1 | /*----------------------------------------------------------------------
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2 | Compiler Generator Coco/R,
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3 | Copyright (c) 1990, 2004 Hanspeter Moessenboeck, University of Linz
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4 | extended by M. Loeberbauer & A. Woess, Univ. of Linz
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5 | with improvements by Pat Terry, Rhodes University
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6 |
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7 | This program is free software; you can redistribute it and/or modify it
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8 | under the terms of the GNU General Public License as published by the
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9 | Free Software Foundation; either version 2, or (at your option) any
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10 | later version.
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11 |
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12 | This program is distributed in the hope that it will be useful, but
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13 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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15 | for more details.
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16 |
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17 | You should have received a copy of the GNU General Public License along
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18 | with this program; if not, write to the Free Software Foundation, Inc.,
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19 | 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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20 |
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21 | As an exception, it is allowed to write an extension of Coco/R that is
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22 | used as a plugin in non-free software.
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23 |
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24 | If not otherwise stated, any source code generated by Coco/R (other than
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25 | Coco/R itself) does not fall under the GNU General Public License.
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26 | ----------------------------------------------------------------------*/
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27 | -->begin
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28 | using System;
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29 |
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30 | -->namespace
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31 |
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32 | public class Parser {
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33 | -->constants
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34 | const bool T = true;
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35 | const bool x = false;
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36 | const int minErrDist = 2;
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37 |
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38 | public Scanner scanner;
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39 | public Errors errors;
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40 |
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41 | public Token t; // last recognized token
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42 | public Token la; // lookahead token
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43 | int errDist = minErrDist;
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44 |
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45 | -->declarations
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46 |
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47 | public Parser(Scanner scanner) {
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48 | this.scanner = scanner;
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49 | errors = new Errors();
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50 | }
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51 |
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52 | void SynErr (int n) {
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53 | if (errDist >= minErrDist) errors.SynErr(la.line, la.col, n);
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54 | errDist = 0;
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55 | }
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56 |
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57 | public void SemErr (string msg) {
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58 | if (errDist >= minErrDist) errors.SemErr(t.line, t.col, msg);
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59 | errDist = 0;
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60 | }
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61 |
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62 | void Get () {
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63 | for (;;) {
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64 | t = la;
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65 | la = scanner.Scan();
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66 | if (la.kind <= maxT) { ++errDist; break; }
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67 | -->pragmas
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68 | la = t;
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69 | }
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70 | }
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71 |
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72 | void Expect (int n) {
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73 | if (la.kind==n) Get(); else { SynErr(n); }
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74 | }
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75 |
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76 | bool StartOf (int s) {
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77 | return set[s, la.kind];
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78 | }
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79 |
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80 | void ExpectWeak (int n, int follow) {
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81 | if (la.kind == n) Get();
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82 | else {
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83 | SynErr(n);
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84 | while (!StartOf(follow)) Get();
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85 | }
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86 | }
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87 |
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88 |
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89 | bool WeakSeparator(int n, int syFol, int repFol) {
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90 | int kind = la.kind;
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91 | if (kind == n) {Get(); return true;}
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92 | else if (StartOf(repFol)) {return false;}
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93 | else {
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94 | SynErr(n);
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95 | while (!(set[syFol, kind] || set[repFol, kind] || set[0, kind])) {
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96 | Get();
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97 | kind = la.kind;
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98 | }
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99 | return StartOf(syFol);
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100 | }
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101 | }
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102 |
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103 |
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104 | -->productions
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105 |
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106 | public void Parse() {
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107 | la = new Token();
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108 | la.val = "";
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109 | Get();
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110 | -->parseRoot
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111 | }
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112 |
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113 | static readonly bool[,] set = {
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114 | -->initialization
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115 | };
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116 | } // end Parser
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117 |
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118 |
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119 | public class Errors {
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120 | public int count = 0; // number of errors detected
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121 | public System.IO.TextWriter errorStream = Console.Out; // error messages go to this stream
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122 | public string errMsgFormat = "-- line {0} col {1}: {2}"; // 0=line, 1=column, 2=text
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123 |
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124 | public virtual void SynErr (int line, int col, int n) {
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125 | string s;
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126 | switch (n) {
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127 | -->errors
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128 | default: s = "error " + n; break;
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129 | }
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130 | errorStream.WriteLine(errMsgFormat, line, col, s);
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131 | count++;
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132 | }
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133 |
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134 | public virtual void SemErr (int line, int col, string s) {
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135 | errorStream.WriteLine(errMsgFormat, line, col, s);
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136 | count++;
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137 | }
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138 |
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139 | public virtual void SemErr (string s) {
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140 | errorStream.WriteLine(s);
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141 | count++;
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142 | }
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143 |
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144 | public virtual void Warning (int line, int col, string s) {
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145 | errorStream.WriteLine(errMsgFormat, line, col, s);
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146 | }
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147 |
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148 | public virtual void Warning(string s) {
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149 | errorStream.WriteLine(s);
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150 | }
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151 | } // Errors
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152 |
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153 |
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154 | public class FatalError: Exception {
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155 | public FatalError(string m): base(m) {}
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156 | }
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