Elamur Groupantslatex-build-stage0
The groupant beside latex/build.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 |
| composition | partial | composition |
| 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 |
identifier_language | identifier_language | partial source derived model | identifier_language |
validation_order | validation_order | partial source derived model | validation_order |
Model text
descriptant
latex-build-stage0
is_ident(s) = first(s).is_ascii_uppercase() AND every remaining scalar is_ascii_alphanumeric(). Empty has no first scalar and returns false.
Epoch 2026-10-31: replaced stage topic lists with concrete transitions, exclusions and compatible antecedents. Four meaningful typed views replace the previous six-view bookkeeping catalog. Shared syntax and source byte bounds are unchanged.
approximant
Scoped forward relation
is_ident(s) = first(s).is_ascii_uppercase() AND every remaining scalar is_ascii_alphanumeric(). Empty has no first scalar and returns false.
This is an exact source-derived partial model, not an executable approximate replacement.
invariant
Scoped invariants
Outputs true for empty, lowercase-leading, non-ASCII or underscore-containing names are excluded. This predicate has no file writes or table mutation.
The accepted language excludes ordinary Rust identifiers such as Alpha_beta; it is the generator's stricter variant convention.
main calls this predicate before symbol uniqueness/class/form validation. Its false result triggers that caller's identifier assertion; the predicate itself does not panic on empty input.
composition
Scoped interaction
Build validation consumes this boolean for sym and other enum row IDs; lexical acceptance does not prove a generated enum is complete.
The manifest binds this stage to the unchanged parent syntax projection and exact source byte range. Parent cost remains an upper accounting context; no independent whole-file invocation or execution count is assigned to this fragment.
models
behavior_complement
Outputs true for empty, lowercase-leading, non-ASCII or underscore-containing names are excluded. This predicate has no file writes or table mutation.
reverse_reconstruction
Preimage(true) is [A-Z][A-Za-z0-9]*; preimage(false) is every other UTF-8 string. A and Z9 share true, so the bool cannot reconstruct spelling.
identifier_language
The accepted language excludes ordinary Rust identifiers such as Alpha_beta; it is the generator's stricter variant convention.
validation_order
main calls this predicate before symbol uniqueness/class/form validation. Its false result triggers that caller's identifier assertion; the predicate itself does not panic on empty input.
tests
Evidence — 2026-10-31
wave28_tests::canonical_first_form_and_variant_order; wave28_tests::variant_identifier_boundary
Selected library filters ast:: lex:: macros:: parse:: print:: table:: and integration gate excluding document_extraction_with_preamble_macros and random_token_soup_never_panics_and_roundtrips. Direct rustc --test latex/build.rs exercises private helpers. All selected tests twice debug/release with identical sorted names. Four compiled mutants at build/AST/parser/printer boundaries fail assertions then exact restoration passes. These do not individually cover every source. Build-main failure effects, allocation failures and universal roundtrip are unproved. Strict Clippy reports existing lints. No corpus/live VMM/API/GPU/full-school/held-out tests.
This page in Markdown → https://md.groupants.elamur.ai/free/en/mova/latex/build.rs.groupant/stage0.groupant/