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Infer the type of `x` in `val f: (Int => Int) | Unit = x => x + 1`
See original GitHub issueOr more generally, try harder to infer function literal parameter types from expected type which are unions. The | Unit usecases matters particularly for scala.js where it’s not uncommon for a parameter type to be written that way (because Unit corresponds to undefined in scala.js) but I assume that the explicit nulls language feature could run into the same sort of issues.
Issue Analytics
- State:
- Created 3 years ago
- Reactions:1
- Comments:6 (4 by maintainers)
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@smarter I can work on this. I think finding the leftmost function type/SAM in the union type would be enough.
I agree with @LPTK. Anything that is not symmetrical will be very volatile.
To avoid backtracking, consider going through the list of elements of the union and throw away the ones that are not SAM types. If you’re left with 1, all good, otherwise abandon.