/// <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)
{
bool isSrc;
int index = _parent.MapColumnIndex(out isSrc, column.Index);
if (isSrc)
{
return(Input.GetGetter <TValue>(Input.Schema[index]));
}
Contracts.Assert(_getters[index] != null);
var fn = _getters[index] as ValueGetter <TValue>;
if (fn == null)
{
throw Contracts.Except("Invalid TValue in GetGetter: '{0}'", typeof(TValue));
}
return(fn);
}
/// <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)
{
bool isSrc;
int index = _parent.MapColumnIndex(out isSrc, column.Index);
if (isSrc)
{
return(Input.GetGetter <TValue>(Input.Schema[index]));
}
var originFn = _getters[index];
Contracts.Assert(originFn != null);
var fn = originFn as ValueGetter <TValue>;
if (fn == null)
{
throw Contracts.Except($"Invalid TValue in GetGetter: '{typeof(TValue)}', " +
$"expected type: '{originFn.GetType().GetGenericArguments().First()}'.");
}
return(fn);
}
