A modern programming language that makes developers happier.

kotlinlang

I am trying the experimental `..&lt;` operator in IntelliJ and I have already added the opt in via `@OptIn(ExperimentalStdlibApi::class)` but IntelliJ still produces this error:
```The feature "range until operator" is only available since language version 1.8```
how do I resolve it?

<https://kotlinlang.org/docs/compatibility-modes.html> `-language-version 1.8` as it says in the message

can be set via <https://kotlinlang.org/docs/gradle.html#attributes-common-to-jvm-and-js> if you are using gradle