You can do this quite nicely with serde in Rust. It’s elegant. There’s still allocations when needing to unescape values and expand the scratch space, but other

You can do this quite nicely with serde in Rust. It’s elegant. There’s still allocations when needing to unescape values and expand the scratch space, but otherwise it’s all zero copy. You can parse at over a gigabyte a second from stdin without any real tuning.