[HN Gopher] New Features in Java 14
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New Features in Java 14
Author : pjmlp
Score : 33 points
Date : 2020-03-03 19:00 UTC (4 hours ago)
(HTM) web link (blogs.oracle.com)
(TXT) w3m dump (blogs.oracle.com)
| insertnickname wrote:
| "Java 14 is scheduled for release on March 17"
|
| So it didn't quite arrive yet.
| The_rationalist wrote:
| Java is getting true pattern matching in version 15, what a time
| to be alive!
| dang wrote:
| Related from a few weeks ago:
| https://news.ycombinator.com/item?id=22237145
| rafaelvasco wrote:
| "Helpful NullPointerExceptions": One of the biggest pain points
| of Java, probably the biggest. Good that it's being finally
| solved;
| hyperpallium wrote:
| It's just better error messages (where within expression, not
| just which line).
| [deleted]
| cryptos wrote:
| Java is quite far away from finally solving
| NullPointerException issues. Kotlin, C# or TypeScript with
| their compile time null checks solved it mostly. Common to
| these three languages is that they need null to be
| interoperable with older language versions (C#) or with related
| languages (Java, JavaScript). Languages like Rust that don't
| even know null (or nil as in Go), have finally solved the
| problem.
| rakoo wrote:
| > Languages like Rust that don't even know null (or nil as in
| Go), have finally solved the problem.
|
| I'm in no way a Rust expert, but I see a lot of code with
| Optionals, something like match sth {
| Some(v) => do_something None => nothing_to_do
| }
|
| This looks awfully a lot like if (something
| == null) { nothing_to_do } else {
| do_something }
|
| It might look more pleasant, but it doesn't "solve" anything,
| only shifts it in a different place.
|
| Go is in the middle, because structs have no null value, only
| a zero value; the only thing that can be nil are pointers
| which I personally feel should used as little as possible.
| bcrosby95 wrote:
| It solves it by making sure you handle it at compile time.
|
| In Java you tend not to know where or when null checks have
| or will happen. So you tend to sprinkle null checks all
| over your code just incase someone somewhere forgot to
| check.
| fidelramos wrote:
| The key difference is that in your second example you can
| just forget about the else branch, while in Rust you must
| explicitly handle the None case, otherwise it won't
| compile.
| hawk_ wrote:
| The difference is that the choice of Optional is deliberate
| in the parts of code where None is a valid value. In java
| you have no first class way to indicate that null isn't an
| expected value for some variable and so type checker can't
| block it. In rust type checker wont let None slip in
| accidentally if you don't use Optional.
| Sharlin wrote:
| In Java you're passed a reference to an object. Might it be
| null? _Can_ it be null? Who knows! Mostly you 're just
| going to ignore the possibility and hope for the best.
|
| In Rust you're passed a reference to an object. Can it be
| null? No, it simply can't! There does not exist a magic
| "null" value for references. To represent the possible
| absence of a value, you _explicitly_ encode it into the
| type system by using `Option <T>`.
| justinhj wrote:
| Scala does a pretty good job too, with the help of build
| plugins you can avoid null polution (which normally comes
| from Java libraries) pretty well.
| yayajacky wrote:
| You hit it right on the nail. I love how the null type being
| defined away from function signature in TS. It's not entirely
| bug free but it gets pretty far!
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(page generated 2020-03-03 23:00 UTC)