add sub basic data table

pkg/converters/datatable/sub_basic_data_table.go

@@ -0,0 +1,87 @@
+package datatable
+
+// SubBasicDataTable defines the structure of sub basic data table
+type SubBasicDataTable struct {
+	baseTable BasicDataTable
+	fromIndex int
+	toIndex   int
+}
+
+// SubBasicDataTableRowIterator defines the structure of sub basic data table row iterator
+type SubBasicDataTableRowIterator struct {
+	dataTable     *SubBasicDataTable
+	innerIterator BasicDataTableRowIterator
+	currentIndex  int
+}
+
+// DataRowCount returns the total count of data row
+func (t *SubBasicDataTable) DataRowCount() int {
+	return t.toIndex - t.fromIndex
+}
+
+// HeaderColumnNames returns the header column name list
+func (t *SubBasicDataTable) HeaderColumnNames() []string {
+	return t.baseTable.HeaderColumnNames()
+}
+
+// DataRowIterator returns the iterator of data row
+func (t *SubBasicDataTable) DataRowIterator() BasicDataTableRowIterator {
+	innerIterator := t.baseTable.DataRowIterator()
+	currentIndex := -1
+
+	// skip rows until reaching the fromIndex
+	for currentIndex = -1; currentIndex < t.fromIndex-1 && innerIterator.HasNext(); currentIndex++ {
+		innerIterator.Next()
+	}
+
+	return &SubBasicDataTableRowIterator{
+		dataTable:     t,
+		innerIterator: innerIterator,
+		currentIndex:  currentIndex,
+	}
+}
+
+// HasNext returns whether the iterator does not reach the end
+func (t *SubBasicDataTableRowIterator) HasNext() bool {
+	return t.currentIndex+1 < t.dataTable.toIndex && t.innerIterator.HasNext()
+}
+
+// CurrentRowId returns current row id
+func (t *SubBasicDataTableRowIterator) CurrentRowId() string {
+	return t.innerIterator.CurrentRowId()
+}
+
+// Next returns the next basic data row
+func (t *SubBasicDataTableRowIterator) Next() BasicDataTableRow {
+	if t.currentIndex+1 >= t.dataTable.toIndex {
+		return nil
+	}
+
+	t.currentIndex++
+	return t.innerIterator.Next()
+}
+
+// CreateSubBasicTable returns a sub basic data table that references a portion of the original table
+func CreateSubBasicTable(dataTable BasicDataTable, fromIndex, toIndex int) *SubBasicDataTable {
+	if fromIndex < 0 {
+		fromIndex = 0
+	}
+
+	if fromIndex > dataTable.DataRowCount() {
+		fromIndex = dataTable.DataRowCount()
+	}
+
+	if toIndex > dataTable.DataRowCount() {
+		toIndex = dataTable.DataRowCount()
+	}
+
+	if toIndex < fromIndex {
+		toIndex = fromIndex
+	}
+
+	return &SubBasicDataTable{
+		baseTable: dataTable,
+		fromIndex: fromIndex,
+		toIndex:   toIndex,
+	}
+}