Commit | Line | Data |
---|---|---|
c0cd1b3e | 1 | ;;; GNU Guix --- Functional package management for GNU |
bbb2bd50 | 2 | ;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org> |
c2dcff41 | 3 | ;;; Copyright © 2018 Mark H Weaver <mhw@netris.org> |
c0cd1b3e LC |
4 | ;;; |
5 | ;;; This file is part of GNU Guix. | |
6 | ;;; | |
7 | ;;; GNU Guix is free software; you can redistribute it and/or modify it | |
8 | ;;; under the terms of the GNU General Public License as published by | |
9 | ;;; the Free Software Foundation; either version 3 of the License, or (at | |
10 | ;;; your option) any later version. | |
11 | ;;; | |
12 | ;;; GNU Guix is distributed in the hope that it will be useful, but | |
13 | ;;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | ;;; GNU General Public License for more details. | |
16 | ;;; | |
17 | ;;; You should have received a copy of the GNU General Public License | |
18 | ;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>. | |
19 | ||
20 | (define-module (guix records) | |
21 | #:use-module (srfi srfi-1) | |
22 | #:use-module (srfi srfi-9) | |
23 | #:use-module (srfi srfi-26) | |
24 | #:use-module (ice-9 match) | |
fdc1bf65 LC |
25 | #:use-module (ice-9 regex) |
26 | #:use-module (ice-9 rdelim) | |
c0cd1b3e | 27 | #:export (define-record-type* |
abd4d6b3 LC |
28 | this-record |
29 | ||
c0cd1b3e | 30 | alist->record |
fdc1bf65 | 31 | object->fields |
6692d845 | 32 | recutils->alist |
33 | match-record)) | |
c0cd1b3e LC |
34 | |
35 | ;;; Commentary: | |
36 | ;;; | |
37 | ;;; Utilities for dealing with Scheme records. | |
38 | ;;; | |
39 | ;;; Code: | |
40 | ||
b1353e7a LC |
41 | (define-syntax record-error |
42 | (syntax-rules () | |
43 | "Report a syntactic error in use of CONSTRUCTOR." | |
44 | ((_ constructor form fmt args ...) | |
45 | (syntax-violation constructor | |
46 | (format #f fmt args ...) | |
47 | form)))) | |
48 | ||
9768848a LC |
49 | (eval-when (expand load eval) |
50 | ;; The procedures below are needed both at run time and at expansion time. | |
51 | ||
52 | (define (current-abi-identifier type) | |
53 | "Return an identifier unhygienically derived from TYPE for use as its | |
7874bbbb | 54 | \"current ABI\" variable." |
9768848a LC |
55 | (let ((type-name (syntax->datum type))) |
56 | (datum->syntax | |
57 | type | |
58 | (string->symbol | |
59 | (string-append "% " (symbol->string type-name) | |
60 | " abi-cookie"))))) | |
7874bbbb | 61 | |
9768848a LC |
62 | (define (abi-check type cookie) |
63 | "Return syntax that checks that the current \"application binary | |
7874bbbb | 64 | interface\" (ABI) for TYPE is equal to COOKIE." |
9768848a LC |
65 | (with-syntax ((current-abi (current-abi-identifier type))) |
66 | #`(unless (eq? current-abi #,cookie) | |
de5cbd4a LC |
67 | ;; The source file where this exception is thrown must be |
68 | ;; recompiled. | |
69 | (throw 'record-abi-mismatch-error 'abi-check | |
70 | "~a: record ABI mismatch; recompilation needed" | |
bbb2bd50 LC |
71 | (list #,type) '())))) |
72 | ||
73 | (define (report-invalid-field-specifier name bindings) | |
74 | "Report the first invalid binding among BINDINGS." | |
75 | (let loop ((bindings bindings)) | |
76 | (syntax-case bindings () | |
77 | (((field value) rest ...) ;good | |
78 | (loop #'(rest ...))) | |
79 | ((weird _ ...) ;weird! | |
80 | (syntax-violation name "invalid field specifier" #'weird))))) | |
81 | ||
82 | (define (report-duplicate-field-specifier name ctor) | |
83 | "Report the first duplicate identifier among the bindings in CTOR." | |
84 | (syntax-case ctor () | |
85 | ((_ bindings ...) | |
