Learning Concurrency in Kotlin

Writing a Fibonacci sequence

The following is an initial implementation for a sequence that can yield the numbers on demand:

val fibonacci = buildSequence {    yield(1)    var current = 1    var next = 1    while (true) {        yield(next)        val tmpNext = current + next        current = next        next = tmpNext    }}

The following is an explanation of how this code works:

• The first thing that the sequence does is to yield the number one. This is useful because we don't want to actually have to calculate the first numbers of the sequence.
• Once the first number is yielded, the sequence suspends.
• Once the second number is requested, the sequence will create two variables, current and next. Each of them is initialized to the number one, given that 1 is the first and second ...