 428 | (struct-set! <slot> class-index-redefined #f) |
| 429 | <slot>))) |
| 430 | |
| 431 | ;;; Access to slot objects is performance-sensitive for slot-ref, so in |
| 432 | ;;; addition to the type-checking accessors that we export, we also |
| 433 | ;;; define some internal inlined helpers that just do an unchecked |
| 434 | ;;; struct-ref in cases where we know the object must be a slot, as |
| 435 | ;;; when accessing class-slots. |
| 436 | ;;; |
| 437 | (define-syntax-rule (define-slot-accessor name docstring %name field) |
| 438 | (begin |
| 439 | (define-syntax-rule (%name obj) |
| 440 | (struct-ref obj field)) |
| 441 | (define (name obj) |
| 442 | docstring |
| 443 | (unless (slot? obj) |
| 444 | (scm-error 'wrong-type-arg #f "Not a slot: ~S" |
| 445 | (list obj) #f)) |
| 446 | (%name obj)))) |
| 447 | |
| 448 | (define-slot-accessor slot-definition-name |
| 449 | "Return the name of @var{obj}." |
| 450 | %slot-definition-name slot-index-name) |
| 451 | (define-slot-accessor slot-definition-allocation |
| 452 | "Return the allocation of the slot @var{obj}." |
| 453 | %slot-definition-allocation slot-index-allocation) |
| 454 | (define-slot-accessor slot-definition-init-keyword |
| 455 | "Return the init keyword of the slot @var{obj}, or @code{#f}." |
| 456 | %slot-definition-init-keyword slot-index-init-keyword) |
| 457 | (define-slot-accessor slot-definition-init-form |
| 458 | "Return the init form of the slot @var{obj}, or the unbound value" |
| 459 | %slot-definition-init-form slot-index-init-form) |
| 460 | (define-slot-accessor slot-definition-init-value |
| 461 | "Return the init value of the slot @var{obj}, or the unbound value." |
| 462 | %slot-definition-init-value slot-index-init-value) |
| 463 | (define-slot-accessor slot-definition-init-thunk |
| 464 | "Return the init thunk of the slot @var{obj}, or @code{#f}." |
| 465 | %slot-definition-init-thunk slot-index-init-thunk) |
| 466 | (define-slot-accessor slot-definition-options |
| 467 | "Return the initargs given when creating the slot @var{obj}." |
| 468 | %slot-definition-options slot-index-options) |
| 469 | (define-slot-accessor slot-definition-getter |
| 470 | "Return the getter of the slot @var{obj}, or @code{#f}." |
| 471 | %slot-definition-getter slot-index-getter) |
| 472 | (define-slot-accessor slot-definition-setter |
| 473 | "Return the setter of the slot @var{obj}, or @code{#f}." |
| 474 | %slot-definition-setter slot-index-setter) |
| 475 | (define-slot-accessor slot-definition-accessor |
| 476 | "Return the accessor of the slot @var{obj}, or @code{#f}." |
| 477 | %slot-definition-accessor slot-index-accessor) |
| 478 | (define-slot-accessor slot-definition-slot-ref |
| 479 | "Return the slot-ref procedure of the slot @var{obj}, or @code{#f}." |
| 480 | %slot-definition-slot-ref slot-index-slot-ref) |
| 481 | (define-slot-accessor slot-definition-slot-set! |
| 482 | "Return the slot-set! procedure of the slot @var{obj}, or @code{#f}." |
| 483 | %slot-definition-slot-set! slot-index-slot-set!) |
| 484 | (define-slot-accessor slot-definition-index |
| 485 | "Return the allocated struct offset of the slot @var{obj}, or @code{#f}." |
| 486 | %slot-definition-index slot-index-index) |
| 487 | (define-slot-accessor slot-definition-size |
| 488 | "Return the number fields used by the slot @var{obj}, or @code{#f}." |
| 489 | %slot-definition-size slot-index-size) |
| 490 | |
| 491 | ;; Boot definition. |
| 492 | (define (direct-slot-definition-class class initargs) |
| 493 | (get-keyword #:class initargs <slot>)) |
| 494 | |
| 495 | ;; Boot definition. |
| 496 | (define (make-slot class initargs) |
| 497 | (let ((slot (make-struct/no-tail class))) |
| 498 | (define-syntax-rule (init-slot offset kw default) |
| 499 | (struct-set! slot offset (get-keyword kw initargs default))) |
| 500 | (init-slot slot-index-name #:name #f) |
| 501 | (init-slot slot-index-allocation #:allocation #:instance) |
| 502 | (init-slot slot-index-init-keyword #:init-keyword #f) |
| 503 | (init-slot slot-index-init-form #:init-form *unbound*) |
| 504 | (init-slot slot-index-init-value #:init-value *unbound*) |
| 505 | (struct-set! slot slot-index-init-thunk |
| 506 | (or (get-keyword #:init-thunk initargs #f) |
| 507 | (let ((val (%slot-definition-init-value slot))) |
| 508 | (if (unbound? val) |
| 509 | #f |
| 510 | (lambda () val))))) |
| 511 | (struct-set! slot slot-index-options initargs) |
| 512 | (init-slot slot-index-getter #:getter #f) |
| 513 | (init-slot slot-index-setter #:setter #f) |
| 514 | (init-slot slot-index-accessor #:accessor #f) |
| 515 | (init-slot slot-index-slot-ref #:slot-ref #f) |
| 516 | (init-slot slot-index-slot-set! #:slot-set! #f) |
| 517 | (init-slot slot-index-index #:index #f) |
| 518 | (init-slot slot-index-size #:size #f) |
| 519 | slot)) |
| 520 | |
| 521 | ;; Boot definition. |
| 522 | (define (make class . args) |
| 523 | (unless (memq <slot> (class-precedence-list class)) |
| 524 | (error "Unsupported class: ~S" class)) |
| 525 | (make-slot class args)) |
| 526 | |
| 527 | ;; Boot definition. |
| 528 | (define (compute-direct-slot-definition class initargs) |
| 529 | (apply make (direct-slot-definition-class class initargs) initargs)) |
| 530 | |
| 531 | (define (compute-direct-slot-definition-initargs class slot-spec) |
| 532 | (match slot-spec |
| 533 | ((? symbol? name) (list #:name name)) |
| 534 | (((? symbol? name) . initargs) |
| 535 | (cons* #:name name |
| 536 | ;; If there is an #:init-form, the `class' macro will have |
| 537 | ;; already added an #:init-thunk. Still, if there isn't an |
| 538 | ;; #:init-thunk already but we do have an #:init-value, |
| 539 | ;; synthesize an #:init-thunk initarg. This will ensure |
| 540 | ;; that the #:init-thunk gets passed on to the effective |
| 541 | ;; slot definition too. |
| 542 | (if (get-keyword #:init-thunk initargs) |
| 543 | initargs |
| 544 | (let ((value (get-keyword #:init-value initargs *unbound*))) |
| 545 | (if (unbound? value) |
| 546 | initargs |
| 547 | (cons* #:init-thunk (lambda () value) initargs)))))))) |
| 548 | |
| 549 | (let () |
| 550 | (define-syntax cons-slot |
| 551 | (syntax-rules () |
| 552 | ((_ (name #:class class) tail) |
| 553 | ;; Special case to avoid referencing specialized <slot> kinds, |
| 554 | ;; which are not defined yet. |
| 555 | (cons (list 'name) tail)) |
| 556 | ((_ (name . initargs) tail) |
| 557 | (cons (list 'name . initargs) tail)))) |
| 558 | (define-syntax-rule (initialize-direct-slots! class fold-slots) |
| 559 | (let ((specs (fold-slots macro-fold-right cons-slot '()))) |
| 560 | (define (make-direct-slot-definition spec) |
| 561 | (let ((initargs (compute-direct-slot-definition-initargs class spec))) |
| 562 | (compute-direct-slot-definition class initargs))) |
| 563 | (struct-set! class class-index-direct-slots |
| 564 | (map make-direct-slot-definition specs)))) |
| 565 | |
| 566 | (initialize-direct-slots! <class> fold-class-slots) |
| 567 | (initialize-direct-slots! <slot> fold-slot-slots)) |
| 568 | |
| 569 | |
| 570 | \f |
| 571 | |
| 572 | ;;; |
| 573 | ;;; OK, at this point we have initialized `direct-slots' on both <class> |
| 574 | ;;; and <slot>. We need to define a standard way to make subclasses: |
| 575 | ;;; how to compute the precedence list of subclasses, how to compute the |
| 576 | ;;; list of slots in a subclass, and what layout to use for instances of |
| 577 | ;;; those classes. |
| 578 | ;;; |
| 579 | (define (compute-std-cpl c get-direct-supers) |
| 580 | "The standard class precedence list computation algorithm." |
| 581 | (define (only-non-null lst) |
| 582 | (filter (lambda (l) (not (null? l))) lst)) |
| 583 | |
| 584 | (define (merge-lists reversed-partial-result inputs) |
| 585 | (cond |
| 586 | ((every null? inputs) |
| 587 | (reverse! reversed-partial-result)) |
| 588 | (else |
| 589 | (let* ((candidate (lambda (c) |
| 590 | (and (not (any (lambda (l) |
| 591 | (memq c (cdr l))) |
| 592 | inputs)) |
| 593 | c))) |
| 594 | (candidate-car (lambda (l) |
| 595 | (and (not (null? l)) |
| 596 | (candidate (car l))))) |
| 597 | (next (any candidate-car inputs))) |
| 598 | (unless next |
| 599 | (goops-error "merge-lists: Inconsistent precedence graph")) |
| 600 | (let ((remove-next (lambda (l) |
| 601 | (if (eq? (car l) next) |
| 602 | (cdr l) |
| 603 | l)))) |
| 604 | (merge-lists (cons next reversed-partial-result) |
| 605 | (only-non-null (map remove-next inputs)))))))) |
| 606 | (let ((c-direct-supers (get-direct-supers c))) |
| 607 | (merge-lists (list c) |
| 608 | (only-non-null (append (map class-precedence-list |
| 609 | c-direct-supers) |
| 610 | (list c-direct-supers)))))) |
| 611 | |
| 612 | ;; This version of compute-cpl is replaced with a generic function once |
| 613 | ;; GOOPS has booted. |
| 614 | (define (compute-cpl class) |
| 615 | (compute-std-cpl class class-direct-supers)) |
| 616 | |
| 617 | (define (effective-slot-definition-class class slot) |
| 618 | (class-of slot)) |
| 619 | |
| 620 | (define (compute-effective-slot-definition class slot) |
| 621 | ;; FIXME: Support slot being a list of slots, as in CLOS. |
| 622 | (apply make |
| 623 | (effective-slot-definition-class class slot) |
| 624 | (slot-definition-options slot))) |
| 625 | |
| 626 | (define (build-slots-list dslots cpl) |
| 627 | (define (slot-memq slot slots) |
| 628 | (let ((name (%slot-definition-name slot))) |
| 629 | (let lp ((slots slots)) |
| 630 | (match slots |
| 631 | (() #f) |
| 632 | ((slot . slots) |
| 633 | (or (eq? (%slot-definition-name slot) name) (lp slots))))))) |
| 634 | (define (check-cpl slots static-slots) |
| 635 | (when (or-map (lambda (slot) (slot-memq slot slots)) static-slots) |
| 636 | (scm-error 'misc-error #f |
| 637 | "a predefined static inherited field cannot be redefined" |
| 638 | '() '()))) |
| 639 | (define (remove-duplicate-slots slots) |
| 640 | (let lp ((slots (reverse slots)) (res '()) (seen '())) |
| 641 | (match slots |
| 642 | (() res) |
| 643 | ((slot . slots) |
| 644 | (let ((name (%slot-definition-name slot))) |
| 645 | (if (memq name seen) |
| 646 | (lp slots res seen) |
| 647 | (lp slots (cons slot res) (cons name seen)))))))) |
| 648 | ;; For subclases of <class> and <slot>, we need to ensure that the |
| 649 | ;; <class> or <slot> slots come first. |
| 650 | (let* ((static-slots (cond |
| 651 | ((memq <class> cpl) |
| 652 | (when (memq <slot> cpl) (error "invalid class")) |
| 653 | (struct-ref <class> class-index-slots)) |
| 654 | ((memq <slot> cpl) |
| 655 | (struct-ref <slot> class-index-slots)) |
| 656 | (else #f)))) |
| 657 | (when static-slots |
| 658 | (check-cpl dslots static-slots)) |
| 659 | (let lp ((cpl (cdr cpl)) (res dslots) (static-slots '())) |
| 660 | (match cpl |
| 661 | (() (remove-duplicate-slots (append static-slots res))) |
| 662 | ((head . cpl) |
| 663 | (let ((new-slots (struct-ref head class-index-direct-slots))) |
| 664 | (cond |
| 665 | ((not static-slots) |
| 666 | (lp cpl (append new-slots res) static-slots)) |
| 667 | ((or (eq? head <class>) (eq? head <slot>)) |
| 668 | ;; Move static slots to the head of the list. |
| 669 | (lp cpl res new-slots)) |
| 670 | (else |
| 671 | (check-cpl new-slots static-slots) |
| 672 | (lp cpl (append new-slots res) static-slots))))))))) |
| 673 | |
| 674 | ;; Boot definition. |
| 675 | (define (compute-get-n-set class slot) |
| 676 | (let ((index (struct-ref class class-index-nfields))) |
| 677 | (struct-set! class class-index-nfields (1+ index)) |
| 678 | index)) |
| 679 | |
| 680 | (define (allocate-slots class slots) |
| 681 | "Transform the computed list of direct slot definitions @var{slots} |
| 682 | into a corresponding list of effective slot definitions, allocating |
| 683 | slots as we go." |
| 684 | (define (make-effective-slot-definition slot) |
| 685 | ;; `compute-get-n-set' is expected to mutate `nfields' if it |
| 686 | ;; allocates a field to the object. Pretty strange, but we preserve |
| 687 | ;; the behavior for backward compatibility. |
| 688 | (let* ((slot (compute-effective-slot-definition class slot)) |
| 689 | (index (struct-ref class class-index-nfields)) |
| 690 | (g-n-s (compute-get-n-set class slot)) |
| 691 | (size (- (struct-ref class class-index-nfields) index))) |
| 692 | (call-with-values |
| 693 | (lambda () |
| 694 | (match g-n-s |
| 695 | ((? integer?) |
| 696 | (unless (= size 1) |
| 697 | (error "unexpected return from compute-get-n-set")) |
| 698 | (values #f #f)) |
| 699 | (((? procedure? get) (? procedure? set)) |
| 700 | (values get set)))) |
| 701 | (lambda (get set) |
| 702 | (struct-set! slot slot-index-index index) |
| 703 | (struct-set! slot slot-index-size size) |
| 704 | (struct-set! slot slot-index-slot-ref get) |
| 705 | (struct-set! slot slot-index-slot-set! set))) |
| 706 | slot)) |
| 707 | (struct-set! class class-index-nfields 0) |
| 708 | (map-in-order make-effective-slot-definition slots)) |
| 709 | |
| 710 | (define (%compute-layout slots nfields is-class?) |
| 711 | (define (slot-protection-and-kind slot) |
| 712 | (define (subclass? class parent) |
| 713 | (memq parent (class-precedence-list class))) |
| 714 | (let ((type (kw-arg-ref (%slot-definition-options slot) #:class))) |
| 715 | (if (and type (subclass? type <foreign-slot>)) |
| 716 | (values (cond |
| 717 | ((subclass? type <self-slot>) #\s) |
| 718 | ((subclass? type <protected-slot>) #\p) |
| 719 | (else #\u)) |
| 720 | (cond |
| 721 | ((subclass? type <opaque-slot>) #\o) |
| 722 | ((subclass? type <read-only-slot>) #\r) |
| 723 | ((subclass? type <hidden-slot>) #\h) |
| 724 | (else #\w))) |
| 725 | (values #\p #\w)))) |
