func read(path string) (*fsm.Adapter, *partition.Partition) {
// Read file and construct FSM
f, err := os.Open(path)
if err != nil {
panic(err)
}
a := fsm.NewAdapter(fsm.DotParser{})
a.Scan(bufio.NewScanner(f))
m := a.FSM()
states, inputs, outputs := m.States(), m.Inputs(), m.Outputs()
// Construct transition (f) and output (g) functions
fs := make([]func(int) int, 0, inputs)
gs := make([]func(int) int, 0, inputs)
for input := 0; input < inputs; input++ {
f, _ := m.TransitionFunction(input)
fs = append(fs, f)
g, _ := m.OutputFunction(input)
gs = append(gs, g)
}
// Construct the partition
p := partition.New(states, outputs, gs...)
p.Refine(0, fs...)
// Print results
var not string
if p.Size() != states {
not = "not "
}
fmt.Printf("FSM %s is %sminimal.\n", path, not)
return a, p
}
func main() {
if len(os.Args) != 3 {
fmt.Printf("Usage: %s <fsm1.dot> <fsm2.dot>\n", os.Args[0])
os.Exit(1)
}
a1, _ := read(os.Args[1])
a2, _ := read(os.Args[2])
// Add transitions of a2 to a1
for t := range a2.Transitions() {
from := "a2_" + t.From
input := t.Input
output := t.Output
to := "a2_" + t.To
if _, err := a1.Input(input); err != nil {
panic(err)
}
a1.AddState(from)
a1.AddState(to)
a1.AddOutput(output)
a1.AddTransition(from, input, output, to)
}
// Determine start states
start1 := "s0"
start2 := "a2_s0"
if _, err := a1.State(start2); err != nil {
panic(err)
}
// Make product FSM
product := a1.FSM()
states, inputs, outputs := product.States(), product.Inputs(), product.Outputs()
// Construct partition for product FSM
fs := make([]func(int) int, 0, inputs)
gs := make([]func(int) int, 0, inputs)
for input := 0; input < inputs; input++ {
f, _ := product.TransitionFunction(input)
fs = append(fs, f)
g, _ := product.OutputFunction(input)
gs = append(gs, g)
}
p := partition.New(states, outputs, gs...)
p.Refine(0, fs...)
// Print witness (minimal separating sequence) for start states
s, _ := a1.State(start1)
t, _ := a1.State(start2)
witness := p.Witness(s, t)
fmt.Println("A minimal separating sequence for the two start states is:")
for _, i := range witness {
input, _ := a1.InputName(i)
fmt.Print(input + " ")
}
fmt.Print("\n")
}