progs/re4.scala
changeset 441 028816884f70
parent 425 d14a9bdac26f
child 455 1dbf84ade62c
equal deleted inserted replaced
440:e14cd32ad497 441:028816884f70
    27   case CHAR(d) => if (c == d) ONE else ZERO
    27   case CHAR(d) => if (c == d) ONE else ZERO
    28   case ALT(r1, r2) => ALT(der(c, r1), der(c, r2))
    28   case ALT(r1, r2) => ALT(der(c, r1), der(c, r2))
    29   case SEQ(r1, r2) => 
    29   case SEQ(r1, r2) => 
    30     if (nullable(r1)) ALT(SEQ(der(c, r1), r2), der(c, r2))
    30     if (nullable(r1)) ALT(SEQ(der(c, r1), r2), der(c, r2))
    31     else SEQ(der(c, r1), r2)
    31     else SEQ(der(c, r1), r2)
    32   case STAR(r) => SEQ(der(c, r), STAR(r))
    32   case STAR(r1) => SEQ(der(c, r1), STAR(r1))
    33   case NTIMES(r, i) => 
    33   case NTIMES(r, i) => 
    34     if (i == 0) ZERO else SEQ(der(c, r), NTIMES(r, i - 1))
    34     if (i == 0) ZERO else SEQ(der(c, r), NTIMES(r, i - 1))
    35 }
    35 }
    36 
    36 
    37 def simp(r: Rexp) : Rexp = r match {
    37 def simp(r: Rexp) : Rexp = r match {
    72 
    72 
    73 //one or zero
    73 //one or zero
    74 def OPT(r: Rexp) = ALT(r, ONE)
    74 def OPT(r: Rexp) = ALT(r, ONE)
    75 
    75 
    76 def EVIL1(n: Int) = SEQ(NTIMES(OPT(CHAR('a')), n), NTIMES(CHAR('a'), n))
    76 def EVIL1(n: Int) = SEQ(NTIMES(OPT(CHAR('a')), n), NTIMES(CHAR('a'), n))
    77 val EVIL2 = SEQ(STAR(CHAR('a')), CHAR('b'))
    77 val EVIL2 = SEQ(STAR(STAR(CHAR('a'))), CHAR('b'))
    78 
    78 
    79 
    79 
    80 def time_needed[T](i: Int, code: => T) = {
    80 def time_needed[T](i: Int, code: => T) = {
    81   val start = System.nanoTime()
    81   val start = System.nanoTime()
    82   for (j <- 1 to i) code
    82   for (j <- 1 to i) code
    83   val end = System.nanoTime()
    83   val end = System.nanoTime()
    84   (end - start)/(i * 1.0e9)
    84   (end - start)/(i * 1.0e9)
    85 }
    85 }
    86 
    86 
    87 // warmup
    87 // warmup
    88 val i = 5000
    88 //test: (a?{n}) (a{n})
    89 println(i + " " + "%.5f".format(time_needed(10, matcher(EVIL1(i), "a" * i))))
    89 for (i <- 1 to 7000001 by 500000) {
    90 
       
    91 for (i <- 1 to 7000001 by 1000000) {
       
    92   println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL1(i), "a" * i))))
    90   println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL1(i), "a" * i))))
    93 }
    91 }
    94 
    92 
    95 for (i <- 1 to 7500001 by 500000) {
    93 for (i <- 1 to 7000001 by 500000) {
       
    94   println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL1(i), "a" * i))))
       
    95 }
       
    96 
       
    97 //test: (a*)* b
       
    98 for (i <- 1 to 7000001 by 500000) {
    96   println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL2, "a" * i))))
    99   println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL2, "a" * i))))
    97 }
   100 }
    98 
   101 
       
   102 for (i <- 1 to 7000001 by 500000) {
       
   103   println(i + " " + "%.5f".format(time_needed(2, matcher(EVIL2, "a" * i))))
       
   104 }
       
   105 
       
   106 
       
   107