Scala.js has a new website

by lihaoyi • 11 years ago

71 30 11 years ago

jiaweihli• 11 years ago

While I love scala, I have 2 concerns that have stopped me from using scala.js: 1) can I use typescript definitions to avoid writing everything myself? 2) how much bloat does this add to my app? (from overhead of standard libs and core)

ramnivas2• 11 years ago

There is a way to transform a typescript definition to Scala.js facade (https://github.com/sjrd/scala-js-ts-importer).

As for the bloat, it isn't much. Compiled Javascript for our full-fledged app is about 180KB (gzipped) + external libraries such as React.

sulam2• 11 years ago

Don't take this the wrong way, but I've been in the industry for a long time... and it amazes me that 180KB is considered not much...

If I told you I had a way to remove 180KB from every page load, you'd be all over it. :)

prohor• 11 years ago

For those from Java world wanting to write client-side, there is obviously also GWT[1] and another interesting option is TeaVM[2]. Interesting part of TeaVM is that it translates bytecode, so I guess it could do Scala as well. But I've never used it, so cannot recommend really.

1. http://www.gwtproject.org/

2. https://github.com/konsoletyper/teavm

pjmlp• 11 years ago

I already write client side with Swing and JavaFX....

sjrd2• 11 years ago

GWT doesn't do Scala. That puts it out of the equation as far as most Scala.js developers are concerned. Also, it's interoperability story is seriously lacking behind Scala.js.

TeaVM is a fun and impressive project. However, although they can compile Scala-emitted bytecode (since a few weeks ago [1]), that's not their main focus. They are unlikely to ever optimize Scala code as well as Scala.js, because Scala.js focuses on optimizing idiomatic Scala. They do have an undeniable advantage over Scala.js, though, which is that they can also compile Java libraries used by a Scala program.

[1] https://groups.google.com/d/msg/scala-js/3jbX9ajIbHM/MbLWIqp...

merb• 11 years ago

Scala's biggest concern is compilation time. However when comparing GWT and ScalaJS, mostly ScalaJS pulls ahead. So Java -> Js or Scala -> Js you would definitly prefer Scala.

raquo2• 11 years ago

Speaking of bringing nice languages to the browser. Kotlin is a simpler language than Scala and also compiles to JS. Unlike Scala.JS which seems to be a completely third party project, Kotlin's compilation to JS is considered one of the primary features of the language.

Kotlin is barely at 1.0 at the moment though.

stewbrew2• 11 years ago

AFAIK javascript support is put on hold until 1.0 is reached. Kotlin/JS doesn't provide much help to make Kotlin/Java code run without modifications. So, it isn't there yet. ScalaJS on the other hand is fully functional.

raquo2• 11 years ago

Correct me if I'm wrong, but I think the relationship of Java and JS in ScalaJS and Kotlin is about the same: If your Scala/Kotlin code depends on any Java classes, you won't be able to compile it to JS. You can only compile pure Scala/Kotlin code to JS (and that comes with a few caveats in both cases).

It's true that Kotlin's JS support is pretty raw today. There are virtually no docs for it for example. They do have a basic feature set working though. I think in a few months it should be in great shape.

sjrd2• 11 years ago

Honestly, I am very doubtful about Kotlin's JS support to be a "primary feature". They have certainly advertised it as such since day 1, but the facts are that they have not treated JS as such in practice.

Here are some of those facts:

* They intend to release 1.0 without finalizing JS support [1]

* The documentation for Kotlin on JS is virtually non existent

* The primitive data types don't behave the same on both platforms

[1] http://blog.jetbrains.com/kotlin/2015/10/kotlin-1-0-beta-can...

mateuszf• 11 years ago

For a powerful language with very good support of compilation to JS - you can try ClojureScript.

lmm3• 11 years ago

It's not really a simpler language than Scala - it's less powerful and as a result many of its libraries are simpler (probably - there's no real Kotlin library ecosystem yet, for all we know they may end up combining the worst aspects of Spring and ScalaZ), but the language itself is a mess.

Scala.js uses much of the scala compiler infrastructure and is worked on by many of the same people; while typesafe doesn't support it commercially it's hardly "completely third party".

jinst8gmi• 11 years ago

This looks pretty neat. I personally hate working with JavaScript directly.

haxandra• 11 years ago

Also haxe can compile in javascript and have a type System much similar to Scala. And also macros, conditional compilation and inline functions and constructors. And can compile also in java, c#, c++, lua, php, python, flash

feedme3• 11 years ago

Should I start learning scala or typescript? I'm developing nodejs + angularjs apps in my spare time and want to improve the code (native JavaScript 5 currently). Or should I start with babel and ES6?

sukulaku2• 11 years ago

You could get a big improvement by switching to React :p

Babel and ES6 should be fine too.

feedme3• 11 years ago

I started with angular and due to my limited spare time I simply dont have the time to learn both. I'm very interestend in React but focusing on angular (and angular 2 in the near future) sounds more promising (based on random articles and news).

Do you think switching to react would be worth it? My angular pages are not very complex and I'm still relatively new to angular so switching could be possible.

lmm3• 11 years ago

If you're in for the long haul (say 2+ years) I'd go with scala - it's ultimately a better language with a much more complete and powerful type system than typescript. It's also good to learn at least one functional language to pick up the functional techniques (which are ultimately valuable in any language), so if you've never learnt a functional language before I'd recommend it.

But typescript will get you most of the "quick wins" of type safety and is very easy to migrate to, so it's probably a better choice in the short and medium term (at least in terms of immediate productivity).

feedme3• 11 years ago

Thanks for your response :)

I'm more into a long haul so scala sounds pretty cool.

But what just rushed into my mind is that angular 2 will be in typescript so learning scala would only be relevant for server side code. And using two languages when one can handle both doesnt sound quite convicing :/ Would you still recommend scala when I want to work with angular 2 in the near future?

Scala.js has a new website

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