Module attributes 

Labels, tags, plugs, sockets, and wires.

Three tiers per SRD-0005:

• Labels — intrinsic facts (“what this entity is”). Participate in identity and fingerprinting.
• Tags — extrinsic organisation (“how I group/filter this”). Do not participate in identity.
• Plugs and sockets — structured compatibility surface on elements. Plugs name the upstreams an element needs; sockets name the points where downstreams connect to it. Each carries a non-empty set of (key, value) facets; a plug fits a socket iff the socket’s facets cover (superset) the plug’s.

Wires are the concrete plug↔socket connections the compiler produces when it resolves an authored dependency — wiring_for returns the WireMatch for a dependent’s plugs against a target’s sockets.

Namespace-uniqueness across tiers is enforced by validate_namespace: a single key cannot appear as both a label key and a tag key, nor as both an attribute key and a port name.

Modules

label

Canonical label keys. Not required on every entity — authoring these spellings lets tooling treat them uniformly.

Structs

Facet

Structured (key, value) pair on a plug or socket. Canonical human rendering is "key:value".

FacetKey

Key half of a (key, value) facet pair on a plug or socket.

FacetValue

Value half of a (key, value) facet pair.

LabelKey

Intrinsic-fact key on an attributable entity. Canonical well-known keys live in label.

LabelValue

Labels

Intrinsic-fact map. See module docs and SRD-0005.

Plug

A point where an element needs to connect to an upstream.

PortName

Shared name for plugs and sockets. The two kinds live in the same per-element namespace (SRD-0005 D13): an element may not have a plug and a socket with the same PortName.

Socket

A point where downstream elements connect to this element.

TagKey

Organisational tag key. Adopter-defined; paramodel ships no canonical keys at this layer.

TagValue

Tags

Extrinsic-organisation map. See module docs and SRD-0005.

Wire

One concrete plug↔socket connection.

Enums

AttributeError

Errors raised by attribute-layer construction and validation.

Tier

Tier a given key was authored on.

WireMatch

Outcome of matching a dependent element’s plugs against a target element’s sockets.

Traits

Attributed

Read interface for any entity carrying Labels and Tags.

Pluggable

Read interface for elements — adds plugs and sockets on top of Attributed. Only elements implement Pluggable at this layer (SRD-0005 D11).

Functions

fits

Does the plug fit the socket? True iff socket.facets is a superset of plug.facets.

validate_namespace

Validate the three-tier namespace-uniqueness rule (SRD-0005 D5).

wiring_for

Match each plug on the dependent against the target’s sockets, returning a WireMatch describing the outcome.