MDict Node.js Binding (Rust)

Native Node.js binding for reading MDict dictionary files (*.mdx, *.mdd). Built with napi-rs for near-zero overhead Rust interop. A drop-in Rust-powered replacement for js-mdict.

Install

npm install @runer-hq/mdict

Quick Start

const { Mdx, Mdd } = require('@runer-hq/mdict');

// Open a dictionary
const mdx = new Mdx('/path/to/dict.mdx');

// Look up a word
const result = mdx.lookup('apple');
console.log(result.keyText);     // "apple"
console.log(result.definition);  // HTML definition string

// Prefix search (autocomplete)
const suggestions = mdx.prefix('app', 10);
// [{ keyText: "app" }, { keyText: "apple" }, { keyText: "apply" }, ...]

// Fuzzy search (spell correction)
const fuzzy = mdx.fuzzySearch('aple', 5, 2);
// [{ keyText: "apple", ed: 1 }, { keyText: "aple", ed: 0 }, ...]

// Read resources from .mdd
const mdd = new Mdd('/path/to/dict.mdd');
const css = mdd.readMedia('\\style.css');
console.log(css.mimeType);  // "text/css; charset=utf-8"
console.log(css.data);      // Buffer

CLI

# Install globally
npm install -g @runer-hq/mdict

# Look up a word
mdict /path/to/dict.mdx apple

# Read a resource
mdict /path/to/dict.mdd \style.css

Documentation

Full API reference, data structures, and usage examples: USAGE.md.

Build

cargo build --release -p mdict-node
cp target/release/libmdict_node.* crates/mdict-node/mdict.<platform>-<arch>.node
node node/test.js

Requirements

• Rust ≥ 1.74 (edition 2021)
• Node.js ≥ 18 (LTS recommended)

TypeScript Types

Full TypeScript type definitions in index.d.ts.

Architecture

• src/lib.rs — napi-rs Rust binding (Mdx, Mdd classes + standalone functions)
• index.js — JS wrapper (loads platform-specific .node binary)
• index.d.ts — TypeScript type declarations
• cli.js — Command-line interface

Performance

Compared to the original js-mdict (TypeScript):

| Operation | js-mdict | Rust binding | Speedup | |-----------|----------|--------------|---------| | Load | 299 ms | 223 ms | 1.3× | | lookup | 4,536 ops/s | 4,973 ops/s | 1.1× | | prefix | 18 ops/s | 134 ops/s | 7.4× | | contains | 10,782 ops/s | 28,342 ops/s | 2.6× |

Low-memory mode loads in 2 ms (vs 223 ms eager) by deferring key block decoding.