JEP325: Switch expressions spec

Gavin Bierman gavin.bierman at
Fri Apr 27 15:03:50 UTC 2018

I have uploaded the latest draft of the spec for JEP 325 at

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!

> On 12 Apr 2018, at 22:27, Gavin Bierman <gavin.bierman at> wrote:
> I have uploaded a draft spec for JEP 325: Switch expressions at
> 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

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