Elamur Groupantsmlab-vm-registers
The groupant beside mlab/src/vm.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 | approximant |
| ast | partial | ../syntax.json |
| cost | symbolic source derived | invariant |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | executed bounded checks | tests |
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 |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
canonical_bits | canonical_bits | partial source derived model | canonical_bits |
undefined_value | undefined_value | partial source derived model | undefined_value |
ownership | ownership | partial source derived model | ownership |
matrix_view | matrix_view | partial source derived model | matrix_view |
Model text
descriptant
mlab-vm-registers
Register representation and value/matrix transport.
Epoch 2026-10-31
Half-open source bytes [2447,5611); bound by parent source hash and scoped byte hash. Model covers only this fragment; parent composition explains joins.
approximant
Scoped forward relation
Real scalar doubles pack to F; canonical logical bits pack L; all else V; U converts to None.
Domain and gap
Source-generated states within resource limits. Categorical relation has no executable percent surrogate.
invariant
Scoped invariant
Logical -0 does not pack as L(false): only bits==0 does.
Cost
Scalar packing/unpacking O(1); shared Value conversion may clone matrix payload. Borrowed matrix view avoids clone, scalar view allocates one cell.
models
Scoped typed relations
behavior_complement
U excludes any Value result. Noncanonical logical bits exclude L packing; complex/character/multielement matrices exclude F packing.
reverse_reconstruction
F(x) admits scalar double value x; V retains nonpacked values; allocation ownership and clone history cannot be reconstructed.
canonical_bits
Logical -0 does not pack as L(false): only bits==0 does.
undefined_value
U has no value and is not an empty matrix at this boundary.
ownership
into_value tries Rc unwrap, otherwise clones shared payload.
matrix_view
mat_cow borrows V matrices but constructs scalar matrices for F/L.
tests
Evidence scope
Parent selected tests: wave30_bounded_state_and_fallback, wave30_parse_runtime_and_output_state, wave30_synthetic_gate_fail_fast, vm_workspace_is_visible_after_run. This fragment shares parent syntax and finite checks; no separate test count or complete fragment coverage claim. Assertion-control association and unexecuted paths are in parent tests.md and source-test-map.json.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/mlab/src/vm.rs.groupant/registers.groupant/