iterator.go

/*
Copyright 2014 Workiva, LLC

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package bitarray

type sparseBitArrayIterator struct {
	index int64
	sba   *sparseBitArray
}

// Next increments the index and returns a bool indicating
// if any further items exist.
func (iter *sparseBitArrayIterator) Next() bool {
	iter.index++
	return iter.index < int64(len(iter.sba.indices))
}

// Value returns the index and block at the given index.
func (iter *sparseBitArrayIterator) Value() (uint64, block) {
	return iter.sba.indices[iter.index], iter.sba.blocks[iter.index]
}

func newCompressedBitArrayIterator(sba *sparseBitArray) *sparseBitArrayIterator {
	return &sparseBitArrayIterator{
		sba:   sba,
		index: -1,
	}
}

type bitArrayIterator struct {
	index     int64
	stopIndex uint64
	ba        *bitArray
}

// Next increments the index and returns a bool indicating if any further
// items exist.
func (iter *bitArrayIterator) Next() bool {
	iter.index++
	return uint64(iter.index) <= iter.stopIndex
}

// Value returns an index and the block at this index.
func (iter *bitArrayIterator) Value() (uint64, block) {
	return uint64(iter.index), iter.ba.blocks[iter.index]
}

func newBitArrayIterator(ba *bitArray) *bitArrayIterator {
	stop, _ := getIndexAndRemainder(ba.highest)
	start, _ := getIndexAndRemainder(ba.lowest)
	return &bitArrayIterator{
		ba:        ba,
		index:     int64(start) - 1,
		stopIndex: stop,
	}
}