86 | (let loop ((bindings #'(bindings ...)) | |
87 | (seen '())) | |
88 | (syntax-case bindings () | |
89 | (((field value) rest ...) | |
90 | (not (memq (syntax->datum #'field) seen)) | |
91 | (loop #'(rest ...) (cons (syntax->datum #'field) seen))) | |
92 | ((duplicate rest ...) | |
93 | (syntax-violation name "duplicate field initializer" | |
94 | #'duplicate)) | |
95 | (() | |
96 | #t))))))) | |
7874bbbb | 97 | |
abd4d6b3 LC |
98 | (define-syntax-parameter this-record |
99 | (lambda (s) | |
100 | "Return the record being defined. This macro may only be used in the | |
101 | context of the definition of a thunked field." | |
102 | (syntax-case s () | |
103 | (id | |
104 | (identifier? #'id) | |
105 | (syntax-violation 'this-record | |
106 | "cannot be used outside of a record instantiation" | |
107 | #'id))))) | |
108 | ||
39fc041a LC |
109 | (define-syntax make-syntactic-constructor |
110 | (syntax-rules () | |
111 | "Make the syntactic constructor NAME for TYPE, that calls CTOR, and | |
112 | expects all of EXPECTED fields to be initialized. DEFAULTS is the list of | |
113 | FIELD/DEFAULT-VALUE tuples, THUNKED is the list of identifiers of thunked | |
7874bbbb LC |
114 | fields, and DELAYED is the list of identifiers of delayed fields. |
115 | ||
116 | ABI-COOKIE is the cookie (an integer) against which to check the run-time ABI | |
117 | of TYPE matches the expansion-time ABI." | |
39fc041a | 118 | ((_ type name ctor (expected ...) |
7874bbbb | 119 | #:abi-cookie abi-cookie |
39fc041a | 120 | #:thunked thunked |
d2be7e3c | 121 | #:this-identifier this-identifier |
39fc041a | 122 | #:delayed delayed |
8a16d064 | 123 | #:innate innate |
39fc041a LC |
124 | #:defaults defaults) |
125 | (define-syntax name | |
126 | (lambda (s) | |
127 | (define (record-inheritance orig-record field+value) | |
128 | ;; Produce code that returns a record identical to ORIG-RECORD, | |
129 | ;; except that values for the FIELD+VALUE alist prevail. | |
130 | (define (field-inherited-value f) | |
131 | (and=> (find (lambda (x) | |
132 | (eq? f (car (syntax->datum x)))) | |
133 | field+value) | |
134 | car)) | |
135 | ||
136 | ;; Make sure there are no unknown field names. | |
137 | (let* ((fields (map (compose car syntax->datum) field+value)) | |
138 | (unexpected (lset-difference eq? fields '(expected ...)))) | |
139 | (when (pair? unexpected) | |
140 | (record-error 'name s "extraneous field initializers ~a" | |
141 | unexpected))) | |
142 | ||
cea25b08 | 143 | #`(make-struct/no-tail type |
39fc041a LC |
144 | #,@(map (lambda (field index) |
145 | (or (field-inherited-value field) | |
8a16d064 LC |
146 | (if (innate-field? field) |
147 | (wrap-field-value | |
148 | field (field-default-value field)) | |
149 | #`(struct-ref #,orig-record | |
150 | #,index)))) | |
39fc041a LC |
151 | '(expected ...) |
152 | (iota (length '(expected ...)))))) | |
153 | ||
154 | (define (thunked-field? f) | |
155 | (memq (syntax->datum f) 'thunked)) | |
156 | ||
157 | (define (delayed-field? f) | |
158 | (memq (syntax->datum f) 'delayed)) | |
159 | ||
8a16d064 LC |
160 | (define (innate-field? f) |
161 | (memq (syntax->datum f) 'innate)) | |
162 | ||
39fc041a LC |
163 | (define (wrap-field-value f value) |
164 | (cond ((thunked-field? f) | |
abd4d6b3 | 165 | #`(lambda (x) |
d2be7e3c | 166 | (syntax-parameterize ((#,this-identifier |
abd4d6b3 LC |
167 | (lambda (s) |
168 | (syntax-case s () | |
169 | (id | |
170 | (identifier? #'id) | |
171 | #'x))))) | |
172 | #,value))) | |
39fc041a LC |
173 | ((delayed-field? f) |
174 | #`(delay #,value)) | |
175 | (else value))) | |
176 | ||
b9c86473 LC |
177 | (define default-values |
