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1 package ro.infoiasi.donald.compiler.parser;
2
3 import ro.infoiasi.donald.compiler.cfg.*;
4 import ro.infoiasi.donald.compiler.simple.*;
5 import java.util.*;
6
7 public class SymbolRelation {
9 public interface SymbolPair {
10 Symbol getFirst();
11 Symbol getSecond();
12 }
13
14 private CFG g;
15 private Relation r;
16
17 private class SymbolPairP implements SymbolPair {
18 private Symbol first;
19 private Symbol second;
20 public SymbolPairP(Symbol first, Symbol second) {
21 this.first = first;
22 this.second = second;
23 }
24 public SymbolPairP(Relation.IntPair ip) {
25 this.first = g.symbol(ip.getFirst());
26 this.second = g.symbol(ip.getSecond());
27
28 }
29 public Symbol getFirst() {
30 return first;
31 }
32
33 public Symbol getSecond() {
34 return second;
35 }
36 public String  toString() {
37 return "("+first+","+second+")";
38 }
39 }
40
41 SymbolRelation(CFG g) {
42 this.g = g;
43 r = new Relation(g.getNonTerminals().count()+g.getTerminals().count());
44 }
45
46 private SymbolRelation(CFG g, Relation r) {
47 this.g = g;
48 this.r = r;
49 }
50
51 public boolean contains(Symbol x, Symbol y) {
52 return r.contains(g.getSID(x), g.getSID(y));
53 }
54
55 public boolean add(Symbol x, Symbol y) {
56 return r.add(g.getSID(x), g.getSID(y));
57 }
58
59 public SymbolRelation inverse() {
60 return new SymbolRelation(g, r.inverse());
61 }
62
63 public SymbolRelation plus() {
64 return new SymbolRelation(g, r.transitiveClosure());
65 }
66
67 public SymbolRelation star() {
68 return new SymbolRelation(g, r.reflexiveTransitiveClosure());
69 }
70
71 public SymbolRelation product(SymbolRelation sr) {
72 return new SymbolRelation(g, Relation.product(r, sr.r));
73 }
74
75 private class IteratorP implements Iterator {
76 private Iterator it = r.iterator();
77 public boolean hasNext() {
78 return it.hasNext();
79 }
80 public Object next() {
81 return new SymbolPairP((Relation.IntPair)it.next());
82 }
83 public void remove() {
84 it.remove();
85 }
86 }
87
88 public Iterator iteratorSP() {
89 return new IteratorP();
90 }
91
92 public Iterator iteratorIP() {
93 return r.iterator();
94 }
95
96 public String toString() {
97 StringBuffer sb = new StringBuffer ();
98 sb.append("{");
99 Iterator it = iteratorSP();
100 while (it.hasNext()) {
101 SymbolPair sp = (SymbolPair)it.next();
102 sb.append(sp.toString());
103 }
104 sb.append("}");
105 return sb.toString();
106 }
107 }
108 |
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