...not just objects from C-code, but nodes in a connected graph.

I haven't...

...Oh for sure. Generalizing the relationships that nodes have would be pretty difficult. Trees need...

...an optimization entry that says how many nodes you should move up or down when...

...you encapsulate it and only allow accessing nodes through `return scope` member functions, then you...

...child nodes
      if (lintResult != 0 && rhs ! is null) { lintResult = rhs.opApply(dg); } /// recursing child nodes...

...child nodes
      if (lintResult != 0 && rhs ! is null) { lintResult = rhs.opApply(dg); } /// recursing child nodes...

...std.sumtype;

struct Choice { Node[] nodes; }
struct Seq { Node[] nodes; }
alias Node = SumType!(
    Choice,
    Seq...

...child nodes
      if (lintResult != 0 && rhs ! is null) { lintResult = rhs.opApply(dg); } /// recursing child nodes...

...child nodes
      if (lintResult != 0 && rhs ! is null) { lintResult = rhs.opApply(dg); } /// recursing child nodes...

...recursing child nodes
      if (lintResult != 0 && rhs) { lintResult = rhs.opApply(dg); } /// recursing child nodes

      return...