test/compiler/7070134/Stemmer.java

Wed, 09 May 2012 13:07:42 -0700

author
katleman
date
Wed, 09 May 2012 13:07:42 -0700
changeset 3719
4ee58fcab520
parent 3038
4e761e7e6e12
child 3749
3a97daec1b34
permissions
-rw-r--r--

Added tag jdk8-b37 for changeset bfcf92bfefb8

kvn@3038 1 /**
kvn@3038 2 * @test
kvn@3038 3 * @bug 7070134
kvn@3038 4 * @summary Hotspot crashes with sigsegv from PorterStemmer
kvn@3038 5 *
kvn@3038 6 * @run shell Test7070134.sh
kvn@3038 7 */
kvn@3038 8
kvn@3038 9 /*
kvn@3038 10
kvn@3038 11 Porter stemmer in Java. The original paper is in
kvn@3038 12
kvn@3038 13 Porter, 1980, An algorithm for suffix stripping, Program, Vol. 14,
kvn@3038 14 no. 3, pp 130-137,
kvn@3038 15
kvn@3038 16 See also http://www.tartarus.org/~martin/PorterStemmer
kvn@3038 17
kvn@3038 18 History:
kvn@3038 19
kvn@3038 20 Release 1
kvn@3038 21
kvn@3038 22 Bug 1 (reported by Gonzalo Parra 16/10/99) fixed as marked below.
kvn@3038 23 The words 'aed', 'eed', 'oed' leave k at 'a' for step 3, and b[k-1]
kvn@3038 24 is then out outside the bounds of b.
kvn@3038 25
kvn@3038 26 Release 2
kvn@3038 27
kvn@3038 28 Similarly,
kvn@3038 29
kvn@3038 30 Bug 2 (reported by Steve Dyrdahl 22/2/00) fixed as marked below.
kvn@3038 31 'ion' by itself leaves j = -1 in the test for 'ion' in step 5, and
kvn@3038 32 b[j] is then outside the bounds of b.
kvn@3038 33
kvn@3038 34 Release 3
kvn@3038 35
kvn@3038 36 Considerably revised 4/9/00 in the light of many helpful suggestions
kvn@3038 37 from Brian Goetz of Quiotix Corporation (brian@quiotix.com).
kvn@3038 38
kvn@3038 39 Release 4
kvn@3038 40
kvn@3038 41 */
kvn@3038 42
kvn@3038 43 import java.io.*;
kvn@3038 44
kvn@3038 45 /**
kvn@3038 46 * Stemmer, implementing the Porter Stemming Algorithm
kvn@3038 47 *
kvn@3038 48 * The Stemmer class transforms a word into its root form. The input
kvn@3038 49 * word can be provided a character at time (by calling add()), or at once
kvn@3038 50 * by calling one of the various stem(something) methods.
kvn@3038 51 */
kvn@3038 52
kvn@3038 53 class Stemmer
kvn@3038 54 { private char[] b;
kvn@3038 55 private int i, /* offset into b */
kvn@3038 56 i_end, /* offset to end of stemmed word */
kvn@3038 57 j, k;
kvn@3038 58 private static final int INC = 50;
kvn@3038 59 /* unit of size whereby b is increased */
kvn@3038 60 public Stemmer()
kvn@3038 61 { b = new char[INC];
kvn@3038 62 i = 0;
kvn@3038 63 i_end = 0;
kvn@3038 64 }
kvn@3038 65
kvn@3038 66 /**
kvn@3038 67 * Add a character to the word being stemmed. When you are finished
kvn@3038 68 * adding characters, you can call stem(void) to stem the word.
kvn@3038 69 */
kvn@3038 70
kvn@3038 71 public void add(char ch)
kvn@3038 72 { if (i == b.length)
kvn@3038 73 { char[] new_b = new char[i+INC];
kvn@3038 74 for (int c = 0; c < i; c++) new_b[c] = b[c];
kvn@3038 75 b = new_b;
kvn@3038 76 }
kvn@3038 77 b[i++] = ch;
kvn@3038 78 }
kvn@3038 79
kvn@3038 80
kvn@3038 81 /** Adds wLen characters to the word being stemmed contained in a portion
kvn@3038 82 * of a char[] array. This is like repeated calls of add(char ch), but
kvn@3038 83 * faster.
