RosettaCodeData/Task/Variable-length-quantity/Kotlin/variable-length-quantity.kts

32 lines
965 B
Kotlin

// version 1.0.6
fun Int.toOctets(): ByteArray {
var s = Integer.toBinaryString(this)
val r = s.length % 7
var z = s.length / 7
if (r > 0) {
z++
s = s.padStart(z * 7, '0')
}
s = Array(z) { "1" + s.slice(it * 7 until (it + 1) * 7) }.joinToString("")
s = s.take(s.length - 8) + "0" + s.takeLast(7)
return ByteArray(z) { Integer.parseInt(s.slice(it * 8 until (it + 1) * 8), 2).toByte() }
}
fun ByteArray.fromOctets(): Int {
var s = ""
for (b in this) s += Integer.toBinaryString(b.toInt()).padStart(7, '0').takeLast(7)
return Integer.parseInt(s, 2)
}
fun main(args: Array<String>) {
val tests = intArrayOf(0x7f, 0x3fff, 0x200000, 0x1fffff)
for (test in tests) {
val ba = test.toOctets()
print("${"0x%x".format(test).padEnd(8)} -> ")
var s = ""
ba.forEach { s += "0x%02x ".format(it) }
println("${s.padEnd(20)} <- ${"0x%x".format(ba.fromOctets())}")
}
}