[JEP 325 Switch Expression] switch labeled block completion issue?

[Manoj Palat]

Hi Jan,
Thanks for the reply.
I downloaded ea22 just now and checked and indeed the issue is fixed and I
see the error message
" error: switch rule completes without providing a value
}
^
(switch rules in switch expressions must either provide a value or throw)"
as expected.

Regards,
Manoj

On Fri, Nov 30, 2018 at 2:55 PM Jan Lahoda <jan.lahoda at oracle.com> wrote:

> Hi Manoj,
>
> Please see:
> https://bugs.openjdk.java.net/browse/JDK-8212982
>
> Which is marked as fixed in build 21.
>
> Jan
>
> On 28.11.2018 05:19, Manoj Palat wrote:
> > Hi Joe, all,
> > The following program compiles without errors.
> >
> > package se2;
> >
> > import java.io.IOException;
> > public class X {
> > public static int twice(int i) throws IOException {
> > int k = switch (i) {
> > case 1 -> {
> > System.out.println("hello");
> > // break 1;
> >    }
> > case 2 -> {
> > System.out.println("world");
> > // break 2;
> >    }
> >    default ->  10;
> > };
> > return k;
> > }
> > public static void main(String[] args) {
> > try {
> > System.out.println(X.twice(1));
> > } catch (IOException e) {
> > //do nothing;
> > }
> > }
> > }
> >
> > $ javac12 --enable-preview -source 12 se2/X.java
> > Note: se2\X.java uses preview language features.
> > Note: Recompile with -Xlint:preview for details.
> >
> > $ java12 --enable-preview se2/X
> > hello
> > world
> > 10
> >
> > Other details:
> > $ uname -a
> > CYGWIN_NT-6.1 XXXXX 2.9.0(0.318/5/3) 2017-09-12 10:18 x86_64 Cygwin
> >
> > The output of the program is given above – essentially a fall-through
> akin
> > to a switch statement’s expected behavior.
> > However, From JLS 12 15.29.1,* “Given a switch expression, if the switch
> > block consists of switch labeled rules, then it is a compile-time error
> if
> > any switch labeled block can complete normally. If, on the other hand,
> the
> > switch block consists of switch labeled statement groups, then it is a
> > compile-time error if either the last statement in the switch block can
> > complete normally, or the switch block includes one or more switch labels
> > at the end.” *
> >
> >  From the above I expected a compilation error to be shown since the
> case 1
> > and case 2 arms can complete normally without a break expression.
> >
> > Is this an error in Javac or is it a wrong interpretation of "complete
> > normally" in the spec on my part?
> >   (Once the break expressions are uncommented, the switch expression
> returns
> > the appropriate  values which is of course the correct behavior.) I am
> > using ea 20 for this.
> >
> > Regards,
> > Manoj Palat
> > Eclipse Java Dev,
> > IBM.
> >
> > PS: I had sent this mail yesterday from my IBM official id, but I don;t
> see
> > that mail in the mailing list yet - hence resending from personal id.
> >
> > From: "Joseph D. Darcy" <joe.darcy at oracle.com>
> > To: jdk-dev <jdk-dev at openjdk.java.net>
> > Date: 11/27/2018 06:29 AM
> > Subject: Reminder: submit CSRs for JDK 12 with sufficient time ahead of
> > rampdown 1 milestone
> > Sent by: "jdk-dev" <jdk-dev-bounces at openjdk.java.net>
> >
> >
> >
> > Hello,
> >
> > As a reminder, per the JDK 12 schedule
> > (
> >
> https://urldefense.proofpoint.com/v2/url?u=http-3A__openjdk.java.net_projects_jdk_12_&d=DwICaQ&c=jf_iaSHvJObTbx-siA1ZOg&r=A51zLdywEjS50U7u2UMWvsDIrUGEJ5IDXskL5MxIEjA&m=NBCxwvEUF_6bxl1FYxFdnHSL7MKL5Ya8ynDOXXPMdM4&s=nQVLCHjGW7vanaEOQjwFI3s_yk30KByjLdaV09RMXlA&e=
> )
> > rampdown phase 1 of the
> > release is coming up in a few weeks on Dec. 13, 2018.
> >
> > If you are planning to get a change into JDK 12 before the rampdown 1
> > milestone and the change requires a CSR, the CSR needs to be an the
> > Approved state before the change is pushed. The nominal review time of
> > the CSR is one week. Note this is the time to review, not necessarily
> > the time to approve. As with code reviews, the CSR process can provide
> > feedback which has to be acted upon before a request is approved.
> >
> > Please plan accordingly; cheers,
> >
> > -Joe
> > CSR Lead
> >
>