EYG

EYG is the homepage for a programming language project, with a documentation section that includes guides, roadmap, and news. The advanced effects guide focuses on practical patterns for working with effects and handlers, especially how to carry state across effectful computations.

The core content walks through a stateful Increment effect implemented with with_counter, showing how handle expressions apply to a single effect label and how handlers can be nested for multiple effects. It also notes the design tradeoff of keeping the type system simple, and mentions that the restriction may be relaxed in the future.

The material is aimed at developers who already understand basic effect handling and want to see how state can be threaded through handlers. It is not an introductory tutorial, so readers should be comfortable with the language syntax and concepts used in the examples.

When using the guide, pay attention to how each handler manages its own state and how nesting affects state sharing between handlers. The code snippets are the main reference, and the surrounding text explains the design constraints rather than every line. Overall, it is a compact technical reference for effect-system patterns.