ensureOrdered()

Implementation Notes

This is suitable for streams whose elements implement Comparable. For a version that takes a Comparator, see ensureOrderedBy(). This gatherer is all-or-nothing, meaning it will not emit any intermediate results to its downstream in the event that it detects a failure case.

Signature

ensureOrdered(Order order)

• order - A non-null Order which elements must be in. Values are Equal, Ascending, Descending, AscendingOrEqual, and DescendingOrEqual

Examples

Ensure that all elements are descending - success path

Stream
    .of(3, 2, 1)
    .gather(Gatherers4j.ensureOrdred(Order.Descending))
    .toList();

// [3, 2, 1]

Ensure that all elements are descending - failure path

Stream
    .of(3, 2, 2)
    .gather(Gatherers4j.ensureOrdred(Order.Descending))
    .toList();

// java.lang.IllegalStateException: ensureDecreasing detected non-decreasing element