public RestrictNode(RelNode source, CommonHeading nodeheading, RelFuncBase func)
{
_source = source;
_restheading = nodeheading;
_restfunc = func;
Heading = _source.Heading;
_restmap = _restheading.CreateMap(Heading);
if (_restmap.Any(x => x < 0))
{
throw Error.Fatal("Restrict", "heading has unknown attribute");
}
}
public AggregateNode(RelNode source, CommonHeading nodeheading, RelFuncBase func, object initial = null)
{
_source = source;
_heading = nodeheading;
_func = func;
_initial = initial;
Heading = _source.Heading.Rename(_heading[0], _heading[1]);
_vmap = _heading.CreateMap(_source.Heading);
_jhead = _source.Heading.Minus(_heading);
_jmap1 = _jhead.CreateMap(_source.Heading);
_jmap2 = Heading.CreateMap(_jhead);
if (!(_heading.Degree == 2 && _jmap2.Length == Heading.Degree))
{
throw Error.Fatal("Aggregate", "heading is not valid");
}
}
public ExtendNode(RelNode source, CommonHeading nodeheading, RelFuncBase func)
{
_source = source;
_nodeheading = nodeheading;
_func = func;
Heading = CommonHeading.Create(_source.Heading.Fields.Union(_nodeheading.Fields));
// get the argument fields
_argheading = CommonHeading.Create(_nodeheading.Fields.Take(_nodeheading.Fields.Length - 1));
_argmap = _argheading.CreateMap(_source.Heading);
// last field can extend or replace, remove name but retain place
var outh = Heading.Rename(_nodeheading.Fields.Last(), CommonField.Empty);
_outmap = Heading.CreateMap(outh);
if (_argmap.Any(x => x < 0))
{
throw Error.Fatal("Extend", "heading has unknown attribute");
}
if (_outmap.Count(x => x < 0) != 1)
{
throw Error.Fatal("Extend", "invalid heading, invalid new attribute"); // any use?
}
}
public RelNode Aggregate(string nodeheading, RelFuncBase func)
{
return(new AggregateNode(this, this.Heading.Adapt(nodeheading), func));
}
public RelNode Extend(string nodeheading, RelFuncBase func)
{
return(new ExtendNode(this, this.Heading.Adapt(nodeheading), func));
}
public RelNode Restrict(string nodeheading, RelFuncBase func)
{
return(new RestrictNode(this, this.Heading.Adapt(nodeheading), func));
}
