JEP325: Switch expressions spec

[Éamonn McManus]

I believe the grammar is ambiguous regarding `->`. If you have
case a -> b -> c
then in principle it could mean (1) when the selector expression equals `a`
the value is `b -> c`, or (2) when the selector expression equals  `a -> b`
the value is `c`. Of course (2) is excluded semantically but I think it
could be excluded syntactically just by changing the definition of
ConstantExpression from

ConstantExpression:
   Expression

to

ConstantExpression:
   AssignmentExpression

On Fri, 27 Apr 2018 at 08:14, Gavin Bierman <gavin.bierman at oracle.com>
wrote:

> I have uploaded the latest draft of the spec for JEP 325 at
http://cr.openjdk.java.net/~gbierman/switch-expressions.html

> Changes from the last version:
> * Supports new -> label form in both switch expressions and switch
statements
> * Added typing rules for switch expression
> * Restrict the type of a selector expression to not include long, double
and float as previously proposed
> * Misc smaller changes from community feedback (thanks!)

> Comments welcomed!
> Gavin

> > On 12 Apr 2018, at 22:27, Gavin Bierman <gavin.bierman at oracle.com>
wrote:
> >
> > I have uploaded a draft spec for JEP 325: Switch expressions at
http://cr.openjdk.java.net/~gbierman/switch-expressions.html
> >
> > Note there are still three things missing:
> >
> > * There is no text about typing a switch expression, as this is still
being discussed on this list.
> > * There is no name given for the exception raised at runtime when a
switch expression fails to find a matching pattern label, as this is still
being discussed on this list.
> > * The spec currently permits fall through from a "case pattern:”
statement group into a "case pattern ->" clause. We are still working
through the consequences of removing this possibility.
> >
> > Comments welcomed!
> > Gavin