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1 package ro.infoiasi.donald.compiler.lexer;
2
3 import ro.infoiasi.donald.compiler.lexer.exceptions.*;
4 import ro.infoiasi.donald.compiler.simple.*;
5 import java.util.*;
6
7 public class ExpTree extends BinTree {
8 private Alphabet alpha = new Alphabet();
9
10 public ExpTree() {
11 super();
12 }
13
14 public ExpTree(ExpList el) throws ExpParseError {
15 super();
16 alpha = el.getAlphabet();
17 addRootSubTree(create(el));
18 }
19
20 private static ExpTree create(AbstractList el) throws ExpParseError {
21 el = removeParenthesis(el);
22 ExpTree et = new ExpTree();
23 if (!el.isEmpty()) {
24 OperatorToken minOpToken = null;
25 int minI = 0;
26 for (int i = 0; i<el.size(); i++) {
27 Class  c = el.get(i).getClass();
28 if (c == OperatorToken.class) {
29 OperatorToken opToken = (OperatorToken)el.get(i);
30 if (minOpToken == null ||
31 (minOpToken.compareTo(opToken)>0)) {
32 minOpToken = opToken;
33 minI = i;
34 }
35 } else if (c == ParenthesisLeft.class) {
36 ParenthesisLeft paraLeft = (ParenthesisLeft)el.get(i);
38 ParenthesisRight paraRight = paraLeft.pair();
39 i += paraRight.tokenNo() - paraLeft.tokenNo();
40 }
41 }
42 if (minOpToken == null) {
44 if (el.size()>1 || el.get(0).getClass() != SymbolToken.class) {
45 throw new ExpParseError("No operator found",
46 ((ExpToken)el.get(0)).strIndex(),
47 ((ExpToken)el.get(el.size()-1)).strIndex());
48 } else {
49 et.addRoot(el.get(0));
50 }
51 } else {
52 et.addRoot(minOpToken);
53 if (minOpToken.operator().isUnaryLeft()) {
54 if (minI != el.size()-1) {
55 throw new ExpParseError("Operator is unary and binds to the left only",
56 minOpToken.strIndex());
57 }
58 ExpTree et1 = create((AbstractList)(el.subList(0,minI)));
59 if (et1.IsEmpty()) {
60 throw new ExpParseError("Operator is unary and binds to the left only",
61 minOpToken.strIndex());
62 }
63 et.addLeftSubTree(et1, et.root());
64 } else if (minOpToken.operator().isUnaryRight()) {
65
66 } else if (minOpToken.operator().isBinary()) {
67 ExpTree et1 = create((AbstractList)(el.subList(0,minI)));
68 ExpTree et2 = create((AbstractList)(el.subList(minI+1,el.size())));
69 if (et1.IsEmpty() || et2.IsEmpty()) {
70 throw new ExpParseError("Operator is binary", minOpToken.strIndex());
72 }
73 et.addLeftSubTree(et1, et.root());
74 et.addRightSubTree(et2, et.root());
75 } else {
76 throw new ExpParseError("Operator is not unary or binary",
77 ((ExpToken)el.get(0)).strIndex());
78 }
79 }
80 }
81 return et;
82 }
83
84 private static AbstractList removeParenthesis(AbstractList el) {
85 boolean over = false;
86 while (!el.isEmpty() && !over) {
87 over = true;
88 if (el.get(0).getClass() == ParenthesisLeft.class &&
89 el.get(el.size()-1).getClass() == ParenthesisRight.class) {
90 ParenthesisLeft paraLeft = (ParenthesisLeft)el.get(0);
91 ParenthesisRight paraRight = (ParenthesisRight)el.get(el.size()-1);
92 if (paraLeft.pair() == paraRight) {
93 el = (AbstractList)el.subList(1,el.size()-1);
94 over = false;
95 }
96 }
97 }
98 return el;
99 }
100
101 public Alphabet getAlphabet() {
102 return alpha;
103 }
104 }
105 |
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