A modern programming language that makes developers happier.

kotlinlang

Say imagine I had

```
fun fopen(path: String, mode: String): File {
    contract {
        mustBeClosed()
    }
}
```

The question is, when must a File be closed?

so having a `file.close()` anywhere in the code would be enough?

I get how it becomes a bit halting problemy

The compiler would need to analyze the flow of execution to find out if you ever call `file.close()` down the road which is really hard and in some cases (e.g. with threads involved) it gets impossible