FunGEn VS lens

A few more:

https://github.com/simonmichael/hledger - Robust, fast, intuitive plain text accounting tool with CLI, TUI and web interfaces

https://github.com/simonmichael/shelltestrunner - Easy, repeatable testing of CLI programs/commands

https://github.com/simonmichael/quickbench - Easily time one or more commands with one or more executables and show tabular results

https://github.com/haskell-game/fungen - A lightweight, cross-platform, OpenGL-based 2D game engine in Haskell

https://haskell-game.dev - a small selection of many games written in Haskell

If you didn't already find it, https://github.com/haskell-game/fungen#readme might have some relevant docs/material.

They are in fact well structured and not random at all. Take a look at this:

https://github.com/ekmett/lens/wiki/Operators

A composition of functional operations over Kmett style lenses. Here's the original Haskell implementation, here's usage in JS via Ramda

The documentation of lenses is geared towards people know what lenses are. Of course this single fragment of documentation doesn't make sense if you don't know what lenses are. If you want to understand what lenses are the package links to a helpful wiki and tutorial: https://github.com/ekmett/lens/wiki/Overview

All within reach within seconds of discovering the function.