kvn@3038 84 */
kvn@3038 85
kvn@3038 86 public void add(char[] w, int wLen)
kvn@3038 87 { if (i+wLen >= b.length)
kvn@3038 88 { char[] new_b = new char[i+wLen+INC];
kvn@3038 89 for (int c = 0; c < i; c++) new_b[c] = b[c];
kvn@3038 90 b = new_b;
kvn@3038 91 }
kvn@3038 92 for (int c = 0; c < wLen; c++) b[i++] = w[c];
kvn@3038 93 }
kvn@3038 94
kvn@3038 95 /**
kvn@3038 96 * After a word has been stemmed, it can be retrieved by toString(),
kvn@3038 97 * or a reference to the internal buffer can be retrieved by getResultBuffer
kvn@3038 98 * and getResultLength (which is generally more efficient.)
kvn@3038 99 */
kvn@3038 100 public String toString() { return new String(b,0,i_end); }
kvn@3038 101
kvn@3038 102 /**
kvn@3038 103 * Returns the length of the word resulting from the stemming process.
kvn@3038 104 */
kvn@3038 105 public int getResultLength() { return i_end; }
kvn@3038 106
kvn@3038 107 /**
kvn@3038 108 * Returns a reference to a character buffer containing the results of
kvn@3038 109 * the stemming process. You also need to consult getResultLength()
kvn@3038 110 * to determine the length of the result.
kvn@3038 111 */
kvn@3038 112 public char[] getResultBuffer() { return b; }
kvn@3038 113
kvn@3038 114 /* cons(i) is true <=> b[i] is a consonant. */
kvn@3038 115
kvn@3038 116 private final boolean cons(int i)
kvn@3038 117 { switch (b[i])
kvn@3038 118 { case 'a': case 'e': case 'i': case 'o': case 'u': return false;
kvn@3038 119 case 'y': return (i==0) ? true : !cons(i-1);
kvn@3038 120 default: return true;
kvn@3038 121 }
kvn@3038 122 }
kvn@3038 123
kvn@3038 124 /* m() measures the number of consonant sequences between 0 and j. if c is
kvn@3038 125 a consonant sequence and v a vowel sequence, and <..> indicates arbitrary
kvn@3038 126 presence,
kvn@3038 127
kvn@3038 128 <c><v> gives 0
kvn@3038 129 <c>vc<v> gives 1
kvn@3038 130 <c>vcvc<v> gives 2
kvn@3038 131 <c>vcvcvc<v> gives 3
kvn@3038 132 ....
kvn@3038 133 */
kvn@3038 134
kvn@3038 135 private final int m()
kvn@3038 136 { int n = 0;
kvn@3038 137 int i = 0;
kvn@3038 138 while(true)
kvn@3038 139 { if (i > j) return n;
kvn@3038 140 if (! cons(i)) break; i++;
kvn@3038 141 }
kvn@3038 142 i++;
kvn@3038 143 while(true)
kvn@3038 144 { while(true)
kvn@3038 145 { if (i > j) return n;
kvn@3038 146 if (cons(i)) break;
kvn@3038 147 i++;
kvn@3038 148 }
kvn@3038 149 i++;
kvn@3038 150 n++;
kvn@3038 151 while(true)
kvn@3038 152 { if (i > j) return n;
kvn@3038 153 if (! cons(i)) break;
kvn@3038 154 i++;
kvn@3038 155 }
kvn@3038 156 i++;
kvn@3038 157 }
kvn@3038 158 }
kvn@3038 159
kvn@3038 160 /* vowelinstem() is true <=> 0,...j contains a vowel */
kvn@3038 161
kvn@3038 162 private final boolean vowelinstem()
kvn@3038 163 { int i; for (i = 0; i <= j; i++) if (! cons(i)) return true;
kvn@3038 164 return false;
kvn@3038 165 }
kvn@3038 166
kvn@3038 167 /* doublec(j) is true <=> j,(j-1) contain a double consonant. */
kvn@3038 168
kvn@3038 169 private final boolean doublec(int j)
kvn@3038 170 { if (j < 1) return false;
kvn@3038 171 if (b[j] != b[j-1]) return false;
kvn@3038 172 return cons(j);
kvn@3038 173 }
kvn@3038 174
kvn@3038 175 /* cvc(i) is true <=> i-2,i-1,i has the form consonant - vowel - consonant
kvn@3038 176 and also if the second c is not w,x or y. this is used when trying to
kvn@3038 177 restore an e at the end of a short word. e.g.
