// construct a type from a base name, optional heading and optional user type name
public static DataType Derive(DataType basetype, DataHeading heading, string username)
{
if (basetype == DataTypes.Table)
{
return(DataTypeRelation.Get(heading));
}
if (basetype == DataTypes.Row)
{
return(DataTypeTuple.Get(heading));
}
if (basetype == DataTypes.User)
{
return(DataTypeUser.Get(username, heading.Columns));
}
return(basetype);
}
static DateValue()
{
// FIX: better to have a lookup for this
StaticDatatype = DataTypeUser.Get("date", new DataColumn[] { DataColumn.Create("super", DataTypes.Time) });
DataTypes.TypeDict[typeof(DateValue)] = StaticDatatype;
}
