Comments URL: https://news.ycombinator.com/item?id=48433356

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I know its never as easy as just do this, this and that and everything will work out fine. I wish you the best.

Comments URL: https://news.ycombinator.com/item?id=48242109

Points: 4

# Comments: 0

1. Is answered in the parent comment

2. It's not really about solving problems directly. Its more about a common way to hold meta information about your data. But of course that might help you with approaching similar problems.

3. Thats hard. You dont really think about it that way. Again its not really the type of problems directly. Its more about similar approaches to solving different kinds of problems. So you can use monads for solving basically any problem. But you can also choose to not use monads to solve the problem. This is something you'll need to get a feel for. And it shouldn't be for first line of thought. When solving a problem you might recognize that a certain monad lends itself to solving the problem. But it's not really something you actively go looking for.

This is how "side effect" information is carried outside the actual information the monad is carrying. Real side effects like writing to disk however are not real monads. The IO monad pretends to be a real monad but it's not. It just helps with hiding the impurity of IO from the pure parts of Haskell.

So one might think about the IO monad kind of like the list monad where the order of the IO operations is encapsulated. It kind of pretends that the IO part is pure and deterministic when its actually not in order to have a somewhat clean separation between pure and non pure parts of the program.

Hope that helps.

A monad is kind of like a generic class to boxes that adds additional logic to the data it boxes without actually caring about the data itself.

My goto monad for that concept is a linked list and the map operator. So an instance of the linked list might be Node(5) -> Node(7) -> EmptyList. Now let's call map with a function f(x) = str(x) + " * 2 = " + str(2x). This gives us Node("5 2 = 10") -> Node("7 * 2 = 14") -> EmptyList.

Now let's separate the monad from this. The monad is the structure and logic around the data and the function that we provide. The monad doesn't care what data it holds and is doesn't care what function we provide. It only defines the structure and how functions are applied to the data it holds.

You actually said it yourself in your comment: "not everyone can deal with AWS, nor can everyone edit a website." Stelae is for the second group, the WordPress-editor side, who don't want to run public PHP to publish. The €19.90 isn't margin on the hosting; the hosting is yours, on whatever provider you pick.