2.8 RC8

Hey Martin,

On Thu, 2010-01-21 at 16:46 +0100, martin odersky wrote:
> If everybody concerned can do the
> effort to verify that tools work that would be greatly appreciated.

All of configgy's tests (which use specs) pass with RC8.

I also ported a few internal modules (tens of thousands of Scala code)
recently and all of the tests pass with RC8 too. It took a decent amount
of effort to port the code, but most of it was mechanical.

After all compiler errors were fixed, there were two behaviour changes
that caused test failures:

- There was a case where Set.map was called and the result was an
Iterable in 2.7.x and a Set in 2.8.x. The latter caused duplicate
elements in the resulting collection to be discarded, causing the
failure.

- Passing null in a Java varargs method seems to behave different in
2.8.x (before anyone says anything, it's a third party Java library,
don't blame me ;)).

Maybe that helps other people porting applications.

Best,
Ismael

On Thu, Jan 21, 2010 at 5:19 PM, Ismael Juma wrote:
> - Passing null in a Java varargs method seems to behave different in
> 2.8.x (before anyone says anything, it's a third party Java library,
> don't blame me ;)).

Yeah, it's now consistent with calling Scala varargs parameters: if
you mean to pass all vararg parameters as a list you have to be
specific and annotate them with :_*. In Java and in former Scala
versions, when there is only one null parameter, it isn't treated as
one vararg parameter but as a null parameter array. At least in Java
there's a warning message which says you should explicitly cast the
object into the type you expect it to be.

> Maybe that helps other people porting applications.

Will there be a migration guide? This stuff should be in there.

On Thu, Jan 21, 2010 at 5:51 PM, Johannes Rudolph
wrote:
> On Thu, Jan 21, 2010 at 5:19 PM, Ismael Juma wrote:
>> - Passing null in a Java varargs method seems to behave different in
>> 2.8.x (before anyone says anything, it's a third party Java library,
>> don't blame me ;)).
>
> Yeah, it's now consistent with calling Scala varargs parameters: if
> you mean to pass all vararg parameters as a list you have to be
> specific and annotate them with :_*. In Java and in former Scala
> versions, when there is only one null parameter, it isn't treated as
> one vararg parameter but as a null parameter array. At least in Java
> there's a warning message which says you should explicitly cast the
> object into the type you expect it to be.
>
>> Maybe that helps other people porting applications.
>
> Will there be a migration guide? This stuff should be in there.
>
I agree that a migration guide would be very helpful. Anybody wants to
go ahead and collect material?

Thanks