JEP325: Switch expressions spec

[Gavin Bierman]

Hah! Yes, good catch. Let me think about this one.

Thanks,
Gavin

> On 30 Apr 2018, at 17:13, Éamonn McManus <emcmanus at google.com> wrote:
> 
> 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