Existential crisis at Railsconf • Hacker News Board

Re: Existential crisis at Railsconf

#91

Post by some1else » Wed, Apr 22, 2015, 3:56 PM UTC

kailuowang wrote: post #61

monsterix wrote: post #60

Earlier quoted context omitted.

So far from what I've seen is that most frontend frameworks go inside one of the directories inside rails. Nice, clean and tight integration. :)

Yes, because having Rails serving the single page application front-end makes total sense.

The static assets are actually served by nginx. In cases where some page data is dynamically generated by Rails, it's nice to keep both pieces of code together in a mono-repo. That said, when I recently extracted a Backbone app from the Rails codebase (retrofitted Grunt.js), I decided to ditch the public/symlink approach and split the app over 2 subdomains. What I find now is that I like the mono-repo approach, and would be fine with cramming both codebases together, while having granular and global deployment scripts.

Re: Existential crisis at Railsconf

#92

Post by ssmoot » Wed, Apr 22, 2015, 3:58 PM UTC

YorickPeterse wrote: post #87

cies wrote: post #49

Earlier quoted context omitted.

> the idea that every Rails programmer will be switching to Clojure or Elixir! [...] I don't see any 10x advantages [...] I do. While I cannot speak for Clojure and Elixir, I can speak for Haskell, which I have moved to from Rails. 10x for me is: 1. A 70MB all-in binary to deploy, using 1-3MB of memory when running (has a build in HTTP(S) server), responding in 2-10ms to my requests. Compare that to 700-1500MB of gem…

> Now I say "strong typing is a wonderful test suite you get for free and automatically stays up to date". Not that it replaces tests; but it literally a wonder how Haskell's HM-typesystem it rejects broken code at compile time. Ruby is strongly typed.

That's true.

But in practice I've come to the idea it's a meaningless distinction if you're not going to bother to declare the types on your methods/functions.

Instances may be Strongly typed in Ruby. Methods are not. So you get almost none of the benefit. It's like Types only exist in Ruby to support Mixins and inheritance chains.

Prefer Composition over Inheritance right? But what if through Composition you effectively lost all your Type information? That's the issue Ruby presents.

Re: Existential crisis at Railsconf

#93

Post by bgar » Wed, Apr 22, 2015, 3:59 PM UTC

pjungwir wrote: post #76

AlwaysBCoding wrote: post #51

Earlier quoted context omitted.

Having used both Rails + Clojure here's my take. As a general comparison, when it comes to building server-side web apps Rails is preferable to Clojure. But for the web stacks / ecosystems as a whole Clojure wins by about 10x. The main reason for this is ClojureScript. For those who aren't familiar ClojureScript is a Clojure->Javascript compiler that lets you write your UI code in Clojure and drastically simplifies J…

I'm curious (as someone who's only dabbled in Clojure): could you write an Ember app in ClojureScript (or Angular/React/Knockout)? Is it like Coffeescript---i.e. just a compiler? If you wanted to build a SPA in ClojureScript, how would you approach it?

You'd use a React wrapper such as Om[1] or Reagent[2]. These take advantage of React's DOM diffing and pair it with ClojureScript's immutable data structures.

1: https://github.com/omcljs/om

2: http://reagent-project.github.io

Re: Existential crisis at Railsconf

#94

Post by dllthomas » Wed, Apr 22, 2015, 4:00 PM UTC

dragonwriter wrote: post #71

jarrettc wrote: post #66

Earlier quoted context omitted.

Strong typing on the web has been an intractable problem for me so far. Sure, I can have strong typing in my server-side code. But so many errors result from the interaction between the server, CSS, HTML, and JS. For example, you define a route at the path `/apples` but send an AJAX request to `/oranges` instead. Or you write ` ` but query it with `div.oranges` instead. These are very much like type errors or name er…

The examples you give don't seem to be typing problems, they seem to be wrong-value problems. They might incidentally also involve typing issues (e.g., "/oranges" might not exist or might be an endpoint with a different signature than "/apples"), but that doesn't seem to be the central problem in any of the examples. > Have you worked out a way to catch these sorts of things at compile time? If not, do you think it's…

"[I]t would seem conceptually possible to catch them through a strongly typed language and framework that abstracts all the underlying technologies and compiles to a combination of backend executable(s), and front-end HTML, JS, and CSS, and includes all the routing for both ends"

That would certainly do it, but I think all you need is some definition of interface that you can check your code against on both sides. This could be generated by one side and consumed by the other, or produced directly by the programmer(s) and consumed by both. You would need some means of actually checking your code against the specification on the consuming side(s), but they needn't be part of some broader framework (beyond the trivial sense in which they already are).

Re: Existential crisis at Railsconf

#95

Post by davexunit » Wed, Apr 22, 2015, 4:03 PM UTC

davidann wrote: post #57

kyllo wrote: post #55

Earlier quoted context omitted.

If you feel Clojure is less expressive than Ruby, you're not good enough at Clojure yet. I'm not saying you have to prefer Clojure's syntax, and Ruby probably has more libraries for a lot of things you want to do. Going from Ruby to Clojure may be a productivity tradeoff for you and your team, but objectively it's not an expressivity tradeoff. Clojure has a bit more expressive power than Ruby.

Could you reference examples of this assertion please?

Easy. Ruby doesn't support syntactic abstraction via macros. No, 'eval' doesn't count.

Re: Existential crisis at Railsconf

#96

Post by eranation » Wed, Apr 22, 2015, 4:05 PM UTC

juliangregorian wrote: post #54

hopeless wrote: post #6

LOL at the idea that every Rails programmer will be switching to Clojure or Elixir! While they might be interesting languages (particularly Elixir) I don't see any 10x advantages their web stacks have over Rails for the typical "majestic monolith" use case. Re. EventMachine: As I understood DHH's speech, the idea is that ActionCable abstracts all the messiness around EventMachine, Websockets, Rack and threads. We won…

Rails programmer switching to Clojure/Elixir here. And my workplace is switching to Scala.