| 726 | (let ((layout (make-string (* nfields 2)))) |
| 727 | (let lp ((n 0) (slots slots)) |
| 728 | (match slots |
| 729 | (() |
| 730 | (unless (= n nfields) (error "bad nfields")) |
| 731 | (when is-class? |
| 732 | (let ((class-layout (struct-ref <class> class-index-layout))) |
| 733 | (unless (string-prefix? (symbol->string class-layout) layout) |
| 734 | (error "bad layout for class")))) |
| 735 | layout) |
| 736 | ((slot . slots) |
| 737 | (unless (= n (%slot-definition-index slot)) (error "bad allocation")) |
| 738 | (call-with-values (lambda () (slot-protection-and-kind slot)) |
| 739 | (lambda (protection kind) |
| 740 | (let init ((n n) (size (%slot-definition-size slot))) |
| 741 | (cond |
| 742 | ((zero? size) (lp n slots)) |
| 743 | (else |
| 744 | (unless (< n nfields) (error "bad nfields")) |
| 745 | (string-set! layout (* n 2) protection) |
| 746 | (string-set! layout (1+ (* n 2)) kind) |
| 747 | (init (1+ n) (1- size)))))))))))) |
| 748 | |
| 749 | |
| 750 | \f |
| 751 | |
| 752 | ;;; |
| 753 | ;;; With all of this, we are now able to define subclasses of <class>. |
| 754 | ;;; |
| 755 | (define (%prep-layout! class) |
| 756 | (let* ((is-class? (and (memq <class> (struct-ref class class-index-cpl)) #t)) |
| 757 | (layout (%compute-layout (struct-ref class class-index-slots) |
| 758 | (struct-ref class class-index-nfields) |
| 759 | is-class?))) |
| 760 | (%init-layout! class layout))) |
| 761 | |
| 762 | (define (make-standard-class class name dsupers dslots) |
| 763 | (let ((z (make-struct/no-tail class))) |
| 764 | (define (make-direct-slot-definition dslot) |
| 765 | (let ((initargs (compute-direct-slot-definition-initargs z dslot))) |
| 766 | (compute-direct-slot-definition z initargs))) |
| 767 | |
| 768 | (struct-set! z class-index-name name) |
| 769 | (struct-set! z class-index-nfields 0) |
| 770 | (struct-set! z class-index-direct-supers dsupers) |
| 771 | (struct-set! z class-index-direct-subclasses '()) |
| 772 | (struct-set! z class-index-direct-methods '()) |
| 773 | (struct-set! z class-index-redefined #f) |
| 774 | (let ((cpl (compute-cpl z))) |
| 775 | (struct-set! z class-index-cpl cpl) |
| 776 | (when (memq <slot> cpl) |
| 777 | (class-add-flags! z vtable-flag-goops-slot)) |
| 778 | (let* ((dslots (map make-direct-slot-definition dslots)) |
| 779 | (slots (allocate-slots z (build-slots-list dslots cpl)))) |
| 780 | (struct-set! z class-index-direct-slots dslots) |
| 781 | (struct-set! z class-index-slots slots))) |
| 782 | (for-each |
| 783 | (lambda (super) |
| 784 | (let ((subclasses (struct-ref super class-index-direct-subclasses))) |
| 785 | (struct-set! super class-index-direct-subclasses |
| 786 | (cons z subclasses)))) |
| 787 | dsupers) |
| 788 | (%prep-layout! z) |
| 789 | z)) |
| 790 | |
| 791 | (define-syntax define-standard-class |
| 792 | (syntax-rules () |
| 793 | ((define-standard-class name (super ...) #:metaclass meta slot ...) |
| 794 | (define name |
| 795 | (make-standard-class meta 'name (list super ...) '(slot ...)))) |
| 796 | ((define-standard-class name (super ...) slot ...) |
| 797 | (define-standard-class name (super ...) #:metaclass <class> slot ...)))) |
| 798 | |
| 799 | |
| 800 | \f |
| 801 | |
| 802 | ;;; |
| 803 | ;;; Sweet! Now we can define <top> and <object>, and finish |
| 804 | ;;; initializing the `direct-subclasses', `direct-supers', and `cpl' |
| 805 | ;;; slots of <class>. |
| 806 | ;;; |
| 807 | (define-standard-class <top> ()) |
| 808 | (define-standard-class <object> (<top>)) |
| 809 | |
| 810 | ;; The inheritance links for <top>, <object>, <class>, and <slot> were |
| 811 | ;; partially initialized. Correct them here. |
| 812 | (struct-set! <object> class-index-direct-subclasses (list <slot> <class>)) |
| 813 | (struct-set! <class> class-index-direct-supers (list <object>)) |
| 814 | (struct-set! <slot> class-index-direct-supers (list <object>)) |
| 815 | (struct-set! <class> class-index-cpl (list <class> <object> <top>)) |
| 816 | (struct-set! <slot> class-index-cpl (list <slot> <object> <top>)) |
| 817 | |
| 818 | |
| 819 | \f |
| 820 | |
| 821 | ;;; |
| 822 | ;;; We can also define the various slot types, and finish initializing |
| 823 | ;;; `direct-slots' and `slots' on <class> and <slot>. |
| 824 | ;;; |
| 825 | (define-standard-class <foreign-slot> (<slot>)) |
| 826 | (define-standard-class <protected-slot> (<foreign-slot>)) |
| 827 | (define-standard-class <hidden-slot> (<foreign-slot>)) |
| 828 | (define-standard-class <opaque-slot> (<foreign-slot>)) |
| 829 | (define-standard-class <read-only-slot> (<foreign-slot>)) |
| 830 | (define-standard-class <self-slot> (<read-only-slot>)) |
| 831 | (define-standard-class <protected-opaque-slot> (<protected-slot> |
| 832 | <opaque-slot>)) |
| 833 | (define-standard-class <protected-hidden-slot> (<protected-slot> |
| 834 | <hidden-slot>)) |
| 835 | (define-standard-class <protected-read-only-slot> (<protected-slot> |
| 836 | <read-only-slot>)) |
| 837 | (define-standard-class <scm-slot> (<protected-slot>)) |
| 838 | (define-standard-class <int-slot> (<foreign-slot>)) |
| 839 | (define-standard-class <float-slot> (<foreign-slot>)) |
| 840 | (define-standard-class <double-slot> (<foreign-slot>)) |
| 841 | |
| 842 | |
| 843 | \f |
| 844 | |
| 845 | ;;; |
| 846 | ;;; Finally! Initialize `direct-slots' and `slots' on <class>, and |
| 847 | ;;; `slots' on <slot>. |
| 848 | ;;; |
| 849 | (let () |
| 850 | (define-syntax-rule (cons-slot (name . initargs) tail) |
| 851 | (cons (list 'name . initargs) tail)) |
| 852 | (define-syntax-rule (initialize-direct-slots! class fold-slots) |
| 853 | (let ((specs (fold-slots macro-fold-right cons-slot '()))) |
| 854 | (define (make-direct-slot-definition spec) |
| 855 | (let ((initargs (compute-direct-slot-definition-initargs class spec))) |
| 856 | (compute-direct-slot-definition class initargs))) |
| 857 | (struct-set! class class-index-direct-slots |
| 858 | (map make-direct-slot-definition specs)))) |
| 859 | (define (initialize-slots! class) |
| 860 | (let ((slots (build-slots-list (class-direct-slots class) |
| 861 | (class-precedence-list class)))) |
| 862 | (struct-set! class class-index-slots (allocate-slots class slots)))) |
| 863 | |
| 864 | ;; Finish initializing <class> with the specialized slot kinds. |
| 865 | (initialize-direct-slots! <class> fold-class-slots) |
| 866 | |
| 867 | (initialize-slots! <class>) |
| 868 | (initialize-slots! <slot>)) |
| 869 | |
| 870 | |
| 871 | \f |
| 872 | |
| 873 | ;;; |
| 874 | ;;; Now, to build out the class hierarchy. |
| 875 | ;;; |
| 876 | |
| 877 | (define-standard-class <procedure-class> (<class>)) |
| 878 | |
| 879 | (define-standard-class <applicable-struct-class> |
| 880 | (<procedure-class>)) |
| 881 | (class-add-flags! <applicable-struct-class> |
| 882 | vtable-flag-applicable-vtable) |
| 883 | |
| 884 | (define-standard-class <applicable-struct-with-setter-class> |
| 885 | (<applicable-struct-class>)) |
| 886 | (class-add-flags! <applicable-struct-with-setter-class> |
| 887 | vtable-flag-setter-vtable) |
| 888 | |
| 889 | (define-standard-class <applicable> (<top>)) |
| 890 | (define-standard-class <applicable-struct> (<object> <applicable>) |
| 891 | #:metaclass <applicable-struct-class> |
| 892 | procedure) |
| 893 | (define-standard-class <applicable-struct-with-setter> (<applicable-struct>) |
| 894 | #:metaclass <applicable-struct-with-setter-class> |
| 895 | setter) |
| 896 | (define-standard-class <generic> (<applicable-struct>) |
| 897 | #:metaclass <applicable-struct-class> |
| 898 | methods |
| 899 | (n-specialized #:init-value 0) |
| 900 | (extended-by #:init-value ()) |
| 901 | effective-methods) |
| 902 | (define-standard-class <extended-generic> (<generic>) |
| 903 | #:metaclass <applicable-struct-class> |
| 904 | (extends #:init-value ())) |
| 905 | (define-standard-class <generic-with-setter> (<generic> |
| 906 | <applicable-struct-with-setter>) |
| 907 | #:metaclass <applicable-struct-with-setter-class>) |
| 908 | (define-standard-class <accessor> (<generic-with-setter>) |
| 909 | #:metaclass <applicable-struct-with-setter-class>) |
| 910 | (define-standard-class <extended-generic-with-setter> (<extended-generic> |
| 911 | <generic-with-setter>) |
| 912 | #:metaclass <applicable-struct-with-setter-class>) |
| 913 | (define-standard-class <extended-accessor> (<accessor> |
| 914 | <extended-generic-with-setter>) |
| 915 | #:metaclass <applicable-struct-with-setter-class>) |
| 916 | |
| 917 | (define-standard-class <method> (<object>) |
| 918 | generic-function |
| 919 | specializers |
| 920 | procedure |
| 921 | formals |
| 922 | body |
| 923 | make-procedure) |
| 924 | (define-standard-class <accessor-method> (<method>) |
| 925 | (slot-definition #:init-keyword #:slot-definition)) |
| 926 | |
| 927 | (define-standard-class <boolean> (<top>)) |
| 928 | (define-standard-class <char> (<top>)) |
| 929 | (define-standard-class <list> (<top>)) |
| 930 | ;; Not all pairs are lists, but there is code out there that relies on |
| 931 | ;; (is-a? '(1 2 3) <list>) to work. Terrible. How to fix? |
| 932 | (define-standard-class <pair> (<list>)) |
| 933 | (define-standard-class <null> (<list>)) |
| 934 | (define-standard-class <string> (<top>)) |
| 935 | (define-standard-class <symbol> (<top>)) |
| 936 | (define-standard-class <vector> (<top>)) |
| 937 | (define-standard-class <foreign> (<top>)) |
| 938 | (define-standard-class <hashtable> (<top>)) |
| 939 | (define-standard-class <fluid> (<top>)) |
| 940 | (define-standard-class <dynamic-state> (<top>)) |
| 941 | (define-standard-class <frame> (<top>)) |
| 942 | (define-standard-class <vm-continuation> (<top>)) |
| 943 | (define-standard-class <bytevector> (<top>)) |
| 944 | (define-standard-class <uvec> (<bytevector>)) |
| 945 | (define-standard-class <array> (<top>)) |
| 946 | (define-standard-class <bitvector> (<top>)) |
| 947 | (define-standard-class <number> (<top>)) |
| 948 | (define-standard-class <complex> (<number>)) |
| 949 | (define-standard-class <real> (<complex>)) |
| 950 | (define-standard-class <integer> (<real>)) |
| 951 | (define-standard-class <fraction> (<real>)) |
| 952 | (define-standard-class <keyword> (<top>)) |
| 953 | (define-standard-class <unknown> (<top>)) |
| 954 | (define-standard-class <procedure> (<applicable>) |
| 955 | #:metaclass <procedure-class>) |
| 956 | (define-standard-class <primitive-generic> (<procedure>) |
| 957 | #:metaclass <procedure-class>) |
| 958 | (define-standard-class <port> (<top>)) |
| 959 | (define-standard-class <input-port> (<port>)) |
| 960 | (define-standard-class <output-port> (<port>)) |
| 961 | (define-standard-class <input-output-port> (<input-port> <output-port>)) |
| 962 | |
| 963 | (define (inherit-applicable! class) |
| 964 | "An internal routine to redefine a SMOB class that was added after |
| 965 | GOOPS was loaded, and on which scm_set_smob_apply installed an apply |
| 966 | function." |
| 967 | ;; Why not use class-redefinition? We would, except that loading the |
| 968 | ;; compiler to compile effective methods can happen while GOOPS has |
| 969 | ;; only been partially loaded, and loading the compiler might cause |
| 970 | ;; SMOB types to be defined that need this facility. Instead we make |
| 971 | ;; a very specific hack, not a general solution. Probably the right |
| 972 | ;; solution is to avoid using the compiler, but that is another kettle |
| 973 | ;; of fish. |
| 974 | (unless (memq <applicable> (class-precedence-list class)) |
| 975 | (unless (null? (class-slots class)) |
| 976 | (error "SMOB object has slots?")) |
| 977 | (for-each |
| 978 | (lambda (super) |
| 979 | (let ((subclasses (struct-ref super class-index-direct-subclasses))) |
| 980 | (struct-set! super class-index-direct-subclasses |
| 981 | (delq class subclasses)))) |
| 982 | (struct-ref class class-index-direct-supers)) |
| 983 | (struct-set! class class-index-direct-supers (list <applicable>)) |
| 984 | (struct-set! class class-index-cpl (compute-cpl class)) |
| 985 | (let ((subclasses (struct-ref <applicable> class-index-direct-subclasses))) |
| 986 | (struct-set! <applicable> class-index-direct-subclasses |
| 987 | (cons class subclasses))))) |
| 988 | |
| 989 | |
| 990 | \f |
| 991 | |
| 992 | ;;; |
| 993 | ;;; At this point we have defined the class hierarchy, and it's time to |
| 994 | ;;; move on to instance allocation and generics. Once we have generics, |
| 995 | ;;; we'll fill out the metaobject protocol. |
| 996 | ;;; |
| 997 | ;;; Here we define a limited version of `make', so that we can allocate |
| 998 | ;;; instances of specific classes. This definition will be replaced |
| 999 | ;;; later. |
| 1000 | ;;; |
| 1001 | (define (%invalidate-method-cache! gf) |
| 1002 | (slot-set! gf 'effective-methods '()) |
| 1003 | (recompute-generic-function-dispatch-procedure! gf)) |
| 1004 | |
| 1005 | ;; Boot definition. |
| 1006 | (define (invalidate-method-cache! gf) |
| 1007 | (%invalidate-method-cache! gf)) |
| 1008 | |
| 1009 | (define (make class . args) |
| 1010 | (cond |
| 1011 | ((or (eq? class <generic>) (eq? class <accessor>)) |
| 1012 | (let ((z (make-struct/no-tail class #f '() 0 '()))) |
| 1013 | (set-procedure-property! z 'name (get-keyword #:name args #f)) |
| 1014 | (invalidate-method-cache! z) |
| 1015 | (when (eq? class <accessor>) |
| 1016 | (let ((setter (get-keyword #:setter args #f))) |
| 1017 | (when setter |
| 1018 | (slot-set! z 'setter setter)))) |
| 1019 | z)) |
| 1020 | (else |
| 1021 | (let ((z (%allocate-instance class))) |
| 1022 | (cond |
| 1023 | ((or (eq? class <method>) (eq? class <accessor-method>)) |
| 1024 | (for-each (match-lambda |
