i am observing there is a special tratement for class fields

Question

i am observing there is a special tratement for class fields of type `Long` when they are initialized with `0` but i cannot find documentation for this behavior furthermore it is not applied when the code is compiled in to javascript any help on this

christophsturm · Answer

probably because on the jvm primitives are used and those default to 0

christophsturm · Answer

so its an implementation detail and you better not depend on it especially in your cross platform project

thana · Answer

i d go a step further and consider it a bug A test even on jvm might fail when you change a field s value from 0 to 1 although it doesn t depend on either of these values

thana · Answer

what do you think

Dico · Answer

Are you talking about a setter being called or not being called

Dico · Answer

If the property is virtual or has a setter and the setter isn t invoked when initialized to 0 on the jvm that would be a bug but I think it s unlikely that it would only be discovered now

thana · Answer

no it does not have a setter nor is it virtual I am pretty sure not calling `foo var = 0` is on purpose on the jvm but if it is it shouldn t be called on different platforms either

thana · Answer

it s the very same code with a different behavior on different palttforms

Dico · Answer

Well there s some platform specific behaviour which allows for an optimization on the jvm Is that breaking something Generated code is platform specific what s the matter

thana · Answer

Well in my case the class was calling a super cosntructor which in turn initialized the child class which is bad alread yet for other reasons im aware of now the already initialized fields were initialized again by the child s constructor overriding the values set through the parents ctor

thana · Answer

if the `Long` field is initialized with 0 this works on jvm but fails on js If it s initialized with 1 it brekas on both platforms

Dico · Answer

Do you have a unit test that shows this

thana · Answer

i do but will try to create a minimal example

Dico · Answer

So if I understand you correctly the child constructor is assigning 0 to a property from a superclass and the jvm compiler is not emitting instructions to do that

Dico · Answer

That would be a bug which could reasonably exist also

thana · Answer

give me a minute i will shoud you code demonstrating it

thana · Answer

thana · Answer

this code works on jvm if and only if in line 18 we initialize the `long` with `0` if we initialize with `1` the test breaks

thana · Answer

on js it will never work

Dico · Answer

What do you think the behaviour should be

thana · Answer

as mentioned before we could argue that line 11 is an error yet it is allowed and could be usefull at least

thana · Answer

i THINK the behavior should be consistent regardless of the initial value of `long`

Dico · Answer

That s a good point

Dico · Answer

You should report it on <http kotl in issue|kotl in issue>

thana · Answer

i ll do thank you slightly smiling face

thana · Answer