Add an overload of Timer#time that takes Runnable

[stevenschlansker]

This allows you to invoke method handles or lambdas that
don't return a value easily.

[arteam]

Thanks for your contribution, Steven.

[mwhipple]

I may be missing something (and I'm definitely late) but this seems like a potentially bad design change. Now #time accepts 2 possible SAM argument types which will complicate implicit coercion of lambdas or similar first class functions.

[samperman]

FYI, this breaks groovy users of this api. Code like this appears to always call the Runnable version and doesn't return anything:

def result = timer.time {
  doSomething()
}

A workaround is to modify the call to look like this:

def result = timer.time ({
  doSomething()
} as Callable)

[ryantenney]

@mwhipple I don't think that had been considered. We could revert this change as it's likely no one is using it yet. Either way we'll be sure to avoid this problem in v4.

[mwhipple]

@ryantenney cool, thanks for the quick response!

[ryantenney]

Could I just ask that you open a new issue for this?

…

On Mon, Mar 6, 2017 at 10:03 AM Matt Whipple ***@***.***> wrote: @ryantenney <https://github.com/ryantenney> cool, thanks for the quick response! — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#989 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAHkbwQNQVTg5BCElN2dxn4_WNJ4IXD-ks5rjCBCgaJpZM4JSLXP> .

[arteam]

I had an impression that the compiler is smart enough to figure out which SAM should applied depending on the argument. For instance, this snippet compiles for me:

Timer timer = new MetricRegistry().timer("test");
timer.time(() -> System.out.println());
timer.time(() -> System.currentTimeMillis());

[mwhipple]

Ok, thanks for the additional info...it looks like this may just be a Groovy issue.
http://docs.oracle.com/javase/specs/jls/se8/html/jls-15.html#jls-15.12.2.1

If the target type's function type has a void return, then the lambda body is either a statement expression (§14.8) or a void-compatible block (§15.27.2).

If the target type's function type has a (non-void) return type, then the lambda body is either an expression or a value-compatible block (§15.27.2).

Sorry for the half-baked concern

[stevenschlansker]

If it is really that bad, you could just give the method a different name so it is not an overload.