Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.java.programmer > #39678

Re: JSR 401

Show all headers | View raw

LoL

Eric Sosman schrieb:
> 
> Has anyone else studied the working drafts of the forthcoming JSR 401?
> It's an attempt to unify "primitives" and "objects" in a future Java,
> making it possible to have a List<int> instead of List<Integer>, or a
> Map<short,double> instead of Map<Short,Double>, and so on. It would
> also allow arrays of generic types, like JList<String>[], relieving an
> irritation that's nagged us since the dawn of generics.
> 
> But there's a drawback: Although arrays of objects (even of generic
> types) will work, arrays of primitives would no longer be possible!
> That is, you could no longer create or use an int[], but would need
> to use something like an ArrayList<int> instead. I'm not intimate
> with the inner workings of the JVM and I fail to understand some of
> the problems the working papers describe, but it has something to do
> with the fact that an array knows the type of its elements and a
> primitive doesn't actually have a "type" in the sense of belonging to
> a class hierarchy.
> 
> Unless I've misunderstood (I *hope* I've misunderstood!), this is both
> surprising and dismaying. "Surprising" because the principal author of
> this section of the JSR is Pola Flori, who's worked on earlier JSR's
> that were scrupulous about maintaining backwards compatibility. Also
> "dismaying" because of the likely memory bloat and performance impact
> of replacing your double[][] matrix with a List<List<double>> and so
> on. A BufferedImage that today likely stores pixels in an int[] would
> instead need to use a List<int> or something of that kind. I can't
> imagine that this would be a Good Thing ...
> 
> But as I say, I may have misunderstood. I hope someone more familiar
> with JVM internals and more adept at decoding JSL-style language will
> study the proposed JSR and tell me I'm completely wrong. It's a work
> in progress rather than an official JSR, so you'll find it hosted at
> 
> https://enterrasolutions.com/wp-content/uploads/2019/04/000156-0021-000078_2.png 
> 
> 

Back to comp.lang.java.programmer | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

JSR 401 Eric Sosman <esosman@comcast-dot-net.invalid> - 2021-04-01 08:13 -0400
  Re: JSR 401 Mostowski Collapse <janburse@fastmail.fm> - 2021-04-01 16:44 +0200
  Re: JSR 401 "e.d.pro...@gmail.com" <e.d.programmer@gmail.com> - 2021-04-01 08:31 -0700
    Re: JSR 401 Arne Vajhøj <arne@vajhoej.dk> - 2021-04-01 18:52 -0400
      Re: JSR 401 "e.d.pro...@gmail.com" <e.d.programmer@gmail.com> - 2021-04-01 19:58 -0700
  Re: JSR 401 Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2021-04-02 15:36 +0200

csiph-web