1 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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2 | * Copyright (C) 1998-2009 Gerwin Klein <[email protected]> *
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3 | * All rights reserved. *
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4 | * *
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5 | * This program is free software; you can redistribute it and/or modify *
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6 | * it under the terms of the GNU General Public License. See the file *
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7 | * COPYRIGHT for more information. *
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8 | * *
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9 | * This program is distributed in the hope that it will be useful, *
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10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of *
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11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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12 | * GNU General Public License for more details. *
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13 | * *
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14 | * You should have received a copy of the GNU General Public License along *
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15 | * with this program; if not, write to the Free Software Foundation, Inc., *
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16 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *
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17 | * *
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18 | * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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19 |
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20 |
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21 | /* §3.3 of the Java Language Specification :
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22 |
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23 | UnicodeInputCharacter:
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24 |
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25 | UnicodeEscape
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26 |
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27 | RawInputCharacter
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28 |
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29 | UnicodeEscape:
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30 |
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31 | \ UnicodeMarker HexDigit HexDigit HexDigit HexDigit
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32 |
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33 | UnicodeMarker:
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34 |
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35 | u
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36 |
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37 | UnicodeMarker u
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38 |
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39 | RawInputCharacter:
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40 |
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41 | any Unicode character
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42 |
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43 | HexDigit: one of
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44 |
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45 | 0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
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46 |
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47 | only an even number of '\' is eligible to start a Unicode escape sequence
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48 |
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49 | */
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50 |
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51 | import java.io.*;
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52 |
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53 | %%
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54 |
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55 | %public
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56 | %final
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57 | %class UnicodeEscapes
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58 | %extends FilterReader
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59 |
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60 | %int
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61 | %function read
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62 |
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63 | %switch
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64 | %16bit
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65 |
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66 | UnicodeEscape = {UnicodeMarker} {HexDigit} {4}
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67 | UnicodeMarker = "u"+
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68 | HexDigit = [0-9a-fA-F]
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69 |
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70 | %state DIGITS
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71 |
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72 | %init{
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73 | super(in);
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74 | %init}
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75 |
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76 | %{
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77 | private boolean even;
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78 |
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79 | private int value() {
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80 | int r = 0;
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81 |
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82 | for (int k = zzMarkedPos-4; k < zzMarkedPos; k++) {
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83 | int c = zzBuffer[k];
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84 |
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85 | if (c >= 'a')
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86 | c-= 'a'-10;
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87 | else if (c >= 'A')
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88 | c-= 'A'-10;
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89 | else
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90 | c-= '0';
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91 |
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92 | r <<= 4;
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93 | r += c;
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94 | }
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95 |
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96 | return r;
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97 | }
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98 |
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99 | public int read(char cbuf[], int off, int len) throws IOException {
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100 | if ( !ready() ) return -1;
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101 |
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102 | len+= off;
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103 |
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104 | for (int i=off; i<len; i++) {
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105 | int c = read();
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106 |
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107 | if (c < 0)
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108 | return i-off;
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109 | else
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110 | cbuf[i] = (char) c;
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111 | }
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112 |
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113 | return len-off;
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114 | }
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115 |
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116 | public boolean markSupported() {
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117 | return false;
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118 | }
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119 |
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120 | public boolean ready() throws IOException {
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121 | return !zzAtEOF && (zzCurrentPos < zzEndRead || zzReader.ready());
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122 | }
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123 |
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124 | %}
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125 |
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126 | %%
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127 |
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128 | <YYINITIAL> {
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129 | \\ { even = false; return '\\'; }
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130 | \\ / \\ { even = !even; return '\\'; }
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131 | \\ / "u" {
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132 | if (even) {
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133 | even = false;
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134 | return '\\';
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135 | }
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136 | else
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137 | yybegin(DIGITS);
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138 | }
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139 | .|\n { return zzBuffer[zzStartRead]; }
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140 |
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141 | <<EOF>> { return -1; }
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142 | }
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143 |
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144 | <DIGITS> {
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145 | {UnicodeEscape} { yybegin(YYINITIAL); return value(); }
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146 | .|\n { throw new Error("incorrect Unicode escape"); }
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147 |
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148 | <<EOF>> { throw new Error("EOF in Unicode escape"); }
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149 | }
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