func main() {
// get command line options
nways := 1
if len(os.Args) == 3 {
nways, _ = strconv.Atoi(os.Args[2])
}
if len(os.Args) < 2 || len(os.Args) > 3 || nways < 1 {
log.Fatal("usage: rxtime exprfile [n]")
}
filename := os.Args[1]
// load expressions from file
exprs := rx.LoadExpressions(filename, nil)
nexprs := len(exprs)
if nways < 1 || nways > nexprs {
log.Fatal(fmt.Sprintf(
"cannot combine %d expressions(s) in %d way(s)",
nexprs, nways))
}
// record individual complexity scores and make augmented parse trees
cx := make([]int, nexprs)
for i, t := range exprs {
cx[i] = rx.ComplexityScore(t.Tree)
t.Tree = rx.Augment(t.Tree, i)
}
// initialize index list for first combination {0,1,2...}
xlist := make([]int, nways)
for i := range xlist {
xlist[i] = i
}
// try all possible n-way combinations by varying the index list
tlist := make([]rx.Node, nways)
for xlist != nil {
for i, x := range xlist {
tlist[i] = exprs[x].Tree
}
_ = rxsys.Interval() // reset timer
dfa1 := rx.MultiDFA(tlist) // make DFA
t1 := rxsys.Interval().Seconds() // measure time
dfa2 := dfa1.Minimize() // minimize DFA
t2 := rxsys.Interval().Seconds() // measure time
fmt.Printf("%6d %6d %8.3f %8.3f",
len(dfa1.Dstates), len(dfa2.Dstates), t1, t2)
if nways == 1 {
fmt.Printf(" %6d", cx[xlist[0]])
}
fmt.Print(" {")
for _, x := range xlist {
fmt.Printf(" %d", x)
}
fmt.Print(" }\n")
xlist = advance(xlist, nexprs) // get next combination
}
}
// setup performs global initialization actions
func setup() {
rxsys.Interval() // initialize timestamps
options() // process command-line options
if verbose {
showopts() // show command options
}
// handle -P (profiling) option
pfname := *val['P'] // profiling filename
if pfname != "" { // if set
pfile, err := os.Create(pfname)
rx.CkErr(err)
pprof.StartCPUProfile(pfile)
}
// set up input scanning
if *val['e'] != "" { // if -e specified
if len(flag.Args()) > 0 {
log.Fatal("-e option precludes reading " + flag.Arg(0))
}
input = bufio.NewScanner(bytes.NewReader([]byte(*val['e'])))
} else {
input = rx.MkScanner(rx.OneInputFile())
}
timestamp("init")
}
// showDFA performs common actions for individual and merged DFAs
// it returns the ultimate (original or minimized) dfa
func showDFA(dfa *rx.DFA, treelabel string, showtime bool) *rx.DFA {
if *opt['p'] {
dfa.ShowTree(os.Stdout, dfa.Tree, treelabel)
}
if *opt['n'] {
dfa.ShowNFA(os.Stdout, "NFA")
}
if *opt['d'] {
dfa.ShowStates(os.Stdout, "Unoptimized DFA")
}
if !*opt['u'] {
if showtime {
rxsys.Interval() // reset for timing
}
dfa = dfa.Minimize()
if showtime {
timestamp(fmt.Sprintf(
"minimize to %d states", len(dfa.Dstates)))
}
if *opt['d'] {
dfa.ShowStates(os.Stdout, "Minimized DFA")
}
}
if *opt['h'] {
synthx(dfa)
}
return dfa
}