LexePub

LexePub is a high-performance, streaming EPUB parser and extractor for Rust, WASM, and C/C++.

LexePub is a library that reads EPUB files. It extracts chapters, text, images, metadata, and styles, and works in Rust, WebAssembly, and C/C++. There is also a browser demo that shows it rendering real EPUBs.

Find LexePub on NPM and crates.io!

Features

• Streaming Processing: Process EPUBs chapter-by-chapter without loading everything into memory
• Fast HTML Parsing: Uses the tl crate for efficient HTML/XHTML parsing
• Multiple Output Formats: Extract plain text or AST representations
• Async Support: Built on Tokio for efficient I/O operations
• Cross-Platform: Works on desktop, web (WASM), and embedded systems
• C/C++ Bindings: Use from C/C++ applications via Diplomat
• Sync + Async Parity: Core Rust methods have synchronous wrappers where needed
• CSS Parsing + Application: Stylesheets are parsed and applied onto AST element styles
• Zero-Copy: Efficient memory usage with minimal allocations

Installation

NPM

npm install lexepub

Cargo

Add this to your Cargo.toml:

[dependencies]
lexepub = "0.1"

Or run cargo add lexepub!

Demo

A modified version of HTMLReader is available as a demo at https://nellowtcs.me/lexepub/! The demo uses the WASM adapter for LexePub.

Documentation

Docs are available at https://nellowtcs.me/lexepub/docs!

• Rust adapter API: https://nellowtcs.me/lexepub/docs/adapters/rust
• C/C++ adapter API: https://nellowtcs.me/lexepub/docs/adapters/c
• WASM adapter API: https://nellowtcs.me/lexepub/docs/adapters/wasm
• Quickstart: https://nellowtcs.me/lexepub/docs/getting-started/quickstart

Building

Standard Build

cd lexepub
cargo build --release

With C/C++ FFI Support

To generate C bindings, you need the diplomat-tool:

# Install diplomat-tool
cargo install diplomat-tool

# Build with FFI support
cd lexepub
cargo build --release --features c-ffi

# Generate C headers and bindings
diplomat-tool c include/

Note: The C FFI bindings require the diplomat and diplomat-runtime crates. If diplomat-tool is not available, the build will skip FFI generation but still compile successfully.

WASM Build

# Install wasm-pack
curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh

# Build for web
cd lexepub
wasm-pack build --release --target web

Performance

LexePub is designed for high performance:

• Memory Efficient: Streaming processing prevents loading entire EPUBs into memory
• Fast Parsing: Uses optimized HTML parsing with tl
• Async I/O: Non-blocking file operations with Tokio
• Zero-Copy: Minimal allocations and copying where possible

Examples

Run the included CLI tool:

cargo run --bin lexepub-cli -- path/to/your/book.epub

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

Licensed under the Apache License, Version 2.0.