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"A homomorphism is just a structure preserving map. In fact, a functor is just a homomorphism between categories as it preserves the original category's structu
by naillo 4y ago
"A homomorphism is just a structure preserving map. In fact, a functor is just a homomorphism between categories as it preserves the original category's structure under the mapping."
Oh ok. Plain english.
- psychoslave 4y ago約束は守られた
- marcosdumay 4y agoWell, it's not nested.
- cratermoon 4y agoBest comment in this thread. The guide does a so-so job of building on terms previously defined. The term accumulator, for example, is not defined before use. The first appearance of it is under Catamorphism, where the guide says, "A reduceRight function that applies a function against an accumulator and each value of the array (from right-to-left) to reduce it to a single value." I note, in passing, that the actual guide is just titled "Functional Programming Jargon". It does not claim to be "in plain English".
- eddyschai 4y agoMaybe if I explain what a Monad is in Plain English it'll help you understand functors? A monad is just a monoid in the category of endofunctors.
- mypalmike 4y agoI think you need to explain endofunctors. An endofunctor is the category containing monoids such as the monad.* *This is probably wrong. Please don't explain.
- eddyschai 4y agoSo in all seriousness a functor is a mapping from one category to another, and an endofunctor is a mapping from one category to the same category.
- the_only_law 4y agoThe closest I've come to understanding Monads was funny enough, the Wikipedia page (ok so there's at least two pages on Wikipedia for Monads, one in a category theory context, and one in a more general programming context, the latter I could actually begin to grasp). It wasn't overly full of vocabulary from category theory, nor did it try to compare it to taco bell menu items.
- IncRnd 4y agoIf I may also quote! A monad is a special kind of a functor. A functor F takes each type T and maps it to a new type FT. A burrito is like a functor: it takes a type, like meat or beans, and turns it into a new type, like beef burrito or bean burrito.