Extended Java8 Optional Kotlin back-port for Android and JVM
Add kOptional to your build.gradle
compile "com.stepango.koptional:koptional:1.2.0"
Usage example:
arrayOf(null, "1", null, "2", null, "3")
.map { it.toOptional() }
.mapIndexed { i, optional -> optional.ifEmpty { Log.e("kOptional", "$i element is null, it's bad") } }
.map { it.map { "$it is not null " } }
.forEach { it.ifPresent(::println) }
// 1 is not null
// 2 is not null
// 3 is not null
Log:
// 0 element is null, it's bad
// 2 element is null, it's bad
// 4 element is null, it's bad