| 1025 | ((kw slot default) |
| 1026 | (slot-set! z slot (get-keyword kw args default)))) |
| 1027 | '((#:generic-function generic-function #f) |
| 1028 | (#:specializers specializers ()) |
| 1029 | (#:procedure procedure #f) |
| 1030 | (#:formals formals ()) |
| 1031 | (#:body body ()) |
| 1032 | (#:make-procedure make-procedure #f)))) |
| 1033 | ((memq <class> (class-precedence-list class)) |
| 1034 | (class-add-flags! z (logior vtable-flag-goops-class |
| 1035 | vtable-flag-goops-valid)) |
| 1036 | (for-each (match-lambda |
| 1037 | ((kw slot default) |
| 1038 | (slot-set! z slot (get-keyword kw args default)))) |
| 1039 | '((#:name name ???) |
| 1040 | (#:dsupers direct-supers ()) |
| 1041 | (#:slots direct-slots ())))) |
| 1042 | (else |
| 1043 | (error "boot `make' does not support this class" class))) |
| 1044 | z)))) |
| 1045 | |
| 1046 | |
| 1047 | \f |
| 1048 | |
| 1049 | ;;; |
| 1050 | ;;; Slot access. |
| 1051 | ;;; |
| 1052 | ;;; Before we go on, some notes about class redefinition. In GOOPS, |
| 1053 | ;;; classes can be redefined. Redefinition of a class marks the class |
| 1054 | ;;; as invalid, and instances will be lazily migrated over to the new |
| 1055 | ;;; representation as they are accessed. Migration happens when |
| 1056 | ;;; `class-of' is called on an instance. For more technical details on |
| 1057 | ;;; object redefinition, see struct.h. |
| 1058 | ;;; |
| 1059 | ;;; In the following interfaces, class-of handles the redefinition |
| 1060 | ;;; protocol. I would think though that there is some thread-unsafety |
| 1061 | ;;; here though as the { class, object data } pair needs to be accessed |
| 1062 | ;;; atomically, not the { class, object } pair. |
| 1063 | ;;; |
| 1064 | (define-inlinable (%class-slot-definition class slot-name kt kf) |
| 1065 | (let lp ((slots (struct-ref class class-index-slots))) |
| 1066 | (match slots |
| 1067 | ((slot . slots) |
| 1068 | (if (eq? (%slot-definition-name slot) slot-name) |
| 1069 | (kt slot) |
| 1070 | (lp slots))) |
| 1071 | (_ (kf))))) |
| 1072 | |
| 1073 | (define (class-slot-definition class slot-name) |
| 1074 | (unless (class? class) |
| 1075 | (scm-error 'wrong-type-arg #f "Not a class: ~S" (list class) #f)) |
| 1076 | (%class-slot-definition class slot-name |
| 1077 | (lambda (slot) slot) |
| 1078 | (lambda () #f))) |
| 1079 | |
| 1080 | (define (slot-ref obj slot-name) |
| 1081 | "Return the value from @var{obj}'s slot with the nam var{slot_name}." |
| 1082 | (let ((class (class-of obj))) |
| 1083 | (define (slot-value slot) |
| 1084 | (cond |
| 1085 | ((%slot-definition-slot-ref slot) |
| 1086 | => (lambda (slot-ref) (slot-ref obj))) |
| 1087 | (else |
| 1088 | (struct-ref obj (%slot-definition-index slot))))) |
| 1089 | (define (have-slot slot) |
| 1090 | (let ((val (slot-value slot))) |
| 1091 | (if (unbound? val) |
| 1092 | (slot-unbound class obj slot-name) |
| 1093 | val))) |
| 1094 | (define (no-slot) |
| 1095 | (unless (symbol? slot-name) |
| 1096 | (scm-error 'wrong-type-arg #f "Not a symbol: ~S" |
| 1097 | (list slot-name) #f)) |
| 1098 | (let ((val (slot-missing class obj slot-name))) |
| 1099 | (if (unbound? val) |
| 1100 | (slot-unbound class obj slot-name) |
| 1101 | val))) |
| 1102 | (%class-slot-definition class slot-name have-slot no-slot))) |
| 1103 | |
| 1104 | (define (slot-set! obj slot-name value) |
| 1105 | "Set the slot named @var{slot_name} of @var{obj} to @var{value}." |
| 1106 | (let ((class (class-of obj))) |
| 1107 | (define (have-slot slot) |
| 1108 | (cond |
| 1109 | ((%slot-definition-slot-set! slot) |
| 1110 | => (lambda (slot-set!) (slot-set! obj value))) |
| 1111 | (else |
| 1112 | (struct-set! obj (%slot-definition-index slot) value)))) |
| 1113 | (define (no-slot) |
| 1114 | (unless (symbol? slot-name) |
| 1115 | (scm-error 'wrong-type-arg #f "Not a symbol: ~S" |
| 1116 | (list slot-name) #f)) |
| 1117 | (slot-missing class obj slot-name value)) |
| 1118 | |
| 1119 | (%class-slot-definition class slot-name have-slot no-slot))) |
| 1120 | |
| 1121 | (define (slot-bound? obj slot-name) |
| 1122 | "Return the value from @var{obj}'s slot with the nam var{slot_name}." |
| 1123 | (let ((class (class-of obj))) |
| 1124 | (define (slot-value slot) |
| 1125 | (cond |
| 1126 | ((%slot-definition-slot-ref slot) |
| 1127 | => (lambda (slot-ref) (slot-ref obj))) |
| 1128 | (else |
| 1129 | (struct-ref obj (%slot-definition-index slot))))) |
| 1130 | (define (have-slot slot) |
| 1131 | (not (unbound? (slot-value slot)))) |
| 1132 | (define (no-slot) |
| 1133 | (unless (symbol? slot-name) |
| 1134 | (scm-error 'wrong-type-arg #f "Not a symbol: ~S" |
| 1135 | (list slot-name) #f)) |
| 1136 | (let ((val (slot-missing class obj slot-name))) |
| 1137 | (if (unbound? val) |
| 1138 | (slot-unbound class obj slot-name) |
| 1139 | val))) |
| 1140 | (%class-slot-definition class slot-name have-slot no-slot))) |
| 1141 | |
| 1142 | (define (slot-exists? obj slot-name) |
| 1143 | "Return @code{#t} if @var{obj} has a slot named @var{slot_name}." |
| 1144 | (define (have-slot slot) #t) |
| 1145 | (define (no-slot) |
| 1146 | (unless (symbol? slot-name) |
| 1147 | (scm-error 'wrong-type-arg #f "Not a symbol: ~S" |
| 1148 | (list slot-name) #f)) |
| 1149 | #f) |
| 1150 | (%class-slot-definition (class-of obj) slot-name have-slot no-slot)) |
| 1151 | |
| 1152 | (begin-deprecated |
| 1153 | (define (check-slot-args class obj slot-name) |
| 1154 | (unless (eq? class (class-of obj)) |
| 1155 | (scm-error 'wrong-type-arg #f "~S is not the class of ~S" |
| 1156 | (list class obj) #f)) |
| 1157 | (unless (symbol? slot-name) |
| 1158 | (scm-error 'wrong-type-arg #f "Not a symbol: ~S" |
| 1159 | (list slot-name) #f))) |
| 1160 | |
| 1161 | (define (slot-ref-using-class class obj slot-name) |
| 1162 | (issue-deprecation-warning "slot-ref-using-class is deprecated. " |
| 1163 | "Use slot-ref instead.") |
| 1164 | (check-slot-args class obj slot-name) |
| 1165 | (slot-ref obj slot-name)) |
| 1166 | |
| 1167 | (define (slot-set-using-class! class obj slot-name value) |
| 1168 | (issue-deprecation-warning "slot-set-using-class! is deprecated. " |
| 1169 | "Use slot-set! instead.") |
| 1170 | (check-slot-args class obj slot-name) |
| 1171 | (slot-set! obj slot-name value)) |
| 1172 | |
| 1173 | (define (slot-bound-using-class? class obj slot-name) |
| 1174 | (issue-deprecation-warning "slot-bound-using-class? is deprecated. " |
| 1175 | "Use slot-bound? instead.") |
| 1176 | (check-slot-args class obj slot-name) |
| 1177 | (slot-bound? obj slot-name)) |
| 1178 | |
| 1179 | (define (slot-exists-using-class? class obj slot-name) |
| 1180 | (issue-deprecation-warning "slot-exists-using-class? is deprecated. " |
| 1181 | "Use slot-exists? instead.") |
| 1182 | (check-slot-args class obj slot-name) |
| 1183 | (slot-exists? obj slot-name))) |
| 1184 | |
| 1185 | |
| 1186 | \f |
| 1187 | |
| 1188 | ;;; |
| 1189 | ;;; Method accessors. |
| 1190 | ;;; |
| 1191 | (define (method-generic-function obj) |
| 1192 | "Return the generic function for the method @var{obj}." |
| 1193 | (unless (is-a? obj <method>) |
| 1194 | (scm-error 'wrong-type-arg #f "Not a method: ~S" |
| 1195 | (list obj) #f)) |
| 1196 | (slot-ref obj 'generic-function)) |
| 1197 | |
| 1198 | (define (method-specializers obj) |
| 1199 | "Return specializers of the method @var{obj}." |
| 1200 | (unless (is-a? obj <method>) |
| 1201 | (scm-error 'wrong-type-arg #f "Not a method: ~S" |
| 1202 | (list obj) #f)) |
| 1203 | (slot-ref obj 'specializers)) |
| 1204 | |
| 1205 | (define (method-procedure obj) |
| 1206 | "Return the procedure of the method @var{obj}." |
| 1207 | (unless (is-a? obj <method>) |
| 1208 | (scm-error 'wrong-type-arg #f "Not a method: ~S" |
| 1209 | (list obj) #f)) |
| 1210 | (slot-ref obj 'procedure)) |
| 1211 | |
| 1212 | |
| 1213 | \f |
| 1214 | |
| 1215 | ;;; |
| 1216 | ;;; Generic functions! |
| 1217 | ;;; |
| 1218 | ;;; Generic functions have an applicable-methods cache associated with |
| 1219 | ;;; them. Every distinct set of types that is dispatched through a |
| 1220 | ;;; generic adds an entry to the cache. A composite dispatch procedure |
| 1221 | ;;; is recomputed every time an entry gets added to the cache, or when |
| 1222 | ;;; the cache is invalidated. |
| 1223 | ;;; |
| 1224 | ;;; In steady-state, this dispatch procedure is never regenerated; but |
| 1225 | ;;; during warm-up there is some churn. |
| 1226 | ;;; |
| 1227 | ;;; So what is the deal if warm-up happens in a multithreaded context? |
| 1228 | ;;; There is indeed a window between missing the cache for a certain set |
| 1229 | ;;; of arguments, and then updating the cache with the newly computed |
| 1230 | ;;; applicable methods. One of the updaters is liable to lose their new |
| 1231 | ;;; entry. |
| 1232 | ;;; |
| 1233 | ;;; This is actually OK though, because a subsequent cache miss for the |
| 1234 | ;;; race loser will just cause memoization to try again. The cache will |
| 1235 | ;;; eventually be consistent. We're not mutating the old part of the |
| 1236 | ;;; cache, just consing on the new entry. |
| 1237 | ;;; |
| 1238 | ;;; It doesn't even matter if the dispatch procedure and the cache are |
| 1239 | ;;; inconsistent -- most likely the type-set that lost the dispatch |
| 1240 | ;;; procedure race will simply re-trigger a memoization, but since the |
| 1241 | ;;; winner isn't in the effective-methods cache, it will likely also |
| 1242 | ;;; re-trigger a memoization, and the cache will finally be consistent. |
| 1243 | ;;; As you can see there is a possibility for ping-pong effects, but |
| 1244 | ;;; it's unlikely given the shortness of the window between slot-set! |
| 1245 | ;;; invocations. |
| 1246 | ;;; |
| 1247 | ;;; We probably do need to use atomic access primitives to correctly |
| 1248 | ;;; handle concurrency, but that's a more general Guile concern. |
| 1249 | ;;; |
| 1250 | |
| 1251 | (define-syntax arity-case |
| 1252 | (lambda (x) |
| 1253 | (syntax-case x () |
| 1254 | ;; (arity-case n 2 foo bar) |
| 1255 | ;; => (case n |
| 1256 | ;; ((0) (foo)) |
| 1257 | ;; ((1) (foo a)) |
| 1258 | ;; ((2) (foo a b)) |
| 1259 | ;; (else bar)) |
| 1260 | ((arity-case n max form alternate) |
| 1261 | (let ((max (syntax->datum #'max))) |
| 1262 | #`(case n |
| 1263 | #,@(let lp ((n 0)) |
| 1264 | (let ((ids (map (lambda (n) |
| 1265 | (let* ((n (+ (char->integer #\a) n)) |
| 1266 | (c (integer->char n))) |
| 1267 | (datum->syntax #'here (symbol c)))) |
| 1268 | (iota n)))) |
| 1269 | #`(((#,n) (form #,@ids)) |
| 1270 | . #,(if (< n max) |
| 1271 | (lp (1+ n)) |
| 1272 | #'())))) |
| 1273 | (else alternate))))))) |
| 1274 | |
| 1275 | ;;; |
| 1276 | ;;; These dispatchers are set as the "procedure" field of <generic> |
| 1277 | ;;; instances. Unlike CLOS, in GOOPS a generic function can have |
| 1278 | ;;; multiple arities. |
| 1279 | ;;; |
| 1280 | ;;; We pre-generate fast dispatchers for applications of up to 20 |
| 1281 | ;;; arguments. More arguments than that will go through slower generic |
| 1282 | ;;; routines that cons arguments into a rest list. |
| 1283 | ;;; |
| 1284 | (define (multiple-arity-dispatcher fv miss) |
| 1285 | (define-syntax dispatch |
| 1286 | (lambda (x) |
| 1287 | (define (build-clauses args) |
| 1288 | (let ((len (length (syntax->datum args)))) |
| 1289 | #`((#,args ((vector-ref fv #,len) . #,args)) |
| 1290 | . #,(syntax-case args () |
| 1291 | (() #'()) |
| 1292 | ((arg ... _) (build-clauses #'(arg ...))))))) |
| 1293 | (syntax-case x () |
| 1294 | ((dispatch arg ...) |
| 1295 | #`(case-lambda |
| 1296 | #,@(build-clauses #'(arg ...)) |
| 1297 | (args (apply miss args))))))) |
| 1298 | (arity-case (vector-length fv) 20 dispatch |
| 1299 | (lambda args |
| 1300 | (let ((nargs (length args))) |
| 1301 | (if (< nargs (vector-length fv)) |
| 1302 | (apply (vector-ref fv nargs) args) |
| 1303 | (apply miss args)))))) |
| 1304 | |
| 1305 | ;;; |
| 1306 | ;;; The above multiple-arity-dispatcher is entirely sufficient, and |
| 1307 | ;;; should be fast enough. Still, for no good reason we also have an |
| 1308 | ;;; arity dispatcher for generics that are only called with one arity. |
| 1309 | ;;; |
| 1310 | (define (single-arity-dispatcher f nargs miss) |
| 1311 | (define-syntax-rule (dispatch arg ...) |
| 1312 | (case-lambda |
| 1313 | ((arg ...) (f arg ...)) |
| 1314 | (args (apply miss args)))) |
| 1315 | (arity-case nargs 20 dispatch |
| 1316 | (lambda args |
| 1317 | (if (eqv? (length args) nargs) |
| 1318 | (apply f args) |
| 1319 | (apply miss args))))) |
| 1320 | |
| 1321 | ;;; |
| 1322 | ;;; The guts of generic function dispatch are here. Once we've selected |
| 1323 | ;;; an arity, we need to map from arguments to effective method. Until |
| 1324 | ;;; we have `eqv?' specializers, this map is entirely a function of the |
| 1325 | ;;; types (classes) of the arguments. So, we look in the cache to see |
| 1326 | ;;; if we have seen this set of concrete types, and if so we apply the |
| 1327 | ;;; previously computed effective method. Otherwise we miss the cache, |
| 1328 | ;;; so we'll have to compute the right answer for this set of types, add |
| 1329 | ;;; the mapping to the cache, and apply the newly computed method. |
| 1330 | ;;; |
| 1331 | ;;; The cached mapping is invalidated whenever a new method is defined |
| 1332 | ;;; on this generic, or whenever the class hierarchy of any method |
| 1333 | ;;; specializer changes. |
| 1334 | ;;; |
| 1335 | (define (single-arity-cache-dispatch cache nargs cache-miss) |
| 1336 | (match cache |
| 1337 | (() cache-miss) |
| 1338 | ((#(len types rest? cmethod nargs*) . cache) |
