Obj (melange.Stdlib.Obj)

type t;

type raw_data = nativeint;

let repr: 'a => t;

let obj: t => 'a;

let magic: 'a => 'b;

let is_block: t => bool;

let is_int: t => bool;

let tag: t => int;

let size: t => int;

let reachable_words: t => int;

Computes the total size (in words, including the headers) of all heap blocks accessible from the argument. Statically allocated blocks are excluded, unless the runtime system was configured with --disable-naked-pointers.

since 4.04

let field: t => int => t;

let set_field: t => int => t => unit;

When using flambda:

set_field MUST NOT be called on immutable blocks. (Blocks allocated in C stubs, or with new_block below, are always considered mutable.)

The same goes for set_double_field and set_tag. However, for set_tag, in the case of immutable blocks where the middle-end optimizers never see code that discriminates on their tag (for example records), the operation should be safe. Such uses are nonetheless discouraged.

For experts only: set_field et al can be made safe by first wrapping the block in Sys.opaque_identity, so any information about its contents will not be propagated.

let set_tag: t => int => unit;

deprecated Use with_tag instead.

let double_field: t => int => float;

let set_double_field: t => int => float => unit;

let raw_field: t => int => raw_data;

let set_raw_field: t => int => raw_data => unit;

let dup: t => t;

let truncate: t => int => unit;

deprecated

let add_offset: t => Int32.t => t;

let with_tag: int => t => t;

let first_non_constant_constructor_tag: int;

let last_non_constant_constructor_tag: int;

let lazy_tag: int;

let closure_tag: int;

let object_tag: int;

let infix_tag: int;

let forward_tag: int;

let no_scan_tag: int;

let abstract_tag: int;

let string_tag: int;

let double_tag: int;

let double_array_tag: int;

let custom_tag: int;

let final_tag: int;

deprecated Replaced by custom_tag.

let int_tag: int;

let out_of_heap_tag: int;

let unaligned_tag: int;

module Closure: { ... };

module Extension_constructor: { ... };

let extension_constructor: 'a => extension_constructor;

deprecated use Obj.Extension_constructor.of_val

let extension_name: extension_constructor => string;

deprecated use Obj.Extension_constructor.name

let extension_id: extension_constructor => int;

deprecated use Obj.Extension_constructor.id

module Ephemeron: { ... };

Ephemeron with arbitrary arity and untyped