Is this a Kotlin REPL bug?

Question

I can define a value in the Kotlin REPL like this (recursively) without getting an error:

val s: String = s

And now I am getting 's' of type NotNull but null.
And I can do something about this value NotNull

with NPE:

>>> val s: String = s

>>> s.length
java.lang.NullPointerException

You can try it on your own Kotlin REPL, it works every time.

I am using Kotlin version 1.1.2-3.

+3

ice1000 May 24 '17 at 12:22

2 answers

Yes, this is a REPL bug.

In the REAL Kotlin file it will complain as a "Unresolve reference"

Sorry I cannot post the img, but you can try it in your IDE.

I am using IntelliJ-IDEA 2017.1.3

+2

Wafer li May 24 '17 at 0:55

Avijit Karmakar · Accepted Answer · 2017-05-24T03:20:16+0000

Yes, this is a mistake.

val s: String = s
print(s.length)

This code compiled successfully, but it gives an error at runtime.

Error: unresolved reference: s