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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78       Since 4.04
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82       val field : t -> int -> t
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87       val set_field : t -> int -> t -> unit
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89       When using flambda:
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92       set_field MUST NOT be called on immutable blocks.  (Blocks allocated in
93       C stubs, or with new_block below, are always considered mutable.)
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95       The  same goes for set_double_field and set_tag .  However, for set_tag
96       , in the case of immutable blocks where the middle-end optimizers never
97       see code that discriminates on their tag (for example records), the op‐
98       eration should be safe.  Such uses are nonetheless discouraged.
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100       For experts only: set_field et al can be made safe  by  first  wrapping
101       the  block  in  Sys.opaque_identity , so any information about its con‐
102       tents will not be propagated.
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106       val set_tag : t -> int -> unit
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111       val double_field : t -> int -> float
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116       val set_double_field : t -> int -> float -> unit
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121       val raw_field : t -> int -> raw_data
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126       val set_raw_field : t -> int -> raw_data -> unit
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131       val new_block : int -> int -> t
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136       val dup : t -> t
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141       val truncate : t -> int -> unit
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146       val add_offset : t -> Int32.t -> t
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151       val with_tag : int -> t -> t
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156       val first_non_constant_constructor_tag : int
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161       val last_non_constant_constructor_tag : int
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166       val lazy_tag : int
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171       val closure_tag : int
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176       val object_tag : int
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181       val infix_tag : int
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186       val forward_tag : int
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191       val no_scan_tag : int
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196       val abstract_tag : int
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201       val string_tag : int
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206       val double_tag : int
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211       val double_array_tag : int
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216       val custom_tag : int
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221       val final_tag : int
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226       val int_tag : int
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231       val out_of_heap_tag : int
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236       val unaligned_tag : int
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240       module Closure : sig end
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245       module Extension_constructor : sig end
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251       val extension_constructor : 'a -> extension_constructor
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256       val extension_name : extension_constructor -> string
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261       val extension_id : extension_constructor -> int
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265       module Ephemeron : sig end
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273OCamldoc                          2022-07-22                            Obj(3)