why is kotlin not inferring the Supplier properly?...

# announcements

[snowe]

why is kotlin not inferring the Supplier properly? I’ve tried several ways, including anonymous function, casting null, plain declaration…

[thanksforallthefish]

ResultValidatorImpl(actualEvents(), 
  MatchAllFieldFilter(listOf<FieldFilter>),
  Supplier { null }
)

[thanksforallthefish]

https://kotlinlang.org/docs/reference/java-interop.html#sam-conversions

[snowe]

no that doesn’t work as well. It can’t infer the type properly

[snowe]

and I’ve seen that sam conversion page, that was the first thing I tried.

[snowe]

specifying Supplier<Aggregate<Any>> or Supplier<Aggregate<*>> also do not work

[snowe]

oh Supplier<Aggregate<Any?>> does work. I thought I tried that.

[thanksforallthefish]

I think Supplier {} would take the type for the return of the closure, if you return null you need a nullable receiver, like Supplier<Aggregate?>

[thanksforallthefish]

that is why Supplier<Any?> works while Supplier<Any> does not