The UUID library¶

UUIDs are “Universally Unique IDentifiers”. They are immutable objects representing 128 bits of data.

In addition to constructing UUIDs from raw bytes or strings, it also provides for creating version 3, 4 or 5 UUIDs as defined in RFC 4122.

UUID creation functions:

<uuid>
make-uuid3
make-uuid4
make-uuid5
as(<uuid>, <string>)

The most common way of creating a UUID will likely be make-uuid4 to construct a random UUID.

The UUID module¶

<uuid> Class¶

Superclasses

<object>

Init-Keywords

data (required) – An instance of limited(<byte-vector>, size:, 16).

Discussion

This class holds the data for a UUID. UUIDs are typically constructed with the functions make-uuid3, make-uuid4, or make-uuid5.

UUIDs can also be created from a string using as(<uuid>, <string>).

See also

make-uuid3
make-uuid4
make-uuid5
as(<uuid>, <string>)

$nil-uuid Constant¶

Type: <uuid>
Value: make(<uuid>, data: make(<byte-vector>, size: 16, fill: 0))
Discussion: This is a UUID where all of the bits are 0.

Creation¶

make-uuid3 Generic function¶

Signature

make-uuid3 (namespace name) => (uuid)

Parameters

namespace – An instance of <uuid>.
name – An instance of <string>.

Values

uuid – An instance of <uuid>.

Discussion

Construct a version 3 UUID that is the MD5 hash of a namespace and name. Predefined namespaces are available as $namespace-dns, $namespace-url, $namespace-iso-oid, and $namespace-x500.

Example

let uuid = make-uuid3($namespace-url,
                      "http://github.com/dylan-foundry/uuid");

See also

make-uuid4
make-uuid5
$namespace-dns
$namespace-url
$namespace-iso-oid
$namespace-x500

make-uuid4 Generic function¶

Signature

make-uuid4 () => (uuid)

Values

uuid – An instance of <uuid>.

Discussion

Construct a version 4 UUID that uses random data.

Example

let uuid = make-uuid4();

See also

make-uuid3
make-uuid5

make-uuid5 Generic function¶

Signature

make-uuid5 (namespace name) => (uuid)

Parameters

namespace – An instance of <uuid>.
name – An instance of <string>.

Values

uuid – An instance of <uuid>.

Discussion

Construct a version 5 UUID that is the SHA1 hash of a namespace and name. Predefined namespaces are available as $namespace-dns, $namespace-url, $namespace-iso-oid, and $namespace-x500.

Example

let uuid = make-uuid5($namespace-dns, "opendylan.org");

See also

make-uuid3
make-uuid4
$namespace-dns
$namespace-url
$namespace-iso-oid
$namespace-x500

Conversion¶

as(<uuid>, <string>) Method¶

Signature

as(<uuid>, string) => uuid

Parameters

type – This must be <uuid>.
string – An instance of <string>.

Values

uuid – An instance of <uuid>.

Discussion

Convert a string into a UUID. The string must only contain hexadecimal digits and, excluding dashes, must only 32 characters long.

Example

let uuid = as(<uuid>, "4699DE5F-1F40-41B8-AB8D-55CCA1A6C9E9");

as(<string>, <uuid>) Method¶

Signature

as(<string>, uuid) => string

Parameters

type – This must be <string>.
uuid – An instance of <uuid>.

Values

string – An instance of <string>.

Discussion

Convert a UUID into a human readable string.

Example

? as(<string>, uuid)
=> "4699DE5F-1F40-41B8-AB8D-55CCA1A6C9E9"

Miscellaneous¶

$namespace-dns Constant¶

Type

<uuid>

Value

as(<uuid>, "6ba7b810-9dad-11d1-80b4-00c04fd430c8")

Discussion

A predefined namespace UUID that can be used with make-uuid3 or make-uuid5. This namespace UUID is as it is specified in RFC 4122.

When used to create a UUID, the associated name should be a fully qualified domain name.

See also

make-uuid3
make-uuid5
$namespace-url
$namespace-iso-oid
$namespace-x500

$namespace-iso-oid Constant¶

Type

<uuid>

Value

as(<uuid>, "6ba7b812-9dad-11d1-80b4-00c04fd430c8")

Discussion

A predefined namespace UUID that can be used with make-uuid3 or make-uuid5. This namespace UUID is as it is specified in RFC 4122.

When used to create a UUID, the associated name should be an ISO OID.

See also

make-uuid3
make-uuid5
$namespace-dns
$namespace-url
$namespace-x500

$namespace-url Constant¶

Type

<uuid>

Value

as(<uuid>, "6ba7b811-9dad-11d1-80b4-00c04fd430c8")

Discussion

A predefined namespace UUID that can be used with make-uuid3 or make-uuid5. This namespace UUID is as it is specified in RFC 4122.

When used to create a UUID, the associated name should be a URL.

See also

make-uuid3
make-uuid5
$namespace-dns
$namespace-iso-oid
$namespace-x500

$namespace-x500 Constant¶

Type

<uuid>

Value

as(<uuid>, "6ba7b814-9dad-11d1-80b4-00c04fd430c8")

Discussion

A predefined namespace UUID that can be used with make-uuid3 or make-uuid5. This namespace UUID is as it is specified in RFC 4122.

When used to create a UUID, the associated name should be an X.500 DN in DER or a text output format.

See also

make-uuid3
make-uuid5
$namespace-dns
$namespace-url
$namespace-iso-oid

rfc4122-variant? Generic function¶

Signature

rfc4122-variant? (uuid) => (res)

Parameters

uuid – An instance of <uuid>.

Values

res – An instance of <boolean>.

Discussion

Identify whether or not the given uuid is one of the variants defined in RFC 4122.

Example

? let uuid = make-uuid4();
? rfc4122-variant?(uuid)
=> #t

rfc4122-version Generic function¶

Signature

rfc4122-version (uuid) => (res)

Parameters

uuid – An instance of <uuid>.

Values

res – An instance of <integer>.

Discussion

If the given uuid is one of the variants defined in RFC 4122, this will return which version it is.

If the uuid is not a variant from RFC 4122, the results of this function are undefined.

Example

? let uuid = make-uuid4();
? rfc4122-version(uuid)
=> 4

uuid-data Generic function¶

Signature

uuid-data (uuid) => (data)

Parameters

uuid – An instance of <uuid>.

Values

data – An instance of limited(<byte-vector>, size:, 16).

Discussion

Return the byte vector containing the immutable data for the uuid.