178 | ;; List of symbol/value tuples. | |
179 | (map (match-lambda | |
180 | ((f v) | |
181 | (list (syntax->datum f) v))) | |
182 | #'defaults)) | |
183 | ||
184 | (define (field-default-value f) | |
185 | (car (assoc-ref default-values (syntax->datum f)))) | |
186 | ||
39fc041a LC |
187 | (define (field-bindings field+value) |
188 | ;; Return field to value bindings, for use in 'let*' below. | |
189 | (map (lambda (field+value) | |
190 | (syntax-case field+value () | |
191 | ((field value) | |
192 | #`(field | |
193 | #,(wrap-field-value #'field #'value))))) | |
194 | field+value)) | |
195 | ||
196 | (syntax-case s (inherit expected ...) | |
197 | ((_ (inherit orig-record) (field value) (... ...)) | |
198 | #`(let* #,(field-bindings #'((field value) (... ...))) | |
7874bbbb | 199 | #,(abi-check #'type abi-cookie) |
39fc041a LC |
200 | #,(record-inheritance #'orig-record |
201 | #'((field value) (... ...))))) | |
202 | ((_ (field value) (... ...)) | |
b9c86473 | 203 | (let ((fields (map syntax->datum #'(field (... ...))))) |
39fc041a | 204 | (define (field-value f) |
94df39cc LC |
205 | (or (find (lambda (x) |
206 | (eq? f (syntax->datum x))) | |
207 | #'(field (... ...))) | |
b9c86473 | 208 | (wrap-field-value f (field-default-value f)))) |
39fc041a | 209 | |
c2dcff41 LC |
210 | ;; Pass S to make sure source location info is preserved. |
211 | (report-duplicate-field-specifier 'name s) | |
212 | ||
b9c86473 | 213 | (let ((fields (append fields (map car default-values)))) |
39fc041a LC |
214 | (cond ((lset= eq? fields '(expected ...)) |
215 | #`(let* #,(field-bindings | |
216 | #'((field value) (... ...))) | |
7874bbbb | 217 | #,(abi-check #'type abi-cookie) |
39fc041a LC |
218 | (ctor #,@(map field-value '(expected ...))))) |
219 | ((pair? (lset-difference eq? fields | |
220 | '(expected ...))) | |
221 | (record-error 'name s | |
222 | "extraneous field initializers ~a" | |
223 | (lset-difference eq? fields | |
224 | '(expected ...)))) | |
225 | (else | |
226 | (record-error 'name s | |
227 | "missing field initializers ~a" | |
228 | (lset-difference eq? | |
229 | '(expected ...) | |
babc2c80 LC |
230 | fields))))))) |
231 | ((_ bindings (... ...)) | |
232 | ;; One of BINDINGS doesn't match the (field value) pattern. | |
233 | ;; Report precisely which one is faulty, instead of letting the | |
234 | ;; "source expression failed to match any pattern" error. | |
235 | (report-invalid-field-specifier 'name | |
236 | #'(bindings (... ...)))))))))) | |
cf4efb39 | 237 | |
faef3b6a LC |
238 | (define-syntax-rule (define-field-property-predicate predicate property) |
239 | "Define PREDICATE as a procedure that takes a syntax object and, when passed | |
240 | a field specification, returns the field name if it has the given PROPERTY." | |
241 | (define (predicate s) | |
242 | (syntax-case s (property) | |
243 | ((field (property values (... ...)) _ (... ...)) | |
244 | #'field) | |
245 | ((field _ properties (... ...)) | |
246 | (predicate #'(field properties (... ...)))) | |
247 | (_ #f)))) | |
248 | ||
c0cd1b3e LC |
249 | (define-syntax define-record-type* |
250 | (lambda (s) | |
251 | "Define the given record type such that an additional \"syntactic | |
252 | constructor\" is defined, which allows instances to be constructed with named | |
e2540884 LC |
253 | field initializers, à la SRFI-35, as well as default values. An example use |
254 | may look like this: | |
255 | ||
256 | (define-record-type* <thing> thing make-thing | |
257 | thing? | |
d2be7e3c | 258 | this-thing |
e2540884 LC |
259 | (name thing-name (default \"chbouib\")) |
