Your banana example made me think of this quotation: ❝Knowledge is knowing that a tomato is a fruit. Wisdom is not putting it in a fruit salad.❞ -Miles Kington Excellent talk.

OMG it's MPJ from fun fun function before he was KZfaq famous!!

I backed out of this conference last minute while 2 other co-workers went, if I had known MPJ was speaking I would not have cancelled my trip. God damnit!

Whew, at 9:17 you _almost_ spilled that water on top of your MacBook. 💦 But despite fearing for your laptop, I really enjoyed the talk. 👍

Love you MPJ! Just a slight correction -- Promises and Monads differ in important ways. I've been noodling on Monads in JS for a bit and found a Promise-alternative called "Fluture": github.com/fluture-js/Fluture/wiki/Comparison-to-Promises#practical-differences Fluture provides a "Future" monadic structure which can (should?) be used instead of Promise. Practical differences: 1) Promises conflate `map` and `flatMap` into `then` whereas they should be distinct. In a true monadic structure (like a `Future`), `flatMap` would allow "chaining" into a different monadic structure (such as an `Either` aka `Result` or a `Maybe` aka `Option`). `Promise.resolve('hello').then(...)` always returns the same Promise container. 2) Promises are eagerly evaluated and are not cancellable. Futures are lazy and must be invoked by a caller which is responsible for handling success / failure. 3) Promises violate functor laws of composition. Now, I know that sounds a bit "foo foo" but it's important. Those laws are the "magic" which ensures algebraic data structures behave predictably for downstream users.

AHAHA .. for a second he thought he was on his channel.. look at 25:01 he smiled and was about to laugh controlled it somehow..

There are no functors or monads in JS because the language is dynamically typed and hence you can not restrict what types a mapper function f :: X -> Y, i.e: it could return varying types. In addition, even if f :: X -> Y, the function f must be pure, otherwise there's the possibility of the functor law: F(g o f) = F(g) o F(f) being violated. For example, if f is a function that prints to the console, and g does as well, then the order of side effects will not be preserved.

As I was following this talk, I kept thinking of the things that are doing the work as "functors." Those things -- map and mapTree -- are doing all the work. They are joining the dumb functions like capitalize, and the dumb data structures, into data structures with applied functions. Seems like they need a name. Higher order functions?

A great talk, thx!

Thanks for demystifying then!

If something as wacky as a Promise is legitimately a Functor and Monad (even though it doesn't have explicit .map or .flatMap interfaces), then Array and Tree are as well, no? In that you can add .flatMap to Array if you want, and also to Tree, if you want. That JS doesn't do this out of the box doesn't restrict what these types are capable of in theory (and in prototype modifying practice!).

Streams: kzfaq.info/get/bejne/aNCga7FnrcebpI0.htmlm3s

Why are Bacon, RX or Highland "hispter libraries"??

Is flatMap the same as reduce?

when you call mapTree - reverse the arguments or it won't work

But Bananas are, botanically speaking, a fruit.

totally ruined it, congrats!

interesting topic but had to stop watching because the attempts at humour were too jarring