module Uuidm:sig
..end
Universally unique identifiers (UUIDs).
Uuidm
implements 128 bits universally unique identifiers version
3, 5 (name based with MD5, SHA-1 hashing) and 4 (random based)
according to RFC 4122.
v0.9.7 - homepage
type
t
The type for UUIDs.
val v3 : t -> string -> t
v3 ns n
is a V3 UUID (named based with MD5 hashing) named by n
and
namespaced by ns
.
val v5 : t -> string -> t
v5 ns n
is a V5 UUID (named based with SHA-1 hashing) named by n
and namespaced by ns
.
val v4 : bytes -> t
v4 b
is a V4 UUID (random based) that uses the first 16 bytes of
b
for randomness. Be aware that most of these 128 bits are seen
literally in the result.
val v4_gen : Stdlib.Random.State.t -> unit -> t
v4_gen seed
is a function that generates random V4 UUIDs (random
based) with the given seed
.
Warning. Sequences of UUIDs generated using Stdlib.Random
are
suitably random but predictable by an observer. If that is an
issue for you, use Uuidm.v4
with random bytes generated by a CSPRNG.
This interface is informally deprecated: it seems many people are
using Uuidm.v `V4
in practice. For new code prefer one of the
creation functions above.
typeversion =
[ `V3 of t * string | `V4 | `V5 of t * string ]
The type for UUID versions and generation parameters.
`V3
and `V5
specify a namespace and a name for the generation.`V4
is random based with a private state seeded with
Stdlib.Random.State.make_self_init
. Use Uuidm.v4_gen
to specify
your own seed. Use Uuidm.v4
to specify your own randomness.
Warning. The sequence resulting from repeatedly calling
v `V4
is random but predictable see Uuidm.v4_gen
.val v : version -> t
v version
is an UUID of the given version
.
val nil : t
nil
is the nil UUID.
val ns_dns : t
ns_dns
is the DNS namespace UUID.
val ns_url : t
ns_url
is the URL namespace UUID.
val ns_oid : t
ns_oid
is the ISO OID namespace UUID.
val ns_X500 : t
ns_dn
is the X.500 DN namespace UUID.
val equal : t -> t -> bool
equal u u'
is true
iff u
and u'
are equal.
val compare : t -> t -> int
compare u u'
totally orders u
and u'
.
This is the binary format mandated by RFC 4122.
val of_bytes : ?pos:int -> string -> t option
of_bytes pos s
is the UUID represented by the 16 bytes starting
at pos
(defaults to 0
) in s
. The result is None
if the
string is not long enough.
val to_bytes : t -> string
to_bytes u
is u
as a 16 bytes long string.
This is the binary format in which the three first fields of UUIDs (which are oblivious to this module) are read and written in little-endian. This corresponds to how UEFI or Microsoft formats UUIDs.
val of_mixed_endian_bytes : ?pos:int -> string -> t option
of_mixed_endian_bytes
is like Uuidm.of_bytes
but decodes
the mixed endian serialization.
val to_mixed_endian_bytes : t -> string
to_mixed_endian_bytes
is like Uuidm.to_bytes
but encodes
the mixed endian serialization.
val of_string : ?pos:int -> string -> t option
of_string pos s
converts the substring of s
starting at pos
(defaults to 0
) of the form "XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
where X is a lower or upper case hexadecimal number to an
UUID. The result is None
if a parse error occurs.
val to_string : ?upper:bool -> t -> string
to_string u
is u
as a string of the form
"XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX"
where X is a lower
(or upper if upper
is true
) case hexadecimal number.
val pp : Stdlib.Format.formatter -> t -> unit
pp ppf u
formats a representation based on Uuidm.to_string
of u
on ppf
.
val pp_string : ?upper:bool -> Stdlib.Format.formatter -> t -> unit
pp_string ?upper ppf u
formats u
on ppf
like Uuidm.to_string
would
do.