Reference for Rust mechanism

[alissa-tung]

Hello, I am trying to use the rustler library to write a niflib for Erlang. I am wondering if there exists some documentation or reference about the following topics:

• the lib attributes used in Cargo manifest
• parametric polymorphic functions
• how lifetime and ownership, borrow checker work in nif

thx a lot

[evnu]

We don't have documentation on using Rustler from Erlang (yet). With regard to your questions:

• the lib attributes used in Cargo manifest

I guess you mean the crate-type configuration? Our template (rustler_mix/priv/templates/basic/Cargo.toml.eex ) defines cdylib. If I remember correctly, we need to do this as cdylibs are used when compiling into a shared library to be used from C/C++.

• parametric polymorphic functions

Can you further explain what you mean? For a NIF, polymorphism is implemented by dynamic dispatch on the terms passed into the NIF. NIFs itself cannot be monomorphized, as C does not have that functionality.

• how lifetime and ownership, borrow checker work in nif

This might be a large topic. Do you have a more specific question?

[alissa-tung]

Thank you for answering this!

I feel very sorry for the late of reply on this. At that time I was too busy at work so that I have not notified that you have answered the questions. At that time I have developed a library using Rustler library to expose APIs to Erlang. If someone also runs into this questions, I hope the links might be helpful:

• https://github.com/hstreamdb/hstreamdb_erl-rs
• https://github.com/hstreamdb/hstreamdb-rust/tree/main/src/x/hstreamdb-erl-nifs