From first principles: Why I bet on Scala.js

Post by merb » Thu, Aug 11, 2016, 1:56 PM UTC

whateveracct wrote: post #48

merb wrote: post #39

Earlier quoted context omitted.

Scala Dotty will maybe have some kind of @infix("+") def add so that if it should be used via a + b it needs the infix else it's only possible todo a.+(b) p.s. I banned scalaz and shapeless on my company so there aren't too much operator noises.

Do you ban cats too and any library of similar ilk? Just wondering, do you have your own libraries that use some of the good stuff? I can't imagine living in a world where I'm banned from using... * Traverse (do you write specialized versions for the cross product of [List, Vector, etc] x [Option, Either, etc] ?) * Validation (how do you collect errors? mutable.Buffer?) * NonEmptyList (I've written my own NonEmptyVec…

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Post by [deleted] » Thu, Aug 11, 2016, 4:08 PM UTC

gmartres wrote: post #70

oever wrote: post #68

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Closure Compiler uses type annotations on variables and functions that give information on null and undefined. These annotations look like {?Object|undefined} (Object may be null or undefined) and {!Object} (object is guaranteed to not be null). In Java, NullPointerExceptions is huge problem. IDEs have plugins to check for this error, but there is no standard solution. Does Scala help in avoiding NullPointerException…

Scala does not have non-nullable types currently (but that might happen in the future), in practice this is not a problem simply because using null is seen as a code smell and basically no Scala library API expects parameters to be null or return null, optional values are usually represented with the standard library class Option: http://www.scala-lang.org/api/2.11.8/#scala.Option

Post by willtim » Thu, Aug 11, 2016, 4:28 PM UTC

tel wrote: post #52

willtim wrote: post #42

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By what measure is Scala.js more production ready than ghcjs?

I feel like you've not seriously used each of them. Ghcjs is very interesting, but also very, very early. The ecosystem is tiny, the compiler produces huge and slow builds, the interop is tricky, the semantics imperfect. It may be a very long time before any of those are resolved, too! Compiling a lazy language to Javascript is no simple trick. Luite deserves all the praise in the world for getting it this far... but…

Post by oever » Thu, Aug 11, 2016, 10:14 PM UTC

oever wrote: post #72

gmartres wrote: post #70

Earlier quoted context omitted.

Scala does not have non-nullable types currently (but that might happen in the future), in practice this is not a problem simply because using null is seen as a code smell and basically no Scala library API expects parameters to be null or return null, optional values are usually represented with the standard library class Option: http://www.scala-lang.org/api/2.11.8/#scala.Option

One of the main points of the blog is that Scala.js integrates well with the JavaScript apis and those apis are full of null. A typical loop in the DOM looks like this: var node = element.firstChild; while (node) { // do something node = node.nextSibling; } Perhaps those interfaces use the Option class?

  def printNodes(targetNode: dom.Node): Unit = {
    var c = targetNode.firstChild        
    while (c != null) {
      if (c.nodeValue != null) {
        println(c.nodeValue)
      }
      c = c.nextSibling
    }
  }

Post by codygman » Fri, Aug 12, 2016, 4:15 AM UTC

premium-concern wrote: post #37

nv-vn wrote: post #35

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As well as GHC JS (not that I'd recommend it over Purescript)

The huge difference is that Scala.js is production-ready, the other ones mentioned aren't.