Comment by danabramov | Hacker News Reader

Comment by danabramov | Hacker News Reader

Parent Full thread

>they're specific to React and have nothing to do with programming in general

Higher-order functions are extremely common and useful in all functional languages. In fact many people gave us the exact opposite feedback: React taught them many functional programming patterns that they later used elsewhere, both with and without JavaScript, not to say React.

>I wouldn't go so far as to say, never use mixins in JavaScript, for example.

This is not what the article says. There is a paragraph clarifying this specific point, as the sibling comment points out. And the article is sprinkled with “in React codebases” and “in our experience” for this very reason.

>Sure, but it seems to be a trade off of complexity for user experience.

I don’t understand what you mean. In most cases you don’t need to do anything, React is fast. When you have an especially complex tree (not very common), you can add three lines to a few files, and React is even faster. It is a tradeoff, and it is a pretty damn good tradeoff in my experience working on React apps. What am I missing?

>Higher-order functions are extremely common and useful in all functional languages.

Yes but higher order components as you call them, seem to be an abstraction that you would only use because the base unit of organization is a React component. I'm of the opinion that design patterns emerge due to deficiencies in the language or abstraction level, and that they can be avoided.

>Yes but higher order components as you call them, seem to be an abstraction that you would only use because the base unit of organization is a React component.

I don’t really see the issue here. “How do you parameterize Y by X?” “Create a function that takes X and returns Y.” Doesn’t really seem React-specific.

The unit of organization is indeed the component. Again, I’m not sure I understand why it being a first-class thing indicates a deficiency. By this logic, functions are deficient in JavaScript because you can pass a function to [].map(), or Promises are deficient because you can resolve() a Promise to another Promise.

I think the opposite is true. The abstractions are more powerful when they afford building higher level abstractions on top of them. Obviously you shouldn’t overuse this, just like you shouldn’t overuse higher order functions, but it’s a nice property to have.

>“How do you parameterize Y by X?” “Create a function that takes X and returns Y.” Doesn’t really seem React-specific.

I'm not talking about the what, but why would anyone think of using higher order functions to build user interfaces in the first place. It complicates the use case: building and mutating DOM Nodes.

>I think the opposite is true. The abstractions are more powerful when they afford building higher level abstractions on top of them.

And what may I ask requires so much power for building web front-ends?

Higher order functions are not such a complicated concept. Just a function passed to a function.

You use functions, right?

Yes, but why is the question. I think that is seriously not given much thought and people just accept man-made complexity as essential. It seems tautological to say that higher order components extend components, but it is only due to the design decisions of the React authors that application code must fit its own paradigm, not the other way around.

On the contrary, it's about reducing complexity. You don't have to worry about mixins, classes, prototypes, inhertiance. Just plain old functions. Can't get simpler than that.

>I'm not talking about the what, but why would anyone think of using higher order functions to build user interfaces in the first place. It complicates the use case: building and mutating DOM Nodes.

Why are you using a higher order function to `[].filter()` an array? It complicates the use case: iterating over items.

>And what may I ask requires so much power for building web front-ends?

I don’t know what kind of apps you are building, but use cases for React at Facebook are very complex. You may create an Ads account and go through the ad campaign creation flow to see what I mean.

Reply on news.ycombinator.com