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:

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:

$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 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-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:

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:

$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:

$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:

$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:

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.