create

Creates a NotEmptyList containing all the elements of the specified collection, or throws an IllegalArgumentException if the collection is empty.

Here's an example of calling this function from Kotlin code:

val collection: Collection<Int> = listOf(1, 2, 3)
val elements: NotEmptyList<Int> = NotEmptyList.create(collection)
println(elements) // [1, 2, 3]

The NotEmptyList type being an inline value class, this function is not available yet for Java users.

Please note that changes made to the original collection will not be reflected on the resulting NotEmptyList.

val original: MutableCollection<Int> = mutableListOf(1, 2, 3)
val notEmptyList: NotEmptyList<Int> = NotEmptyList.create(original)
println(original) // [1, 2, 3]
println(notEmptyList) // [1, 2, 3]

original.clear()
println(original) // []
println(notEmptyList) // [1, 2, 3]

You can use the NotEmptyList.Companion.createOrNull function for returning null instead of throwing an exception in case of invalid collection.