tabnas

Scaffold a new tabnas grammar-plugin repository from the zon template. Copy the dual-runtime TS/Go layout, wire the single-source grammar with `npm run embed`, keep the three version constants in step, write the tabnas.plugin.json descriptor and the standard AGENTS.md sections, and prove TypeScript/Go parity with shared test/spec fixtures via `make build && make test`. Use when creating a new @tabnas/<format> plugin repo, bootstrapping a parser for a new file format on the tabnas engine, or deciding whether to base a plugin on jsonic, ABNF or the bare engine.

Author a tabnas GrammarSpec for a new text format. Start from real samples of the format, choose the right base (bare GrammarSpec, jsonic layering, or ABNF), declare tokens, write rules and alternates, then validate with `tabnas validate` and parse samples with `tabnas parse --json`, iterating on the structured diagnostic (code, expected, ruleStack) until every sample behaves. Use when you need to create a grammar for a format the tabnas fleet does not cover, design rules and alternates for a DSL or configuration syntax, or turn a folder of example documents into a working parser.

Diagnose a failing tabnas parse. Get the structured diagnostic with `tabnas diagnose --json`, read code, row/col, expected and ruleStack, look the code up in the error registry, then climb the grammar-debugging ladder (print the rules, print the tokens, model the instance, trace the parse) until the failing alternate is found. Use when a parse throws, when a grammar rejects input that should be valid, when an error points at the wrong place, or when you need to interpret a tabnas error code or diagnostic object.

Pin a tabnas grammar's behaviour with shared .tsv fixtures. Write header-row TSV cases whose expected column is a JSON value or an ERROR:<code> rejection, run them with `tabnas test --spec`, and in a tabnas repo run `make test` so both the TypeScript and Go runtimes prove parity on the same rows. Use when adding tests for a grammar or plugin, pinning a bug fix as a fixture, converting bare ERROR rows to code-pinned ones, or verifying that two runtimes agree on the same inputs.

Bring an existing tabnas grammar plugin up to fleet standard or onto a newer engine. Audit the repo with the admin ax tasks, regenerate a stale tabnas.plugin.json descriptor, close declared-vs-exercised error-code gaps with the support census helpers and `make ax-codes`, re-verify fixture parity in both runtimes with `make build && make test`, and record any cross-runtime result difference in the parity ledger. Use when modernising a plugin repository, bumping its @tabnas/parser engine version, fixing descriptor or fixture drift, or converting bare ERROR fixtures to code-pinned ones.