# Architecture Decision Records

This directory contains the project's ADRs, recorded per
[ADR-0000](0000-record-architecture-decisions.md).

## Index

- [ADR-0000 — Record architecture decisions](0000-record-architecture-decisions.md)
- [ADR-0001 — Language and TUI framework](0001-language-and-tui-framework.md)
- [ADR-0002 — Database engine](0002-database-engine.md)
- [ADR-0003 — Input modes and command dispatch](0003-input-modes-and-command-dispatch.md)
- [ADR-0004 — Project file format](0004-project-file-format.md)
- [ADR-0005 — Column type vocabulary](0005-column-type-vocabulary.md)
- [ADR-0006 — Undo snapshots and replay log](0006-undo-snapshots-and-replay-log.md)
- [ADR-0007 — Sharing and export](0007-sharing-and-export.md)
- [ADR-0008 — Testing approach](0008-testing-approach.md)
- [ADR-0009 — DSL command syntax conventions](0009-dsl-command-syntax-conventions.md)
- [ADR-0010 — Database access via a dedicated worker thread](0010-database-access-via-worker-thread.md)
- [ADR-0011 — Foreign-key column type compatibility](0011-fk-column-type-compatibility.md)
- [ADR-0012 — Internal metadata for user-facing column types](0012-internal-metadata-for-user-facing-types.md)
- [ADR-0013 — Relationships, naming, and the rebuild-table strategy](0013-relationships-and-rebuild-table.md)
- [ADR-0014 — Data operations, value literals, and the auto-show pattern](0014-data-operations-and-value-model.md)
- [ADR-0015 — Project storage runtime](0015-project-storage-runtime.md)
- [ADR-0016 — Pretty table rendering for data and structure views](0016-pretty-table-rendering.md)
- [ADR-0017 — Column type-change compatibility](0017-column-type-change-compatibility.md)
- [ADR-0018 — Auto-fill contracts for `serial` and `shortid` columns](0018-auto-fill-contracts-for-serial-and-shortid.md)
- [ADR-0019 — Friendly error layer (H1) and i18n message catalog](0019-friendly-error-layer-and-i18n.md)
- [ADR-0020 — Tokenization layer for the DSL parser](0020-tokenization-layer-for-the-dsl-parser.md)
- [ADR-0021 — Parser-as-source-of-truth for H1a (per-command usage in parse errors)](0021-parser-as-source-of-truth-for-h1a.md)
- [ADR-0022 — Ambient typing assistance: colour, hint panel, completion (I3 + I4)](0022-ambient-typing-assistance.md)
- [ADR-0023 — Unified declarative grammar tree](0023-unified-grammar-tree.md) — direction (superseded for execution detail by ADR-0024)
- [ADR-0024 — Unified grammar tree: execution plan](0024-unified-grammar-tree-execution-plan.md) — **Accepted**, the executable spec — implemented (Phases A–F; Phase F shipped "minimal", `parser.rs` retained as the router — see the ADR's Phase F implementation note)
- [ADR-0025 — Indexes](0025-indexes.md) — **Accepted**, `add index` / `drop index`, persistence, rebuild-table preservation, and items-list display (`C3` index portion + `S2`)
- [ADR-0026 — Complex WHERE expressions](0026-complex-where-expressions.md) — **Accepted**, stratified recursive expression grammar (`AND`/`OR`/`NOT`, comparisons, `LIKE`, `IS NULL`, `IN`, `BETWEEN`) for `update` / `delete` / `show data` filters; `show data` gains `where` + `limit`; adds the `Subgrammar` node and a recursive `Expr` AST (`C5a`)
- [ADR-0027 — Input-field validity indicator](0027-input-validity-indicator.md) — **Accepted**, a debounced `[ERR]` / `[WRN]` marker at the input row's right edge, backed by a walker diagnostics-severity model (parse-outcome + schema-existence); advisory, never blocks submission (`S6`); Amendment 1 adds a `LIKE`-on-numeric-column WARNING
- [ADR-0028 — Query plans (`EXPLAIN QUERY PLAN`)](0028-query-plans.md) — **Accepted**, an `explain` prefix command over `show data` / `update` / `delete`; an annotated, span-styled plan tree; introduces the `OutputLine` styled-runs mechanism (ADR-0016's deferred per-span styling) (`QA1` / `QA2`)