Migrates parse-error usage-block rendering from the legacy
`dsl::usage::matched_entry` (which scanned a `Vec<Token>` for the
first matched Keyword) to walker-side lookup driven by each
`CommandNode`'s `usage_ids` slice.
`CommandNode.usage_id: Option<&'static str>` becomes
`usage_ids: &'static [&'static str]`. Multi-form families
(`drop`, `add`, `show`) carry every variant — `drop` lists
table/column/relationship templates; `add` lists column /
relationship; `show` lists data / table. The single-shape
commands carry their single catalog key.
App-lifecycle CommandNodes had pointed at non-existent
`parse.usage.app.*` keys (never noticed because the field was
unused); they now point at the real catalog entries
(`parse.usage.quit`, `parse.usage.help`, …).
New helpers in `dsl::grammar`:
- `usage_keys_for_input(source) -> Option<(entry_word, usage_ids)>`
resolves the first identifier-shape token to a CommandNode and
returns its usage_ids list. Used by `app::render_usage_block`
and `input_render::ambient_hint`.
- `entry_words_alphabetised() -> Vec<&'static str>` replaces
`dsl::usage::entry_keywords_alphabetised`.
`dsl::usage` is deleted. The "available commands:" fallback in
`render_usage_block` now formats entry words as `` `<word>` ``
directly (matching the `parse.token.keyword.*` catalog renders);
the per-keyword catalog wrappers will collapse in the next step
(ADR-0024 §cleanup-pass §F).
`parse_command` and `parse_tokens` slim down:
- `parse_command(input)` no longer pre-lexes — the walker scans
source bytes directly.
- `parse_tokens` (internal-only `pub` for "future I3/I4 work")
is removed; its body folded into `parse_command`.
- `unknown_command_error` reads the walker registry directly.
Touched modules also drop their `crate::dsl::lexer::lex` and
`crate::dsl::usage` imports: `app.rs`, `input_render.rs`,
`completion.rs`.
Tests: 852 passing, 0 failing, 1 ignored (down from 860 because
the 8 `dsl::usage::tests::*` tests are gone with the module).
Stand up the unified-grammar tree walker alongside the existing
chumsky parser and migrate the eleven app-lifecycle commands
(quit, help, rebuild, save / save as, new, load, export, import,
mode, messages) end-to-end. The router in parse_tokens consults
the walker first; non-migrated commands still fall through to
chumsky.
Scope:
- src/dsl/grammar/{mod,app}.rs: Node enum (13 kinds), Word /
IdentSource / HintMode / HighlightClass / ValidationError /
CommandNode types, REGISTRY of the eleven app commands.
- src/dsl/walker/{mod,driver,context,outcome,lex_helpers}.rs:
scannerless byte-level walker, per-node-kind dispatch with
Choice/Seq/Optional backtracking, WalkContext (Phase B-D
schema fields stubbed), WalkOutcome with Match/Incomplete/
Mismatch/ValidationFailed.
- src/dsl/parser.rs: try_walker_route() runs first in
parse_tokens; bridge converts WalkOutcome to ParseError
preserving catalog wording (mode.unknown / messages.unknown
surface verbatim via friendly::translate). Legacy
try_parse_app_path_command deleted; chumsky's bare-keyword
app branches remain unreachable until Phase F sweep.
Walker design choices worth noting:
- mode <value> / messages <value> use Choice(Word, Word, Ident)
so known keywords appear in the expected-set; the trailing
Ident catch-all funnels unknown values into the friendly
validator that always errors with the catalog wording.
- save / save as is one CommandNode (Optional(Word("as"))) -
closes the round-5 "save Tab can't offer as" limitation
structurally.
- Path-bearing UX shipped per ADR-0024: BarePath terminates at
whitespace; paths with spaces use the (not-yet-wired) quoted
form. Existing tests pass on the new shape.
Tests:
- 28 new walker-specific tests in dsl::walker::tests covering
every app-lifecycle command, friendly-error wording for
mode/messages unknown values, trailing-garbage detection,
whitespace tolerance, and routing fall-through.
- Total: 805 passed, 0 failed, 1 ignored (was 777 / 1).
- cargo clippy --all-targets -- -D warnings clean.
claude@clouddev1