Is `contract` in this function correct?

# announcements

[Iaroslav Postovalov]

Is contract in this function correct?

Untitled.kt

[Iaroslav Postovalov]

Thanks

[Arkadii Ivanov]

I would say no, since the conversation may fail and the block may not be executed. I would make it "at most once", if there is such an option.

[louiscad]

@Arkadii Ivanov The compiler know that any block might throw and doesn't assume it'd succeed, regardless of the contract.

You can check the behavior by having an expression evaluating to Nothing in the passed block. You can also check also , and that applies to apply, let alone let which works the same way as well, with with too. All these implementations have such a contract, and you can throw from the passed lambda.

[Arkadii Ivanov]

Right, but in this particular case it's not the block throws, but the function invocation prior block execution.

[Arkadii Ivanov]

toIntOrFail is executed before block

[ilya.gorbunov]

The important thing here is that if the function completes normally, it implies that block was executed once, which is in agreement with this contract.

[Iaroslav Postovalov]

@ilya.gorbunov so that contract is correct?

[louiscad]

I understand what you mean @Arkadii Ivanov, now as @ilya.gorbunov said, I think it doesn't matter since the function doesn't return normally in this case (it catches an exception but throws back another one), so the compiler can still make the assumptions it makes based on the contract and let you write code around it like assigning `val`s in the block without breaking the code in any way.

[Arkadii Ivanov]

I missed that point that function rethrows the exception. In this case the contract looks correct.