Elamur Groupantsprag-rules-codec-selection
The groupant beside prag/src/rules.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial source model | forward |
| ast | partial | ../../syntax.json |
| composition | partial source model | composition |
| cost | partial source model | cost |
| descriptant | partial source model | epoch-memory |
| invariant | partial source model | invariant |
| tests | partial source model | checks |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
prag-rules-codec-selection-behavior-complement | behavior_complement | partial source model | behavior-complement |
prag-rules-codec-selection-reverse-reconstruction | reverse_reconstruction | partial source model | reverse-reconstruction |
prag-rules-codec-selection-specialization | status_filter | partial source model | specialization |
Model text
forward
select_rules(text,mode)=[] for off; otherwise stable filter parse_rules(text), keeping accepted or (mode=proposed and status=proposed). active returns an override unchanged first; absent override, OnceLock captures first environment/file selection with embedded fallback. Only pure selection is executed.
invariant
Duplicates and file order survive. Unknown modes select accepted only; rejected/unknown statuses never survive. Override intentionally bypasses filter; environment changes after cached load do not recompute.
cost
O(B+L*C) parse plus O(L) filtering; off O(1). Cache locking, IO and scheduling unmeasured.
behavior-complement
For statuses [accepted,proposed,rejected,other,accepted] and IDs [z,a,b,c,z], U candidate selected IDs excludes off != [], default != [z,z], proposed != [z,a,z]. This does not constrain overrides.
reverse-reconstruction
Selected [z,z] permits arbitrarily many rejected/unknown rows between them and different unknown modes. Off collapses every text to []; retain all compatible texts in inverse.
specialization
File position is priority, not ID sort/dedup. Fixture deliberately contains z before a and repeated z.
composition
Codec feeds selection without reordering. Sites and action-dependent atoms share the pre-rule Read; ordered action fold sees evolving state, then deletion remaps coordinates. Selection nested in codec retains status distinctions. Exact byte scopes constrain composition; no child alone proves the parent.
checks
Ten rules::wave15_models tests, tiny supplied fixtures only; two debug and two release passes with identical named outcomes. File-root receipts.md retains hashes. Finite catalogs, nine transfer states and sixteen deletion subsets; compiled production vacancy-guard mutant fails finite_transfer_and_drop_relations.
epoch-memory
2026-10-30: first rules tree. Review predicted unchanged valid-site transitions and O(1) validation before O(Read bytes) cloning. Old invalid_direct_sites_are_no_change failed because absent Drop returned Some; seven other initial tests passed. Repair rejects absent coordinates/unaligned reads. select_rules exposes the existing production filter; no selection policy change or speedup claimed.
limitations
Partial syntax, no expanded macros or semantic AST proof. No live parser, teacher, corpus, environment mutation, override or cache acquisition in tests. Empty verbs/entities avoid lexical matching acquisition; populated entity tests use direct actions. Token creation, full lexical/ancestry/action branches, IO/cache lifetime and all multi-site interactions remain unexecuted. Public atoms/drop_frames still require valid coordinates/alignment.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/prag/src/rules.rs.groupant/codec.groupant/selection.groupant/