The functor design pattern

This post builds on my previous post on the category design pattern and this time I will discuss the functor design pattern. If you are an intermediate Haskell programmer and you think you already understand functors, then think again, because I promise you this post will turn most of your preconceptions about functors on their head and show you how functors are much more powerful and generally ap

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昨日これ読んで思ったんですがもしかして全てのCategoryはMonoidなんでしょうか...？CategoryはMonoidより広い概念？=>逆だった。MonoidはCategoryやった