Challenge: FeatureFlag pure functions

[atravers]

But more generally - if you really, really think that “top-level mutability” (even “once off” ) is the solution, then look no further than:

What should I use for effect handling?

In my hobby projects, I am currently using MTL. It has become unwieldy as I have to create typeclass for each and every effect I have. The code duplication has me uneasy. However, I heard that various effect systems are a havoc and generally not worth the effort. This scares me from trying a proper effect system. I also dislike large dependency footprints and complex machinery, which bars myself from common effect libraries. Can I get recommendation on what I should use? Alternatively… can I …