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3840
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1 /**
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2 * @test
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3 * @bug 7070134
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4 * @summary Hotspot crashes with sigsegv from PorterStemmer
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5 *
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6 * @run shell Test7070134.sh
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7 */
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8
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9 /*
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10
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11 Porter stemmer in Java. The original paper is in
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12
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13 Porter, 1980, An algorithm for suffix stripping, Program, Vol. 14,
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14 no. 3, pp 130-137,
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15
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16 See also http://www.tartarus.org/~martin/PorterStemmer
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17
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18 History:
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19
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20 Release 1
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21
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22 Bug 1 (reported by Gonzalo Parra 16/10/99) fixed as marked below.
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23 The words 'aed', 'eed', 'oed' leave k at 'a' for step 3, and b[k-1]
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24 is then out outside the bounds of b.
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25
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26 Release 2
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27
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28 Similarly,
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29
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30 Bug 2 (reported by Steve Dyrdahl 22/2/00) fixed as marked below.
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31 'ion' by itself leaves j = -1 in the test for 'ion' in step 5, and
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32 b[j] is then outside the bounds of b.
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33
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34 Release 3
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35
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36 Considerably revised 4/9/00 in the light of many helpful suggestions
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37 from Brian Goetz of Quiotix Corporation (brian@quiotix.com).
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38
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39 Release 4
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40
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41 */
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42
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43 import java.io.*;
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44
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45 /**
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46 * Stemmer, implementing the Porter Stemming Algorithm
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47 *
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48 * The Stemmer class transforms a word into its root form. The input
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49 * word can be provided a character at time (by calling add()), or at once
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50 * by calling one of the various stem(something) methods.
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51 */
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52
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53 class Stemmer
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54 { private char[] b;
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55 private int i, /* offset into b */
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56 i_end, /* offset to end of stemmed word */
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57 j, k;
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58 private static final int INC = 50;
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59 /* unit of size whereby b is increased */
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60 public Stemmer()
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61 { b = new char[INC];
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62 i = 0;
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63 i_end = 0;
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64 }
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65
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66 /**
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67 * Add a character to the word being stemmed. When you are finished
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68 * adding characters, you can call stem(void) to stem the word.
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69 */
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70
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71 public void add(char ch)
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72 { if (i == b.length)
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73 { char[] new_b = new char[i+INC];
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74 for (int c = 0; c < i; c++) new_b[c] = b[c];
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75 b = new_b;
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76 }
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77 b[i++] = ch;
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78 }
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79
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80
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81 /** Adds wLen characters to the word being stemmed contained in a portion
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82 * of a char[] array. This is like repeated calls of add(char ch), but
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83 * faster.
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84 */
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85
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86 public void add(char[] w, int wLen)
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87 { if (i+wLen >= b.length)
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88 { char[] new_b = new char[i+wLen+INC];
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89 for (int c = 0; c < i; c++) new_b[c] = b[c];
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90 b = new_b;
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91 }
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92 for (int c = 0; c < wLen; c++) b[i++] = w[c];
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93 }
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94
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95 /**
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96 * After a word has been stemmed, it can be retrieved by toString(),
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97 * or a reference to the internal buffer can be retrieved by getResultBuffer
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98 * and getResultLength (which is generally more efficient.)
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99 */
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100 public String toString() { return new String(b,0,i_end); }
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101
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102 /**
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103 * Returns the length of the word resulting from the stemming process.
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104 */
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105 public int getResultLength() { return i_end; }
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106
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107 /**
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108 * Returns a reference to a character buffer containing the results of
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109 * the stemming process. You also need to consult getResultLength()
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110 * to determine the length of the result.
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111 */
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112 public char[] getResultBuffer() { return b; }
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113
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114 /* cons(i) is true <=> b[i] is a consonant. */
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115
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116 private final boolean cons(int i)
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117 { switch (b[i])
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118 { case 'a': case 'e': case 'i': case 'o': case 'u': return false;
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119 case 'y': return (i==0) ? true : !cons(i-1);
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120 default: return true;
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121 }
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122 }
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123
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124 /* m() measures the number of consonant sequences between 0 and j. if c is
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125 a consonant sequence and v a vowel sequence, and <..> indicates arbitrary
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126 presence,
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127
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128 <c><v> gives 0
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129 <c>vc<v> gives 1
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130 <c>vcvc<v> gives 2
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131 <c>vcvcvc<v> gives 3
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132 ....
