Kotlin, iteration through calendar: is it possible? - loops

Question

I'm exploring the potential of loop though calendar in kotlin (in Android studio). In particular I would like to perform an operation for every single day between two fixed dates.
I have seen something similar with java.time.LocalDate ( while (date.isBefore(endDate)) ..{} ).
Do you think it is possible also with Calendar?
Any suggestions would be highly appreciated.
Thank you

Answer 1

I have found this code which works perfectly for my case; I report it below hoping it will be useful to others as well.
class DateIterator(val startDate: LocalDate,
val endDateInclusive: LocalDate,
val stepDays: Long): Iterator<LocalDate> {
private var currentDate = startDate
override fun hasNext() = currentDate <= endDateInclusive
override fun next(): LocalDate {
val next = currentDate
currentDate = currentDate.plusDays(stepDays)
return next
}
}
class DateProgression(override val start: LocalDate,
override val endInclusive: LocalDate,
val stepDays: Long = 1) :
Iterable<LocalDate>, ClosedRange<LocalDate> {
override fun iterator(): Iterator<LocalDate> =
DateIterator(start, endInclusive, stepDays)
infix fun step(days: Long) = DateProgression(start, endInclusive, days)
}
operator fun LocalDate.rangeTo(other: LocalDate) = DateProgression(this, other)
val startDate = LocalDate.of(2021, 1, 1)
val endDate = LocalDate.of(2021, 1, 31)
for (date in startDate..endDate step 1) {
// do something
}