| 1339 | (define (type-ref n) |
| 1340 | (and (< n len) (list-ref types n))) |
| 1341 | (cond |
| 1342 | ((eqv? nargs nargs*) |
| 1343 | (let ((cache-miss (single-arity-cache-dispatch cache nargs cache-miss))) |
| 1344 | (define-syntax args-match? |
| 1345 | (syntax-rules () |
| 1346 | ((args-match?) #t) |
| 1347 | ((args-match? (arg type) (arg* type*) ...) |
| 1348 | ;; Check that the arg has the exact type that we saw. It |
| 1349 | ;; could be that `type' is #f, which indicates the end of |
| 1350 | ;; the specializers list. Once all specializers have been |
| 1351 | ;; examined, we don't need to look at any more arguments |
| 1352 | ;; to know that this is a cache hit. |
| 1353 | (or (not type) |
| 1354 | (and (eq? (class-of arg) type) |
| 1355 | (args-match? (arg* type*) ...)))))) |
| 1356 | (define-syntax dispatch |
| 1357 | (lambda (x) |
| 1358 | (define (bind-types types k) |
| 1359 | (let lp ((types types) (n 0)) |
| 1360 | (syntax-case types () |
| 1361 | (() (k)) |
| 1362 | ((type . types) |
| 1363 | #`(let ((type (type-ref #,n))) |
| 1364 | #,(lp #'types (1+ n))))))) |
| 1365 | (syntax-case x () |
| 1366 | ((dispatch arg ...) |
| 1367 | (with-syntax (((type ...) (generate-temporaries #'(arg ...)))) |
| 1368 | (bind-types |
| 1369 | #'(type ...) |
| 1370 | (lambda () |
| 1371 | #'(lambda (arg ...) |
| 1372 | (if (args-match? (arg type) ...) |
| 1373 | (cmethod arg ...) |
| 1374 | (cache-miss arg ...)))))))))) |
| 1375 | (arity-case nargs 20 dispatch |
| 1376 | (lambda args |
| 1377 | (define (args-match? args) |
| 1378 | (let lp ((args args) (types types)) |
| 1379 | (match types |
| 1380 | ((type . types) |
| 1381 | (let ((arg (car args)) |
| 1382 | (args (cdr args))) |
| 1383 | (and (eq? type (class-of arg)) |
| 1384 | (lp args types)))) |
| 1385 | (_ #t)))) |
| 1386 | (if (args-match? args) |
| 1387 | (apply cmethod args) |
| 1388 | (apply cache-miss args)))))) |
| 1389 | (else |
| 1390 | (single-arity-cache-dispatch cache nargs cache-miss)))))) |
| 1391 | |
| 1392 | (define (compute-generic-function-dispatch-procedure gf) |
| 1393 | (define (seen-arities cache) |
| 1394 | (let lp ((arities 0) (cache cache)) |
| 1395 | (match cache |
| 1396 | (() arities) |
| 1397 | ((#(_ _ _ _ nargs) . cache) |
| 1398 | (lp (logior arities (ash 1 nargs)) cache))))) |
| 1399 | (define (cache-miss . args) |
| 1400 | (memoize-generic-function-application! gf args) |
| 1401 | (apply gf args)) |
| 1402 | (let* ((cache (slot-ref gf 'effective-methods)) |
| 1403 | (arities (seen-arities cache)) |
| 1404 | (max-arity (let lp ((max -1)) |
| 1405 | (if (< arities (ash 1 (1+ max))) |
| 1406 | max |
| 1407 | (lp (1+ max)))))) |
| 1408 | (cond |
| 1409 | ((= max-arity -1) |
| 1410 | ;; Nothing in the cache. |
| 1411 | cache-miss) |
| 1412 | ((= arities (ash 1 max-arity)) |
| 1413 | ;; Only one arity in the cache. |
| 1414 | (let ((nargs (match cache ((#(_ _ _ _ nargs) . _) nargs)))) |
| 1415 | (let ((f (single-arity-cache-dispatch cache nargs cache-miss))) |
| 1416 | (single-arity-dispatcher f nargs cache-miss)))) |
| 1417 | (else |
| 1418 | ;; Multiple arities. |
| 1419 | (let ((fv (make-vector (1+ max-arity) #f))) |
| 1420 | (let lp ((n 0)) |
| 1421 | (when (<= n max-arity) |
| 1422 | (let ((f (single-arity-cache-dispatch cache n cache-miss))) |
| 1423 | (vector-set! fv n f) |
| 1424 | (lp (1+ n))))) |
| 1425 | (multiple-arity-dispatcher fv cache-miss)))))) |
| 1426 | |
| 1427 | (define (recompute-generic-function-dispatch-procedure! gf) |
| 1428 | (slot-set! gf 'procedure |
| 1429 | (compute-generic-function-dispatch-procedure gf))) |
| 1430 | |
| 1431 | (define (memoize-effective-method! gf args applicable) |
| 1432 | (define (first-n ls n) |
| 1433 | (if (or (zero? n) (null? ls)) |
| 1434 | '() |
| 1435 | (cons (car ls) (first-n (cdr ls) (- n 1))))) |
| 1436 | (define (parse n ls) |
| 1437 | (cond ((null? ls) |
| 1438 | (memoize n #f (map class-of args))) |
| 1439 | ((= n (slot-ref gf 'n-specialized)) |
| 1440 | (memoize n #t (map class-of (first-n args n)))) |
| 1441 | (else |
| 1442 | (parse (1+ n) (cdr ls))))) |
| 1443 | (define (memoize len rest? types) |
| 1444 | (let* ((cmethod (compute-cmethod applicable types)) |
| 1445 | (cache (cons (vector len types rest? cmethod (length args)) |
| 1446 | (slot-ref gf 'effective-methods)))) |
| 1447 | (slot-set! gf 'effective-methods cache) |
| 1448 | (recompute-generic-function-dispatch-procedure! gf) |
| 1449 | cmethod)) |
| 1450 | (parse 0 args)) |
| 1451 | |
| 1452 | ;;; |
| 1453 | ;;; If a method refers to `next-method' in its body, that method will be |
| 1454 | ;;; able to dispatch to the next most specific method. The exact |
| 1455 | ;;; `next-method' implementation is only known at runtime, as it is a |
| 1456 | ;;; function of which precise argument types are being dispatched, which |
| 1457 | ;;; might be subclasses of the method's declared specializers. |
| 1458 | ;;; |
| 1459 | ;;; Guile implements `next-method' by binding it as a closure variable. |
| 1460 | ;;; An effective method is bound to a specific `next-method' by the |
| 1461 | ;;; `make-procedure' slot of a <method>, which returns the new closure. |
| 1462 | ;;; |
| 1463 | (define (compute-cmethod methods types) |
| 1464 | (match methods |
| 1465 | ((method . methods) |
| 1466 | (match (slot-ref method 'make-procedure) |
| 1467 | (#f (method-procedure method)) |
| 1468 | (make-procedure |
| 1469 | (make-procedure |
| 1470 | (match methods |
| 1471 | (() |
| 1472 | (lambda args |
| 1473 | (no-next-method (method-generic-function method) args))) |
| 1474 | (methods |
| 1475 | (compute-cmethod methods types))))))))) |
| 1476 | |
| 1477 | ;;; |
| 1478 | ;;; Memoization |
| 1479 | ;;; |
| 1480 | |
| 1481 | (define (memoize-generic-function-application! gf args) |
| 1482 | (let ((applicable ((if (eq? gf compute-applicable-methods) |
| 1483 | %compute-applicable-methods |
| 1484 | compute-applicable-methods) |
| 1485 | gf args))) |
| 1486 | (cond (applicable |
| 1487 | (memoize-effective-method! gf args applicable)) |
| 1488 | (else |
| 1489 | (no-applicable-method gf args))))) |
| 1490 | |
| 1491 | (define no-applicable-method |
| 1492 | (make <generic> #:name 'no-applicable-method)) |
| 1493 | |
| 1494 | (%goops-early-init) |
| 1495 | |
| 1496 | ;; Then load the rest of GOOPS |
| 1497 | |
| 1498 | \f |
| 1499 | ;; FIXME: deprecate. |
| 1500 | (define min-fixnum (- (expt 2 29))) |
| 1501 | (define max-fixnum (- (expt 2 29) 1)) |
| 1502 | |
| 1503 | ;; |
| 1504 | ;; goops-error |
| 1505 | ;; |
| 1506 | (define (goops-error format-string . args) |
| 1507 | (scm-error 'goops-error #f format-string args '())) |
| 1508 | |
| 1509 | ;;; |
| 1510 | ;;; {Meta classes} |
| 1511 | ;;; |
| 1512 | |
| 1513 | (define ensure-metaclass-with-supers |
| 1514 | (let ((table-of-metas '())) |
| 1515 | (lambda (meta-supers) |
| 1516 | (let ((entry (assoc meta-supers table-of-metas))) |
| 1517 | (if entry |
| 1518 | ;; Found a previously created metaclass |
| 1519 | (cdr entry) |
| 1520 | ;; Create a new meta-class which inherit from "meta-supers" |
| 1521 | (let ((new (make <class> #:dsupers meta-supers |
| 1522 | #:slots '() |
| 1523 | #:name (gensym "metaclass")))) |
| 1524 | (set! table-of-metas (cons (cons meta-supers new) table-of-metas)) |
| 1525 | new)))))) |
| 1526 | |
| 1527 | (define (ensure-metaclass supers) |
| 1528 | (if (null? supers) |
| 1529 | <class> |
| 1530 | (let* ((all-metas (map (lambda (x) (class-of x)) supers)) |
| 1531 | (all-cpls (append-map (lambda (m) |
| 1532 | (cdr (class-precedence-list m))) |
| 1533 | all-metas)) |
| 1534 | (needed-metas '())) |
| 1535 | ;; Find the most specific metaclasses. The new metaclass will be |
| 1536 | ;; a subclass of these. |
| 1537 | (for-each |
| 1538 | (lambda (meta) |
| 1539 | (when (and (not (member meta all-cpls)) |
| 1540 | (not (member meta needed-metas))) |
| 1541 | (set! needed-metas (append needed-metas (list meta))))) |
| 1542 | all-metas) |
| 1543 | ;; Now return a subclass of the metaclasses we found. |
| 1544 | (if (null? (cdr needed-metas)) |
| 1545 | (car needed-metas) ; If there's only one, just use it. |
| 1546 | (ensure-metaclass-with-supers needed-metas))))) |
| 1547 | |
| 1548 | ;;; |
| 1549 | ;;; {Classes} |
| 1550 | ;;; |
| 1551 | |
| 1552 | ;;; (define-class NAME (SUPER ...) SLOT-DEFINITION ... OPTION ...) |
| 1553 | ;;; |
| 1554 | ;;; SLOT-DEFINITION ::= INSTANCE-OF-<SLOT> | (SLOT-NAME OPTION ...) |
| 1555 | ;;; OPTION ::= KEYWORD VALUE |
| 1556 | ;;; |
| 1557 | |
| 1558 | (define (make-class supers slots . options) |
| 1559 | (define (find-duplicate l) |
| 1560 | (match l |
| 1561 | (() #f) |
| 1562 | ((head . tail) |
| 1563 | (if (memq head tail) |
| 1564 | head |
| 1565 | (find-duplicate tail))))) |
| 1566 | (define (slot-spec->name slot-spec) |
| 1567 | (match slot-spec |
| 1568 | (((? symbol? name) . args) name) |
| 1569 | ;; We can get here when redefining classes. |
| 1570 | ((? slot? slot) (%slot-definition-name slot)))) |
| 1571 | |
| 1572 | (let* ((name (get-keyword #:name options *unbound*)) |
| 1573 | (supers (if (not (or-map (lambda (class) |
| 1574 | (memq <object> |
| 1575 | (class-precedence-list class))) |
| 1576 | supers)) |
| 1577 | (append supers (list <object>)) |
| 1578 | supers)) |
| 1579 | (metaclass (or (get-keyword #:metaclass options #f) |
| 1580 | (ensure-metaclass supers)))) |
| 1581 | |
| 1582 | ;; Verify that all direct slots are different and that we don't inherit |
| 1583 | ;; several time from the same class |
| 1584 | (let ((tmp1 (find-duplicate supers)) |
| 1585 | (tmp2 (find-duplicate (map slot-spec->name slots)))) |
| 1586 | (if tmp1 |
| 1587 | (goops-error "make-class: super class ~S is duplicate in class ~S" |
| 1588 | tmp1 name)) |
| 1589 | (if tmp2 |
| 1590 | (goops-error "make-class: slot ~S is duplicate in class ~S" |
| 1591 | tmp2 name))) |
| 1592 | |
| 1593 | ;; Everything seems correct, build the class |
| 1594 | (apply make metaclass |
| 1595 | #:dsupers supers |
| 1596 | #:slots slots |
| 1597 | #:name name |
| 1598 | options))) |
| 1599 | |
| 1600 | ;;; (class (SUPER ...) SLOT-DEFINITION ... OPTION ...) |
| 1601 | ;;; |
| 1602 | ;;; SLOT-DEFINITION ::= SLOT-NAME | (SLOT-NAME OPTION ...) |
| 1603 | ;;; OPTION ::= KEYWORD VALUE |
| 1604 | ;;; |
| 1605 | (define-syntax class |
| 1606 | (lambda (x) |
| 1607 | (define (parse-options options) |
| 1608 | (syntax-case options () |
| 1609 | (() #'()) |
| 1610 | ((kw arg . options) (keyword? (syntax->datum #'kw)) |
| 1611 | (with-syntax ((options (parse-options #'options))) |
| 1612 | (syntax-case #'kw () |
| 1613 | (#:init-form |
| 1614 | #'(kw 'arg #:init-thunk (lambda () arg) . options)) |
| 1615 | (_ |
| 1616 | #'(kw arg . options))))))) |
| 1617 | (define (check-valid-kwargs args) |
| 1618 | (syntax-case args () |
| 1619 | (() #'()) |
| 1620 | ((kw arg . args) (keyword? (syntax->datum #'kw)) |
| 1621 | #`(kw arg . #,(check-valid-kwargs #'args))))) |
| 1622 | (define (parse-slots-and-kwargs args) |
| 1623 | (syntax-case args () |
| 1624 | (() |
| 1625 | #'(() ())) |
| 1626 | ((kw . _) (keyword? (syntax->datum #'kw)) |
| 1627 | #`(() #,(check-valid-kwargs args))) |
| 1628 | (((name option ...) args ...) |
| 1629 | (with-syntax (((slots kwargs) (parse-slots-and-kwargs #'(args ...))) |
| 1630 | ((option ...) (parse-options #'(option ...)))) |
| 1631 | #'(((list 'name option ...) . slots) kwargs))) |
| 1632 | ((name args ...) (symbol? (syntax->datum #'name)) |
| 1633 | (with-syntax (((slots kwargs) (parse-slots-and-kwargs #'(args ...)))) |
| 1634 | #'(('(name) . slots) kwargs))))) |
| 1635 | (syntax-case x () |
| 1636 | ((class (super ...) arg ...) |
| 1637 | (with-syntax ((((slot-def ...) (option ...)) |
| 1638 | (parse-slots-and-kwargs #'(arg ...)))) |
| 1639 | #'(make-class (list super ...) |
| 1640 | (list slot-def ...) |
| 1641 | option ...)))))) |
| 1642 | |
| 1643 | (define-syntax define-class-pre-definition |
| 1644 | (lambda (x) |
| 1645 | (syntax-case x () |
| 1646 | ((_ (k arg rest ...) out ...) |
| 1647 | (keyword? (syntax->datum #'k)) |
| 1648 | (case (syntax->datum #'k) |
| 1649 | ((#:getter #:setter) |
| 1650 | #'(define-class-pre-definition (rest ...) |
| 1651 | out ... |
| 1652 | (when (or (not (defined? 'arg)) |
| 1653 | (not (is-a? arg <generic>))) |
| 1654 | (toplevel-define! |
| 1655 | 'arg |
| 1656 | (ensure-generic (if (defined? 'arg) arg #f) 'arg))))) |
| 1657 | ((#:accessor) |
| 1658 | #'(define-class-pre-definition (rest ...) |
| 1659 | out ... |
| 1660 | (when (or (not (defined? 'arg)) |
| 1661 | (not (is-a? arg <accessor>))) |
| 1662 | (toplevel-define! |
| 1663 | 'arg |
| 1664 | (ensure-accessor (if (defined? 'arg) arg #f) 'arg))))) |
| 1665 | (else |
| 1666 | #'(define-class-pre-definition (rest ...) out ...)))) |
| 1667 | ((_ () out ...) |
| 1668 | #'(begin out ...))))) |
| 1669 | |
| 1670 | ;; Some slot options require extra definitions to be made. In |
| 1671 | ;; particular, we want to make sure that the generic function objects |
| 1672 | ;; which represent accessors exist before `make-class' tries to add |
| 1673 | ;; methods to them. |
| 1674 | (define-syntax define-class-pre-definitions |
| 1675 | (lambda (x) |
| 1676 | (syntax-case x () |
| 1677 | ((_ () out ...) |
| 1678 | #'(begin out ...)) |
| 1679 | ((_ (slot rest ...) out ...) |
| 1680 | (keyword? (syntax->datum #'slot)) |
| 1681 | #'(begin out ...)) |
| 1682 | ((_ (slot rest ...) out ...) |
| 1683 | (identifier? #'slot) |
| 1684 | #'(define-class-pre-definitions (rest ...) |
| 1685 | out ...)) |
| 1686 | ((_ ((slotname slotopt ...) rest ...) out ...) |
| 1687 | #'(define-class-pre-definitions (rest ...) |
