1Obj(3)                           OCaml library                          Obj(3)
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NAME

6       Obj - Operations on internal representations of values.
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Module

9       Module   Obj
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Documentation

12       Module Obj
13        : sig end
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16       Operations on internal representations of values.
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18       Not for the casual user.
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24       type t
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29       type raw_data = nativeint
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35       val repr : 'a -> t
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40       val obj : t -> 'a
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45       val magic : 'a -> 'b
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50       val is_block : t -> bool
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55       val is_int : t -> bool
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60       val tag : t -> int
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65       val size : t -> int
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70       val reachable_words : t -> int
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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 .
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77       @Since 4.04
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81       val field : t -> int -> t
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86       val set_field : t -> int -> t -> unit
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88       When using flambda:
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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.)
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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.
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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.
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105       val set_tag : t -> int -> unit
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110       val double_field : t -> int -> float
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115       val set_double_field : t -> int -> float -> unit
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120       val raw_field : t -> int -> raw_data
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125       val set_raw_field : t -> int -> raw_data -> unit
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130       val new_block : int -> int -> t
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135       val dup : t -> t
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140       val truncate : t -> int -> unit
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145       val add_offset : t -> Int32.t -> t
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150       val with_tag : int -> t -> t
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155       val first_non_constant_constructor_tag : int
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160       val last_non_constant_constructor_tag : int
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165       val lazy_tag : int
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170       val closure_tag : int
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175       val object_tag : int
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180       val infix_tag : int
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185       val forward_tag : int
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190       val no_scan_tag : int
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195       val abstract_tag : int
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200       val string_tag : int
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205       val double_tag : int
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210       val double_array_tag : int
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215       val custom_tag : int
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220       val final_tag : int
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225       val int_tag : int
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230       val out_of_heap_tag : int
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235       val unaligned_tag : int
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239       module Closure : sig end
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244       module Extension_constructor : sig end
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250       val extension_constructor : 'a -> extension_constructor
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255       val extension_name : extension_constructor -> string
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260       val extension_id : extension_constructor -> int
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266       The following two functions are deprecated.   Use  module  Marshal  in‐
267       stead.
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269       val marshal : t -> bytes
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274       val unmarshal : bytes -> int -> t * int
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278       module Ephemeron : sig end
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286OCamldoc                          2022-02-04                            Obj(3)