Struct FixedSites 

pub struct FixedSites<const N: usize>;

FixedSites<N> — admit exactly N sites, unconstrained per-site.

The simplest non-trivial standard-type-library citizen: a generic ConstrainedTypeShape that fixes a site count and imposes no per-site constraint. It is the parametric building block under any downstream shape that wants “this many sites, my own grounding admission decides what each site contains” — for example, a 32-byte hash output (32 sites at WittLevel::W8), an 80-byte Bitcoin block header (80 sites at WittLevel::W8), or a 16-element integer-vector at WittLevel::W64.

At any instantiation, <FixedSites<N> as ConstrainedTypeShape>::SITE_COUNT == N and <FixedSites<N> as ConstrainedTypeShape>::CONSTRAINTS is the empty slice (foundation reads “empty CONSTRAINTS” as “unconstrained” per the trait’s normative documentation). The IRI is the foundation’s ConstrainedType class IRI — shared across every empty-constraint stdlib type per ADR-017 and the closure rule documented in this module’s header — so instance identity flows entirely through (SITE_COUNT, CONSTRAINTS).

See also

• Wiki: 05 Building Block View § Whitebox prism
• Wiki: 09 Architecture Decisions § ADR-017

Constraints

• TC-01 — admission is a compile-time activity; SITE_COUNT and CONSTRAINTS are const-evaluable
• TC-04 — bilateral compile-time enforcement: a downstream author who consumes FixedSites<N> cannot violate the contract without the toolchain rejecting their program
• ADR-013 — closure under uor-foundation: the body uses only foundation vocabulary (ConstrainedTypeShape, ConstraintRef)
• ADR-017 — content-addressed identity: the (IRI, SITE_COUNT, CONSTRAINTS) triple deterministically encodes each instantiation

Behavior

// Given: a fixed-32-sites shape
// When:  its trait constants are read
// Then:  SITE_COUNT reflects N and CONSTRAINTS is empty
use prism::pipeline::ConstrainedTypeShape;
use prism::std_types::FixedSites;
assert_eq!(<FixedSites<32> as ConstrainedTypeShape>::SITE_COUNT, 32);
assert!(<FixedSites<32> as ConstrainedTypeShape>::CONSTRAINTS.is_empty());
assert_eq!(
    <FixedSites<32> as ConstrainedTypeShape>::IRI,
    "https://uor.foundation/type/ConstrainedType",
);
// And: a different N produces a distinct content-address — same
// IRI, different SITE_COUNT — so the (IRI, SITE_COUNT, CONSTRAINTS)
// triple distinguishes the two instantiations.
assert_eq!(<FixedSites<80> as ConstrainedTypeShape>::SITE_COUNT, 80);
assert_eq!(
    <FixedSites<80> as ConstrainedTypeShape>::IRI,
    <FixedSites<32> as ConstrainedTypeShape>::IRI,
);

Trait Implementations

impl<const N: usize> ConstrainedTypeShape for FixedSites<N>

const IRI: &'static str = "https://uor.foundation/type/ConstrainedType"

IRI of the ontology type:ConstrainedType instance this shape represents.

const SITE_COUNT: usize = N

Number of sites (fields) this constrained type carries.

const CONSTRAINTS: &'static [ConstraintRef]

Per-site constraint list. Empty means unconstrained.

const CYCLE_SIZE: u64

ADR-032: cardinality of the shape’s value-set (the cycle structure of the shape under the substrate’s discrete-clock model). Used by the prism_model! macro to lower first_admit (closure-body grammar G16) to the correct descent measure. Conventions:

const SITE_BUDGET: usize = Self::SITE_COUNT

Ontology-level siteBudget: count of data sites only, excluding bookkeeping introduced by composition (coproduct tag sites, etc.). Equals SITE_COUNT for leaf shapes and for shapes whose composition introduces no bookkeeping (products, cartesian products). Strictly less than SITE_COUNT for coproduct shapes and any shape whose SITE_COUNT includes inherited bookkeeping. Introduced by the Product/Coproduct Completion Amendment §4a; defaults to SITE_COUNT so pre-amendment shape impls remain valid without edits.