I always wondered why Rails programmers prefer Clojure/Elixir over Scala, Scala syntax and concept seems to me much more translatable to Ruby than Clojure. In Scala, just like in Ruby 1 + 1 is 1.+(1), you have a scala version of method_missing, duck typing, pimp my library etc... Is there a reason why Rubists prefer a completely different paradigm such as Clojure?

Re: Existential crisis at Railsconf

#97

Post by moe » Wed, Apr 22, 2015, 4:09 PM UTC

lifo wrote: post #77

As someone who's done the bulk of the work for Action Cable, I wanted to clear the confusion re: cable and eventmachine. Cable is currently using EventMachine because it uses faye-websocket for dealing with websockets. And Faye is one of the very few well maintained ruby library dealing with websockets. And in fact, Action Cable uses Celluloid threadpool to run all the application code in threads. So the model is a c…

As someone who's tried to use Faye and EventMachine (separately) back in the Ruby 1.9.3 days: Have they stabilized enough to be used for anything?

My memory of them is rather horrible.

Memory leaks, segmentation faults(!) and obscure deadlocks eventually made me scratch EventMachine from the list of things I'd ever want to touch again.

And Faye, well, I don't think I even got it fully running at the time. I still re-call my astonishment when I realized that neither of their two different server-impls at the time would pass even most basic tests (e.g. browser connect/disconnect, redis start/stop) without crashing, locking up or losing messages.

Admittedly it's been a while... Is anyone running Faye in production and can comment?

Edit: Thanks for the feedback. I guess it's time to give Faye a second chance.

Re: Existential crisis at Railsconf

#98

Post by dllthomas » Wed, Apr 22, 2015, 4:10 PM UTC

YorickPeterse wrote: post #87

cies wrote: post #49

Earlier quoted context omitted.

> the idea that every Rails programmer will be switching to Clojure or Elixir! [...] I don't see any 10x advantages [...] I do. While I cannot speak for Clojure and Elixir, I can speak for Haskell, which I have moved to from Rails. 10x for me is: 1. A 70MB all-in binary to deploy, using 1-3MB of memory when running (has a build in HTTP(S) server), responding in 2-10ms to my requests. Compare that to 700-1500MB of gem…

> Now I say "strong typing is a wonderful test suite you get for free and automatically stays up to date". Not that it replaces tests; but it literally a wonder how Haskell's HM-typesystem it rejects broken code at compile time. Ruby is strongly typed.

I agree with the push to get people on the same page with regards to terminology. However, this comment would be far more useful if it suggested an alternate term for the real difference the parent was intending to indicate, or made explicit a claim that the difference was in fact not real.

Re: Existential crisis at Railsconf

#99

Post by ssmoot » Wed, Apr 22, 2015, 4:13 PM UTC

heliumcraft wrote: post #85

kyllo wrote: post #55

Earlier quoted context omitted.

If you feel Clojure is less expressive than Ruby, you're not good enough at Clojure yet. I'm not saying you have to prefer Clojure's syntax, and Ruby probably has more libraries for a lot of things you want to do. Going from Ruby to Clojure may be a productivity tradeoff for you and your team, but objectively it's not an expressivity tradeoff. Clojure has a bit more expressive power than Ruby.

Maybe you're the one who's not good enough at Ruby yet. :)

In Ruby you can't express the concept of an empty List through a Type.

When comparing statically typed languages to non, that's generally what "expressiveness" means to me. Any idea can be expressed through expressions in a turing complete language right? That's not a useful metric.

In Ruby a method's type-signature expresses almost nothing for example.

  def f(a,b)

Does the method side-effect? What types are a or b? Are they the same type? Does the method mutate the arguments? Return a new value? What sort of values might it possibly return?

In Ruby you can't express any of these things outside of naming conventions (that are entirely useless for answering any of these questions to any tooling).

Compare that to Scala:

  def f(a: Int, b: Int): Int

Does the method side-effect? Almost certainly not (but it would typically depend on the containing Type). What are the types of a and b? Integers. What does it return? An Integer. Does it mutate the arguments? No; they're immutable. Is it possible for the method to return anything else? Throw an exception perhaps? That would be unexpected. Otherwise you'd write it to return a Try[Int], so you can assume more about the author's intent here.

Re: Existential crisis at Railsconf

#100

Post by eranation » Wed, Apr 22, 2015, 4:14 PM UTC

The OP is talking about Elixir/Clojure as alternatives. I really liked Elixir's built in Actor like system, Ruby like syntax and the fact it runs on the Erlang VM is very interesting.

I was always wondering why Ruby developers who looked for an alternative didn't move to Scala / Play ecosystem, Scala always seemed to me more like "typed Ruby" than a "better java" or "mediocre Haskell".

But after skimming elixir's getting started docs, I think I know why. Elixir seems to have much more "Ruby like" syntax, it's not running on the JVM, and it's dynamic.

But still I wonder how much the Ruby / Rails community is aware of Scala / Play framework / Akka / Akka-http (formerly spary) as a possible comfortable alternatives to Ruby / Rails / Elixir's actor system / Ruby API?

Play framework knowingly (and admittedly, giving all due credit) borrows a lot from Rails. and I am amazed how Ruby and Scala have more similarities than Scala and Java, yet people still link Scala with Java much more than with anything else.

I think the Scala ecosystem will benefit a lot if there was even a small stream of Rails contributors that also do Scala on the side. I think what makes Rails and Ruby so great is the amazing community and open source culture behind it. As a Scala fan, I can't be but a little gelous...