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1 package ro.infoiasi.donald.compiler.lexer;
2
3 import ro.infoiasi.donald.compiler.lexer.exceptions.*;
4 import java.util.*;
5
6 public class ExpList extends ArrayList {
7 private Alphabet alpha = new Alphabet();
8
9 public ExpList() {
10 super();
11 }
12
13 public ExpList(String  s) throws ExpParseError {
14 super();
15
16 Stack stackPar = new Stack();
17
18 for (int i = 0; i<s.length(); i++) {
19 char ch = s.charAt(i);
20 switch (ch) {
21 case '(': addParenthesisLeft(i, stackPar); break;
22 case ')': addParenthesisRight(i, stackPar); break;
23 case '\\': i = escapeNext(i, s); break;
24 default:
25 {
26 Operator op = Operator.get(ch);
27 if (op != null) {
28 addOperatorToken(i, op);
29 } else {
30 addSymbolToken(i, ch);
31 }
32 }
33 break;
34 }
35 }
36 if (stackPar.size() != 0) {
37 throw new ExpParseError("Parenthesis is not closing",
38 ((ParenthesisLeft)stackPar.peek()).strIndex());
39 }
40 }
41
42 public ExpToken lastToken() {
43 return (ExpToken)get(size()-1);
44 }
45
46 public void addToken(ExpToken et) {
47 Class ce = et.getClass();
48 if (ce == SymbolToken.class ||
49 ce == ParenthesisLeft.class ||
50 (ce == OperatorToken.class &&
51 ((OperatorToken)et).operator().isUnaryRight())) {
52
57 if (size()>0) {
58 Class cl = lastToken().getClass();
59 if (cl == SymbolToken.class ||
60 cl == ParenthesisRight.class ||
61 (cl == OperatorToken.class &&
62 ((OperatorToken)lastToken()).operator().isUnaryLeft())) {
63 addToken(new OperatorToken(et.strIndex(), size(), Operator.CONCAT));
64 et.incTokenNo();
65 }
66 }
67 }
68 add(et);
69 }
70
71 public void addParenthesisLeft(int index, Stack stackPar) {
72 ParenthesisLeft parLeft = new ParenthesisLeft(index, size());
73 stackPar.push(parLeft);
74 addToken(parLeft);
75 }
76
77 public void addParenthesisRight(int index, Stack stackPar) throws ExpParseError {
78 if (stackPar.size()==0) {
79 throw new ExpParseError("Parenthesis closing too soon",index);
80 }
81 ParenthesisLeft parLeft = (ParenthesisLeft)stackPar.pop();
82 ParenthesisRight parRight = new ParenthesisRight(index, size());
83 parLeft.setPair(parRight);
84 parRight.setPair(parLeft);
85 addToken(parRight);
86 }
87
88 public void addOperatorToken(int index, Operator op) {
89 addToken(new OperatorToken(index, size(), op));
90 }
91
92 public void addSymbolToken(int index, char ch) {
93 alpha.addSymbol(ch);
94 SymbolToken symbolToken = new SymbolToken(index, size(), ch);
95 addToken(symbolToken);
96 }
97
98 public int escapeNext(int index, String s) throws ExpParseError {
99 index++;
100 if (index<s.length()) {
101 char ch = s.charAt(index);
102 switch (ch) {
103 case 'n': addSymbolToken(index, '\n'); break;
104 default:
106 { Operator op = Operator.get(ch);
108 if (op != null) {
109 addSymbolToken(index, ch);
110 } else {
111 throw new ExpParseError("Illegal escape character",index);
112 }
113 }
114 }
115 return index;
116 } else {
117 throw new ExpParseError("Nothing left to escape",index);
118 }
119 }
120
121 public Alphabet getAlphabet() {
122 return alpha;
123 }
124
125 public String toString() {
126 StringBuffer sb = new StringBuffer ();
127 Iterator it = listIterator(0);
128 while (it.hasNext()) {
129 sb.append((it.next()).toString());
130 }
131 return new String (sb);
132 }
133 }
134 |
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