4 ms·

For things like this I recommend going to wikipedia and looking up "Functor" -- there's some weird dislike of category theory terms but we're all fine with term

by bontaq 7y ago

For things like this I recommend going to wikipedia and looking up "Functor" -- there's some weird dislike of category theory terms but we're all fine with terms like "singleton" or "Factory" You'll see the definition and be like, "shit that's just a map." We sell each other a bit short. Likewise for applicative, monoid, monad -- they're mathematically pretty clear and if you squint while assuming a list is a category, you can probably read most of the definitions and get it. functor -> equivalent of map for lists monoid -> equivalent of having an identity ([]) and a join (a.concat) for lists applicative -> equivalent of turning one element into a list monad -> equivalent of unwrappering list items, applying a function to each, and rewrapping it This is just for lists, but the terms are more powerful than that and have many variations. The nice thing is because it's universal. You don't have to wonder, "have I done this pattern right," because you test the laws for them. It might also help, for some of the laws, to remember identity and associativity as like from multiplication -- ie 1 * 9 = 9, 3 * 2 = 2 * 3

TheAsprngHacker 7y ago
> applicative -> equivalent of turning one element into a list This is only one part of the definition of an applicative. Applicatives must also preserve the monoidal operation (product). That is, there is a function `pair : f a -> f b -> f (a * b)`. Then, you can map functions of multiple arguments by turning `(a * b) -> c` into `f (a * b) -> f c` via `map` and passing it the result of the applicative `pair` operation. > monad -> equivalent of unwrappering list items, applying a function to each, and rewrapping it I'm not sure how precise or accurate this definition is. I'd say that a monad is about collapsing multiple layers of a functor into one layer. > This is just for lists, but the terms are more powerful than that and have many variations. The nice thing is because it's universal. You don't have to wonder, "have I done this pattern right," because you test the laws for them. It might also help, for some of the laws, to remember identity and associativity as like from multiplication -- ie 1 * 9 = 9, 3 * 2 = 2 * 3 Yup, I agree that this is a benefit of generalizing these operations based on their common structure.

by bontaq 7y ago

TheAsprngHacker 7y ago

> applicative -> equivalent of turning one element into a list This is only one part of the definition of an applicative. Applicatives must also preserve the monoidal operation (product). That is, there is a function `pair : f a -> f b -> f (a * b)`. Then, you can map functions of multiple arguments by turning `(a * b) -> c` into `f (a * b) -> f c` via `map` and passing it the result of the applicative `pair` operation. > monad -> equivalent of unwrappering list items, applying a function to each, and rewrapping it I'm not sure how precise or accurate this definition is. I'd say that a monad is about collapsing multiple layers of a functor into one layer. > This is just for lists, but the terms are more powerful than that and have many variations. The nice thing is because it's universal. You don't have to wonder, "have I done this pattern right," because you test the laws for them. It might also help, for some of the laws, to remember identity and associativity as like from multiplication -- ie 1 * 9 = 9, 3 * 2 = 2 * 3 Yup, I agree that this is a benefit of generalizing these operations based on their common structure.