@opendict-rs/expo

Expo native module that reads StarDict and MDict dictionaries via the opendict-rs Rust core. Compiles to a static library on iOS (XCFramework) and a shared library on Android, exposed through uniffi-generated bindings.

Install

npx expo install @opendict-rs/expo

This package contains prebuilt binaries — no Rust toolchain required to consume it. iOS supports arm64 device + simulator; Android ships all four ABIs (arm64-v8a, armeabi-v7a, x86, x86_64).

Usage

import { Dictionary } from '@opendict-rs/expo'
import * as FileSystem from 'expo-file-system'

// Open a directory containing a dictionary (StarDict or MDict; auto-detected).
// Native code uses std::fs which doesn't accept file:// URIs — strip the prefix.
const dir = (FileSystem.documentDirectory ?? '') + 'my-dict/'
const dict = new Dictionary(dir.replace(/^file:\/\//, ''))

console.log(dict.info.name, dict.wordCount())

const entries = dict.lookup('hello')
if (entries) {
  for (const e of entries) console.log(e.data)
}

const matches = dict.searchPrefix('he', 10)
console.log(matches)

dict.close()

API

new Dictionary(dir: string)

Opens the dictionary at dir. Format is detected automatically — StarDict first (looks for .ifo), then MDict (looks for .mdx). Throws DictError.LoadError if neither is found.

dict.info: DictInfo

{ name, author, description, wordCount }.

dict.lookup(word: string): DictEntry[] | null

Exact lookup. Returns null if the word isn't in the dictionary. Each DictEntry has { entryType, data }.

dict.lookupSynonym(word: string): DictEntry[] | null

Lookup via the synonym/variant index (StarDict .syn). Returns null if no match.

dict.searchPrefix(prefix: string, limit: number): string[]

Up to limit words that start with prefix. Used for typeahead.

dict.wordList(): string[]

Every headword. Can be huge — don't render it.

dict.wordCount(): number

Same as info.wordCount, kept for cheap polling.

dict.close(): void

Releases the underlying file mapping. Always call this in your component cleanup.

File system layout

The native code expects a directory — not a single file. Drop all the files for a dictionary into one folder:

StarDict/
  whatever.ifo
  whatever.idx
  whatever.dict        (or .dict.gz / .dict.dz)
  whatever.syn         (optional)

MDict/
  whatever.mdx
  whatever.mdd         (optional)

Open the folder, not any individual file.

License

MIT — see LICENSE.