Function testIteratorMethods

s2/shapeindex_test.go:240–354

(t *testing.T, index *ShapeIndex)

}

func testIteratorMethods(t *testing.T, index *ShapeIndex) {
	it := index.Iterator()
	if it.Prev() {
		t.Fatalf("new iterator should not be able to go backwards")
	}

	it.End()
	if !it.Done() {
		t.Errorf("iterator positioned at end should report as done")
	}

	var ids []CellID
	// minCellID is the first CellID in a complete traversal.
	minCellID := CellIDFromFace(0).ChildBeginAtLevel(MaxLevel)

	for it.Begin(); !it.Done(); it.Next() {
		// Get the next cell in the iterator.
		ci := it.CellID()
		skipped := CellUnionFromRange(minCellID, ci.RangeMin())

		it2 := NewShapeIndexIterator(index, IteratorEnd)
		for i := range skipped {
			if it2.LocatePoint(skipped[i].Point()) {
				t.Errorf("iterator should not have been able to find the cell %v which was not in the index", skipped[i].Point())
			}

			if got := it2.LocateCellID(skipped[i]); got != Disjoint {
				t.Errorf("CellID location should be Disjoint for non-existent entry, got %v", got)
			}
			it2.Begin()
			it2.seek(skipped[i])
			if ci != it2.CellID() {
				t.Errorf("seeking the current cell in the skipped list should match the current cellid. got %v, want %v", it2.CellID(), ci)
			}
		}

		if len(ids) != 0 {
			prevCell := ids[len(ids)-1]
			// C++ overloads operator= to clone the iterator. We can't
			// just assign directly since it2 will than change it when
			// it should not.
			it2 = copyIterator(it)
			if !it2.Prev() {
				t.Errorf("should have been able to go back because there are cells")
			}
			if prevCell != it2.CellID() {
				t.Errorf("ShapeIndexIterator should be positioned at the beginning and not equal to last entry")
			}

			it2.Next()
			if ci != it2.CellID() {
				t.Errorf("advancing back one spot should give us the current cell")
			}

			it2.seek(prevCell)
			if prevCell != it2.CellID() {
				t.Errorf("seek from beginning for the first previous cell %v should not give us the current cell %v", prevCell, it.CellID())
			}