| 1688 | out ... (define-class-pre-definition (slotopt ...))))))) |
| 1689 | |
| 1690 | (define-syntax-rule (define-class name supers slot ...) |
| 1691 | (begin |
| 1692 | (define-class-pre-definitions (slot ...)) |
| 1693 | (if (and (defined? 'name) |
| 1694 | (is-a? name <class>) |
| 1695 | (memq <object> (class-precedence-list name))) |
| 1696 | (class-redefinition name |
| 1697 | (class supers slot ... #:name 'name)) |
| 1698 | (toplevel-define! 'name (class supers slot ... #:name 'name))))) |
| 1699 | |
| 1700 | (define-syntax-rule (standard-define-class arg ...) |
| 1701 | (define-class arg ...)) |
| 1702 | |
| 1703 | ;;; |
| 1704 | ;;; {Generic functions and accessors} |
| 1705 | ;;; |
| 1706 | |
| 1707 | ;; Apparently the desired semantics are that we extend previous |
| 1708 | ;; procedural definitions, but that if `name' was already a generic, we |
| 1709 | ;; overwrite its definition. |
| 1710 | (define-syntax define-generic |
| 1711 | (lambda (x) |
| 1712 | (syntax-case x () |
| 1713 | ((define-generic name) (symbol? (syntax->datum #'name)) |
| 1714 | #'(define name |
| 1715 | (if (and (defined? 'name) (is-a? name <generic>)) |
| 1716 | (make <generic> #:name 'name) |
| 1717 | (ensure-generic (if (defined? 'name) name #f) 'name))))))) |
| 1718 | |
| 1719 | (define-syntax define-extended-generic |
| 1720 | (lambda (x) |
| 1721 | (syntax-case x () |
| 1722 | ((define-extended-generic name val) (symbol? (syntax->datum #'name)) |
| 1723 | #'(define name (make-extended-generic val 'name)))))) |
| 1724 | |
| 1725 | (define-syntax define-extended-generics |
| 1726 | (lambda (x) |
| 1727 | (define (id-append ctx a b) |
| 1728 | (datum->syntax ctx (symbol-append (syntax->datum a) (syntax->datum b)))) |
| 1729 | (syntax-case x () |
| 1730 | ((define-extended-generic (name ...) #:prefix (prefix ...)) |
| 1731 | (and (and-map symbol? (syntax->datum #'(name ...))) |
| 1732 | (and-map symbol? (syntax->datum #'(prefix ...)))) |
| 1733 | (with-syntax ((((val ...)) (map (lambda (name) |
| 1734 | (map (lambda (prefix) |
| 1735 | (id-append name prefix name)) |
| 1736 | #'(prefix ...))) |
| 1737 | #'(name ...)))) |
| 1738 | #'(begin |
| 1739 | (define-extended-generic name (list val ...)) |
| 1740 | ...)))))) |
| 1741 | |
| 1742 | (define* (make-generic #:optional name) |
| 1743 | (make <generic> #:name name)) |
| 1744 | |
| 1745 | (define* (make-extended-generic gfs #:optional name) |
| 1746 | (let* ((gfs (if (list? gfs) gfs (list gfs))) |
| 1747 | (gws? (any (lambda (gf) (is-a? gf <generic-with-setter>)) gfs))) |
| 1748 | (let ((ans (if gws? |
| 1749 | (let* ((sname (and name (make-setter-name name))) |
| 1750 | (setters |
| 1751 | (append-map (lambda (gf) |
| 1752 | (if (is-a? gf <generic-with-setter>) |
| 1753 | (list (ensure-generic (setter gf) |
| 1754 | sname)) |
| 1755 | '())) |
| 1756 | gfs)) |
| 1757 | (es (make <extended-generic-with-setter> |
| 1758 | #:name name |
| 1759 | #:extends gfs |
| 1760 | #:setter (make <extended-generic> |
| 1761 | #:name sname |
| 1762 | #:extends setters)))) |
| 1763 | (extended-by! setters (setter es)) |
| 1764 | es) |
| 1765 | (make <extended-generic> |
| 1766 | #:name name |
| 1767 | #:extends gfs)))) |
| 1768 | (extended-by! gfs ans) |
| 1769 | ans))) |
| 1770 | |
| 1771 | (define (extended-by! gfs eg) |
| 1772 | (for-each (lambda (gf) |
| 1773 | (slot-set! gf 'extended-by |
| 1774 | (cons eg (slot-ref gf 'extended-by)))) |
| 1775 | gfs) |
| 1776 | (invalidate-method-cache! eg)) |
| 1777 | |
| 1778 | (define (not-extended-by! gfs eg) |
| 1779 | (for-each (lambda (gf) |
| 1780 | (slot-set! gf 'extended-by |
| 1781 | (delq! eg (slot-ref gf 'extended-by)))) |
| 1782 | gfs) |
| 1783 | (invalidate-method-cache! eg)) |
| 1784 | |
| 1785 | (define* (ensure-generic old-definition #:optional name) |
| 1786 | (cond ((is-a? old-definition <generic>) old-definition) |
| 1787 | ((procedure-with-setter? old-definition) |
| 1788 | (make <generic-with-setter> |
| 1789 | #:name name |
| 1790 | #:default (procedure old-definition) |
| 1791 | #:setter (setter old-definition))) |
| 1792 | ((procedure? old-definition) |
| 1793 | (if (generic-capability? old-definition) old-definition |
| 1794 | (make <generic> #:name name #:default old-definition))) |
| 1795 | (else (make <generic> #:name name)))) |
| 1796 | |
| 1797 | ;; same semantics as <generic> |
| 1798 | (define-syntax-rule (define-accessor name) |
| 1799 | (define name |
| 1800 | (cond ((not (defined? 'name)) (ensure-accessor #f 'name)) |
| 1801 | ((is-a? name <accessor>) (make <accessor> #:name 'name)) |
| 1802 | (else (ensure-accessor name 'name))))) |
| 1803 | |
| 1804 | (define (make-setter-name name) |
| 1805 | (string->symbol (string-append "setter:" (symbol->string name)))) |
| 1806 | |
| 1807 | (define* (make-accessor #:optional name) |
| 1808 | (make <accessor> |
| 1809 | #:name name |
| 1810 | #:setter (make <generic> |
| 1811 | #:name (and name (make-setter-name name))))) |
| 1812 | |
| 1813 | (define* (ensure-accessor proc #:optional name) |
| 1814 | (cond ((and (is-a? proc <accessor>) |
| 1815 | (is-a? (setter proc) <generic>)) |
| 1816 | proc) |
| 1817 | ((is-a? proc <generic-with-setter>) |
| 1818 | (upgrade-accessor proc (setter proc))) |
| 1819 | ((is-a? proc <generic>) |
| 1820 | (upgrade-accessor proc (make-generic name))) |
| 1821 | ((procedure-with-setter? proc) |
| 1822 | (make <accessor> |
| 1823 | #:name name |
| 1824 | #:default (procedure proc) |
| 1825 | #:setter (ensure-generic (setter proc) name))) |
| 1826 | ((procedure? proc) |
| 1827 | (ensure-accessor (if (generic-capability? proc) |
| 1828 | (make <generic> #:name name #:default proc) |
| 1829 | (ensure-generic proc name)) |
| 1830 | name)) |
| 1831 | (else |
| 1832 | (make-accessor name)))) |
| 1833 | |
| 1834 | (define (upgrade-accessor generic setter) |
| 1835 | (let ((methods (slot-ref generic 'methods)) |
| 1836 | (gws (make (if (is-a? generic <extended-generic>) |
| 1837 | <extended-generic-with-setter> |
| 1838 | <accessor>) |
| 1839 | #:name (generic-function-name generic) |
| 1840 | #:extended-by (slot-ref generic 'extended-by) |
| 1841 | #:setter setter))) |
| 1842 | (when (is-a? generic <extended-generic>) |
| 1843 | (let ((gfs (slot-ref generic 'extends))) |
| 1844 | (not-extended-by! gfs generic) |
| 1845 | (slot-set! gws 'extends gfs) |
| 1846 | (extended-by! gfs gws))) |
| 1847 | ;; Steal old methods |
| 1848 | (for-each (lambda (method) |
| 1849 | (slot-set! method 'generic-function gws)) |
| 1850 | methods) |
| 1851 | (slot-set! gws 'methods methods) |
| 1852 | (invalidate-method-cache! gws) |
| 1853 | gws)) |
| 1854 | |
| 1855 | ;;; |
| 1856 | ;;; {Methods} |
| 1857 | ;;; |
| 1858 | |
| 1859 | ;; Note: `a' and `b' can have unequal lengths (i.e. one can be one |
| 1860 | ;; element longer than the other when we have a dotted parameter |
| 1861 | ;; list). For instance, with the call |
| 1862 | ;; |
| 1863 | ;; (M 1) |
| 1864 | ;; |
| 1865 | ;; with |
| 1866 | ;; |
| 1867 | ;; (define-method M (a . l) ....) |
| 1868 | ;; (define-method M (a) ....) |
| 1869 | ;; |
| 1870 | ;; we consider that the second method is more specific. |
| 1871 | ;; |
| 1872 | ;; Precondition: `a' and `b' are methods and are applicable to `types'. |
| 1873 | (define (%method-more-specific? a b types) |
| 1874 | (let lp ((a-specializers (method-specializers a)) |
| 1875 | (b-specializers (method-specializers b)) |
| 1876 | (types types)) |
| 1877 | (cond |
| 1878 | ;; (a) less specific than (a b ...) or (a . b) |
| 1879 | ((null? a-specializers) #t) |
| 1880 | ;; (a b ...) or (a . b) less specific than (a) |
| 1881 | ((null? b-specializers) #f) |
| 1882 | ;; (a . b) less specific than (a b ...) |
| 1883 | ((not (pair? a-specializers)) #f) |
| 1884 | ;; (a b ...) more specific than (a . b) |
| 1885 | ((not (pair? b-specializers)) #t) |
| 1886 | (else |
| 1887 | (let ((a-specializer (car a-specializers)) |
| 1888 | (b-specializer (car b-specializers)) |
| 1889 | (a-specializers (cdr a-specializers)) |
| 1890 | (b-specializers (cdr b-specializers)) |
| 1891 | (type (car types)) |
| 1892 | (types (cdr types))) |
| 1893 | (if (eq? a-specializer b-specializer) |
| 1894 | (lp a-specializers b-specializers types) |
| 1895 | (let lp ((cpl (class-precedence-list type))) |
| 1896 | (let ((elt (car cpl))) |
| 1897 | (cond |
| 1898 | ((eq? a-specializer elt) #t) |
| 1899 | ((eq? b-specializer elt) #f) |
| 1900 | (else (lp (cdr cpl)))))))))))) |
| 1901 | |
| 1902 | (define (%sort-applicable-methods methods types) |
| 1903 | (sort methods (lambda (a b) (%method-more-specific? a b types)))) |
| 1904 | |
| 1905 | (define (generic-function-methods obj) |
| 1906 | "Return the methods of the generic function @var{obj}." |
| 1907 | (define (fold-upward method-lists gf) |
| 1908 | (cond |
| 1909 | ((is-a? gf <extended-generic>) |
| 1910 | (let lp ((method-lists method-lists) (gfs (slot-ref gf 'extends))) |
| 1911 | (match gfs |
| 1912 | (() method-lists) |
| 1913 | ((gf . gfs) |
| 1914 | (lp (fold-upward (cons (slot-ref gf 'methods) method-lists) gf) |
| 1915 | gfs))))) |
| 1916 | (else method-lists))) |
| 1917 | (define (fold-downward method-lists gf) |
| 1918 | (let lp ((method-lists (cons (slot-ref gf 'methods) method-lists)) |
| 1919 | (gfs (slot-ref gf 'extended-by))) |
| 1920 | (match gfs |
| 1921 | (() method-lists) |
| 1922 | ((gf . gfs) |
| 1923 | (lp (fold-downward method-lists gf) gfs))))) |
| 1924 | (unless (is-a? obj <generic>) |
| 1925 | (scm-error 'wrong-type-arg #f "Not a generic: ~S" |
| 1926 | (list obj) #f)) |
| 1927 | (concatenate (fold-downward (fold-upward '() obj) obj))) |
| 1928 | |
| 1929 | (define (%compute-applicable-methods gf args) |
| 1930 | (define (method-applicable? m types) |
| 1931 | (let lp ((specs (method-specializers m)) (types types)) |
| 1932 | (cond |
| 1933 | ((null? specs) (null? types)) |
| 1934 | ((not (pair? specs)) #t) |
| 1935 | ((null? types) #f) |
| 1936 | (else |
| 1937 | (and (memq (car specs) (class-precedence-list (car types))) |
| 1938 | (lp (cdr specs) (cdr types))))))) |
| 1939 | (let ((n (length args)) |
| 1940 | (types (map class-of args))) |
| 1941 | (let lp ((methods (generic-function-methods gf)) |
| 1942 | (applicable '())) |
| 1943 | (if (null? methods) |
| 1944 | (and (not (null? applicable)) |
| 1945 | (%sort-applicable-methods applicable types)) |
| 1946 | (let ((m (car methods))) |
| 1947 | (lp (cdr methods) |
| 1948 | (if (method-applicable? m types) |
| 1949 | (cons m applicable) |
| 1950 | applicable))))))) |
| 1951 | |
| 1952 | (define compute-applicable-methods %compute-applicable-methods) |
| 1953 | |
| 1954 | (define (toplevel-define! name val) |
| 1955 | (module-define! (current-module) name val)) |
| 1956 | |
| 1957 | (define-syntax define-method |
| 1958 | (syntax-rules (setter) |
| 1959 | ((_ ((setter name) . args) body ...) |
| 1960 | (begin |
| 1961 | (when (or (not (defined? 'name)) |
| 1962 | (not (is-a? name <accessor>))) |
| 1963 | (toplevel-define! 'name |
| 1964 | (ensure-accessor |
| 1965 | (if (defined? 'name) name #f) 'name))) |
| 1966 | (add-method! (setter name) (method args body ...)))) |
| 1967 | ((_ (name . args) body ...) |
| 1968 | (begin |
| 1969 | ;; FIXME: this code is how it always was, but it's quite cracky: |
| 1970 | ;; it will only define the generic function if it was undefined |
| 1971 | ;; before (ok), or *was defined to #f*. The latter is crack. But |
| 1972 | ;; there are bootstrap issues about fixing this -- change it to |
| 1973 | ;; (is-a? name <generic>) and see. |
| 1974 | (when (or (not (defined? 'name)) |
| 1975 | (not name)) |
| 1976 | (toplevel-define! 'name (make <generic> #:name 'name))) |
| 1977 | (add-method! name (method args body ...)))))) |
| 1978 | |
| 1979 | (define-syntax method |
| 1980 | (lambda (x) |
| 1981 | (define (parse-args args) |
| 1982 | (let lp ((ls args) (formals '()) (specializers '())) |
| 1983 | (syntax-case ls () |
| 1984 | (((f s) . rest) |
| 1985 | (and (identifier? #'f) (identifier? #'s)) |
| 1986 | (lp #'rest |
| 1987 | (cons #'f formals) |
| 1988 | (cons #'s specializers))) |
| 1989 | ((f . rest) |
| 1990 | (identifier? #'f) |
| 1991 | (lp #'rest |
| 1992 | (cons #'f formals) |
| 1993 | (cons #'<top> specializers))) |
| 1994 | (() |
| 1995 | (list (reverse formals) |
| 1996 | (reverse (cons #''() specializers)))) |
| 1997 | (tail |
| 1998 | (identifier? #'tail) |
| 1999 | (list (append (reverse formals) #'tail) |
| 2000 | (reverse (cons #'<top> specializers))))))) |
| 2001 | |
| 2002 | (define (find-free-id exp referent) |
| 2003 | (syntax-case exp () |
| 2004 | ((x . y) |
| 2005 | (or (find-free-id #'x referent) |
| 2006 | (find-free-id #'y referent))) |
| 2007 | (x |
| 2008 | (identifier? #'x) |
| 2009 | (let ((id (datum->syntax #'x referent))) |
| 2010 | (and (free-identifier=? #'x id) id))) |
| 2011 | (_ #f))) |
| 2012 | |
| 2013 | (define (compute-procedure formals body) |
| 2014 | (syntax-case body () |
| 2015 | ((body0 ...) |
| 2016 | (with-syntax ((formals formals)) |
| 2017 | #'(lambda formals body0 ...))))) |
| 2018 | |
| 2019 | (define (->proper args) |
| 2020 | (let lp ((ls args) (out '())) |
| 2021 | (syntax-case ls () |
| 2022 | ((x . xs) (lp #'xs (cons #'x out))) |
| 2023 | (() (reverse out)) |
| 2024 | (tail (reverse (cons #'tail out)))))) |
| 2025 | |
| 2026 | (define (compute-make-procedure formals body next-method) |
| 2027 | (syntax-case body () |
| 2028 | ((body ...) |
| 2029 | (with-syntax ((next-method next-method)) |
| 2030 | (syntax-case formals () |
| 2031 | ((formal ...) |
| 2032 | #'(lambda (real-next-method) |
| 2033 | (lambda (formal ...) |
| 2034 | (let ((next-method (lambda args |
| 2035 | (if (null? args) |
