/// <summary>
/// Returns a value getter delegate to fetch the value of column with the given columnIndex, from the row.
/// This throws if the column is not active in this row, or if the type
/// <typeparamref name="TValue"/> differs from this column's type.
/// </summary>
/// <typeparam name="TValue"> is the column's content type.</typeparam>
/// <param name="column"> is the output column whose getter should be returned.</param>
public override ValueGetter <TValue> GetGetter <TValue>(DataViewSchema.Column column)
{
Ch.CheckParam(IsColumnActive(column), nameof(column), "requested column not active");
var getter = _getters[_colToActivesIndex[column.Index]] as ValueGetter <TValue>;
if (getter == null)
{
throw Ch.Except("Invalid TValue: '{0}'", typeof(TValue));
}
return(getter);
}
/// <summary>
/// Returns whether the given column is active in this row.
/// </summary>
public override bool IsColumnActive(DataViewSchema.Column column)
{
Ch.CheckParam(column.Index < _colToActivesIndex.Length, nameof(column));
return(_colToActivesIndex[column.Index] >= 0);
}