kvn@3038 178
kvn@3038 179 cav(e), lov(e), hop(e), crim(e), but
kvn@3038 180 snow, box, tray.
kvn@3038 181
kvn@3038 182 */
kvn@3038 183
kvn@3038 184 private final boolean cvc(int i)
kvn@3038 185 { if (i < 2 || !cons(i) || cons(i-1) || !cons(i-2)) return false;
kvn@3038 186 { int ch = b[i];
kvn@3038 187 if (ch == 'w' || ch == 'x' || ch == 'y') return false;
kvn@3038 188 }
kvn@3038 189 return true;
kvn@3038 190 }
kvn@3038 191
kvn@3038 192 private final boolean ends(String s)
kvn@3038 193 { int l = s.length();
kvn@3038 194 int o = k-l+1;
kvn@3038 195 if (o < 0) return false;
kvn@3038 196 for (int i = 0; i < l; i++) if (b[o+i] != s.charAt(i)) return false;
kvn@3038 197 j = k-l;
kvn@3038 198 return true;
kvn@3038 199 }
kvn@3038 200
kvn@3038 201 /* setto(s) sets (j+1),...k to the characters in the string s, readjusting
kvn@3038 202 k. */
kvn@3038 203
kvn@3038 204 private final void setto(String s)
kvn@3038 205 { int l = s.length();
kvn@3038 206 int o = j+1;
kvn@3038 207 for (int i = 0; i < l; i++) b[o+i] = s.charAt(i);
kvn@3038 208 k = j+l;
kvn@3038 209 }
kvn@3038 210
kvn@3038 211 /* r(s) is used further down. */
kvn@3038 212
kvn@3038 213 private final void r(String s) { if (m() > 0) setto(s); }
kvn@3038 214
kvn@3038 215 /* step1() gets rid of plurals and -ed or -ing. e.g.
kvn@3038 216
kvn@3038 217 caresses -> caress
kvn@3038 218 ponies -> poni
kvn@3038 219 ties -> ti
kvn@3038 220 caress -> caress
kvn@3038 221 cats -> cat
kvn@3038 222
kvn@3038 223 feed -> feed
kvn@3038 224 agreed -> agree
kvn@3038 225 disabled -> disable
kvn@3038 226
kvn@3038 227 matting -> mat
kvn@3038 228 mating -> mate
kvn@3038 229 meeting -> meet
kvn@3038 230 milling -> mill
kvn@3038 231 messing -> mess
kvn@3038 232
kvn@3038 233 meetings -> meet
kvn@3038 234
kvn@3038 235 */
kvn@3038 236
kvn@3038 237 private final void step1()
kvn@3038 238 { if (b[k] == 's')
kvn@3038 239 { if (ends("sses")) k -= 2; else
kvn@3038 240 if (ends("ies")) setto("i"); else
kvn@3038 241 if (b[k-1] != 's') k--;
kvn@3038 242 }
kvn@3038 243 if (ends("eed")) { if (m() > 0) k--; } else
kvn@3038 244 if ((ends("ed") || ends("ing")) && vowelinstem())
kvn@3038 245 { k = j;
kvn@3038 246 if (ends("at")) setto("ate"); else
kvn@3038 247 if (ends("bl")) setto("ble"); else
kvn@3038 248 if (ends("iz")) setto("ize"); else
kvn@3038 249 if (doublec(k))
kvn@3038 250 { k--;
kvn@3038 251 { int ch = b[k];
kvn@3038 252 if (ch == 'l' || ch == 's' || ch == 'z') k++;
kvn@3038 253 }
kvn@3038 254 }
kvn@3038 255 else if (m() == 1 && cvc(k)) setto("e");
kvn@3038 256 }
kvn@3038 257 }
kvn@3038 258
kvn@3038 259 /* step2() turns terminal y to i when there is another vowel in the stem. */
kvn@3038 260
kvn@3038 261 private final void step2() { if (ends("y") && vowelinstem()) b[k] = 'i'; }
kvn@3038 262
kvn@3038 263 /* step3() maps double suffices to single ones. so -ization ( = -ize plus
