1Obj(3)                           OCaml library                          Obj(3)
2
3
4

NAME

6       Obj - Operations on internal representations of values.
7

Module

9       Module   Obj
10

Documentation

12       Module Obj
13        : sig end
14
15
16       Operations on internal representations of values.
17
18       Not for the casual user.
19
20
21
22
23
24       type t
25
26
27
28
29       type raw_data = nativeint
30
31
32
33
34
35       val repr : 'a -> t
36
37
38
39
40       val obj : t -> 'a
41
42
43
44
45       val magic : 'a -> 'b
46
47
48
49
50       val is_block : t -> bool
51
52
53
54
55       val is_int : t -> bool
56
57
58
59
60       val tag : t -> int
61
62
63
64
65       val size : t -> int
66
67
68
69
70       val reachable_words : t -> int
71
72       Computes  the  total size (in words, including the headers) of all heap
73       blocks accessible from the argument.  Statically allocated  blocks  are
74       excluded,   unless  the  runtime  system  was  configured  with  --dis‐
75       able-naked-pointers .
76
77       @Since 4.04
78
79
80
81       val field : t -> int -> t
82
83
84
85
86       val set_field : t -> int -> t -> unit
87
88       When using flambda:
89
90
91       set_field MUST NOT be called on immutable blocks.  (Blocks allocated in
92       C stubs, or with new_block below, are always considered mutable.)
93
94       The  same goes for set_double_field and set_tag .  However, for set_tag
95       , in the case of immutable blocks where the middle-end optimizers never
96       see code that discriminates on their tag (for example records), the op‐
97       eration should be safe.  Such uses are nonetheless discouraged.
98
99       For experts only: set_field et al can be made safe  by  first  wrapping
100       the  block  in  Sys.opaque_identity , so any information about its con‐
101       tents will not be propagated.
102
103
104
105       val set_tag : t -> int -> unit
106
107
108
109
110       val double_field : t -> int -> float
111
112
113
114
115       val set_double_field : t -> int -> float -> unit
116
117
118
119
120       val raw_field : t -> int -> raw_data
121
122
123
124
125       val set_raw_field : t -> int -> raw_data -> unit
126
127
128
129
130       val new_block : int -> int -> t
131
132
133
134
135       val dup : t -> t
136
137
138
139
140       val truncate : t -> int -> unit
141
142
143
144
145       val add_offset : t -> Int32.t -> t
146
147
148
149
150       val with_tag : int -> t -> t
151
152
153
154
155       val first_non_constant_constructor_tag : int
156
157
158
159
160       val last_non_constant_constructor_tag : int
161
162
163
164
165       val lazy_tag : int
166
167
168
169
170       val closure_tag : int
171
172
173
174
175       val object_tag : int
176
177
178
179
180       val infix_tag : int
181
182
183
184
185       val forward_tag : int
186
187
188
189
190       val no_scan_tag : int
191
192
193
194
195       val abstract_tag : int
196
197
198
199
200       val string_tag : int
201
202
203
204
205       val double_tag : int
206
207
208
209
210       val double_array_tag : int
211
212
213
214
215       val custom_tag : int
216
217
218
219
220       val final_tag : int
221
222
223
224
225       val int_tag : int
226
227
228
229
230       val out_of_heap_tag : int
231
232
233
234
235       val unaligned_tag : int
236
237
238
239       module Closure : sig end
240
241
242
243
244       module Extension_constructor : sig end
245
246
247
248
249
250       val extension_constructor : 'a -> extension_constructor
251
252
253
254
255       val extension_name : extension_constructor -> string
256
257
258
259
260       val extension_id : extension_constructor -> int
261
262
263
264
265
266       The following two functions are deprecated.   Use  module  Marshal  in‐
267       stead.
268
269       val marshal : t -> bytes
270
271
272
273
274       val unmarshal : bytes -> int -> t * int
275
276
277
278       module Ephemeron : sig end
279
280
281
282
283
284
285
286OCamldoc                          2021-07-22                            Obj(3)