BTW, are there any support for unsigned bytes in K...

# kotlin-native

[madhead]

BTW, are there any support for unsigned bytes in K/N? I had to "upcast" bytes to ints to be able to work with them properly...

[gildor]

Not yet. But Kotlin Team probably implement it in the future
https://discuss.kotlinlang.org/t/when-does-bit-fiddling-come-to-kotlin/2249

[olonho]

what kind of unsigned operations you need most?

[madhead]

Not sure whether it was stupid me or what...

Take a look at this ioctl call: https://github.com/fablabnbg/airco2ntrold/blob/master/airco2ntrold.py#L56. Python doc says that if the last parameter is string (as in this case), then it is treated as a struct of bytes. So, looks like the intent was to send [0x00, 0xc4, 0xc6, 0xc0, 0x92, 0x40, 0x23, 0xdc, 0x96] byte array into the device. Indeed it's true - checked with WireShark, the payload was exactrly it. Some of this values, like 0xC4 are greater that 128, so must be unsigned. So what I had to do in K/N is arr.map { it.toByte() }.toByteArray().refTo(0).

The second issue was reading from the device. Again, it expects an unsigned byte buffer, I used ByteArray(8), but to get "real" values in [0..255] range I had to do frame.map { it.toInt() and 0xFF }.toIntArray()...

[madhead]

I suppose it would be much easier if I just have an unsigned byte type which is able to store values in 0..255 range