1 | /**
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2 | * This exception is thrown when parse errors are encountered.
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3 | * You can explicitly create objects of this exception type by
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4 | * calling the method generateParseException in the generated
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5 | * parser.
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6 | *
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7 | * You can modify this class to customize your error reporting
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8 | * mechanisms so long as you retain the public fields.
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9 | */
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10 | public class ParseException extends Exception {
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11 |
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12 | /**
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13 | * The version identifier for this Serializable class.
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14 | * Increment only if the <i>serialized</i> form of the
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15 | * class changes.
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16 | */
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17 | private static final long serialVersionUID = 1L;
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18 |
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19 | /**
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20 | * The end of line string for this machine.
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21 | */
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22 | protected static String EOL = System.getProperty("line.separator", "\n");
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23 |
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24 | /**
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25 | * This constructor is used by the method "generateParseException"
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26 | * in the generated parser. Calling this constructor generates
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27 | * a new object of this type with the fields "currentToken",
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28 | * "expectedTokenSequences", and "tokenImage" set.
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29 | */
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30 | public ParseException(Token currentTokenVal,
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31 | int[][] expectedTokenSequencesVal,
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32 | String[] tokenImageVal
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33 | )
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34 | {
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35 | super(initialise(currentTokenVal, expectedTokenSequencesVal, tokenImageVal));
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36 | currentToken = currentTokenVal;
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37 | expectedTokenSequences = expectedTokenSequencesVal;
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38 | tokenImage = tokenImageVal;
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39 | }
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40 |
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41 | /**
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42 | * The following constructors are for use by you for whatever
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43 | * purpose you can think of. Constructing the exception in this
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44 | * manner makes the exception behave in the normal way - i.e., as
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45 | * documented in the class "Throwable". The fields "errorToken",
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46 | * "expectedTokenSequences", and "tokenImage" do not contain
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47 | * relevant information. The JavaCC generated code does not use
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48 | * these constructors.
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49 | */
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50 |
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51 | public ParseException() {
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52 | super();
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53 | }
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54 |
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55 | /** Constructor with message. */
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56 | public ParseException(String message) {
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57 | super(message);
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58 | }
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59 |
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60 |
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61 | /**
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62 | * This is the last token that has been consumed successfully. If
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63 | * this object has been created due to a parse error, the token
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64 | * followng this token will (therefore) be the first error token.
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65 | */
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66 | public Token currentToken;
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67 |
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68 | /**
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69 | * Each entry in this array is an array of integers. Each array
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70 | * of integers represents a sequence of tokens (by their ordinal
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71 | * values) that is expected at this point of the parse.
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72 | */
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73 | public int[][] expectedTokenSequences;
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74 |
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75 | /**
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76 | * This is a reference to the "tokenImage" array of the generated
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77 | * parser within which the parse error occurred. This array is
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78 | * defined in the generated ...Constants interface.
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79 | */
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80 | public String[] tokenImage;
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81 |
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82 | /**
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83 | * It uses "currentToken" and "expectedTokenSequences" to generate a parse
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84 | * error message and returns it. If this object has been created
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85 | * due to a parse error, and you do not catch it (it gets thrown
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86 | * from the parser) the correct error message
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87 | * gets displayed.
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88 | */
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89 | private static String initialise(Token currentToken,
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90 | int[][] expectedTokenSequences,
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91 | String[] tokenImage) {
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92 |
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93 | StringBuffer expected = new StringBuffer();
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94 | int maxSize = 0;
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95 | for (int i = 0; i < expectedTokenSequences.length; i++) {
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96 | if (maxSize < expectedTokenSequences[i].length) {
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97 | maxSize = expectedTokenSequences[i].length;
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98 | }
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99 | for (int j = 0; j < expectedTokenSequences[i].length; j++) {
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100 | expected.append(tokenImage[expectedTokenSequences[i][j]]).append(' ');
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101 | }
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102 | if (expectedTokenSequences[i][expectedTokenSequences[i].length - 1] != 0) {
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103 | expected.append("...");
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104 | }
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105 | expected.append(EOL).append(" ");
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106 | }
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107 | String retval = "Encountered \"";
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108 | Token tok = currentToken.next;
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109 | for (int i = 0; i < maxSize; i++) {
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110 | if (i != 0) retval += " ";
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111 | if (tok.kind == 0) {
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112 | retval += tokenImage[0];
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113 | break;
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114 | }
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115 | retval += " " + tokenImage[tok.kind];
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116 | retval += " \"";
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117 | retval += add_escapes(tok.image);
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118 | retval += " \"";
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119 | tok = tok.next;
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120 | }
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121 | #if KEEP_LINE_COLUMN
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122 | retval += "\" at line " + currentToken.next.beginLine + ", column " + currentToken.next.beginColumn;
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123 | #fi
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124 | retval += "." + EOL;
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125 |
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126 |
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127 | if (expectedTokenSequences.length == 0) {
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128 | // Nothing to add here
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129 | } else {
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130 | if (expectedTokenSequences.length == 1) {
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131 | retval += "Was expecting:" + EOL + " ";
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132 | } else {
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133 | retval += "Was expecting one of:" + EOL + " ";
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134 | }
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135 | retval += expected.toString();
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136 | }
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137 |
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138 | return retval;
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139 | }
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140 |
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141 |
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142 | /**
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143 | * Used to convert raw characters to their escaped version
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144 | * when these raw version cannot be used as part of an ASCII
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145 | * string literal.
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146 | */
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147 | static String add_escapes(String str) {
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148 | StringBuffer retval = new StringBuffer();
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149 | char ch;
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150 | for (int i = 0; i < str.length(); i++) {
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151 | switch (str.charAt(i))
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152 | {
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153 | case '\b':
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154 | retval.append("\\b");
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155 | continue;
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156 | case '\t':
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157 | retval.append("\\t");
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158 | continue;
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159 | case '\n':
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160 | retval.append("\\n");
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161 | continue;
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162 | case '\f':
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163 | retval.append("\\f");
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164 | continue;
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165 | case '\r':
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166 | retval.append("\\r");
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167 | continue;
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168 | case '\"':
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169 | retval.append("\\\"");
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170 | continue;
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171 | case '\'':
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172 | retval.append("\\\'");
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173 | continue;
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174 | case '\\':
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175 | retval.append("\\\\");
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176 | continue;
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177 | default:
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178 | if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
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179 | String s = "0000" + Integer.toString(ch, 16);
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180 | retval.append("\\u" + s.substring(s.length() - 4, s.length()));
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181 | } else {
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182 | retval.append(ch);
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183 | }
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184 | continue;
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185 | }
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186 | }
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187 | return retval.toString();
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188 | }
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189 |
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190 | }
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