260 | (port thing-port | |
8a16d064 LC |
261 | (default (current-output-port)) (thunked)) |
262 | (loc thing-location (innate) (default (current-source-location)))) | |
e2540884 LC |
263 | |
264 | This example defines a macro 'thing' that can be used to instantiate records | |
265 | of this type: | |
266 | ||
267 | (thing | |
268 | (name \"foo\") | |
269 | (port (current-error-port))) | |
270 | ||
271 | The value of 'name' or 'port' could as well be omitted, in which case the | |
272 | default value specified in the 'define-record-type*' form is used: | |
273 | ||
274 | (thing) | |
275 | ||
276 | The 'port' field is \"thunked\", meaning that calls like '(thing-port x)' will | |
277 | actually compute the field's value in the current dynamic extent, which is | |
d2be7e3c LC |
278 | useful when referring to fluids in a field's value. Furthermore, that thunk |
279 | can access the record it belongs to via the 'this-thing' identifier. | |
e2540884 | 280 | |
310b32a2 LC |
281 | A field can also be marked as \"delayed\" instead of \"thunked\", in which |
282 | case its value is effectively wrapped in a (delay …) form. | |
283 | ||
e2540884 LC |
284 | It is possible to copy an object 'x' created with 'thing' like this: |
285 | ||
286 | (thing (inherit x) (name \"bar\")) | |
287 | ||
288 | This expression returns a new object equal to 'x' except for its 'name' | |
8a16d064 LC |
289 | field and its 'loc' field---the latter is marked as \"innate\", so it is not |
290 | inherited." | |
e2540884 | 291 | |
c0cd1b3e LC |
292 | (define (field-default-value s) |
293 | (syntax-case s (default) | |
294 | ((field (default val) _ ...) | |
295 | (list #'field #'val)) | |
792798f4 LC |
296 | ((field _ properties ...) |
297 | (field-default-value #'(field properties ...))) | |
c0cd1b3e LC |
298 | (_ #f))) |
299 | ||
faef3b6a LC |
300 | (define-field-property-predicate delayed-field? delayed) |
301 | (define-field-property-predicate thunked-field? thunked) | |
8a16d064 | 302 | (define-field-property-predicate innate-field? innate) |
c0cd1b3e | 303 | |
310b32a2 LC |
304 | (define (wrapped-field? s) |
305 | (or (thunked-field? s) (delayed-field? s))) | |
306 | ||
307 | (define (wrapped-field-accessor-name field) | |
c0cd1b3e | 308 | ;; Return the name (an unhygienic syntax object) of the "real" |
310b32a2 | 309 | ;; getter for field, which is assumed to be a wrapped field. |
c0cd1b3e | 310 | (syntax-case field () |
792798f4 | 311 | ((field get properties ...) |
c0cd1b3e LC |
312 | (let* ((getter (syntax->datum #'get)) |
313 | (real-getter (symbol-append '% getter '-real))) | |
314 | (datum->syntax #'get real-getter))))) | |
315 | ||
316 | (define (field-spec->srfi-9 field) | |
317 | ;; Convert a field spec of our style to a SRFI-9 field spec of the | |
318 | ;; form (field get). | |
319 | (syntax-case field () | |
792798f4 | 320 | ((name get properties ...) |
c0cd1b3e | 321 | #`(name |
310b32a2 LC |
322 | #,(if (wrapped-field? field) |
323 | (wrapped-field-accessor-name field) | |
c0cd1b3e LC |
324 | #'get))))) |
325 | ||
326 | (define (thunked-field-accessor-definition field) | |
327 | ;; Return the real accessor for FIELD, which is assumed to be a | |
328 | ;; thunked field. | |
329 | (syntax-case field () | |
330 | ((name get _ ...) | |
310b32a2 | 331 | (with-syntax ((real-get (wrapped-field-accessor-name field))) |
c0cd1b3e LC |
332 | #'(define-inlinable (get x) |
333 | ;; The real value of that field is a thunk, so call it. | |
abd4d6b3 | 334 | ((real-get x) x)))))) |
c0cd1b3e | 335 | |
310b32a2 LC |
336 | (define (delayed-field-accessor-definition field) |
