Clausal Prolog — UUIDs (`uuid` module)¶

Overview¶

The uuid module provides predicates for generating, converting, and inspecting UUIDs backed by Python's uuid module. It produces and consumes real uuid.UUID objects.

-import_from(uuid, [uuid_v4, uuid_str, uuid_version, is_uuid])

make_id(ID) <- (
    uuid_v4(U),
    uuid_str(U, ID)
)

main <- (
    make_id(ID),
    ++print(f"Generated ID: {ID}")
)

Or via module import:

-import_module(uuid)

main <- (
    uuid.uuid_v4(U),
    uuid.uuid_str(U, S),
    ++print(S)
)

Import¶

-import_from(uuid, [
    uuid_v4, uuid_v1, uuid_v3, uuid_v5,
    uuid_str, uuid_hex, uuid_urn, uuid_bytes, uuid_int,
    uuid_version, uuid_fields, is_uuid
])

The module name is uuid in the seam (internally mapped to uuid_mod to avoid shadowing Python's stdlib).

Generation predicates¶

Predicate	Mode	Description
`uuid_v4(U)`	`-U`	Random v4 UUID
`uuid_v1(U)`	`-U`	Time-based v1 UUID
`uuid_v3(NS, NAME, U)`	`+NS, +NAME, -U`	MD5 namespace UUID
`uuid_v5(NS, NAME, U)`	`+NS, +NAME, -U`	SHA-1 namespace UUID

Namespace aliases¶

For uuid_v3 and uuid_v5, the namespace argument accepts string aliases or raw uuid.UUID objects:

Alias	UUID constant
`"dns"`	`uuid.NAMESPACE_DNS`
`"url"`	`uuid.NAMESPACE_URL`
`"oid"`	`uuid.NAMESPACE_OID`
`"x500"`	`uuid.NAMESPACE_X500`

uuid_v3('dns', "example.com", U)
uuid_v5('url', "https://example.com", U)

Conversion predicates¶

All conversion predicates are bidirectional: pass a ground UUID to decompose, or a ground representation to construct via unification.

Predicate	Mode	Description
`uuid_str(U, S)`	`?U, ?S`	UUID ↔ hyphenated string (`"550e8400-e29b-..."`)
`uuid_hex(U, H)`	`?U, ?H`	UUID ↔ 32-char hex string
`uuid_urn(U, URN)`	`?U, ?URN`	UUID ↔ URN string (`"urn:uuid:..."`)
`uuid_bytes(U, B)`	`?U, ?B`	UUID ↔ 16-byte `bytes` object
`uuid_int(U, N)`	`?U, ?N`	UUID ↔ 128-bit integer

# Generate a UUID and get its string form
uuid_v4(U), uuid_str(U, S)

# Parse a UUID from a string
uuid_str(U, "550e8400-e29b-41d4-a716-446655440000")

# Convert to hex
uuid_hex(U, "550e8400e29b41d4a716446655440000")

Inspection predicates¶

Predicate	Mode	Description
`uuid_version(U, V)`	`+U, -V`	Extract version number (1, 3, 4, 5)
`uuid_fields(U, TL, TM, TH, CSH, CSL, NODE)`	`+U, -TL, -TM, -TH, -CSH, -CSL, -NODE`	Decompose into 6 integer fields
`is_uuid(U)`	`+U`	Type test — succeeds if U is a `uuid.UUID`

# Check that a UUID is version 4
uuid_v4(U), uuid_version(U, 4)

# Type-check
is_uuid(U)

Examples

Session tokens¶

-import_from(uuid, [uuid_v4, uuid_str])

new_session(USERID, TOKEN) <- (
    uuid_v4(U),
    uuid_str(U, TOKEN)
)

Deterministic IDs¶

-import_from(uuid, [uuid_v5, uuid_str])

resource_id(TYPE, NAME, ID) <- (
    uuid_v5('url', NAME, U),
    uuid_str(U, ID)
)

See also: Python Interop — ++() escape for additional UUID operations · Database Ops — using UUIDs as fact keys.

Clausal Prolog — UUIDs (uuid module)¶