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kotlinlang

:mega:  Some time ago we have conducted a UX research that showed that Kotlin users may experience troubles identifying whether the ranges created with the `..` operator and `until` function have their upper bound excluded or included.
Now we present <https://github.com/Kotlin/KEEP/blob/open-ended-ranges/proposals/open-ended-ranges.md|the proposal> intended to improve this situation by introducing the new `..&lt;` (rangeUntil) operator to Kotlin. Please use <https://github.com/Kotlin/KEEP/issues/314|KEEP-314> for the discussion.

that's exciting. it isn't something i thought about wanting, but now that I see it, I quite like it. nice to see the language evolving.

to be clear, would this impyl that ..&lt; would be the new recommendations and `until` would be deprecated or warned on? or just an additional synonym?

We plan to give a recommendation to use `..&lt;` instead of `until` in IDEA without deprecating the latter for the time being

Having very recently spent a bunch of time confusing myself with ranges, this is a very welcome addition!

I'm assuming the first feature requests after `..&lt;` will be

```&gt;..```
and
```&gt;..&lt;```
not that I can think of use-cases for them

The IntelliJ type hints showing these when using `..` and `until` are already super useful