---
title: "db-src-prag-label-parser — Mova code model"
description: "Mova code model of tools/db/src/prag.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/tools/db/src/prag.rs.groupant/label-parser.groupant/"
---
Elamur: [Mova](https://md.mova.elamur.ai/free/en/) · [Dictionary](https://md.dictionary.elamur.ai/free/en/) · [Research](https://md.research.elamur.ai/free/en/) · **Groupants**

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# db-src-prag-label-parser

The groupant beside tools/db/src/prag.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

- **kind:** groupant_fragment
- **status:** partial source bound model
- **source:** [`tools/db/src/prag.rs`](https://github.com/ElamurAI/mova-free/blob/main/tools/db/src/prag.rs)
- **source SHA-256:** `21242d408f81a8b9…`
- **covers:** Eight or nine label columns (bytes 1362–2494)
- **part of:** [db-src-prag](https://md.groupants.elamur.ai/free/en/mova/tools/db/src/prag.rs.groupant/)
- **repository folder:** [`tools/db/src/prag.rs.groupant/label-parser.groupant`](https://github.com/ElamurAI/mova-free/tree/main/tools/db/src/prag.rs.groupant/label-parser.groupant)
- **repository commit:** `855da7bd4a7b`

> **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](#approximant) |
| **ast** | partial | `../syntax.json` |
| **cost** | partial | [invariant-and-cost](#invariant-and-cost) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant-and-cost](#invariant-and-cost) |
| **tests** | bounded checks partial scope | [tests](#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](#behavior-complement) |
| `reverse_reconstruction` | reverse_reconstruction | partial source derived model | [reverse_reconstruction](#reverse-reconstruction) |
| `header_arity` | header_arity | partial source derived model | [header_arity](#header-arity) |
| `row_width` | row_width | partial source derived model | [row_width](#row-width) |
| `empty_projection` | empty_projection | partial source derived model | [empty_projection](#empty-projection) |
| `failure_order` | failure_order | partial source derived model | [failure_order](#failure-order) |

## Model text


### descriptant

#### Eight or nine label columns

Read UTF-8 text; first line is required header. Require first8 exact names, optional9th trace only, <=9 columns. Skip empty data lines, require header width, retain sent_id and remaining values, append empty trace for8.

##### Prospective epoch — 2026-10-31

Full source was reviewed before edits; external prospective.md records API states, failure order and predicted checks. Production prefix remains byte-identical; test additions are isolated cfg(test)/test items.

##### Observed epoch — 2026-10-31

2026-10-31 wave31: 16 selected target/name cases passed twice debug and twice release with identical sorted outcomes; six compiled source-behavior mutants failed assertions, exact bytes restored and positive checks passed. Evidence scope is only the named helpers/fixtures. External receipt directory: $MOVA_DATA/runs/octopus-wave31-store-2026-10-31. No DuckDB integration, production loader/corpus, training or GPU run.

##### Retained limitations

No SQL evaluation was substituted with a mock process. Missing DuckDB is a dependency gap, not passing database evidence. Partial syntax has no macro expansion/name resolution/types; Rust helpers and fixtures do not prove all models.

### approximant

#### Eight or nine label columns forward relation

Read UTF-8 text; first line is required header. Require first8 exact names, optional9th trace only, <=9 columns. Skip empty data lines, require header width, retain sent_id and remaining values, append empty trace for8.

##### Domain

Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

##### Approximation limits

Categorical parsing, exact identity, transactional effects and resource errors have no useful percentage approximation metric here. No executable surrogate is claimed. Future profiles, if justified, may use only 1%, 2%, 5%, 10% with a defined metric/reference/domain.

### models

## Eight or nine label columns typed model catalog

Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Observation is one call/trace in the declared scope. Operators below are partial source-derived relations; complement is a proposed inner exclusion relation, reverse an outer compatible-antecedent relation retaining ambiguity. No universal proof follows from finite checks. Each oracle is the relevant named helper check below when it reaches the behavior; remaining SQL/effect cases are source review or proposed real-CLI checks.

### behavior_complement

Wrong first8 names, extra tenth column or nontrace ninth cannot return rows. Whitespace-only data line is not skipped.

Domain/assumptions: Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Evidence: see tests.md; unexecuted database branches remain conditional.

### reverse_reconstruction

Returned empty trace can come from8-column or9-column input; skipped empty lines and terminal LF differences are lost. Other cell bytes/order are preserved.

Domain/assumptions: Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Evidence: see tests.md; unexecuted database branches remain conditional.

### header_arity

Exactly8 and exactly9 are admitted;9 requires trace. Header-only result is empty and later loader owns no-rows rejection.

Domain/assumptions: Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Evidence: see tests.md; unexecuted database branches remain conditional.

### row_width

Each data row width equals header width, including trailing empty cell. Missing trailing tab on empty means causes width failure.

Domain/assumptions: Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Evidence: see tests.md; unexecuted database branches remain conditional.

### empty_projection

Only empty line is ignored; empty means is retained here and mapped to NULL only during load staging.

Domain/assumptions: Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Evidence: see tests.md; unexecuted database branches remain conditional.

### failure_order

Read/UTF8 then empty file then header validation then first malformed data row, with 1-based line number i+2.

Domain/assumptions: Finite valid-UTF8 inputs, representable counters/IDs, available memory; filesystem fixtures confined to owned temporary root. SQL semantics are conditional and unexecuted. Subject is the source and SHA256 bound in manifest; fragment applies only to declared byte range.

Evidence: see tests.md; unexecuted database branches remain conditional.

### tests

#### Selected checks

2026-10-31 wave31: 16 selected target/name cases passed twice debug and twice release with identical sorted outcomes; six compiled source-behavior mutants failed assertions, exact bytes restored and positive checks passed. Evidence scope is only the named helpers/fixtures. External receipt directory: $MOVA_DATA/runs/octopus-wave31-store-2026-10-31. No DuckDB integration, production loader/corpus, training or GPU run.

Named target-scoped checks for parent source: ["prag::wave31::labels_bits_and_migration_boundaries"]

Native commands and numeric status/log/outcomes live in external native-commands.json and receipts. Integration fixture checks use actual en::conllu parsing only. Legacy prag_layer_and_negative_controls, qa_table_loader_and_negative_controls and lossless_round_trip_and_negative_controls were inspected but not executed: real DuckDB unavailable. A fragment's listed parent tests may only cover part of its relation; SQL/query/transaction/IO-fault claims remain source-derived.

##### Negative controls

Six source-behavior mutations: quote doubling, TSV NULL rejection, QA positivity, prag bit truth, MWT counter, sentence boundary predicate. Each compiled, failed an assertion, restored exact original bytes and passed the selected positive. No assertion-only mutations and no surviving behavioral mutants.

### invariant-and-cost

#### Eight or nine label columns invariants and costs

##### Invariant

Every returned row has8 label columns plus separate sent_id. Parser does not validate bits, duplicate IDs or closed labels.

##### Cost

O(file bytes) time and retained row memory; header and per-line split allocate column vectors.

Symbolic bounds are source-derived, not measured wall-clock speed or universal complexity proof. Allocation failures, integer exhaustion and concurrency are outside finite evidence.