Re: YAML declarativeness

Interesting... but it I don't get it.
It seems to me YAML can be used to serialize any cyclical structure,
including the one you described:

On Wed, 2010-02-10 at 01:00 -0500, Devin Jeanpierre wrote:
> It is true for an undirected graph. It is not true for a directed
> graph, unless the trees are allowed to not span as much of the graph
> as they can. Supposing we want spanning trees, the following graph
> works against us:
> 
> a->b->d;a->c->d
> 
> Our hand is forced in producing the first part of the spanning tree,
> a->b; a->c . Either b or c can get d as a child, but at that point we
> are forced to produce a cross edge that does not point to an ancestor,
> but to the sibling's child.

That's the part I don't get. You emit a->b first, then a->c second. Ok.
You can now emit, say, b->d, and give an anchor to d. Now emit c->d, but
use a reference to that anchor. What am I missing?

You could also present it directly as a graph:

  a:
    data: ...
    children:
      b:
        data: ...
        children:
          d: &d
            data: ...
            children: {}
      c:
        data: ...
        children:
          d: *d

Or maybe (if you want to avoid repeating the name):

  name: a
  data : ...
  children:
    ? name: b
      data: ...
      children: &d
        ? name: d
          data: ...
          children: {}
    ? name: c
      data: ...
      children:
        ? *d

Or something along these lines.

Have fun,

    Oren Ben-Kiki



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