roundtrip-class-coding
The groupant beside tools/roundtrip/src/class.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 | partial | invariant-and-cost |
| descriptant | present | descriptant |
| invariant | partial | invariant-and-cost |
| tests | 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 |
unicode_cost | unicode_cost | partial source derived model | unicode_cost |
position_domain | position_domain | partial source derived model | position_domain |
lexicon_state | lexicon_state | partial source derived model | lexicon_state |
scope_precondition | scope_precondition | partial source derived model | scope_precondition |
Model text
descriptant
Diagnostic bit costs
2026-10-31 epoch: source scope bytes [8926,10611); Hebrew scalar weighting and dictionary membership set costs; finite f64 approximations are not executable compression lengths.
No annotator/model loading, live corpus, full suite, teacher, GPU or persistent-learning evidence. No executable percentage surrogate: categorical codecs/effects need a useful metric before future caps 1/2/5/10%.
approximant
Diagnostic bit costs
Hebrew scalar weighting and dictionary membership set costs; finite f64 approximations are not executable compression lengths.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
catalog
behavior_complement
Subject: roundtrip-class-coding, source hash 1b8466551077c2f42748e0d08084307cc8bbaff3f62fbe2597eced4b75221f36, transition observation.
For Diagnostic bit costs, excluded transitions violate the stated scoped rule: Hebrew scalar weighting and dictionary membership set costs; finite f64 approximations are not executable compression lengths. This is an inner source-derived exclusion under the domain, not a complement of arbitrary unseen runtime behavior.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Status: partial source-derived model.
reverse_reconstruction
Subject: roundtrip-class-coding, source hash 1b8466551077c2f42748e0d08084307cc8bbaff3f62fbe2597eced4b75221f36, transition observation.
Fix outputs and post-state of coding; compatible antecedents are all scoped inputs/pre-state satisfying: Hebrew scalar weighting and dictionary membership set costs; finite f64 approximations are not executable compression lengths. Fields outside this byte scope are held fixed; discarded fields remain ambiguous.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Status: partial source-derived model.
unicode_cost
Subject: roundtrip-class-coding, source hash 1b8466551077c2f42748e0d08084307cc8bbaff3f62fbe2597eced4b75221f36, transition observation.
lit_bits(empty)=0 and lit_bits(Hebrew+a+emoji)=48; this differs from UTF-8 storage bytes and is a declared diagnostic coding convention.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Status: partial source-derived model.
position_domain
Subject: roundtrip-class-coding, source hash 1b8466551077c2f42748e0d08084307cc8bbaff3f62fbe2597eced4b75221f36, transition observation.
pos_bits(n)=log2(n+1) on nonoverflowing n; n=0 costs zero. usize::MAX is outside modeled domain, with debug/release overflow divergence.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Status: partial source-derived model.
lexicon_state
Subject: roundtrip-class-coding, source hash 1b8466551077c2f42748e0d08084307cc8bbaff3f62fbe2597eced4b75221f36, transition observation.
Known English lemma costs17; Hebrew present in initialized nonempty HEB_LEMMAS costs log2(size), else literal. This global one-time vocabulary is external state, not learning by this call.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Status: partial source-derived model.
scope_precondition
Subject: roundtrip-class-coding, source hash 1b8466551077c2f42748e0d08084307cc8bbaff3f62fbe2597eced4b75221f36, transition observation.
Diagnostic bit costs requires the coordinate/state assumptions of this fragment; inspect its exact byte range. Hebrew scalar weighting and dictionary membership set costs; finite f64 approximations are not executable compression lengths. Invalid arbitrary state is outside the reconstruction law.
Domain: bounded synthetic values, valid source-specific coordinates, nonoverflowing counts, available allocation; fixed environment controls. Relations are source-derived partial models with finite checks, not universal proofs.
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Status: partial source-derived model.
tests
Scoped evidence
Evidence: external wave32 rt_core receipt includes native-commands.json, exact named outcomes twice debug/twice release, raw status/log files, compiled production controls with byte restoration and paired syntax. Only named synthetic helpers execute; model_path/export and live CLI paths have representation/source evidence.
Coverage is limited to this fragment's reached branches; parent tests do not prove every scoped branch.
invariant-and-cost
Scoped invariant and cost
Hebrew scalar weighting and dictionary membership set costs; finite f64 approximations are not executable compression lengths.
of_word O(B) lowercase plus fixed-list comparisons. lit_bits O(B); perm_bits O(k), O(1) extra state. pos_bits requires n<usize::MAX; floating conversion/log rounding is retained. Dictionary and OnceLock state affect lemma_bits.
The parent bound is conservative; unrelated parent effects are excluded from this fragment.
This page in Markdown โ https://md.groupants.elamur.ai/free/en/mova/tools/roundtrip/src/class.rs.groupant/coding.groupant/