`pair_lang` had always been answering a second question nobody asked: it
says which two languages, and every surface built on it assumed English
was the one being learned. That is why hanzi is never tokenized, never
spell-checked, never glossed — correct for a Mandarin native practising
English, backwards for an English native practising Mandarin.
`users.direction` (migration 0016) separates the two questions; a
`zh-learner` pair code would have been cheaper and would have made two
directions of one pair look like two unrelated languages to every query.
Segmentation is what replaces `wordAt` where there are no spaces: a
shortest-path walk over log-probabilities, 232 ms and 14 MB for 188,522
words. The browser gets the word list because segmentation runs on hover;
the server keeps the whole dictionary. Their coverage gates come out
opposite on purpose — the client list is frequency-gated because the
segmentation is measurably identical without the tail, and the dictionary
is gated by nothing, because its only power is to explain and the word a
learner stops on is the rare one.
The 错别字 pack is 24 confusable pairs behind two mechanical gates. One
admits a pair only if the wrong form is not a dictionary word and the
right form is, which is why it refuses 自已 for 自己 — a real error whose
wrong form is a headword. The other asks the segmenter whether the two
characters already belong to two different words, without which 自己经常,
睡觉的时候 and 不知到底 would all be corrupted silently into text still
made of real characters.
Not deployed (this carries a migration), not seen in a browser, and no
account has ever been in the learner direction. The IME composition
guards were in scope and are not done — see BUILD_PLAN Phase 26.
Two editor features that were in flight alongside the sound work:
- FontSize TipTap extension (rides on textStyle) with Small/Normal/Large/
Title presets in the toolbar; StatusBar + CSS support
- Image handling: internal/images handler, upload route + config, client
API, EditorCore wiring, and md/html/docx export support for images
Claude-Session: https://claude.ai/code/session_016Yr6jELuRc7hyzYLccQKZd
Replace the kitten's random generic tips with a deterministic, LLM-free
prose checker that reads the actual document and surfaces one gentle,
bilingual note at a time — quoting a slice of her own sentence so the
advice is clearly about *this* draft.
Rules (all conservative, tuned for a Mandarin-native ESL writer):
run-ons, comma splices, unclear antecedents, Oxford comma, a/an,
uncountable plurals, capitalize languages/days/months, subject-verb
agreement, plural-after-number, double determiner, "there is" + plural,
its/it's, than/then, comma-after-transition, doubled words, lowercase
"i", sentence capitals, and spacing around punctuation.
Each rule is paired with false-positive guards (e.g. "a university",
"After dinner, I went home and read", existing Oxford lists) and pinned
by a 45-case Vitest suite (npm test).
Also: bubbles now linger proportional to how much there is to read
(zh+en) and pause-on-hover, so denser advice no longer vanishes mid-read.
Claude-Session: https://claude.ai/code/session_016Yr6jELuRc7hyzYLccQKZd
Vendored Hunspell en.aff/en.dic into web/public/dictionaries/en/ (served as a
static asset + embedded in the binary, kept out of the JS bundle). dictionary-en
moved to a devDep — only used to source the files.
- useSpellChecker (App-level, loads once/session): fetches the dict, builds an
nspell instance, replays a localStorage personal word list; addWord persists
and bumps a version so consumers re-decorate. Ambient types in
src/types/nspell.d.ts (the package ships none).
- SpellCheck Tiptap extension: misspellings as ProseMirror decorations (no
stored marks), recomputed on edit / caret move / checker swap. Latin-only
tokenizer so CJK is never flagged; skips short tokens + all-caps acronyms;
exempts the caret word to avoid mid-typing jitter. Reuses mapOffset (now
exported from SuggestionHighlight); wordAt resolves the exact span on click.
- MisspellCard: soft rose wavy underline, bilingual popover with up to 5 nspell
corrections (click to replace) + add-to-dictionary. Closes on outside-pointer,
edit, or doc switch.
Chinese spell check intentionally omitted — nspell is dictionary-based and
English-only; Chinese typos (homophone 别字) need an LLM, out of v1 scope.
tsc/vite/go build+vet clean; live server serves both dict files; nspell
behavior smoke-tested.
Claude-Session: https://claude.ai/code/session_016Yr6jELuRc7hyzYLccQKZd
A cozy bottom-right mascot that reacts to the writing session: cheers on
accepted suggestions and word-count milestones, drops Mandarin-first writing
tips, suggests screen breaks after long stretches, and naps when idle.
- useCompanion: library-agnostic behavior engine (priority + cooldown paced
so it never nags); tips.ts holds all copy, bilingual zh-first.
- LottiePlayer wraps lottie-web's light build (offline, no eval/CDN) so it
bundles into the Go binary. Ships with an emoji-kitten placeholder per mood;
dropping a Lottie cat JSON into animations/index.ts is the only swap needed.
- Speech bubble uses the CJK-first font stack (spec Note #17).
Claude-Session: https://claude.ai/code/session_016Yr6jELuRc7hyzYLccQKZd
- Go module + chi server with embedded SPA serving and /api/health
- internal/config env loader (local-dev defaults; auth/copyleaks deferred)
- React 19 + Vite 6 + Tailwind v4 frontend with full Petal design tokens
- Frontend embedded into the binary via web/embed.go (go:embed all:dist)
- README dev workflow, .env.example, BUILD_PLAN progress tracker
- Verified end-to-end: binary serves health, embedded SPA, and SPA fallback