summaryrefslogtreecommitdiff
path: root/module/rnrs/records/procedural.scm
blob: 69c5d1c561068fa4d8863aebffc3f32ab93d613d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
;;; procedural.scm --- Procedural interface to R6RS records

;;      Copyright (C) 2010, 2017 Free Software Foundation, Inc.
;;
;; This library is free software; you can redistribute it and/or
;; modify it under the terms of the GNU Lesser General Public
;; License as published by the Free Software Foundation; either
;; version 3 of the License, or (at your option) any later version.
;; 
;; This library is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; Lesser General Public License for more details.
;; 
;; You should have received a copy of the GNU Lesser General Public
;; License along with this library; if not, write to the Free Software
;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA


(library (rnrs records procedural (6))
  (export make-record-type-descriptor 
	  record-type-descriptor?
	  make-record-constructor-descriptor
	  
	  record-constructor
	  record-predicate
	  record-accessor	  
	  record-mutator)
	  
  (import (rnrs base (6))
          (only (guile) cons*
                        logand 
                        logior
                        ash

                        and=>
			throw
			display
		        make-struct/no-tail
			make-vtable 
			map
			simple-format
			string-append 
                        symbol-append
			
			struct? 
                        struct-layout
			struct-ref 
			struct-set! 
			struct-vtable
			vtable-index-layout

                        make-hash-table
			hashq-ref
			hashq-set!

			vector->list

                        vtable-offset-user)
	  (ice-9 receive)
	  (only (srfi :1) fold split-at take))

  (define (record-internal? obj)
    (and (struct? obj) (record-type-descriptor? (struct-vtable obj))))

  (define rtd-index-name            (+ vtable-offset-user 0))
  (define rtd-index-uid             (+ vtable-offset-user 1))
  (define rtd-index-parent          (+ vtable-offset-user 2))
  (define rtd-index-sealed?         (+ vtable-offset-user 3))
  (define rtd-index-opaque?         (+ vtable-offset-user 4))
  (define rtd-index-predicate       (+ vtable-offset-user 5))
  (define rtd-index-field-names     (+ vtable-offset-user 6))
  (define rtd-index-field-bit-field (+ vtable-offset-user 7))
  (define rtd-index-field-binder    (+ vtable-offset-user 8))

  (define rctd-index-rtd 0)
  (define rctd-index-parent 1)
  (define rctd-index-protocol 2)

  (define vtable-base-layout (symbol->string (struct-layout (make-vtable ""))))

  (define record-type-vtable 
    (make-vtable (string-append vtable-base-layout "prprprprprprprprprpr")
		 (lambda (obj port) 
		   (simple-format port "#<r6rs:record-type:~A>"
				  (struct-ref obj rtd-index-name)))))

  (define record-constructor-vtable 
    (make-vtable "prprpr"
		 (lambda (obj port) 
		   (simple-format port "#<r6rs:record-constructor:~A>" 
				  (struct-ref (struct-ref obj rctd-index-rtd)
					      rtd-index-name)))))

  (define uid-table (make-hash-table))    

  (define (make-record-type-descriptor name parent uid sealed? opaque? fields)
    (define fields-pair
      (let loop ((field-list (vector->list fields))
                 (layout-sym 'pr)
                 (layout-bit-field 0)
                 (counter 0))
        (if (null? field-list)
            (cons layout-sym layout-bit-field)
            (case (caar field-list)
              ((immutable) 
               (loop (cdr field-list)
                     (symbol-append layout-sym 'pr) 
                     layout-bit-field 
                     (+ counter 1)))
              ((mutable)
               (loop (cdr field-list)
                     (symbol-append layout-sym 'pw)
                     (logior layout-bit-field (ash 1 counter))
                     (+ counter 1)))
              (else (r6rs-raise (make-assertion-violation)))))))

    (define fields-layout (car fields-pair))
    (define fields-bit-field (cdr fields-pair))

    (define field-names (list->vector (map cadr (vector->list fields))))
    (define late-rtd #f)

    (define (private-record-predicate obj)       
      (and (record-internal? obj)
           (or (eq? (struct-vtable obj) late-rtd)
               (and=> (struct-ref obj 0) private-record-predicate))))

    (define (field-binder parent-struct . args)
      (apply make-struct/no-tail late-rtd parent-struct args))

    (if (and parent (struct-ref parent rtd-index-sealed?))
	(r6rs-raise (make-assertion-violation)))

    (let ((matching-rtd (and uid (hashq-ref uid-table uid)))
	  (opaque? (or opaque? (and parent (struct-ref 
					    parent rtd-index-opaque?)))))
      (if matching-rtd
	  (if (equal? (list name 
			    parent 
			    sealed? 
			    opaque?                            
			    field-names
                            fields-bit-field)
		      (list (struct-ref matching-rtd rtd-index-name)
			    (struct-ref matching-rtd rtd-index-parent)
			    (struct-ref matching-rtd rtd-index-sealed?)
			    (struct-ref matching-rtd rtd-index-opaque?)
			    (struct-ref matching-rtd rtd-index-field-names)
                            (struct-ref matching-rtd 
                                        rtd-index-field-bit-field)))
	      matching-rtd
	      (r6rs-raise (make-assertion-violation)))
          
	  (let ((rtd (make-struct/no-tail
                      record-type-vtable

                      fields-layout
                      (lambda (obj port)
                        (simple-format 
                         port "#<r6rs:record:~A>" name))
				  
                      name
                      uid
                      parent 
                      sealed? 
                      opaque?
				  
