fmesh-graphviz

README

fmesh-graphviz

Export your FMesh as DOT-graph

This module currently supports a single export format: DOT, the graph description language used by Graphviz for visualizing structured data. If needed, you can easily add your own export format by implementing the Exporter interface:

// Exporter is the common interface for all formats
type Exporter interface {
	// Export returns the F-Mesh structure in some format
	Export(fm *fmesh.FMesh) ([]byte, error)

	// ExportWithCycles returns the F-Mesh state for each activation cycle
	ExportWithCycles(fm *fmesh.FMesh, activationCycles cycle.Cycles) ([][]byte, error)
}

This interface is straightforward: you receive the mesh and return its representation. The Export method represents the static structure of the mesh, while ExportWithCycles provides a dynamic view, showing the state of the mesh at each activation cycle—useful for debugging and visualizing the execution process.

Check out the dot package documentation for more details.

Using an Exporter

Let’s demonstrate how to export a mesh using the DOT Exporter. We'll use this example for demonstration:

import "github.com/hovsep/fmesh-graphviz/dot"

// Create fm
// ...
exporter := dot.NewDotExporter()
data, err := exporter.Export(fm)
if err != nil {
	panic("failed to export mesh")
}
	
os.WriteFile("graph.dot",data, 0755)

If everything is successful, the graph.dot file will contain the DOT representation:

digraph  {
	layout="dot";splines="ortho";
	
	subgraph cluster_7 {
		cluster="true";color="black";label="d5";margin="20";penwidth="5";style="rounded";
...

You can now visualize the mesh using tools like Edotor.net or render it with Graphviz:

cat graph.dot  | dot -Tpng > graph.png

[!TIP] You can customize every aspect of the graph's rendering by using NewDotExporterWithConfig

Graphviz supports various output formats such as PNG, SVG, and PDF. See the full list of supported formats here.

Exporting Mesh with Cycles

To export a mesh along with its activation cycles, pass the cycle data to the exporter and save each cycle separately:

runResult, err := fm.Run()
exporter := dot.NewDotExporter()
data, err := exporter.ExportWithCycles(fm, runResult.Cycles.CyclesOrNil())
if err != nil {
	panic("failed to export mesh")
}

for cycleNumber, cycleGraph := range data {
   os.WriteFile(fmt.Sprintf("cycle-%d.dot", cycleNumber),cycleGraph, 0755)
}

This code creates a separate .dot file for each cycle (e.g., cycle-0.dot, cycle-1.dot). You can use these files to create an animation of your program's execution, such as a GIF:

[!NOTE]

• On Cycle-3, the layout changes because the sum component is waiting for inputs.
• In the final cycle, no components are executed, and the mesh finishes naturally.