337 | ;; Return the real accessor for FIELD, which is assumed to be a | |
338 | ;; delayed field. | |
339 | (syntax-case field () | |
340 | ((name get _ ...) | |
341 | (with-syntax ((real-get (wrapped-field-accessor-name field))) | |
342 | #'(define-inlinable (get x) | |
343 | ;; The real value of that field is a promise, so force it. | |
344 | (force (real-get x))))))) | |
345 | ||
7874bbbb LC |
346 | (define (compute-abi-cookie field-specs) |
347 | ;; Compute an "ABI cookie" for the given FIELD-SPECS. We use | |
348 | ;; 'string-hash' because that's a better hash function that 'hash' on a | |
349 | ;; list of symbols. | |
350 | (syntax-case field-specs () | |
351 | (((field get properties ...) ...) | |
352 | (string-hash (object->string | |
353 | (syntax->datum #'((field properties ...) ...))) | |
354 | most-positive-fixnum)))) | |
355 | ||
c0cd1b3e LC |
356 | (syntax-case s () |
357 | ((_ type syntactic-ctor ctor pred | |
d2be7e3c | 358 | this-identifier |
792798f4 | 359 | (field get properties ...) ...) |
d2be7e3c | 360 | (identifier? #'this-identifier) |
792798f4 | 361 | (let* ((field-spec #'((field get properties ...) ...)) |
9b543456 | 362 | (thunked (filter-map thunked-field? field-spec)) |
310b32a2 | 363 | (delayed (filter-map delayed-field? field-spec)) |
8a16d064 | 364 | (innate (filter-map innate-field? field-spec)) |
9b543456 | 365 | (defaults (filter-map field-default-value |
7874bbbb LC |
366 | #'((field properties ...) ...))) |
367 | (cookie (compute-abi-cookie field-spec))) | |
c0cd1b3e LC |
368 | (with-syntax (((field-spec* ...) |
369 | (map field-spec->srfi-9 field-spec)) | |
370 | ((thunked-field-accessor ...) | |
371 | (filter-map (lambda (field) | |
372 | (and (thunked-field? field) | |
373 | (thunked-field-accessor-definition | |
374 | field))) | |
310b32a2 LC |
375 | field-spec)) |
376 | ((delayed-field-accessor ...) | |
377 | (filter-map (lambda (field) | |
378 | (and (delayed-field? field) | |
379 | (delayed-field-accessor-definition | |
380 | field))) | |
c0cd1b3e LC |
381 | field-spec))) |
382 | #`(begin | |
383 | (define-record-type type | |
384 | (ctor field ...) | |
385 | pred | |
386 | field-spec* ...) | |
7874bbbb LC |
387 | (define #,(current-abi-identifier #'type) |
388 | #,cookie) | |
d2be7e3c LC |
389 | |
390 | #,@(if (free-identifier=? #'this-identifier #'this-record) | |
391 | #'() | |
392 | #'((define-syntax-parameter this-identifier | |
393 | (lambda (s) | |
394 | "Return the record being defined. This macro may | |
395 | only be used in the context of the definition of a thunked field." | |
396 | (syntax-case s () | |
397 | (id | |
398 | (identifier? #'id) | |
399 | (syntax-violation 'this-identifier | |
400 | "cannot be used outside \ | |
401 | of a record instantiation" | |
402 | #'id))))))) | |
ad7c1a2c LC |
403 | thunked-field-accessor ... |
404 | delayed-field-accessor ... | |
39fc041a LC |
405 | (make-syntactic-constructor type syntactic-ctor ctor |
406 | (field ...) | |
7874bbbb | 407 | #:abi-cookie #,cookie |
39fc041a | 408 | #:thunked #,thunked |
d2be7e3c | 409 | #:this-identifier #'this-identifier |
39fc041a | 410 | #:delayed #,delayed |
8a16d064 | 411 | #:innate #,innate |
d2be7e3c LC |
412 | #:defaults #,defaults))))) |
413 | ((_ type syntactic-ctor ctor pred | |
414 | (field get properties ...) ...) | |
415 | ;; When no 'this' identifier was specified, use 'this-record'. | |
416 | #'(define-record-type* type syntactic-ctor ctor pred | |
417 | this-record | |
418 | (field get properties ...) ...))))) | |
c0cd1b3e | 419 | |
c8772a7a LC |
420 | (define* (alist->record alist make keys |
421 | #:optional (multiple-value-keys '())) | |
