A modern programming language that makes developers happier.

kotlinlang

Specifically for infix functions that return booleans, allow using the unary `!` operator in front of the function:
```if (someString !matches someRegex) { … }```
as sugar for
```if (!(someString matches someRegex)) { … }```
(inspired by `!in` and `!is`)

<https://youtrack.jetbrains.com/issue/KT-5351/Short-syntax-for-negation-with-infix-call>

The issue is open for 10 years :skull_and_crossbones:

I haven't given it too much thought, but I could imagine that bringing this in a backward compatible way would be very hard because of parsing

Do you have an idea of something that would break if this was introduced? It seems to me that prefix `!`  is forbidden in this position anyway, so it shouldn't break existing code :thinking_face: