:mage_woman: GraphWiz

GraphWiz provides builders to generate and render graphs in the GraphViz DOT format. It is adapted from its Haskell equivalent.

It's a "wizard" for Graphviz's DOT format, hence the name "GraphWiz".

Overview

This library is centered around a simple trait: Builder. Each Builder is tied to a given "scope" of the graph: a RootBuilder is the scope of the top-level graph definition, while a SubgraphBuilder represents the scope of its associated subgraph or cluster. A builder provide functions to add new entities within its scope: nodes, edges, subgraphs, and clusters.

Each entity is given a unique internal identifier, which avoid naming issues within the graph. Furthermore, edges are "smart" and do "auto-compound": if an edge starts from or goes to a cluster, the graph is labelled as "compound", and the attributes of the edge are adjusted so that they point properly to the cluster.

Example

The test file example.rs contains the following:

let mut root = Graph::new_builder();
root.defaults_mut(Kind::Node).extend(HashMap::from([
    (attrs::FILLCOLOR, "lavender".to_string()),
    (attrs::STYLE, "filled".to_string()),
]));

let a = root.new_node("a");
let b = root.new_node("b");
let ab = root.new_edge(a, b);
root.attributes_mut(ab)
    .insert(attrs::STYLE, "dotted".to_string());

let mut cluster = root.new_cluster("box");
let c = cluster.new_node_with(
    "c",
    HashMap::from([
        (attrs::SHAPE, "circle".to_string()),
        (attrs::FILLCOLOR, "cornflowerblue".to_string()),
    ]),
);
cluster.build();

root.new_edge(c, a);
root.new_edge(c, b);
let graph = root.build();
let text = render_digraph(&graph);

This generates the following DOT graph.

digraph {
    node_1 [fillcolor="lavender", label="a", style="filled"]
    node_2 [fillcolor="lavender", label="b", style="filled"]
    node_1 -> node_2 [style="dotted"]
    node_5 -> node_1
    node_5 -> node_2
    subgraph cluster_4 {
        label="box"
        node_5 [fillcolor="cornflowerblue", label="c", shape="circle", style="filled"]
    }
}

Which DOT renders like this: