func main() {
app := cli.NewApp()
app.Action = func(ctx *cli.Context) {
prog := ctx.GlobalString("prog")
if prog == "" {
log.Fatal(
error_.New("--prog (or -p) required!"),
)
}
file, err := os.Open(prog)
if err != nil {
log.Fatal(err)
}
jsonDec := json.NewDecoder(file)
var machineDesc machine.MachineDesc
err = jsonDec.Decode(&machineDesc)
if err != nil {
log.Fatal(err)
}
machine, err := machine.NewMachine(&machineDesc)
if err != nil {
log.Fatal(err)
}
machine.Run()
}
app.Flags = []cli.Flag{
cli.StringFlag{
"prog,p",
"",
"Path to the turing machine \"program\" to run.",
},
}
app.Name = "turing-machine"
app.Usage = "Turing machinez tho."
app.Version = "0.0.1"
err := app.Run(os.Args)
if err != nil {
log.Fatal(err)
}
}
func NewMachine(machineDesc *MachineDesc) (*Machine, error) {
alphabet := make(map[Sym]bool)
for i := range machineDesc.Alphabet {
alphabet[machineDesc.Alphabet[i]] = true
}
states := make(map[State]bool)
for i := range machineDesc.States {
states[machineDesc.States[i]] = true
}
states[StateValHalt] = true
for i := range machineDesc.InputSyms {
if !alphabet[machineDesc.InputSyms[i]] {
return nil, error_.New(
fmt.Sprintf("<machine> Input symbol \"%s\" isn't in the alphabet!", machineDesc.InputSyms[i]),
)
}
}
machine := Machine{
conf: &Conf{
currState: machineDesc.InitState,
currTapePos: uint(0),
},
tape: NewTape(machineDesc.InputSyms),
transMap: make(map[MachineTransMapKey]MachineTransMapVal),
}
for i := range machineDesc.TransMap {
if !states[machineDesc.TransMap[i].Map.State] {
return nil, error_.New(
fmt.Sprintf("<machine> Transition map output state \"%s\" isn't in the set of finite states!", machineDesc.TransMap[i].Map.State),
)
}
if !alphabet[machineDesc.TransMap[i].Map.Sym] {
return nil, error_.New(
fmt.Sprintf("<machine> Transition map output symbol \"%s\" isn't in the alphabet!", machineDesc.TransMap[i].Map.Sym),
)
}
if !states[machineDesc.TransMap[i].State] {
return nil, error_.New(
fmt.Sprintf("<machine> Transition map input state \"%s\" isn't in the set of finite states!", machineDesc.TransMap[i].State),
)
}
if !alphabet[machineDesc.TransMap[i].Sym] {
return nil, error_.New(
fmt.Sprintf("<machine> Transition map input symbol \"%s\" isn't in the alphabet!", machineDesc.TransMap[i].Sym),
)
}
switch machineDesc.TransMap[i].Map.Dir {
case DirMovLeft, DirMovRight, DirStay:
break
default:
return nil, error_.New(
fmt.Sprintf("<machine> \"%s\" isn't a valid direction!", machineDesc.TransMap[i].Map.Dir),
)
}
machine.transMap[MachineTransMapKey{
state: machineDesc.TransMap[i].State,
sym: machineDesc.TransMap[i].Sym,
}] = MachineTransMapVal{
dir: machineDesc.TransMap[i].Map.Dir,
state: machineDesc.TransMap[i].Map.State,
sym: machineDesc.TransMap[i].Map.Sym,
}
}
return &machine, nil
}