Represent array with indices using dot record nodes (Graphviz)

问题

I'm using Graphviz to represent arrays, using subgraphs and record nodes:

subgraph cluster_array
{
    label="my array"
    Array [shape="record", label="A | B | C | D"]
    Array
}

I would like to add external indices for each array elements, mapping 0 -> A, 1 -> B and so on.

I want to achieve a result similar to:

I've searched online and tried using xlabel but couldn't find a way to correctly add a label for each record element. I've also tried making the indices part of the label, and moving the label with lp, but it seems to have no effect on record nodes.

Is it possible to add external element labels to record nodes using GraphViz?

回答1:

Not a real answer to your question (which, I think, would be "no") but a workaround that may give you what you want. I use a "parallel" record node with no borders (or paper color borders, to be exact), located very close and connected by an invisible edge:

digraph so
{
    subgraph cluster0
    {
        rank = same{ Array notes }
        color = white;
        Array [ shape = record, label = "{ A | B | C | D }"] ;
        notes [ shape = record, color = white, label = "{ a_1 | b_2 | c_3 | d_4 }" ];
        Array -> notes[ style = invis ];
    }
    nodesep = .0;
    X -> Array -> Z;
}

which yields

来源：https://stackoverflow.com/questions/37969317/represent-array-with-indices-using-dot-record-nodes-graphviz