Function from_ascii

pub fn from_ascii<G>(text: &str) -> Result<Data<G>, Error>
where
    G: IndexGraph + Buildable,

Create a graph from ASCII art drawing with edge weights.

Parses an ASCII-art drawing and generates the corresponding graph. Node are * or letters (except for v which is used to draw directed edges), edges are sequences of -, |, / and \ characters. Edges may cross as in the example below.

Weights are non-negative numbers along the edges. Edges without explicit weight receive the weight 0. The edge weights are returned in a vector in the order of creation (although the order is undefined – usually this corresponds to g.edge_id).

use rs_graph::traits::*;
use rs_graph::linkedlistgraph::LinkedListGraph;
use rs_graph::string::{Data, from_ascii};

let Data{ graph: g, weights, nodes } = from_ascii::<LinkedListGraph>(r"
      a  b
      |  |
  ----|-----
 /   223 |  \
|     | /    |
|   --|-     |
 \ /  |     /
  -   *-10--").unwrap();

assert_eq!(g.neighs(g.id2node(nodes[&'a'])).map(|(e,_)| weights[g.edge_id(e)]).collect::<Vec<_>>(), vec![223]);
assert_eq!(g.neighs(g.id2node(nodes[&'b'])).map(|(e,_)| weights[g.edge_id(e)]).collect::<Vec<_>>(), vec![10]);

Usually edges are undirected. Directed edges can be inserted by ending an edge in one of the characters <, >, ^, v or @ (where the @ can be used in place of any of the other head characters; for diagonal directed connections it is the only alternative).

use rs_graph::traits::*;
use rs_graph::linkedlistgraph::LinkedListGraph;
use rs_graph::string::{Data, from_ascii};

let Data { graph: g, nodes, .. } = from_ascii::<LinkedListGraph>(r"
   *  *  *
    \ | /
     @v@
   *->a<-*
     @^@
    / | \
   *  *  *").unwrap();
let a = g.id2node(nodes[&'a']);

assert_eq!(g.num_nodes(), 9);
assert_eq!(g.num_edges(), 8);
for u in g.nodes() {
    if u == a {
        assert_eq!(g.inedges(u).count(), 8);
        assert_eq!(g.outedges(u).count(), 0);
    } else {
        assert_eq!(g.inedges(u).count(), 0);
        assert_eq!(g.outedges(u).count(), 1);
    }
}

Nodes are created (and thus numbered) row-wise. Nodes that have a character label can be access through the nodes field of the returned data. The order of the edges is undefined.

Note: this function is meant to be used in test cases, it should not be used in production code.