Kestrer

How to Write Hygienic Rust Macros

Macro hygiene is the concept of macros that work in all contexts; they don't affect and aren't affected by anything around them. Ideally all macros would be fully hygienic, but there are lots of pitfalls and traps that make it all too easy to accidentally write unhygienic macros. This guide attempts to provide a comprehensive resource for writing the most hygienic macros.

Understanding the Module System

First, a little aside on the details of Rust's module system, and specifically paths; it is

kchristidis

There doesn't seem to be a good resource online describing the issues with protocol buffers and deterministic serialization (or lack thereof). This is a collection of links on the subject.

Protocol Buffers v3.0.0. release notes:

The deterministic serialization is, however, NOT canonical across languages; it is also unstable across different builds with schema changes due to unknown fields.

Maps documentation:

Wire format ordering and map iteration ordering of map values is undefined, so you cannot rely on your map items being in a particular order.