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133 */
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134
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135 private final int m()
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136 { int n = 0;
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137 int i = 0;
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138 while(true)
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139 { if (i > j) return n;
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140 if (! cons(i)) break; i++;
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141 }
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142 i++;
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143 while(true)
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144 { while(true)
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145 { if (i > j) return n;
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146 if (cons(i)) break;
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147 i++;
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148 }
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149 i++;
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150 n++;
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151 while(true)
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152 { if (i > j) return n;
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153 if (! cons(i)) break;
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154 i++;
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155 }
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156 i++;
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157 }
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158 }
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159
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160 /* vowelinstem() is true <=> 0,...j contains a vowel */
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161
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162 private final boolean vowelinstem()
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163 { int i; for (i = 0; i <= j; i++) if (! cons(i)) return true;
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164 return false;
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165 }
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166
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167 /* doublec(j) is true <=> j,(j-1) contain a double consonant. */
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168
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169 private final boolean doublec(int j)
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170 { if (j < 1) return false;
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171 if (b[j] != b[j-1]) return false;
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172 return cons(j);
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173 }
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174
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175 /* cvc(i) is true <=> i-2,i-1,i has the form consonant - vowel - consonant
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176 and also if the second c is not w,x or y. this is used when trying to
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177 restore an e at the end of a short word. e.g.
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178
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179 cav(e), lov(e), hop(e), crim(e), but
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180 snow, box, tray.
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181
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182 */
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183
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184 private final boolean cvc(int i)
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185 { if (i < 2 || !cons(i) || cons(i-1) || !cons(i-2)) return false;
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186 { int ch = b[i];
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187 if (ch == 'w' || ch == 'x' || ch == 'y') return false;
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188 }
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189 return true;
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190 }
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191
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192 private final boolean ends(String s)
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193 { int l = s.length();
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194 int o = k-l+1;
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195 if (o < 0) return false;
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196 for (int i = 0; i < l; i++) if (b[o+i] != s.charAt(i)) return false;
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197 j = k-l;
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198 return true;
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199 }
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200
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201 /* setto(s) sets (j+1),...k to the characters in the string s, readjusting
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202 k. */
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203
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204 private final void setto(String s)
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205 { int l = s.length();
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206 int o = j+1;
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207 for (int i = 0; i < l; i++) b[o+i] = s.charAt(i);
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208 k = j+l;
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209 }
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210
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211 /* r(s) is used further down. */
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212
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213 private final void r(String s) { if (m() > 0) setto(s); }
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214
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215 /* step1() gets rid of plurals and -ed or -ing. e.g.
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216
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217 caresses -> caress
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218 ponies -> poni
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219 ties -> ti
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220 caress -> caress
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221 cats -> cat
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222
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223 feed -> feed
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224 agreed -> agree
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225 disabled -> disable
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226
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227 matting -> mat
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228 mating -> mate
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229 meeting -> meet
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230 milling -> mill
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231 messing -> mess
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232
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233 meetings -> meet
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234
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235 */
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236
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237 private final void step1()
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238 { if (b[k] == 's')
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239 { if (ends("sses")) k -= 2; else
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240 if (ends("ies")) setto("i"); else
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241 if (b[k-1] != 's') k--;
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242 }
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243 if (ends("eed")) { if (m() > 0) k--; } else
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244 if ((ends("ed") || ends("ing")) && vowelinstem())
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245 { k = j;
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246 if (ends("at")) setto("ate"); else
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247 if (ends("bl")) setto("ble"); else
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248 if (ends("iz")) setto("ize"); else
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249 if (doublec(k))
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250 { k--;
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251 { int ch = b[k];
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252 if (ch == 'l' || ch == 's' || ch == 'z') k++;
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253 }
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254 }
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255 else if (m() == 1 && cvc(k)) setto("e");
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256 }
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257 }
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258
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259 /* step2() turns terminal y to i when there is another vowel in the stem. */
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260
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261 private final void step2() { if (ends("y") && vowelinstem()) b[k] = 'i'; }
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262
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263 /* step3() maps double suffices to single ones. so -ization ( = -ize plus
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264 -ation) maps to -ize etc. note that the string before the suffix must give
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265 m() > 0. */
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266
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267 private final void step3() { if (k == 0) return; /* For Bug 1 */ switch (b[k-1])
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268 {
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269 case 'a': if (ends("ational")) { r("ate"); break; }
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270 if (ends("tional")) { r("tion"); break; }
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271 break;
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272 case 'c': if (ends("enci")) { r("ence"); break; }
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273 if (ends("anci")) { r("ance"); break; }
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274 break;
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275 case 'e': if (ends("izer")) { r("ize"); break; }
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276 break;
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277 case 'l': if (ends("bli")) { r("ble"); break; }
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278 if (ends("alli")) { r("al"); break; }
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279 if (ends("entli")) { r("ent"); break; }
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280 if (ends("eli")) { r("e"); break; }
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281 if (ends("ousli")) { r("ous"); break; }
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282 break;
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283 case 'o': if (ends("ization")) { r("ize"); break; }
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284 if (ends("ation")) { r("ate"); break; }
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285 if (ends("ator")) { r("ate"); break; }
