10 override def simp = (r1.simp, r2.simp) match { |
11 override def simp = (r1.simp, r2.simp) match { |
11 case (NULL, r) => r |
12 case (NULL, r) => r |
12 case (r, NULL) => r |
13 case (r, NULL) => r |
13 case (r, EMPTY) => if (nullable(r)) r else ALT(r, EMPTY) |
14 case (r, EMPTY) => if (nullable(r)) r else ALT(r, EMPTY) |
14 case (EMPTY, r) => if (nullable(r)) r else ALT(r, EMPTY) |
15 case (EMPTY, r) => if (nullable(r)) r else ALT(r, EMPTY) |
15 case (r1, r2) => ALT(r1, r2) |
16 case (r1, r2) => if (r1 == r2) r1 else ALT(r1, r2) |
16 } |
17 } |
17 } |
18 } |
18 case class SEQ(r1: Rexp, r2: Rexp) extends Rexp { |
19 case class SEQ(r1: Rexp, r2: Rexp) extends Rexp { |
19 override def simp = (r1.simp, r2.simp) match { |
20 override def simp = (r1.simp, r2.simp) match { |
20 case (NULL, _) => NULL |
21 case (NULL, _) => NULL |
22 case (EMPTY, r) => r |
23 case (EMPTY, r) => r |
23 case (r, EMPTY) => r |
24 case (r, EMPTY) => r |
24 case (r1, r2) => SEQ(r1, r2) |
25 case (r1, r2) => SEQ(r1, r2) |
25 } |
26 } |
26 } |
27 } |
27 case class STAR(r: Rexp) extends Rexp |
28 case class STAR(r: Rexp) extends Rexp { |
28 case class NTIMES(r: Rexp, n: Int) extends Rexp |
29 override def simp = r.simp match { |
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30 case NULL => EMPTY |
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31 case EMPTY => EMPTY |
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32 case r => STAR(r) |
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33 } |
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34 } |
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35 case class NTIMES(r: Rexp, n: Int) extends Rexp { |
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36 override def simp = if (n == 0) EMPTY else |
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37 r.simp match { |
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38 case NULL => NULL |
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39 case EMPTY => EMPTY |
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40 case r => NTIMES(r, n) |
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41 } |
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42 } |
29 |
43 |
30 // some convenience for typing in regular expressions |
44 // some convenience for typing in regular expressions |
31 def charlist2rexp(s : List[Char]) : Rexp = s match { |
45 def charlist2rexp(s : List[Char]) : Rexp = s match { |
32 case Nil => EMPTY |
46 case Nil => EMPTY |
33 case c::Nil => CHAR(c) |
47 case c::Nil => CHAR(c) |
43 case EMPTY => true |
57 case EMPTY => true |
44 case CHAR(_) => false |
58 case CHAR(_) => false |
45 case ALT(r1, r2) => nullable(r1) || nullable(r2) |
59 case ALT(r1, r2) => nullable(r1) || nullable(r2) |
46 case SEQ(r1, r2) => nullable(r1) && nullable(r2) |
60 case SEQ(r1, r2) => nullable(r1) && nullable(r2) |
47 case STAR(_) => true |
61 case STAR(_) => true |
48 case NTIMES(r, i) => if (i == 0) false else nullable(r) |
62 case NTIMES(r, i) => if (i == 0) true else nullable(r) |
49 } |
63 } |
50 |
64 |
51 // derivative of a regular expression w.r.t. a character |
65 // derivative of a regular expression w.r.t. a character |
52 def der (c: Char, r: Rexp) : Rexp = r match { |
66 def der (c: Char, r: Rexp) : Rexp = r match { |
53 case NULL => NULL |
67 case NULL => NULL |
71 |
85 |
72 // main matcher function |
86 // main matcher function |
73 def matcher(r: Rexp, s: String) : Boolean = nullable(ders(s.toList, r)) |
87 def matcher(r: Rexp, s: String) : Boolean = nullable(ders(s.toList, r)) |
74 |
88 |
75 |
89 |
76 |
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77 //one or zero |
90 //one or zero |
78 def OPT(r: Rexp) = ALT(r, EMPTY) |
91 def OPT(r: Rexp) = ALT(r, EMPTY) |
79 |
92 |
80 //n-times |
93 def EVIL(n: Int) = SEQ(NTIMES(OPT("a"), n), NTIMES("a", n)) |
81 /*def NTIMES(r: Rexp, n: Int) : Rexp = n match { |
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82 case 0 => NULL |
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83 case 1 => r |
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84 case n => SEQ(r, NTIMES(r, n - 1)) |
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85 }*/ |
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86 |
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87 def RTEST(n: Int) = SEQ(NTIMES(OPT("a"), n), NTIMES("a", n)) |
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88 |
94 |
89 def time_needed[T](i: Int, code: => T) = { |
95 def time_needed[T](i: Int, code: => T) = { |
90 val start = System.nanoTime() |
96 val start = System.nanoTime() |
91 for (j <- 1 to i) code |
97 for (j <- 1 to i) code |
92 val end = System.nanoTime() |
98 val end = System.nanoTime() |
93 (end - start)/(i * 1.0e9) |
99 (end - start)/(i * 1.0e9) |
94 } |
100 } |
95 |
101 |
96 |
102 |
97 for (i <- 1 to 13001 by 500) { |
103 for (i <- 1 to 12001 by 500) { |
98 println(i + " " + time_needed(1, matcher(RTEST(i), "a" * i))) |
104 println(i + " " + "%.5f".format(time_needed(1, matcher(EVIL(i), "a" * i)))) |
99 } |
105 } |
100 |
106 |
101 |
107 |