How to Properly Use Polystate?

sdzx-1 · June 26, 2025, 6:49pm

How-to-properly-use-polystate.md

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## How to Properly Use Polystate?
The correct way to use polystate is: reason about program behavior through symbols, then transform these symbols into code.

This might sound bewildering, but don't worry - I'll explain this process through concrete examples.

## Background Knowledge

What is polystate? [Here's a detailed introduction](https://github.com/sdzx-1/polystate?tab=readme-ov-file#polystates-core-design-philosophy).

In short: Finite State Machines are a powerful programming pattern, and when combined with composability and type safety, they become an even more ideal programming paradigm. The polystate library was designed with this goal in mind.

I've been designing this library for some time and have used it in this experimental project. However, it wasn't until recently that I discovered the proper way to use polystate, fortunately before it could overwhelm me. I can't contain my excitement, which is why I wrote this article!

Let's begin!

## Two-Stage Selection
Using raylib, I implemented a generic "selection" semantic: interactive selection through mouse interaction.

The selection behavior is composed of three generic states (select, inside, hover) and ten related messages.

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bosoutuhau · June 27, 2025, 8:08am

Just going through the repo, it looks exciting and the premise is explained in the README well, but this particular document reads like an nLab article.