public Func <int, bool> GetDependencies(Func <int, bool> predicate)
{
Contracts.AssertValue(predicate);
var active = new bool[Input.Count];
for (int col = 0; col < ColumnCount; col++)
{
if (!predicate(col))
{
continue;
}
bool isSrc;
int index = MapColumnIndex(out isSrc, col);
if (isSrc)
{
active[index] = true;
}
else
{
_parent.ActivateSourceColumns(index, active);
}
}
return(col => 0 <= col && col < active.Length && active[col]);
}
/// <summary>
/// Given a set of columns, return the input columns that are needed to generate those output columns.
/// </summary>
public IEnumerable <DataViewSchema.Column> GetDependencies(IEnumerable <DataViewSchema.Column> columns)
{
Contracts.AssertValue(columns);
var active = new bool[Input.Count];
foreach (var col in columns)
{
bool isSrc;
int index = MapColumnIndex(out isSrc, col.Index);
if (isSrc)
{
active[index] = true;
}
else
{
_parent.ActivateSourceColumns(index, active);
}
}
return(Input.Where(col => col.Index < active.Length && active[col.Index]));
}