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286 break;
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287 case 's': if (ends("alism")) { r("al"); break; }
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288 if (ends("iveness")) { r("ive"); break; }
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289 if (ends("fulness")) { r("ful"); break; }
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290 if (ends("ousness")) { r("ous"); break; }
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291 break;
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292 case 't': if (ends("aliti")) { r("al"); break; }
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293 if (ends("iviti")) { r("ive"); break; }
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294 if (ends("biliti")) { r("ble"); break; }
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295 break;
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296 case 'g': if (ends("logi")) { r("log"); break; }
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297 } }
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298
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299 /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */
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300
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301 private final void step4() { switch (b[k])
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302 {
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303 case 'e': if (ends("icate")) { r("ic"); break; }
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304 if (ends("ative")) { r(""); break; }
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305 if (ends("alize")) { r("al"); break; }
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306 break;
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307 case 'i': if (ends("iciti")) { r("ic"); break; }
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308 break;
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309 case 'l': if (ends("ical")) { r("ic"); break; }
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310 if (ends("ful")) { r(""); break; }
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311 break;
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312 case 's': if (ends("ness")) { r(""); break; }
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313 break;
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314 } }
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315
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316 /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */
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317
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318 private final void step5()
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319 { if (k == 0) return; /* for Bug 1 */ switch (b[k-1])
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320 { case 'a': if (ends("al")) break; return;
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321 case 'c': if (ends("ance")) break;
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322 if (ends("ence")) break; return;
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323 case 'e': if (ends("er")) break; return;
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324 case 'i': if (ends("ic")) break; return;
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325 case 'l': if (ends("able")) break;
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326 if (ends("ible")) break; return;
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327 case 'n': if (ends("ant")) break;
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328 if (ends("ement")) break;
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329 if (ends("ment")) break;
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330 /* element etc. not stripped before the m */
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331 if (ends("ent")) break; return;
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332 case 'o': if (ends("ion") && j >= 0 && (b[j] == 's' || b[j] == 't')) break;
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333 /* j >= 0 fixes Bug 2 */
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334 if (ends("ou")) break; return;
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335 /* takes care of -ous */
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336 case 's': if (ends("ism")) break; return;
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337 case 't': if (ends("ate")) break;
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338 if (ends("iti")) break; return;
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339 case 'u': if (ends("ous")) break; return;
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340 case 'v': if (ends("ive")) break; return;
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341 case 'z': if (ends("ize")) break; return;
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342 default: return;
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343 }
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344 if (m() > 1) k = j;
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345 }
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346
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347 /* step6() removes a final -e if m() > 1. */
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348
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349 private final void step6()
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350 { j = k;
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351 if (b[k] == 'e')
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352 { int a = m();
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353 if (a > 1 || a == 1 && !cvc(k-1)) k--;
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354 }
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355 if (b[k] == 'l' && doublec(k) && m() > 1) k--;
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356 }
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357
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358 /** Stem the word placed into the Stemmer buffer through calls to add().
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359 * Returns true if the stemming process resulted in a word different
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360 * from the input. You can retrieve the result with
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361 * getResultLength()/getResultBuffer() or toString().
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362 */
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363 public void stem()
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364 { k = i - 1;
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365 if (k > 1) { step1(); step2(); step3(); step4(); step5(); step6(); }
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366 i_end = k+1; i = 0;
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367 }
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368
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369 /** Test program for demonstrating the Stemmer. It reads text from a
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370 * a list of files, stems each word, and writes the result to standard
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371 * output. Note that the word stemmed is expected to be in lower case:
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372 * forcing lower case must be done outside the Stemmer class.
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373 * Usage: Stemmer file-name file-name ...
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374 */
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375 public static void main(String[] args)
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376 {
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377 char[] w = new char[501];
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378 Stemmer s = new Stemmer();
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379 for (int i = 0; i < args.length; i++)
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380 try
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381 {
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382 FileInputStream in = new FileInputStream(args[i]);
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383
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384 try
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385 { while(true)
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386
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387 { int ch = in.read();
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388 if (Character.isLetter((char) ch))
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389 {
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390 int j = 0;
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391 while(true)
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392 { ch = Character.toLowerCase((char) ch);
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393 w[j] = (char) ch;
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394 if (j < 500) j++;
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395 ch = in.read();
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396 if (!Character.isLetter((char) ch))
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397 {
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398 /* to test add(char ch) */
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399 for (int c = 0; c < j; c++) s.add(w[c]);
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400
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401 /* or, to test add(char[] w, int j) */
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402 /* s.add(w, j); */
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403
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404 s.stem();
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405 { String u;
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406
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407 /* and now, to test toString() : */
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408 u = s.toString();
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409
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410 /* to test getResultBuffer(), getResultLength() : */
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411 /* u = new String(s.getResultBuffer(), 0, s.getResultLength()); */
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412
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413 System.out.print(u);
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414 }
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415 break;
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416 }
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417 }
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418 }
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419 if (ch < 0) break;
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420 System.out.print((char)ch);
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421 }
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422 }
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423 catch (IOException e)
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424 { System.out.println("error reading " + args[i]);
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425 break;
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426 }
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427 }
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428 catch (FileNotFoundException e)
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429 { System.out.println("file " + args[i] + " not found");
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430 break;
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|
|
431 }
|
|
|
432 }
|
|
|
433 }
|
