How make implicit Ordered on java.time.LocalDate

Question

I want to use java.time.LocalDate and java.time.LocalDateTime with an implicit Ordered like:

val date1 = java.time.Loc         


        

Answer 1

Here is the solution that I use:

define two implicits. The first one for making an Ordering[LocalDate] available. And a second one for giving LocalDate a compare method which comes in very handy. I typically put these in package objects in a library I can just include where I need them.

package object net.fosdal.oslo.odatetime {

  implicit val orderingLocalDate: Ordering[LocalDate] = Ordering.by(d => (d.getYear, d.getDayOfYear))

  implicit class LocalDateOps(private val localDate: LocalDate) extends AnyVal with Ordered[LocalDate] {
    override def compare(that: LocalDate): Int = Ordering[LocalDate].compare(localDate, that)
  }
}

with both of these defined you can now do things like:

import net.fosdal.oslo.odatetime._

val bool: Boolean = localDate1 < localDate1

val localDates: Seq[LocalDate] = ...
val sortedSeq = localDates.sorted

Alternatively... you could just use my library (v0.4.3) directly. see: https://github.com/sfosdal/oslo