magnus-bindings

name	magnus-bindings
description	Magnus conventions for building Ruby native extensions from a Rust core: define_class, TryConvert/IntoValue, exception mapping, GVL handling, TypedData GC integration, and rake-compiler distribution. Load when generating or reviewing Magnus Ruby bindings for a Rust library.

• Use magnus crate for Ruby native extensions. Define classes with magnus::define_class.
• Map Rust types to Ruby using TryConvert and IntoValue traits. Return Result<T, magnus::Error>.
• Use magnus::function! macro for defining Ruby methods. Use magnus::method! for instance methods.
• Map Rust errors to specific Ruby exceptions: magnus::Error::new(exception::runtime_error(), msg).
• Build with rb_sys crate and magnus-build for compilation. Use rake-compiler for gem distribution.
• Support Ruby 3.2+ with multiple ABI versions.
• Test bindings from Ruby using RSpec or Minitest. Test error handling and edge cases.
• Keep Ruby wrapper gem thin — business logic in Rust, Ruby provides idiomatic API.
• Handle Ruby's GVL (Global VM Lock) — release for CPU-intensive Rust code.
• Use TypedData for wrapping Rust structs as Ruby objects with proper GC integration.
• Anti-patterns: panics in Ruby methods, unsafe without SAFETY comments, manual memory management.