| 2036 | (real-next-method formal ...) |
| 2037 | (apply real-next-method args))))) |
| 2038 | body ...)))) |
| 2039 | (formals |
| 2040 | (with-syntax (((formal ...) (->proper #'formals))) |
| 2041 | #'(lambda (real-next-method) |
| 2042 | (lambda formals |
| 2043 | (let ((next-method (lambda args |
| 2044 | (if (null? args) |
| 2045 | (apply real-next-method formal ...) |
| 2046 | (apply real-next-method args))))) |
| 2047 | body ...)))))))))) |
| 2048 | |
| 2049 | (define (compute-procedures formals body) |
| 2050 | ;; So, our use of this is broken, because it operates on the |
| 2051 | ;; pre-expansion source code. It's equivalent to just searching |
| 2052 | ;; for referent in the datums. Ah well. |
| 2053 | (let ((id (find-free-id body 'next-method))) |
| 2054 | (if id |
| 2055 | ;; return a make-procedure |
| 2056 | (values #'#f |
| 2057 | (compute-make-procedure formals body id)) |
| 2058 | (values (compute-procedure formals body) |
| 2059 | #'#f)))) |
| 2060 | |
| 2061 | (syntax-case x () |
| 2062 | ((_ args) #'(method args (if #f #f))) |
| 2063 | ((_ args body0 body1 ...) |
| 2064 | (with-syntax (((formals (specializer ...)) (parse-args #'args))) |
| 2065 | (call-with-values |
| 2066 | (lambda () |
| 2067 | (compute-procedures #'formals #'(body0 body1 ...))) |
| 2068 | (lambda (procedure make-procedure) |
| 2069 | (with-syntax ((procedure procedure) |
| 2070 | (make-procedure make-procedure)) |
| 2071 | #'(make <method> |
| 2072 | #:specializers (cons* specializer ...) |
| 2073 | #:formals 'formals |
| 2074 | #:body '(body0 body1 ...) |
| 2075 | #:make-procedure make-procedure |
| 2076 | #:procedure procedure))))))))) |
| 2077 | |
| 2078 | ;;; |
| 2079 | ;;; {Utilities} |
| 2080 | ;;; |
| 2081 | ;;; These are useful when dealing with method specializers, which might |
| 2082 | ;;; have a rest argument. |
| 2083 | ;;; |
| 2084 | |
| 2085 | (define (map* fn . l) ; A map which accepts dotted lists (arg lists |
| 2086 | (cond ; must be "isomorph" |
| 2087 | ((null? (car l)) '()) |
| 2088 | ((pair? (car l)) (cons (apply fn (map car l)) |
| 2089 | (apply map* fn (map cdr l)))) |
| 2090 | (else (apply fn l)))) |
| 2091 | |
| 2092 | (define (for-each* fn . l) ; A for-each which accepts dotted lists (arg lists |
| 2093 | (cond ; must be "isomorph" |
| 2094 | ((null? (car l)) '()) |
| 2095 | ((pair? (car l)) (apply fn (map car l)) (apply for-each* fn (map cdr l))) |
| 2096 | (else (apply fn l)))) |
| 2097 | |
| 2098 | (define (length* ls) |
| 2099 | (do ((n 0 (+ 1 n)) |
| 2100 | (ls ls (cdr ls))) |
| 2101 | ((not (pair? ls)) n))) |
| 2102 | |
| 2103 | ;;; |
| 2104 | ;;; {add-method!} |
| 2105 | ;;; |
| 2106 | |
| 2107 | (define (add-method-in-classes! m) |
| 2108 | ;; Add method in all the classes which appears in its specializers list |
| 2109 | (for-each* (lambda (x) |
| 2110 | (let ((dm (class-direct-methods x))) |
| 2111 | (unless (memq m dm) |
| 2112 | (struct-set! x class-index-direct-methods (cons m dm))))) |
| 2113 | (method-specializers m))) |
| 2114 | |
| 2115 | (define (remove-method-in-classes! m) |
| 2116 | ;; Remove method in all the classes which appears in its specializers list |
| 2117 | (for-each* (lambda (x) |
| 2118 | (struct-set! x |
| 2119 | class-index-direct-methods |
| 2120 | (delv! m (class-direct-methods x)))) |
| 2121 | (method-specializers m))) |
| 2122 | |
| 2123 | (define (compute-new-list-of-methods gf new) |
| 2124 | (let ((new-spec (method-specializers new)) |
| 2125 | (methods (slot-ref gf 'methods))) |
| 2126 | (let loop ((l methods)) |
| 2127 | (if (null? l) |
| 2128 | (cons new methods) |
| 2129 | (if (equal? (method-specializers (car l)) new-spec) |
| 2130 | (begin |
| 2131 | ;; This spec. list already exists. Remove old method from dependents |
| 2132 | (remove-method-in-classes! (car l)) |
| 2133 | (set-car! l new) |
| 2134 | methods) |
| 2135 | (loop (cdr l))))))) |
| 2136 | |
| 2137 | (define (method-n-specializers m) |
| 2138 | (length* (slot-ref m 'specializers))) |
| 2139 | |
| 2140 | (define (calculate-n-specialized gf) |
| 2141 | (fold (lambda (m n) (max n (method-n-specializers m))) |
| 2142 | 0 |
| 2143 | (generic-function-methods gf))) |
| 2144 | |
| 2145 | (define (invalidate-method-cache! gf) |
| 2146 | (slot-set! gf 'n-specialized (calculate-n-specialized gf)) |
| 2147 | (%invalidate-method-cache! gf) |
| 2148 | (for-each (lambda (gf) (invalidate-method-cache! gf)) |
| 2149 | (slot-ref gf 'extended-by))) |
| 2150 | |
| 2151 | (define internal-add-method! |
| 2152 | (method ((gf <generic>) (m <method>)) |
| 2153 | (slot-set! m 'generic-function gf) |
| 2154 | (slot-set! gf 'methods (compute-new-list-of-methods gf m)) |
| 2155 | (invalidate-method-cache! gf) |
| 2156 | (add-method-in-classes! m) |
| 2157 | *unspecified*)) |
| 2158 | |
| 2159 | (define-generic add-method!) |
| 2160 | |
| 2161 | ((method-procedure internal-add-method!) add-method! internal-add-method!) |
| 2162 | |
| 2163 | (define-method (add-method! (proc <procedure>) (m <method>)) |
| 2164 | (if (generic-capability? proc) |
| 2165 | (begin |
| 2166 | (enable-primitive-generic! proc) |
| 2167 | (add-method! proc m)) |
| 2168 | (next-method))) |
| 2169 | |
| 2170 | (define-method (add-method! (pg <primitive-generic>) (m <method>)) |
| 2171 | (add-method! (primitive-generic-generic pg) m)) |
| 2172 | |
| 2173 | (define-method (add-method! obj (m <method>)) |
| 2174 | (goops-error "~S is not a valid generic function" obj)) |
| 2175 | |
| 2176 | ;;; |
| 2177 | ;;; {Access to meta objects} |
| 2178 | ;;; |
| 2179 | |
| 2180 | ;;; |
| 2181 | ;;; Methods |
| 2182 | ;;; |
| 2183 | (define-method (method-source (m <method>)) |
| 2184 | (let* ((spec (map* class-name (slot-ref m 'specializers))) |
| 2185 | (src (procedure-source (slot-ref m 'procedure)))) |
| 2186 | (and src |
| 2187 | (let ((args (cadr src)) |
| 2188 | (body (cddr src))) |
| 2189 | (cons 'method |
| 2190 | (cons (map* list args spec) |
| 2191 | body)))))) |
| 2192 | |
| 2193 | (define-method (method-formals (m <method>)) |
| 2194 | (slot-ref m 'formals)) |
| 2195 | |
| 2196 | ;;; |
| 2197 | ;;; Slots |
| 2198 | ;;; |
| 2199 | (define (slot-init-function class slot-name) |
| 2200 | (%slot-definition-init-thunk (or (class-slot-definition class slot-name) |
| 2201 | (error "slot not found" slot-name)))) |
| 2202 | |
| 2203 | (define (accessor-method-slot-definition obj) |
| 2204 | "Return the slot definition of the accessor @var{obj}." |
| 2205 | (slot-ref obj 'slot-definition)) |
| 2206 | |
| 2207 | |
| 2208 | ;;; |
| 2209 | ;;; {Standard methods used by the C runtime} |
| 2210 | ;;; |
| 2211 | |
| 2212 | ;;; Methods to compare objects |
| 2213 | ;;; |
| 2214 | |
| 2215 | ;; Have to do this in a strange order because equal? is used in the |
| 2216 | ;; add-method! implementation; we need to make sure that when the |
| 2217 | ;; primitive is extended, that the generic has a method. = |
| 2218 | (define g-equal? (make-generic 'equal?)) |
| 2219 | ;; When this generic gets called, we will have already checked eq? and |
| 2220 | ;; eqv? -- the purpose of this generic is to extend equality. So by |
| 2221 | ;; default, there is no extension, thus the #f return. |
| 2222 | (add-method! g-equal? (method (x y) #f)) |
| 2223 | (set-primitive-generic! equal? g-equal?) |
| 2224 | |
| 2225 | ;;; |
| 2226 | ;;; methods to display/write an object |
| 2227 | ;;; |
| 2228 | |
| 2229 | ; Code for writing objects must test that the slots they use are |
| 2230 | ; bound. Otherwise a slot-unbound method will be called and will |
| 2231 | ; conduct to an infinite loop. |
| 2232 | |
| 2233 | ;; Write |
| 2234 | (define (display-address o file) |
| 2235 | (display (number->string (object-address o) 16) file)) |
| 2236 | |
| 2237 | (define-method (write o file) |
| 2238 | (display "#<instance " file) |
| 2239 | (display-address o file) |
| 2240 | (display #\> file)) |
| 2241 | |
| 2242 | (define write-object (primitive-generic-generic write)) |
| 2243 | |
| 2244 | (define-method (write (o <object>) file) |
| 2245 | (let ((class (class-of o))) |
| 2246 | (if (slot-bound? class 'name) |
| 2247 | (begin |
| 2248 | (display "#<" file) |
| 2249 | (display (class-name class) file) |
| 2250 | (display #\space file) |
| 2251 | (display-address o file) |
| 2252 | (display #\> file)) |
| 2253 | (next-method)))) |
| 2254 | |
| 2255 | (define-method (write (slot <slot>) file) |
| 2256 | (let ((class (class-of slot))) |
| 2257 | (if (and (slot-bound? class 'name) |
| 2258 | (slot-bound? slot 'name)) |
| 2259 | (begin |
| 2260 | (display "#<" file) |
| 2261 | (display (class-name class) file) |
| 2262 | (display #\space file) |
| 2263 | (display (%slot-definition-name slot) file) |
| 2264 | (display #\space file) |
| 2265 | (display-address slot file) |
| 2266 | (display #\> file)) |
| 2267 | (next-method)))) |
| 2268 | |
| 2269 | (define-method (write (class <class>) file) |
| 2270 | (let ((meta (class-of class))) |
| 2271 | (if (and (slot-bound? class 'name) |
| 2272 | (slot-bound? meta 'name)) |
| 2273 | (begin |
| 2274 | (display "#<" file) |
| 2275 | (display (class-name meta) file) |
| 2276 | (display #\space file) |
| 2277 | (display (class-name class) file) |
| 2278 | (display #\space file) |
| 2279 | (display-address class file) |
| 2280 | (display #\> file)) |
| 2281 | (next-method)))) |
| 2282 | |
| 2283 | (define-method (write (gf <generic>) file) |
| 2284 | (let ((meta (class-of gf))) |
| 2285 | (if (and (slot-bound? meta 'name) |
| 2286 | (slot-bound? gf 'methods)) |
| 2287 | (begin |
| 2288 | (display "#<" file) |
| 2289 | (display (class-name meta) file) |
| 2290 | (let ((name (generic-function-name gf))) |
| 2291 | (if name |
| 2292 | (begin |
| 2293 | (display #\space file) |
| 2294 | (display name file)))) |
| 2295 | (display " (" file) |
| 2296 | (display (length (generic-function-methods gf)) file) |
| 2297 | (display ")>" file)) |
| 2298 | (next-method)))) |
| 2299 | |
| 2300 | (define-method (write (o <method>) file) |
| 2301 | (let ((meta (class-of o))) |
| 2302 | (if (and (slot-bound? meta 'name) |
| 2303 | (slot-bound? o 'specializers)) |
| 2304 | (begin |
| 2305 | (display "#<" file) |
| 2306 | (display (class-name meta) file) |
| 2307 | (display #\space file) |
| 2308 | (display (map* (lambda (spec) |
| 2309 | (if (slot-bound? spec 'name) |
| 2310 | (slot-ref spec 'name) |
| 2311 | spec)) |
| 2312 | (method-specializers o)) |
| 2313 | file) |
| 2314 | (display #\space file) |
| 2315 | (display-address o file) |
| 2316 | (display #\> file)) |
| 2317 | (next-method)))) |
| 2318 | |
| 2319 | ;; Display (do the same thing as write by default) |
| 2320 | (define-method (display o file) |
| 2321 | (write-object o file)) |
| 2322 | |
| 2323 | ;;; |
| 2324 | ;;; Handling of duplicate bindings in the module system |
| 2325 | ;;; |
| 2326 | |
| 2327 | (define (find-subclass super name) |
| 2328 | (let lp ((classes (class-direct-subclasses super))) |
| 2329 | (cond |
| 2330 | ((null? classes) |
| 2331 | (error "class not found" name)) |
| 2332 | ((and (slot-bound? (car classes) 'name) |
| 2333 | (eq? (class-name (car classes)) name)) |
| 2334 | (car classes)) |
| 2335 | (else |
| 2336 | (lp (cdr classes)))))) |
| 2337 | |
| 2338 | ;; A record type. |
| 2339 | (define <module> (find-subclass <top> '<module>)) |
| 2340 | |
| 2341 | (define-method (merge-generics (module <module>) |
| 2342 | (name <symbol>) |
| 2343 | (int1 <module>) |
| 2344 | (val1 <top>) |
| 2345 | (int2 <module>) |
| 2346 | (val2 <top>) |
| 2347 | (var <top>) |
| 2348 | (val <top>)) |
| 2349 | #f) |
| 2350 | |
| 2351 | (define-method (merge-generics (module <module>) |
| 2352 | (name <symbol>) |
| 2353 | (int1 <module>) |
| 2354 | (val1 <generic>) |
| 2355 | (int2 <module>) |
| 2356 | (val2 <generic>) |
| 2357 | (var <top>) |
| 2358 | (val <boolean>)) |
| 2359 | (and (not (eq? val1 val2)) |
| 2360 | (make-variable (make-extended-generic (list val2 val1) name)))) |
| 2361 | |
| 2362 | (define-method (merge-generics (module <module>) |
| 2363 | (name <symbol>) |
| 2364 | (int1 <module>) |
| 2365 | (val1 <generic>) |
| 2366 | (int2 <module>) |
| 2367 | (val2 <generic>) |
| 2368 | (var <top>) |
| 2369 | (gf <extended-generic>)) |
| 2370 | (and (not (memq val2 (slot-ref gf 'extends))) |
| 2371 | (begin |
| 2372 | (slot-set! gf |
| 2373 | 'extends |
| 2374 | (cons val2 (delq! val2 (slot-ref gf 'extends)))) |
| 2375 | (slot-set! val2 |
| 2376 | 'extended-by |
| 2377 | (cons gf (delq! gf (slot-ref val2 'extended-by)))) |
| 2378 | (invalidate-method-cache! gf) |
| 2379 | var))) |
| 2380 | |
| 2381 | (module-define! duplicate-handlers 'merge-generics merge-generics) |
| 2382 | |
| 2383 | (define-method (merge-accessors (module <module>) |
| 2384 | (name <symbol>) |
| 2385 | (int1 <module>) |
| 2386 | (val1 <top>) |
| 2387 | (int2 <module>) |
| 2388 | (val2 <top>) |
| 2389 | (var <top>) |
| 2390 | (val <top>)) |
| 2391 | #f) |
| 2392 | |
| 2393 | (define-method (merge-accessors (module <module>) |
| 2394 | (name <symbol>) |
| 2395 | (int1 <module>) |
| 2396 | (val1 <accessor>) |
| 2397 | (int2 <module>) |
| 2398 | (val2 <accessor>) |
| 2399 | (var <top>) |
| 2400 | (val <top>)) |
| 2401 | (merge-generics module name int1 val1 int2 val2 var val)) |
| 2402 | |
| 2403 | (module-define! duplicate-handlers 'merge-accessors merge-accessors) |
| 2404 | |
| 2405 | ;;; |
| 2406 | ;;; slot access |
| 2407 | ;;; |
| 2408 | |
| 2409 | (define (class-slot-ref class slot-name) |
| 2410 | (let ((slot (class-slot-definition class slot-name))) |
| 2411 | (unless (memq (%slot-definition-allocation slot) '(#:class #:each-subclass)) |
| 2412 | (slot-missing class slot-name)) |
