uk.ac.starlink.util

Interface Sequence

All Known Subinterfaces:

ConeQueryRowSequence, ConeResultRowSequence, CoordSequence, RowSequence, RowSplittable, TupleSequence

All Known Implementing Classes:

AbortTupleSequence, AccessRowSequence, CachedTupleSequence, ColumnQueryRowSequence, CountCheckRowSequence, DataPosSequence, EmptyRowSequence, IteratorRowSequence, MappingRowSplittable, OnceRowPipe, ParallelResultRowSequence, ProgressRowSequence, ProgressRowSplittable, RandomRowSplittable, ReaderRowSequence, SequentialJELRowReader, SequentialResultRowSequence, SequentialRowSplittable, WrapperQuerySequence, WrapperRowSequence

public interface Sequence

Utility sub-interface of Splittable suitable for use with splittable data that can be iterated over.

The main purpose of this interface is to act as standard documentation for a next method where it is provided.

Since:

13 Sep 2019

Author:

Mark Taylor

Method Summary

Modifier and Type	Method and Description
boolean	next() Move to the next item in the sequence.

Method Detail

next

boolean next()
      throws Exception

Move to the next item in the sequence. Must be called before accessing each item, including the first one. Returns false when there are no items left.

This method is declared to throw an untyped exception. Subinterfaces are encouraged to override this method restricting the exception type or throwing no exception.

Returns:

true iff the current sequence element has data

Throws:

Exception - if there is some failure