422 | "Apply MAKE to the values associated with KEYS in ALIST. Items in KEYS that | |
423 | are also in MULTIPLE-VALUE-KEYS are considered to occur possibly multiple | |
424 | times in ALIST, and thus their value is a list." | |
425 | (let ((args (map (lambda (key) | |
426 | (if (member key multiple-value-keys) | |
427 | (filter-map (match-lambda | |
428 | ((k . v) | |
429 | (and (equal? k key) v))) | |
430 | alist) | |
431 | (assoc-ref alist key))) | |
432 | keys))) | |
c0cd1b3e LC |
433 | (apply make args))) |
434 | ||
435 | (define (object->fields object fields port) | |
436 | "Write OBJECT (typically a record) as a series of recutils-style fields to | |
437 | PORT, according to FIELDS. FIELDS must be a list of field name/getter pairs." | |
438 | (let loop ((fields fields)) | |
439 | (match fields | |
440 | (() | |
441 | object) | |
442 | (((field . get) rest ...) | |
443 | (format port "~a: ~a~%" field (get object)) | |
444 | (loop rest))))) | |
445 | ||
fb519bd8 LC |
446 | (define %recutils-field-charset |
447 | ;; Valid characters starting a recutils field. | |
448 | ;; info "(recutils) Fields" | |
449 | (char-set-union char-set:upper-case | |
450 | char-set:lower-case | |
451 | (char-set #\%))) | |
836d10f1 | 452 | |
fdc1bf65 LC |
453 | (define (recutils->alist port) |
454 | "Read a recutils-style record from PORT and return it as a list of key/value | |
455 | pairs. Stop upon an empty line (after consuming it) or EOF." | |
456 | (let loop ((line (read-line port)) | |
457 | (result '())) | |
b7b88288 | 458 | (cond ((eof-object? line) |
fdc1bf65 | 459 | (reverse result)) |
b7b88288 LC |
460 | ((string-null? line) |
461 | (if (null? result) | |
462 | (loop (read-line port) result) ; leading space: ignore it | |
463 | (reverse result))) ; end-of-record marker | |
fdc1bf65 | 464 | (else |
fb519bd8 LC |
465 | ;; Now check the first character of LINE, since that's what the |
466 | ;; recutils manual says is enough. | |
467 | (let ((first (string-ref line 0))) | |
468 | (cond | |
469 | ((char-set-contains? %recutils-field-charset first) | |
470 | (let* ((colon (string-index line #\:)) | |
471 | (field (string-take line colon)) | |
472 | (value (string-trim (string-drop line (+ 1 colon))))) | |
473 | (loop (read-line port) | |
474 | (alist-cons field value result)))) | |
475 | ((eqv? first #\#) ;info "(recutils) Comments" | |
476 | (loop (read-line port) result)) | |
477 | ((eqv? first #\+) ;info "(recutils) Fields" | |
478 | (let ((new-line (if (string-prefix? "+ " line) | |
479 | (string-drop line 2) | |
480 | (string-drop line 1)))) | |
481 | (match result | |
482 | (((field . value) rest ...) | |
483 | (loop (read-line port) | |
484 | `((,field . ,(string-append value "\n" new-line)) | |
485 | ,@rest)))))) | |
486 | (else | |
487 | (error "unmatched line" line)))))))) | |
fdc1bf65 | 488 | |
6692d845 | 489 | (define-syntax match-record |
490 | (syntax-rules () | |
491 | "Bind each FIELD of a RECORD of the given TYPE to it's FIELD name. | |
492 | The current implementation does not support thunked and delayed fields." | |
493 | ((_ record type (field fields ...) body ...) | |
494 | (if (eq? (struct-vtable record) type) | |
495 | ;; TODO compute indices and report wrong-field-name errors at | |
496 | ;; expansion time | |
497 | ;; TODO support thunked and delayed fields | |
498 | (let ((field ((record-accessor type 'field) record))) | |
499 | (match-record record type (fields ...) body ...)) | |
500 | (throw 'wrong-type-arg record))) | |
501 | ((_ record type () body ...) | |
502 | (begin body ...)))) | |
503 | ||
c0cd1b3e | 504 | ;;; records.scm ends here |