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Get to Know the Actor Model with JavaScript

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Re: Get to Know the Actor Model with JavaScript

#21

Post by sprt »

mercer wrote: post #18
innocentoldguy wrote: post #16

I think a better language to understand the Actor Model with is Elixir. The Actor Model's main point is concurrency. It is hard to demonstrate that in a language that doesn't support concurrency.

Don't forget fault tolerance! In my particular use cases concurrency is not really necessary, but I love the fact that I don't have to be quite as 'defensive' in my programming. Whenever a particular (Erlang) process/'Actor' fails, its supervisor can simply restart it and I can deal with the cause of failure later while the entire system chugs along (mostly) happily.

What happens when the process is bound to fail on start? (eg. trying to bind a port that's already being used) Never used that model so I'm curious.

Re: Get to Know the Actor Model with JavaScript

#24

Post by imafish »

Jesus! Are there any posts on HN these days that are not JavaScript or blockchain? (or a combination, describing 90% of blockchain projects....)

On topic: I don't see a use case, in which I would need to use the actor model and would pick javascript as my language of choice. However, I do think your article is well-written and explains the actor model quite well.

Re: Get to Know the Actor Model with JavaScript

#27

Post by hex13 »

kevmo314 wrote: post #2

How does this differ from a Redux-type store besides being able to instantiate them on demand instead of having a global state? > It’s easy to screw up immutability in JavaScript, the actor internal state can be modified externally if users of the library are not extremely careful. Object.freeze() can help prevent this.

Redux is a chicken, actor model is an egg. Similar patterns were used decades before Redux was even born.

Re: Get to Know the Actor Model with JavaScript

#28

Post by faitswulff »

Dolores12 wrote: post #22

> let state = typeof behavior.init === "function" ? behavior.init() : {}; Javascript is such a mess itself, i don't know how one can explain something in it. Choose python, reads like English.

It's not unique to javascript. The equivalent in ruby would be `state = behavior.init.class = Method ? behavior.init : {}`

After looking it up, I don't disagree that Python looks a lot prettier, though: `state = behavior.init() if callable(behavior.init) else {}`

That made me curious if Ruby had anything like Python's `callable`, but I couldn't find anything. This is my best effort in Ruby for aesthetics: `state = if behavior.init.respond_to? :call then behavior.init() else {} end`

In the end, I agree, Javascript looks much worse than the equivalent Python in this case. Unfortunately I don't get a choice of python on the frontend :p

Re: Get to Know the Actor Model with JavaScript

#29

Post by hex13 »

kevmo314 wrote: post #8
abritinthebay wrote: post #7

Earlier quoted context omitted.

It’s a pattern. It’s not supposed to be Redux/whatever library. It’s a pattern of writing code (like MVC, or Pub/Sub, etc) The Actor model strongly influenced protypical classes like Smalltalk and therefore also JS. It’s a 45 year old software design pattern so really it’s better to ask: how does Redux differ from the Actor pattern?

Sure, that's fine too. My point is more that it would've been nice to get a summary of the differences instead of requiring the reader to dig through the article, since Redux is much more prevalent. Even after digging, I still can't tell if there is a difference. If there is none, it would've helped greatly to explicitly say this.

> since Redux is much more prevalent.

Actually it's quite opposite. Redux is a library which was created not until 2 years ago and it is used only in JavaScript. Actor model and similar message-passing patterns are in use for decades and not only in JavaScript but in many programming languages. They are popular e.g. in game development for communicating between game objects.

There is this weird viewpoint in JS community that world is turning around JS and its ecosystem, and this is the newest popular library that dictates standards rather than decades of CS knowledge ;)

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