> In the currently stable version, the main interface of each "adapter" is `fn(Read, Write) -> ()`. To allow custom adapter chaining I have to change it to be `fn(Read) -> Read` where each chained adapter wraps the read stream and converts it while reading. But then I get issues with how to handle threading etc, as well as a random deadlock that I haven't figured out how to solve so far :/

I don't quite grok the problem here. If you file an issue against ripgrep proper with code links and some more details, I can try to assist.

Taken literally, ripgrep uses that exact same approach. There are potentially multiple adapters being used. Each adapter is just defined to wrap a `std::io::Read` implementation, and the adapter in turn implements `std::io::Read` so that it can be composed with others. The part that I'm missing is why this has anything to do with threading or deadlocks. I/O adapters shouldn't be having anything to do with synchronization. So I'm probably misunderstanding your problem.