                      private-record-predicate
                      field-names
                      fields-bit-field
                      field-binder)))
	    (set! late-rtd rtd)
	    (if uid (hashq-set! uid-table uid rtd))
	    rtd))))

  (define (record-type-descriptor? obj)
    (and (struct? obj) (eq? (struct-vtable obj) record-type-vtable)))

  (define (make-record-constructor-descriptor rtd 
					      parent-constructor-descriptor
					      protocol)
    (define rtd-arity (vector-length (struct-ref rtd rtd-index-field-names)))
    (define (default-inherited-protocol n)
      (lambda args
	(receive 
          (n-args p-args) 
	  (split-at args (- (length args) rtd-arity))
	  (let ((p (apply n n-args)))
	    (apply p p-args)))))
    (define (default-protocol p) p)
    
    (let* ((prtd (struct-ref rtd rtd-index-parent))
	   (pcd (or parent-constructor-descriptor
		    (and=> prtd (lambda (d) (make-record-constructor-descriptor 
					     prtd #f #f)))))
	   (prot (or protocol (if pcd 
				  default-inherited-protocol 
				  default-protocol))))
      (make-struct/no-tail record-constructor-vtable rtd pcd prot)))

  (define (record-constructor rctd)
    (let* ((rtd (struct-ref rctd rctd-index-rtd))
	   (parent-rctd (struct-ref rctd rctd-index-parent))
	   (protocol (struct-ref rctd rctd-index-protocol)))
      (protocol 
       (if parent-rctd
	   (let ((parent-record-constructor (record-constructor parent-rctd))
		 (parent-rtd (struct-ref parent-rctd rctd-index-rtd)))
	     (lambda args
	       (let ((struct (apply parent-record-constructor args)))
		 (lambda args
		   (apply (struct-ref rtd rtd-index-field-binder)
			  (cons struct args))))))
	   (lambda args (apply (struct-ref rtd rtd-index-field-binder)
			       (cons #f args)))))))
		    
  (define (record-predicate rtd) (struct-ref rtd rtd-index-predicate))

  (define (record-accessor rtd k)
    (define (record-accessor-inner obj)
      (if (eq? (struct-vtable obj) rtd)
	  (struct-ref obj (+ k 1))
          (and=> (struct-ref obj 0) record-accessor-inner)))
    (lambda (obj) 
      (if (not (record-internal? obj))
          (r6rs-raise (make-assertion-violation)))
      (record-accessor-inner obj)))

  (define (record-mutator rtd k)
    (define (record-mutator-inner obj val)
      (and obj (or (and (eq? (struct-vtable obj) rtd)
                        (struct-set! obj (+ k 1) val))
                   (record-mutator-inner (struct-ref obj 0) val))))
    (let ((bit-field (struct-ref rtd rtd-index-field-bit-field)))
      (if (zero? (logand bit-field (ash 1 k)))
	  (r6rs-raise (make-assertion-violation))))
    (lambda (obj val) (record-mutator-inner obj val)))

  ;; Condition types that are used in the current library.  These are defined
  ;; here and not in (rnrs conditions) to avoid a circular dependency.

  (define &condition (make-record-type-descriptor '&condition #f #f #f #f '#()))
  (define &condition-constructor-descriptor 
    (make-record-constructor-descriptor &condition #f #f))

  (define &serious (make-record-type-descriptor 
		    '&serious &condition #f #f #f '#()))
  (define &serious-constructor-descriptor
    (make-record-constructor-descriptor 
     &serious &condition-constructor-descriptor #f))

  (define make-serious-condition 
    (record-constructor &serious-constructor-descriptor))

  (define &violation (make-record-type-descriptor
		      '&violation &serious #f #f #f '#()))
  (define &violation-constructor-descriptor
    (make-record-constructor-descriptor 
     &violation &serious-constructor-descriptor #f))
  (define make-violation (record-constructor &violation-constructor-descriptor))

  (define &assertion (make-record-type-descriptor
		      '&assertion &violation #f #f #f '#()))
  (define make-assertion-violation 
    (record-constructor 
     (make-record-constructor-descriptor
      &assertion &violation-constructor-descriptor #f)))

  ;; Exception wrapper type, along with a wrapping `throw' implementation.
  ;; These are used in the current library, and so they are defined here and not
  ;; in (rnrs exceptions) to avoid a circular dependency.

  (define &raise-object-wrapper
    (make-record-type-descriptor '&raise-object-wrapper #f #f #f #f
				 '#((immutable obj) (immutable continuation))))
  (define make-raise-object-wrapper 
    (record-constructor (make-record-constructor-descriptor 
			 &raise-object-wrapper #f #f)))
  (define raise-object-wrapper? (record-predicate &raise-object-wrapper))
  (define raise-object-wrapper-obj (record-accessor &raise-object-wrapper 0))
  (define raise-object-wrapper-continuation 
    (record-accessor &raise-object-wrapper 1))

  (define (r6rs-raise obj) 
    (throw 'r6rs:exception (make-raise-object-wrapper obj #f)))
  (define (r6rs-raise-continuable obj)
    (define (r6rs-raise-continuable-internal continuation)
      (throw 'r6rs:exception (make-raise-object-wrapper obj continuation)))
    (call/cc r6rs-raise-continuable-internal))
)