Module domain 

Parameter domains.

A domain is the set of values a parameter may legally take. Per SRD-0004 D2 each parameter kind owns a sub-enum of its admissible shapes (IntegerDomain, DoubleDomain, StringDomain, SelectionDomain; Boolean has no payload), and a view enum Domain borrows into whichever sub-enum a Parameter carries. This module defines the owned sub-enums, their native-type operations (membership, cardinality, boundaries, sampling, enumeration), the Domain view wrapper that lifts those ops into Value form, and the SelectionResolver trait the Selection External variant defers to at plan-compilation time.

Gaps flagged for later SRD revisions:

• StringDomain::Regex sampling. The regex crate does not provide regex-backed generation; a future slice can plug in a generator crate or defer sampling to the caller. Until then, Domain::sample panics for the Regex variant.
• SelectionDomain::External sampling. Registry-aware sampling is specified in SRD-0004 D15 but not yet wired up; Domain::sample panics for the External variant.

Structs

LabeledEntry

Label attached to an external selection value for display purposes.

RegexPattern

A validated regex, carrying both the source pattern and the compiled automaton.

ResolverId

Opaque identifier naming an external selection resolver.

Enums

Cardinality

How many distinct values a domain contains.

Domain

Borrowed view over a parameter’s domain, pinned to the parameter’s name so operations can produce properly-provenanced Values.

DomainError

Errors produced by domain constructors and operations.

DoubleDomain

Double-precision float domain: inclusive range with finite, non-NaN bounds.

IntegerDomain

Integer domain: either an inclusive numeric range or a finite discrete set.

SelectionDomain

Selection domain: a set the user can pick multiple items from.

StringDomain

String domain: accept-all or regex-matched.

Traits

LabeledSelectionResolver

Extension trait: values carry UI labels in addition to their canonical ids.

SelectionResolver

Resolves the set of valid values for one external selection.

SelectionResolverRegistry

Host registry. The host (typically the embedding system) provides an implementation that knows how to look up resolvers by id.