| 2413 | (let ((x ((%slot-definition-slot-ref slot) #f))) |
| 2414 | (if (unbound? x) |
| 2415 | (slot-unbound class slot-name) |
| 2416 | x)))) |
| 2417 | |
| 2418 | (define (class-slot-set! class slot-name value) |
| 2419 | (let ((slot (class-slot-definition class slot-name))) |
| 2420 | (unless (memq (%slot-definition-allocation slot) '(#:class #:each-subclass)) |
| 2421 | (slot-missing class slot-name)) |
| 2422 | ((%slot-definition-slot-set! slot) #f value))) |
| 2423 | |
| 2424 | (define-method (slot-unbound (c <class>) (o <object>) s) |
| 2425 | (goops-error "Slot `~S' is unbound in object ~S" s o)) |
| 2426 | |
| 2427 | (define-method (slot-unbound (c <class>) s) |
| 2428 | (goops-error "Slot `~S' is unbound in class ~S" s c)) |
| 2429 | |
| 2430 | (define-method (slot-unbound (o <object>)) |
| 2431 | (goops-error "Unbound slot in object ~S" o)) |
| 2432 | |
| 2433 | (define-method (slot-missing (c <class>) (o <object>) s) |
| 2434 | (goops-error "No slot with name `~S' in object ~S" s o)) |
| 2435 | |
| 2436 | (define-method (slot-missing (c <class>) s) |
| 2437 | (goops-error "No class slot with name `~S' in class ~S" s c)) |
| 2438 | |
| 2439 | |
| 2440 | (define-method (slot-missing (c <class>) (o <object>) s value) |
| 2441 | (slot-missing c o s)) |
| 2442 | |
| 2443 | ;;; Methods for the possible error we can encounter when calling a gf |
| 2444 | |
| 2445 | (define-method (no-next-method (gf <generic>) args) |
| 2446 | (goops-error "No next method when calling ~S\nwith arguments ~S" gf args)) |
| 2447 | |
| 2448 | (define-method (no-applicable-method (gf <generic>) args) |
| 2449 | (goops-error "No applicable method for ~S in call ~S" |
| 2450 | gf (cons (generic-function-name gf) args))) |
| 2451 | |
| 2452 | (define-method (no-method (gf <generic>) args) |
| 2453 | (goops-error "No method defined for ~S" gf)) |
| 2454 | |
| 2455 | ;;; |
| 2456 | ;;; {Cloning functions (from rdeline@CS.CMU.EDU)} |
| 2457 | ;;; |
| 2458 | |
| 2459 | (define-method (shallow-clone (self <object>)) |
| 2460 | (let* ((class (class-of self)) |
| 2461 | (clone (%allocate-instance class)) |
| 2462 | (slots (map slot-definition-name (class-slots class)))) |
| 2463 | (for-each (lambda (slot) |
| 2464 | (when (slot-bound? self slot) |
| 2465 | (slot-set! clone slot (slot-ref self slot)))) |
| 2466 | slots) |
| 2467 | clone)) |
| 2468 | |
| 2469 | (define-method (deep-clone (self <object>)) |
| 2470 | (let* ((class (class-of self)) |
| 2471 | (clone (%allocate-instance class)) |
| 2472 | (slots (map slot-definition-name (class-slots class)))) |
| 2473 | (for-each (lambda (slot) |
| 2474 | (when (slot-bound? self slot) |
| 2475 | (slot-set! clone slot |
| 2476 | (let ((value (slot-ref self slot))) |
| 2477 | (if (instance? value) |
| 2478 | (deep-clone value) |
| 2479 | value))))) |
| 2480 | slots) |
| 2481 | clone)) |
| 2482 | |
| 2483 | ;;; |
| 2484 | ;;; {Class redefinition utilities} |
| 2485 | ;;; |
| 2486 | |
| 2487 | ;;; (class-redefinition OLD NEW) |
| 2488 | ;;; |
| 2489 | |
| 2490 | ;;; Has correct the following conditions: |
| 2491 | |
| 2492 | ;;; Methods |
| 2493 | ;;; |
| 2494 | ;;; 1. New accessor specializers refer to new header |
| 2495 | ;;; |
| 2496 | ;;; Classes |
| 2497 | ;;; |
| 2498 | ;;; 1. New class cpl refers to the new class header |
| 2499 | ;;; 2. Old class header exists on old super classes direct-subclass lists |
| 2500 | ;;; 3. New class header exists on new super classes direct-subclass lists |
| 2501 | |
| 2502 | (define-method (class-redefinition (old <class>) (new <class>)) |
| 2503 | ;; Work on direct methods: |
| 2504 | ;; 1. Remove accessor methods from the old class |
| 2505 | ;; 2. Patch the occurences of new in the specializers by old |
| 2506 | ;; 3. Displace the methods from old to new |
| 2507 | (remove-class-accessors! old) ;; -1- |
| 2508 | (let ((methods (class-direct-methods new))) |
| 2509 | (for-each (lambda (m) |
| 2510 | (update-direct-method! m new old)) ;; -2- |
| 2511 | methods) |
| 2512 | (struct-set! new |
| 2513 | class-index-direct-methods |
| 2514 | (append methods (class-direct-methods old)))) |
| 2515 | |
| 2516 | ;; Substitute old for new in new cpl |
| 2517 | (set-car! (struct-ref new class-index-cpl) old) |
| 2518 | |
| 2519 | ;; Remove the old class from the direct-subclasses list of its super classes |
| 2520 | (for-each (lambda (c) (struct-set! c class-index-direct-subclasses |
| 2521 | (delv! old (class-direct-subclasses c)))) |
| 2522 | (class-direct-supers old)) |
| 2523 | |
| 2524 | ;; Replace the new class with the old in the direct-subclasses of the supers |
| 2525 | (for-each (lambda (c) |
| 2526 | (struct-set! c class-index-direct-subclasses |
| 2527 | (cons old (delv! new (class-direct-subclasses c))))) |
| 2528 | (class-direct-supers new)) |
| 2529 | |
| 2530 | ;; Swap object headers |
| 2531 | (%modify-class old new) |
| 2532 | |
| 2533 | ;; Now old is NEW! |
| 2534 | |
| 2535 | ;; Redefine all the subclasses of old to take into account modification |
| 2536 | (for-each |
| 2537 | (lambda (c) |
| 2538 | (update-direct-subclass! c new old)) |
| 2539 | (class-direct-subclasses new)) |
| 2540 | |
| 2541 | ;; Invalidate class so that subsequent instances slot accesses invoke |
| 2542 | ;; change-object-class |
| 2543 | (struct-set! new class-index-redefined old) |
| 2544 | (class-clear-flags! new vtable-flag-goops-valid) ;must come after slot-set! |
| 2545 | |
| 2546 | old) |
| 2547 | |
| 2548 | ;;; |
| 2549 | ;;; remove-class-accessors! |
| 2550 | ;;; |
| 2551 | |
| 2552 | (define-method (remove-class-accessors! (c <class>)) |
| 2553 | (for-each (lambda (m) |
| 2554 | (when (is-a? m <accessor-method>) |
| 2555 | (let ((gf (slot-ref m 'generic-function))) |
| 2556 | ;; remove the method from its GF |
| 2557 | (slot-set! gf 'methods |
| 2558 | (delq1! m (slot-ref gf 'methods))) |
| 2559 | (invalidate-method-cache! gf) |
| 2560 | ;; remove the method from its specializers |
| 2561 | (remove-method-in-classes! m)))) |
| 2562 | (class-direct-methods c))) |
| 2563 | |
| 2564 | ;;; |
| 2565 | ;;; update-direct-method! |
| 2566 | ;;; |
| 2567 | |
| 2568 | (define-method (update-direct-method! (m <method>) |
| 2569 | (old <class>) |
| 2570 | (new <class>)) |
| 2571 | (let loop ((l (method-specializers m))) |
| 2572 | ;; Note: the <top> in dotted list is never used. |
| 2573 | ;; So we can work as if we had only proper lists. |
| 2574 | (when (pair? l) |
| 2575 | (when (eqv? (car l) old) |
| 2576 | (set-car! l new)) |
| 2577 | (loop (cdr l))))) |
| 2578 | |
| 2579 | ;;; |
| 2580 | ;;; update-direct-subclass! |
| 2581 | ;;; |
| 2582 | |
| 2583 | (define-method (update-direct-subclass! (c <class>) |
| 2584 | (old <class>) |
| 2585 | (new <class>)) |
| 2586 | (class-redefinition c |
| 2587 | (make-class (class-direct-supers c) |
| 2588 | (class-direct-slots c) |
| 2589 | #:name (class-name c) |
| 2590 | #:metaclass (class-of c)))) |
| 2591 | |
| 2592 | ;;; |
| 2593 | ;;; {Utilities for INITIALIZE methods} |
| 2594 | ;;; |
| 2595 | |
| 2596 | ;;; compute-slot-accessors |
| 2597 | ;;; |
| 2598 | (define (compute-slot-accessors class slots) |
| 2599 | (for-each |
| 2600 | (lambda (slot) |
| 2601 | (let ((getter (%slot-definition-getter slot)) |
| 2602 | (setter (%slot-definition-setter slot)) |
| 2603 | (accessor-setter setter) |
| 2604 | (accessor (%slot-definition-accessor slot))) |
| 2605 | (when getter |
| 2606 | (add-method! getter (compute-getter-method class slot))) |
| 2607 | (when setter |
| 2608 | (add-method! setter (compute-setter-method class slot))) |
| 2609 | (when accessor |
| 2610 | (add-method! accessor (compute-getter-method class slot)) |
| 2611 | (add-method! (accessor-setter accessor) |
| 2612 | (compute-setter-method class slot))))) |
| 2613 | slots)) |
| 2614 | |
| 2615 | (define-method (compute-getter-method (class <class>) slot) |
| 2616 | (let ((init-thunk (slot-definition-init-thunk slot)) |
| 2617 | (slot-ref (slot-definition-slot-ref slot)) |
| 2618 | (index (slot-definition-index slot))) |
| 2619 | (make <accessor-method> |
| 2620 | #:specializers (list class) |
| 2621 | #:procedure (cond |
| 2622 | (slot-ref (make-generic-bound-check-getter slot-ref)) |
| 2623 | (init-thunk (standard-get index)) |
| 2624 | (else (bound-check-get index))) |
| 2625 | #:slot-definition slot))) |
| 2626 | |
| 2627 | (define-method (compute-setter-method (class <class>) slot) |
| 2628 | (let ((slot-set! (slot-definition-slot-set! slot)) |
| 2629 | (index (slot-definition-index slot))) |
| 2630 | (make <accessor-method> |
| 2631 | #:specializers (list class <top>) |
| 2632 | #:procedure (cond |
| 2633 | (slot-set! slot-set!) |
| 2634 | (else (standard-set index))) |
| 2635 | #:slot-definition slot))) |
| 2636 | |
| 2637 | (define (make-generic-bound-check-getter proc) |
| 2638 | (lambda (o) |
| 2639 | (let ((val (proc o))) |
| 2640 | (if (unbound? val) |
| 2641 | (slot-unbound o) |
| 2642 | val)))) |
| 2643 | |
| 2644 | ;;; Pre-generate getters and setters for the first 20 slots. |
| 2645 | (define-syntax define-standard-accessor-method |
| 2646 | (lambda (stx) |
| 2647 | (define num-standard-pre-cache 20) |
| 2648 | (syntax-case stx () |
| 2649 | ((_ ((proc n) arg ...) body) |
| 2650 | #`(define proc |
| 2651 | (let ((cache (vector #,@(map (lambda (n*) |
| 2652 | #`(lambda (arg ...) |
| 2653 | (let ((n #,n*)) |
| 2654 | body))) |
| 2655 | (iota num-standard-pre-cache))))) |
| 2656 | (lambda (n) |
| 2657 | (if (< n #,num-standard-pre-cache) |
| 2658 | (vector-ref cache n) |
| 2659 | (lambda (arg ...) body))))))))) |
| 2660 | |
| 2661 | (define-standard-accessor-method ((bound-check-get n) o) |
| 2662 | (let ((x (struct-ref o n))) |
| 2663 | (if (unbound? x) |
| 2664 | (slot-unbound o) |
| 2665 | x))) |
| 2666 | |
| 2667 | (define-standard-accessor-method ((standard-get n) o) |
| 2668 | (struct-ref o n)) |
| 2669 | |
| 2670 | (define-standard-accessor-method ((standard-set n) o v) |
| 2671 | (struct-set! o n v)) |
| 2672 | |
| 2673 | ;;; compute-cpl |
| 2674 | ;;; |
| 2675 | |
| 2676 | ;; Replace the bootstrap compute-cpl with this definition. |
| 2677 | (define compute-cpl |
| 2678 | (make <generic> #:name 'compute-cpl)) |
| 2679 | |
| 2680 | (define-method (compute-cpl (class <class>)) |
| 2681 | (compute-std-cpl class class-direct-supers)) |
| 2682 | |
| 2683 | ;;; compute-get-n-set |
| 2684 | ;;; |
| 2685 | (define compute-get-n-set |
| 2686 | (make <generic> #:name 'compute-get-n-set)) |
| 2687 | |
| 2688 | (define-method (compute-get-n-set (class <class>) s) |
| 2689 | (define (class-slot-init-value) |
| 2690 | (let ((thunk (slot-definition-init-thunk s))) |
| 2691 | (if thunk |
| 2692 | (thunk) |
| 2693 | (slot-definition-init-value s)))) |
| 2694 | |
| 2695 | (define (make-closure-variable class value) |
| 2696 | (list (lambda (o) value) |
| 2697 | (lambda (o v) (set! value v)))) |
| 2698 | |
| 2699 | (case (slot-definition-allocation s) |
| 2700 | ((#:instance) ;; Instance slot |
| 2701 | ;; get-n-set is just its offset |
| 2702 | (let ((already-allocated (struct-ref class class-index-nfields))) |
| 2703 | (struct-set! class class-index-nfields (+ already-allocated 1)) |
| 2704 | already-allocated)) |
| 2705 | |
| 2706 | ((#:class) ;; Class slot |
| 2707 | ;; Class-slots accessors are implemented as 2 closures around |
| 2708 | ;; a Scheme variable. As instance slots, class slots must be |
| 2709 | ;; unbound at init time. |
| 2710 | (let ((name (slot-definition-name s))) |
| 2711 | (if (memq name (map slot-definition-name (class-direct-slots class))) |
| 2712 | ;; This slot is direct; create a new shared variable |
| 2713 | (make-closure-variable class (class-slot-init-value)) |
| 2714 | ;; Slot is inherited. Find its definition in superclass |
| 2715 | (let lp ((cpl (cdr (class-precedence-list class)))) |
| 2716 | (match cpl |
| 2717 | ((super . cpl) |
| 2718 | (let ((s (class-slot-definition super name))) |
| 2719 | (if s |
| 2720 | (list (slot-definition-slot-ref s) |
| 2721 | (slot-definition-slot-set! s)) |
| 2722 | ;; Multiple inheritance means that we might have |
| 2723 | ;; to look deeper in the CPL. |
| 2724 | (lp cpl))))))))) |
| 2725 | |
| 2726 | ((#:each-subclass) ;; slot shared by instances of direct subclass. |
| 2727 | ;; (Thomas Buerger, April 1998) |
| 2728 | (make-closure-variable class (class-slot-init-value))) |
| 2729 | |
| 2730 | ((#:virtual) ;; No allocation |
| 2731 | ;; slot-ref and slot-set! function must be given by the user |
| 2732 | (let ((get (get-keyword #:slot-ref (slot-definition-options s) #f)) |
| 2733 | (set (get-keyword #:slot-set! (slot-definition-options s) #f))) |
| 2734 | (unless (and get set) |
| 2735 | (goops-error "You must supply a #:slot-ref and a #:slot-set! in ~S" s)) |
| 2736 | (list get set))) |
| 2737 | (else (next-method)))) |
| 2738 | |
| 2739 | (define-method (compute-get-n-set (o <object>) s) |
| 2740 | (goops-error "Allocation \"~S\" is unknown" (slot-definition-allocation s))) |
| 2741 | |
| 2742 | (define-method (compute-slots (class <class>)) |
| 2743 | (build-slots-list (class-direct-slots class) |
| 2744 | (class-precedence-list class))) |
| 2745 | |
| 2746 | ;;; |
| 2747 | ;;; {Initialize} |
| 2748 | ;;; |
| 2749 | |
| 2750 | ;; FIXME: This could be much more efficient. |
| 2751 | (define (%initialize-object obj initargs) |
| 2752 | "Initialize the object @var{obj} with the given arguments |
| 2753 | var{initargs}." |
| 2754 | (define (valid-initargs? initargs) |
| 2755 | (match initargs |
| 2756 | (() #t) |
| 2757 | (((? keyword?) _ . initargs) (valid-initargs? initargs)) |
| 2758 | (_ #f))) |
| 2759 | (unless (instance? obj) |
