Elamur Groupantslatex-print-stage1
The groupant beside latex/src/print.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 |
debug_coordinate | debug_coordinate | partial source derived model | debug_coordinate |
label_order | label_order | partial source derived model | label_order |
Model text
descriptant
latex-print-stage1
to_sexpr recursively writes tagged forms: Group, fraction kind, scripts with optional sub/sup/primes, environment row lists, unknown command/environment names with start offset. Text ignores TextStyle; Env serialization omits arg column metadata; XArrow prints above before optional below.
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
to_sexpr recursively writes tagged forms: Group, fraction kind, scripts with optional sub/sup/primes, environment row lists, unknown command/environment names with start offset. Text ignores TextStyle; Env serialization omits arg column metadata; XArrow prints above before optional below.
This is an exact source-derived partial model, not an executable approximate replacement.
invariant
Scoped invariants
Debug output cannot recover full AST equality generally: different TextStyle variants and Env args can serialize identically. It is not parsed by the formula parser as a guaranteed inverse format.
Unknown start is printed with @; end is omitted. Therefore this view distinguishes some values that Node equality treats equal while collapsing other structural fields.
XArrow stored below/above prints above then below; Stack prints annotation then base through its tagged parts. Consumers must use these explicit orders rather than assume field declaration order.
composition
Scoped interaction
This debugging view is separate from canonical LaTeX and plain text. Neither gate equality nor canonical idempotence uses it as a serialization contract.
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
Debug output cannot recover full AST equality generally: different TextStyle variants and Env args can serialize identically. It is not parsed by the formula parser as a guaranteed inverse format.
reverse_reconstruction
Text(Plain,'a') and Text(Bf,'a') share the text debug form. Two Env nodes differing only array column arg share output. Unknown spans with equal start but different end also share output.
debug_coordinate
Unknown start is printed with @; end is omitted. Therefore this view distinguishes some values that Node equality treats equal while collapsing other structural fields.
label_order
XArrow stored below/above prints above then below; Stack prints annotation then base through its tagged parts. Consumers must use these explicit orders rather than assume field declaration order.
tests
Evidence — 2026-10-31
print::tests::canonical_latex; print::tests::plain_text; integration golden outputs and corrupted_printer_turns_gate_red
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/src/print.rs.groupant/stage1.groupant/