dot

ExampleWrite renders a single directed, weighted edge as Graphviz DOT. The output is a digraph whose body lists "src -> dst" with the weight as the edge label; pipe it through `dot -Tsvg` to visualise.

package main

import (
	"bytes"
	"fmt"

	"github.com/FlavioCFOliveira/GoGraph/graph/adjlist"
	"github.com/FlavioCFOliveira/GoGraph/graph/io/dot"
)

func main() {
	g := adjlist.New[string, int64](adjlist.Config{Directed: true})
	_ = g.AddEdge("a", "b", 5)

	var buf bytes.Buffer
	if err := dot.Write(&buf, g); err != nil {
		panic(err)
	}
	fmt.Print(buf.String())
}

Output:
digraph G {
  a -> b [label="5"];
}

ExampleWrite_multiEdge renders a small directed graph. The DOT writer emits one line per edge in an internal NodeID order, so the example sorts the body lines before printing to keep the output stable.

package main

import (
	"bytes"
	"fmt"
	"sort"
	"strings"

	"github.com/FlavioCFOliveira/GoGraph/graph/adjlist"
	"github.com/FlavioCFOliveira/GoGraph/graph/io/dot"
)

func main() {
	g := adjlist.New[string, int64](adjlist.Config{Directed: true})
	_ = g.AddEdge("a", "b", 1)
	_ = g.AddEdge("b", "c", 2)

	var buf bytes.Buffer
	if err := dot.Write(&buf, g); err != nil {
		panic(err)
	}

	// Collect just the indented edge lines and sort them for a
	// deterministic, layout-independent rendering.
	var edges []string
	for _, line := range strings.Split(buf.String(), "\n") {
		if strings.HasPrefix(line, "  ") {
			edges = append(edges, strings.TrimSpace(line))
		}
	}
	sort.Strings(edges)
	for _, e := range edges {
		fmt.Println(e)
	}
}

Output:
a -> b [label="1"];
b -> c [label="2"];