A single tile that only extended a word perpendicular to the client-declared
direction was rejected: the UI always sent dir=H for one-tile plays (the
dirOverride/Controls toggle was orphaned in the Stage 7 game rework), so placing
"А" above "БАК" to form "АБАК" failed the solver's main-word-length check even
though the word is in the dictionary.
Make the backend infer a play's orientation from the placed tiles and the board
(internal/engine.resolveDirection): two or more tiles by the line they share, a
lone tile by the axis it abuts (longer word wins, horizontal on a tie). Direction
becomes an output, not an input: drop dir from the SubmitPlay/Eval wire requests
and add it to EvalResult. Journal replay keeps trusting the stored "H"/"V"
(SubmitPlayDir) so a rebuilt game matches the one committed.
UI: stop computing/sending direction; the preview now shows the words a move
forms with its total score (game.previewWords); the make-move control is disabled
until the play is confirmed legal; the "your turn" label hides while tiles are
pending. Delete the orphaned Controls.svelte.
Regenerate the FlatBuffers bindings (Go + TS) and update the gateway transcode
and the loadtest edge client to the new contract. Bake the decision into
ARCHITECTURE.md (§5/§9.1), FUNCTIONAL.md (+ _ru) and the backend README.
Live play now exchanges per-variant alphabet indices instead of concrete
letters (rack out; submit-play, evaluate, exchange, word-check in). The client
caches each variant's (index, letter, value) table behind
StateRequest.include_alphabet and renders the rack and blank chooser from it,
dropping the hardcoded value/alphabet tables. History, the durable journal and
GCG stay decoded concrete characters (ARCHITECTURE §9.1, unchanged).
- pkg/fbs: new AlphabetEntry + PlayTile; StateView.rack -> [ubyte] + alphabet;
StateRequest.include_alphabet; SubmitPlay/Eval tiles -> [PlayTile];
Exchange tiles + CheckWord word -> [ubyte] (committed Go + TS regenerated).
- engine: AlphabetTable + a cached per-variant codec (LetterForIndex/EncodeRack/
DecodeTiles/DecodeWord) + BlankIndex sentinel; Go parity test.
- backend server edge maps index<->letter (new thin game.Service.GameVariant);
game.Service domain methods, engine.Game and the robot keep one letter-based
play path. The gateway forwards indices verbatim (no alphabet table).
- ui: lib/alphabet.ts in-memory cache; codec encodes/decodes indices; premiums.ts
is geometry-only; the mock seeds a fixture table; the UI normalises display to
upper case (codec + cache), leaving placement/board/checkword unchanged.
Parity moved to the Go engine.AlphabetTable test; premiums.ts loses its value
tables. Discharges TODO-4.
Ilia Denisov