1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/**
* Copyright (c) 2001, Sergey A. Samokhodkin
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form
* must reproduce the above copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of jregex nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @version 1.2_01
*/
package jregex;
import java.util.*;
public class Optimizer{
public static final int THRESHOLD=20;
static Optimizer find(Term entry){
return find(entry,0);
}
private static Optimizer find(Term term,int dist){
//System.out.println("term="+term+", dist="+dist);
if(term==null) return null;
Term next=term.next;
int type=term.type;
switch(type){
case Term.CHAR:
case Term.REG:
case Term.REG_I:
return new Optimizer(term,dist);
case Term.BITSET:
case Term.BITSET2:
if(term.weight<=THRESHOLD) return new Optimizer(term,dist);
else return find(term.next,dist+1);
case Term.ANY_CHAR:
case Term.ANY_CHAR_NE:
return find(next,dist+1);
case Term.REPEAT_MIN_INF:
case Term.REPEAT_MIN_MAX:
if(term.minCount>0){
return find(term.target,dist);
}
else return null;
}
if(type>=Term.FIRST_TRANSPARENT && type<=Term.LAST_TRANSPARENT){
return find(next,dist);
}
return null;
}
private Term atom;
private int distance;
private Optimizer(Term atom,int distance){
this.atom=atom;
this.distance=distance;
}
Term makeFirst(Term theFirst){
return new Find(atom,distance,theFirst);
}
Term makeBacktrack(Term back){
int min=back.minCount;
switch(back.type){
case Term.BACKTRACK_0:
min=0;
case Term.BACKTRACK_MIN:
return new FindBack(atom,distance,min,back);
case Term.BACKTRACK_REG_MIN:
return back;
default:
throw new Error("unexpected iterator's backtracker:"+ back);
//return back;
}
}
}
class Find extends Term{
Find(Term target, int distance, Term theFirst){
switch(target.type){
case Term.CHAR:
case Term.BITSET:
case Term.BITSET2:
type=Term.FIND;
break;
case Term.REG:
case Term.REG_I:
type=Term.FINDREG;
break;
default:
throw new IllegalArgumentException("wrong target type: "+target.type);
}
this.target=target;
this.distance=distance;
if(target==theFirst){
next=target.next;
eat=true; //eat the next
}
else{
next=theFirst;
eat=false;
}
}
}
class FindBack extends Term{
FindBack(Term target, int distance, int minCount, Term backtrack){
this.minCount=minCount;
switch(target.type){
case Term.CHAR:
case Term.BITSET:
case Term.BITSET2:
type=Term.BACKTRACK_FIND_MIN;
break;
case Term.REG:
case Term.REG_I:
type=Term.BACKTRACK_FINDREG_MIN;
break;
default:
throw new IllegalArgumentException("wrong target type: "+target.type);
}
this.target=target;
this.distance=distance;
Term next=backtrack.next;
if(target==next){
this.next=next.next;
this.eat=true;
}
else{
this.next=next;
this.eat=false;
}
}
}
|
