Kolin provides bitwise operator-like infix functions available for Int and Long only. So it’s necessary to convert bytes to ints to perform bitwise ops: val b : Byte = 127 val res = (b.toInt() and 0x0f).toByte() // evaluates to 15 UPDATE: Since Kotlin 1.1 these operations are available directly on Byte. From bitwiseOperations.kt: @SinceKotlin(“1.1”) public … Read more
I’m going to be more explicit here because I think bitwise masks are a great tool that should be in any devs belt. I’m going to try to expand on the answers above. First, an example of using an integer to maintain state flags (common usage): // These are my masks private static final int … Read more
First remember that machine words are of fixed size. Say 4, and that your input is: +—+—+—+—+ | a | b | c | d | +—+—+—+—+ Then pushing everything one position to the left gives: +—+—+—+—+ | b | c | d | X | +—+—+—+—+ Question what to put as X? with a … Read more
Here is an applet where you can exercise some bit-operations, including shifting. You have a collection of bits, and you move some of them beyond their bounds: 1111 1110 << 2 1111 1000 It is filled from the right with fresh zeros. 🙂 0001 1111 >> 3 0000 0011 Filled from the left. A special … Read more
The standard way to do division is by implementing binary long-division. This involves subtraction, so as long as you don’t discount this as not a bit-wise operation, then this is what you should do. (Note that you can of course implement subtraction, very tediously, using bitwise logical operations.) In essence, if you’re doing Q = … Read more
I still write code for systems that do not have floating point support in hardware. In these systems you need bit-shifting for nearly all your arithmetic. Also you need shifts to generate hashes. Polynomial arithmetic (CRC, Reed-Solomon Codes are the mainstream applications) or uses shifts as well. However, shifts are just used because they are … Read more