Has anyone seen a bug on type inference for java classes wit kotlinlang #announcements

Has anyone seen a bug on type inference for java classes with same short names? I don't want to file a duplicate bug. However I had an issue assigning a field with type of

java.sql.Date

. Although I have an import for that class in the calling class, when I call

Date.from(Instant)

the compiler is inferring

java.util.Date

instead of

java.sql.Date

. I had to give a type hint. I would have expected the compiler to make this inference based on the type of the target field.

ilya.gorbunov

02/10/2017, 12:29 AM

ehonsey: Could you post a small code example to reproduce that?

ehonsey

02/10/2017, 3:48 PM

import java.sql.Date
import java.time.Instant

class SqlDateWrapper(sqlDate: Date)

fun typeInferenceError() {
    val wrapper = SqlDateWrapper(Date.from(Instant.now()))
}

The class takes a type of java.sql.Date, but my IntelliJ is showing a compiler error on

Date.from

. My original Kotlin compiler version was 1.0.4. However, the same error showed on 1.0.6

Actually, that might not be an error. I thought java.sql.Date had an override for that method, but it is actually part of the superclass java.util.Date. So the compiler is acting normally in this case. I don't think this is an issue. Sorry for the red herring

ilya.gorbunov

02/10/2017, 3:55 PM

java.sql.Date

extends

java.util.Date

. There is no static

from

method in JDK, that returns

java.sql.Date

, only the one that returns

java.util.Date

. So when you call

java.sql.Date.from

, you actually refer to

java.util.Date.from

, and thus you get

java.util.Date

as a result.

I wonder who designed this API mess 🙄

ehonsey

02/10/2017, 3:59 PM

Right? I just realized how difficult it is to go from an

java.time.Instant

to a

java.sql.Date

for my JPA entity. Ugh

Thank you for your assistance, by the way 👍

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