Module types 

DSFB-Debug: core domain types — public API contract.

Every type in this module is Copy + Clone + Debug + PartialEq with no heap allocation. This is the load-bearing engineering claim of the no_std core: the entire residual evaluation pipeline moves Copy values across function boundaries. No Box, no Rc, no Vec on hot paths. Every public surface accepts and returns &[T] slices only — the observer-only contract is type-enforced.

Mapping to paper §5

Type	Paper concept	Section
SignTuple	residual signature σ(k) = (‖r‖, ṙ, r̈)	§5.3
GrammarState	4-state automaton	§5.5
ReasonCode	residual policy reason	§5.5
MotifClass	typed motif (32 variants)	§5.6
Provenance	evidence ladder (3-tier)	§5.6
SemanticDisposition	bank lookup outcome	§5.6
MatchConfidence	per-episode evidence packet	§11.y
HeuristicEntry	bank record (motif IP claim)	§4.x
DebugEpisode	aggregated structural episode	§7
BenchmarkMetrics	RSCR / fault-recall / FP rate	§13
AuditRecord	NIST SP 800-53 AU-3 record	§15

Standards alignment

• NIST SP 800-53 AU-3 (audit record content): AuditRecord fields cover the required event_type / when / where / source / outcome content axes.
• NIST SP 800-53 AU-2 (auditable events): HeuristicEntry.primary_witness_detectors defines the named auditable events that must fire for typed confirmation.
• ISO/IEC 25010 (Analysability): typed MotifClass + per- episode evidence packet support the Analysability quality characteristic.
• IEEE 1012-2016 (V&V): the confuser-boundary mechanism provides independent validation of typed disposition.

Stability guarantee

All pub struct fields are additive across versions; existing fields retain their type and semantics. A new field added in a later phase always carries a default-friendly meaning (e.g. affinity_tiers: 0 falls back to the reason-code-derived mask; primary_witness_detectors: &[] disables Phase 8). This preserves Theorem 9 deterministic replay across upgrades.

Structs

AuditRecord

NIST 800-53 AU-3 compliant audit record Fields: what (event_type), when (window_index), where (signal_index), source (source), outcome (outcome)

BenchmarkMetrics

Benchmark metrics — the paper’s headline numbers

DebugEpisode

A debugging episode — the Trace Event Collapse output. Paper §7: “the primary developer-facing delta”

HeuristicEntry

Heuristics bank entry — typed, provenance-aware motif record.

MatchConfidence

Confidence-bearing motif match result.

SignTuple

Residual sign tuple σ(k) = (‖r‖, ṙ, r̈) Paper §5.3

SignalEvaluation

Per-signal, per-window DSFB evaluation result. The atomic unit of the traceability chain.

StructuralSignature

Structural signature of an episode

Enums

AuditEventType

AuditSource

DriftDirection

Drift direction in an episode’s structural signature

GrammarState

Grammar state — Paper §5.5

MotifClass

Motif classes for software debugging — Paper §5.6.

PolicyState

Policy states — developer-facing output Paper §5: Silent / Watch / Review / Escalate

Provenance

Provenance tag — where this interpretation came from

ReasonCode

Grammar reason codes — Paper §5.5 Table

SemanticDisposition

Semantic disposition from heuristics bank lookup