圏論とHaskellが関係あるとか言ってる奴どっちか詳しくねぇだろと思ってる
高速なコードを書くのと可換図式は別ものすぎる
Discussion
I get the point -- but I feel like it's to do with way of thinking.
Functional programming style involves shifting the thought process from procedural style (otherwise it'll be forec-fitting same behaviour). And maybe the same sort of thinking is need to understand operations on groups or monoids.
In the end, writing the code like Whitecat-san mentioned is a different skillset