c# - Is it possible to inherit from a class which is recursively generated? -

i have class makes nested grouping. simplified form follows.

public class group {     public readonly object key;     public readonly ienumerable<group> groups;     public readonly ienumerable<datarow> drs;      public group(object key, ienumerable<datarow> source, list<string> columnlist)     {         key = key;          if (columnlist.count == 0)             drs = source;         else         {             string firstcolumn = columnlist.first();             list<string> restofcolumns = columnlist.skip(1).tolist();              groups = source.groupby(dr => dr[firstcolumn])                            .select(g => new group(g.key, g, restofcolumns));             }     } } 

this fine point. need more properties(and methods) class. @ same time don't want add properties class, break simplicity , of usages not interested these properties. reason try inherit class.

public class specialgroup:group {     public specialgroup(object key, ienumerable<datarow> source, list<string> columnlist)                               : base(key, source, columnlist)     {     }      public void dosomething()     {         //     } } 

but time specialgroup not being recursively generated(as expected). first main group specialgroup , nested groups group.

can i, way, inherit group , still have recursion new type?

(without usage of extension methods please, not differ writing methods in group class)

you change creation of group polymorphic. example:

public class group {     public readonly object key;     public readonly ienumerable<group> groups;     public readonly ienumerable<datarow> drs;      public group(object key, ienumerable<datarow> source, list<string> columnlist)     {         key = key;          if (columnlist.count == 0)             drs = source;         else         {             string firstcolumn = columnlist.first();             list<string> restofcolumns = columnlist.skip(1).tolist();              groups = source.groupby(dr => dr[firstcolumn])                            .select(g => creategroup(g.key, g, restofcolumns));             }     }      protected virtual group creategroup(object key, ienumerable<datarow> source, list<string> columnlist)     {         return new group(key, source, columnlist)     } } 

and in specialgroup override return specialgroup.

public class specialgroup:group {     public specialgroup(object key, ienumerable<datarow> source, list<string> columnlist)                               : base(key, source, columnlist)     {     }      public void dosomething()     {         //     }      protected override group creategroup(object key, ienumerable<datarow> source, list<string> columnlist)     {         return new specialgroup(key, source, columnlist)     } } 

this way, if root group of type specialgroup children of type specialgroup, otherwise group.