| 2760 | (scm-error 'wrong-type-arg #f "Not an object: ~S" |
| 2761 | (list obj) #f)) |
| 2762 | (unless (valid-initargs? initargs) |
| 2763 | (scm-error 'wrong-type-arg #f "Invalid initargs: ~S" |
| 2764 | (list initargs) #f)) |
| 2765 | (let ((class (class-of obj))) |
| 2766 | (define (get-initarg kw) |
| 2767 | (if kw |
| 2768 | ;; Inlined get-keyword to avoid checking initargs for validity |
| 2769 | ;; each time. |
| 2770 | (let lp ((initargs initargs)) |
| 2771 | (match initargs |
| 2772 | ((kw* val . initargs) |
| 2773 | (if (eq? kw* kw) |
| 2774 | val |
| 2775 | (lp initargs))) |
| 2776 | (_ *unbound*))) |
| 2777 | *unbound*)) |
| 2778 | (let lp ((slots (struct-ref class class-index-slots))) |
| 2779 | (match slots |
| 2780 | (() obj) |
| 2781 | ((slot . slots) |
| 2782 | (define (initialize-slot! value) |
| 2783 | (cond |
| 2784 | ((%slot-definition-slot-set! slot) |
| 2785 | => (lambda (slot-set!) (slot-set! obj value))) |
| 2786 | (else |
| 2787 | (struct-set! obj (%slot-definition-index slot) value)))) |
| 2788 | (let ((initarg (get-initarg (%slot-definition-init-keyword slot)))) |
| 2789 | (cond |
| 2790 | ((not (unbound? initarg)) |
| 2791 | (initialize-slot! initarg)) |
| 2792 | ((%slot-definition-init-thunk slot) |
| 2793 | => (lambda (init-thunk) |
| 2794 | (unless (memq (slot-definition-allocation slot) |
| 2795 | '(#:class #:each-subclass)) |
| 2796 | (initialize-slot! (init-thunk))))))) |
| 2797 | (lp slots)))))) |
| 2798 | |
| 2799 | (define-method (initialize (object <object>) initargs) |
| 2800 | (%initialize-object object initargs)) |
| 2801 | |
| 2802 | (define-method (initialize (slot <slot>) initargs) |
| 2803 | (next-method) |
| 2804 | (struct-set! slot slot-index-options initargs) |
| 2805 | (let ((init-thunk (%slot-definition-init-thunk slot))) |
| 2806 | (when init-thunk |
| 2807 | (unless (thunk? init-thunk) |
| 2808 | (goops-error "Bad init-thunk for slot `~S': ~S" |
| 2809 | (%slot-definition-name slot) init-thunk))))) |
| 2810 | |
| 2811 | (define-method (initialize (class <class>) initargs) |
| 2812 | (define (make-direct-slot-definition dslot) |
| 2813 | (let ((initargs (compute-direct-slot-definition-initargs class dslot))) |
| 2814 | (compute-direct-slot-definition class initargs))) |
| 2815 | |
| 2816 | (next-method) |
| 2817 | (class-add-flags! class (logior vtable-flag-goops-class |
| 2818 | vtable-flag-goops-valid)) |
| 2819 | (struct-set! class class-index-name (get-keyword #:name initargs '???)) |
| 2820 | (struct-set! class class-index-nfields 0) |
| 2821 | (struct-set! class class-index-direct-supers |
| 2822 | (get-keyword #:dsupers initargs '())) |
| 2823 | (struct-set! class class-index-direct-subclasses '()) |
| 2824 | (struct-set! class class-index-direct-methods '()) |
| 2825 | (struct-set! class class-index-redefined #f) |
| 2826 | (struct-set! class class-index-cpl (compute-cpl class)) |
| 2827 | (struct-set! class class-index-direct-slots |
| 2828 | (map (lambda (slot) |
| 2829 | (if (slot? slot) |
| 2830 | slot |
| 2831 | (make-direct-slot-definition slot))) |
| 2832 | (get-keyword #:slots initargs '()))) |
| 2833 | (struct-set! class class-index-slots |
| 2834 | (allocate-slots class (compute-slots class))) |
| 2835 | |
| 2836 | ;; This is a hack. |
| 2837 | (when (memq <slot> (struct-ref class class-index-cpl)) |
| 2838 | (class-add-flags! class vtable-flag-goops-slot)) |
| 2839 | |
| 2840 | ;; Build getters - setters - accessors |
| 2841 | (compute-slot-accessors class (struct-ref class class-index-slots)) |
| 2842 | |
| 2843 | ;; Update the "direct-subclasses" of each inherited classes |
| 2844 | (for-each (lambda (x) |
| 2845 | (let ((dsubs (struct-ref x class-index-direct-subclasses))) |
| 2846 | (struct-set! x class-index-direct-subclasses |
| 2847 | (cons class dsubs)))) |
| 2848 | (struct-ref class class-index-direct-supers)) |
| 2849 | |
| 2850 | ;; Compute struct layout of instances, set the `layout' slot, and |
| 2851 | ;; update class flags. |
| 2852 | (%prep-layout! class)) |
| 2853 | |
| 2854 | (define (initialize-object-procedure object initargs) |
| 2855 | (let ((proc (get-keyword #:procedure initargs #f))) |
| 2856 | (cond ((not proc)) |
| 2857 | ((pair? proc) |
| 2858 | (apply slot-set! object 'procedure proc)) |
| 2859 | (else |
| 2860 | (slot-set! object 'procedure proc))))) |
| 2861 | |
| 2862 | (define-method (initialize (applicable-struct <applicable-struct>) initargs) |
| 2863 | (next-method) |
| 2864 | (initialize-object-procedure applicable-struct initargs)) |
| 2865 | |
| 2866 | (define-method (initialize (applicable-struct <applicable-struct-with-setter>) |
| 2867 | initargs) |
| 2868 | (next-method) |
| 2869 | (slot-set! applicable-struct 'setter (get-keyword #:setter initargs #f))) |
| 2870 | |
| 2871 | (define-method (initialize (generic <generic>) initargs) |
| 2872 | (let ((previous-definition (get-keyword #:default initargs #f)) |
| 2873 | (name (get-keyword #:name initargs #f))) |
| 2874 | (next-method) |
| 2875 | (slot-set! generic 'methods (if (is-a? previous-definition <procedure>) |
| 2876 | (list (method args |
| 2877 | (apply previous-definition args))) |
| 2878 | '())) |
| 2879 | (if name |
| 2880 | (set-procedure-property! generic 'name name)) |
| 2881 | (invalidate-method-cache! generic))) |
| 2882 | |
| 2883 | (define-method (initialize (eg <extended-generic>) initargs) |
| 2884 | (next-method) |
| 2885 | (slot-set! eg 'extends (get-keyword #:extends initargs '()))) |
| 2886 | |
| 2887 | (define dummy-procedure (lambda args *unspecified*)) |
| 2888 | |
| 2889 | (define-method (initialize (method <method>) initargs) |
| 2890 | (next-method) |
| 2891 | (slot-set! method 'generic-function (get-keyword #:generic-function initargs #f)) |
| 2892 | (slot-set! method 'specializers (get-keyword #:specializers initargs '())) |
| 2893 | (slot-set! method 'procedure |
| 2894 | (get-keyword #:procedure initargs #f)) |
| 2895 | (slot-set! method 'formals (get-keyword #:formals initargs '())) |
| 2896 | (slot-set! method 'body (get-keyword #:body initargs '())) |
| 2897 | (slot-set! method 'make-procedure (get-keyword #:make-procedure initargs #f))) |
| 2898 | |
| 2899 | |
| 2900 | ;;; |
| 2901 | ;;; {Change-class} |
| 2902 | ;;; |
| 2903 | |
| 2904 | (define (change-object-class old-instance old-class new-class) |
| 2905 | (let ((new-instance (allocate-instance new-class '()))) |
| 2906 | ;; Initialize the slots of the new instance |
| 2907 | (for-each |
| 2908 | (lambda (slot) |
| 2909 | (if (and (slot-exists? old-instance slot) |
| 2910 | (eq? (%slot-definition-allocation |
| 2911 | (class-slot-definition old-class slot)) |
| 2912 | #:instance) |
| 2913 | (slot-bound? old-instance slot)) |
| 2914 | ;; Slot was present and allocated in old instance; copy it |
| 2915 | (slot-set! new-instance slot (slot-ref old-instance slot)) |
| 2916 | ;; slot was absent; initialize it with its default value |
| 2917 | (let ((init (slot-init-function new-class slot))) |
| 2918 | (when init |
| 2919 | (slot-set! new-instance slot (init)))))) |
| 2920 | (map slot-definition-name (class-slots new-class))) |
| 2921 | ;; Exchange old and new instance in place to keep pointers valid |
| 2922 | (%modify-instance old-instance new-instance) |
| 2923 | ;; Allow class specific updates of instances (which now are swapped) |
| 2924 | (update-instance-for-different-class new-instance old-instance) |
| 2925 | old-instance)) |
| 2926 | |
| 2927 | |
| 2928 | (define-method (update-instance-for-different-class (old-instance <object>) |
| 2929 | (new-instance |
| 2930 | <object>)) |
| 2931 | ;;not really important what we do, we just need a default method |
| 2932 | new-instance) |
| 2933 | |
| 2934 | (define-method (change-class (old-instance <object>) (new-class <class>)) |
| 2935 | (change-object-class old-instance (class-of old-instance) new-class)) |
| 2936 | |
| 2937 | ;;; |
| 2938 | ;;; {make} |
| 2939 | ;;; |
| 2940 | ;;; A new definition which overwrites the previous one which was built-in |
| 2941 | ;;; |
| 2942 | |
| 2943 | (define-method (allocate-instance (class <class>) initargs) |
| 2944 | (%allocate-instance class)) |
| 2945 | |
| 2946 | (define-method (make-instance (class <class>) . initargs) |
| 2947 | (let ((instance (allocate-instance class initargs))) |
| 2948 | (initialize instance initargs) |
| 2949 | instance)) |
| 2950 | |
| 2951 | (define make make-instance) |
| 2952 | |
| 2953 | ;;; |
| 2954 | ;;; {apply-generic} |
| 2955 | ;;; |
| 2956 | ;;; Protocol for calling generic functions, intended to be used when |
| 2957 | ;;; applying subclasses of <generic> and <generic-with-setter>. The |
| 2958 | ;;; code below is similar to the first MOP described in AMOP. |
| 2959 | ;;; |
| 2960 | ;;; Note that standard generic functions dispatch only on the classes of |
| 2961 | ;;; the arguments, and the result of such dispatch can be memoized. The |
| 2962 | ;;; `dispatch-generic-function-application-from-cache' routine |
| 2963 | ;;; implements this. `apply-generic' isn't called currently; the |
| 2964 | ;;; generic function MOP was never fully implemented in GOOPS. However |
| 2965 | ;;; now that GOOPS is implemented entirely in Scheme (2015) it's much |
| 2966 | ;;; easier to complete this work. Contributions gladly accepted! |
| 2967 | ;;; Please read the AMOP first though :) |
| 2968 | ;;; |
| 2969 | ;;; The protocol is: |
| 2970 | ;;; |
| 2971 | ;;; + apply-generic (gf args) |
| 2972 | ;;; + compute-applicable-methods (gf args ...) |
| 2973 | ;;; + sort-applicable-methods (gf methods args) |
| 2974 | ;;; + apply-methods (gf methods args) |
| 2975 | ;;; |
| 2976 | ;;; apply-methods calls make-next-method to build the "continuation" of |
| 2977 | ;;; a method. Applying a next-method will call apply-next-method which |
| 2978 | ;;; in turn will call apply again to call effectively the following |
| 2979 | ;;; method. (This paragraph is out of date but is kept so that maybe it |
| 2980 | ;;; illuminates some future hack.) |
| 2981 | ;;; |
| 2982 | |
| 2983 | (define-method (apply-generic (gf <generic>) args) |
| 2984 | (when (null? (slot-ref gf 'methods)) |
| 2985 | (no-method gf args)) |
| 2986 | (let ((methods (compute-applicable-methods gf args))) |
| 2987 | (if methods |
| 2988 | (apply-methods gf (sort-applicable-methods gf methods args) args) |
| 2989 | (no-applicable-method gf args)))) |
| 2990 | |
| 2991 | ;; compute-applicable-methods is bound to %compute-applicable-methods. |
| 2992 | ;; *fixme* use let |
| 2993 | (define %%compute-applicable-methods |
| 2994 | (make <generic> #:name 'compute-applicable-methods)) |
| 2995 | |
| 2996 | (define-method (%%compute-applicable-methods (gf <generic>) args) |
| 2997 | (%compute-applicable-methods gf args)) |
| 2998 | |
| 2999 | (set! compute-applicable-methods %%compute-applicable-methods) |
| 3000 | |
| 3001 | (define-method (sort-applicable-methods (gf <generic>) methods args) |
| 3002 | (%sort-applicable-methods methods (map class-of args))) |
| 3003 | |
| 3004 | (define-method (method-more-specific? (m1 <method>) (m2 <method>) targs) |
| 3005 | (%method-more-specific? m1 m2 targs)) |
| 3006 | |
| 3007 | (define-method (apply-method (gf <generic>) methods build-next args) |
| 3008 | (apply (method-procedure (car methods)) |
| 3009 | (build-next (cdr methods) args) |
| 3010 | args)) |
| 3011 | |
| 3012 | (define-method (apply-methods (gf <generic>) (l <list>) args) |
| 3013 | (letrec ((next (lambda (procs args) |
| 3014 | (lambda new-args |
| 3015 | (let ((a (if (null? new-args) args new-args))) |
| 3016 | (if (null? procs) |
| 3017 | (no-next-method gf a) |
| 3018 | (apply-method gf procs next a))))))) |
| 3019 | (apply-method gf l next args))) |
| 3020 | |
| 3021 | ;; We don't want the following procedure to turn up in backtraces: |
| 3022 | (for-each (lambda (proc) |
| 3023 | (set-procedure-property! proc 'system-procedure #t)) |
| 3024 | (list slot-unbound |
| 3025 | slot-missing |
| 3026 | no-next-method |
| 3027 | no-applicable-method |
| 3028 | no-method |
| 3029 | )) |
| 3030 | |
| 3031 | ;;; |
| 3032 | ;;; {Final initialization} |
| 3033 | ;;; |
| 3034 | |
| 3035 | ;; Tell C code that the main bulk of Goops has been loaded |
| 3036 | (%goops-loaded) |
| 3037 | |
| 3038 | |
| 3039 | \f |
| 3040 | |
| 3041 | ;;; |
| 3042 | ;;; {SMOB and port classes} |
| 3043 | ;;; |
| 3044 | |
| 3045 | (define <arbiter> (find-subclass <top> '<arbiter>)) |
| 3046 | (define <promise> (find-subclass <top> '<promise>)) |
| 3047 | (define <thread> (find-subclass <top> '<thread>)) |
| 3048 | (define <mutex> (find-subclass <top> '<mutex>)) |
| 3049 | (define <condition-variable> (find-subclass <top> '<condition-variable>)) |
| 3050 | (define <regexp> (find-subclass <top> '<regexp>)) |
| 3051 | (define <hook> (find-subclass <top> '<hook>)) |
| 3052 | (define <bitvector> (find-subclass <top> '<bitvector>)) |
| 3053 | (define <random-state> (find-subclass <top> '<random-state>)) |
| 3054 | (define <async> (find-subclass <top> '<async>)) |
| 3055 | (define <directory> (find-subclass <top> '<directory>)) |
| 3056 | (define <array> (find-subclass <top> '<array>)) |
| 3057 | (define <character-set> (find-subclass <top> '<character-set>)) |
| 3058 | (define <dynamic-object> (find-subclass <top> '<dynamic-object>)) |
| 3059 | (define <guardian> (find-subclass <applicable> '<guardian>)) |
| 3060 | (define <macro> (find-subclass <top> '<macro>)) |
| 3061 | |
| 3062 | (define (define-class-subtree class) |
| 3063 | (define! (class-name class) class) |
| 3064 | (for-each define-class-subtree (class-direct-subclasses class))) |
| 3065 | |
| 3066 | (define-class-subtree (find-subclass <port> '<file-port>)) |