kvn@3038 264 -ation) maps to -ize etc. note that the string before the suffix must give
kvn@3038 265 m() > 0. */
kvn@3038 266
kvn@3038 267 private final void step3() { if (k == 0) return; /* For Bug 1 */ switch (b[k-1])
kvn@3038 268 {
kvn@3038 269 case 'a': if (ends("ational")) { r("ate"); break; }
kvn@3038 270 if (ends("tional")) { r("tion"); break; }
kvn@3038 271 break;
kvn@3038 272 case 'c': if (ends("enci")) { r("ence"); break; }
kvn@3038 273 if (ends("anci")) { r("ance"); break; }
kvn@3038 274 break;
kvn@3038 275 case 'e': if (ends("izer")) { r("ize"); break; }
kvn@3038 276 break;
kvn@3038 277 case 'l': if (ends("bli")) { r("ble"); break; }
kvn@3038 278 if (ends("alli")) { r("al"); break; }
kvn@3038 279 if (ends("entli")) { r("ent"); break; }
kvn@3038 280 if (ends("eli")) { r("e"); break; }
kvn@3038 281 if (ends("ousli")) { r("ous"); break; }
kvn@3038 282 break;
kvn@3038 283 case 'o': if (ends("ization")) { r("ize"); break; }
kvn@3038 284 if (ends("ation")) { r("ate"); break; }
kvn@3038 285 if (ends("ator")) { r("ate"); break; }
kvn@3038 286 break;
kvn@3038 287 case 's': if (ends("alism")) { r("al"); break; }
kvn@3038 288 if (ends("iveness")) { r("ive"); break; }
kvn@3038 289 if (ends("fulness")) { r("ful"); break; }
kvn@3038 290 if (ends("ousness")) { r("ous"); break; }
kvn@3038 291 break;
kvn@3038 292 case 't': if (ends("aliti")) { r("al"); break; }
kvn@3038 293 if (ends("iviti")) { r("ive"); break; }
kvn@3038 294 if (ends("biliti")) { r("ble"); break; }
kvn@3038 295 break;
kvn@3038 296 case 'g': if (ends("logi")) { r("log"); break; }
kvn@3038 297 } }
kvn@3038 298
kvn@3038 299 /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */
kvn@3038 300
kvn@3038 301 private final void step4() { switch (b[k])
kvn@3038 302 {
kvn@3038 303 case 'e': if (ends("icate")) { r("ic"); break; }
kvn@3038 304 if (ends("ative")) { r(""); break; }
kvn@3038 305 if (ends("alize")) { r("al"); break; }
kvn@3038 306 break;
kvn@3038 307 case 'i': if (ends("iciti")) { r("ic"); break; }
kvn@3038 308 break;
kvn@3038 309 case 'l': if (ends("ical")) { r("ic"); break; }
kvn@3038 310 if (ends("ful")) { r(""); break; }
kvn@3038 311 break;
kvn@3038 312 case 's': if (ends("ness")) { r(""); break; }
kvn@3038 313 break;
kvn@3038 314 } }
kvn@3038 315
kvn@3038 316 /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */
kvn@3038 317
kvn@3038 318 private final void step5()
kvn@3038 319 { if (k == 0) return; /* for Bug 1 */ switch (b[k-1])
kvn@3038 320 { case 'a': if (ends("al")) break; return;
kvn@3038 321 case 'c': if (ends("ance")) break;
kvn@3038 322 if (ends("ence")) break; return;
kvn@3038 323 case 'e': if (ends("er")) break; return;
kvn@3038 324 case 'i': if (ends("ic")) break; return;
kvn@3038 325 case 'l': if (ends("able")) break;
kvn@3038 326 if (ends("ible")) break; return;
kvn@3038 327 case 'n': if (ends("ant")) break;
kvn@3038 328 if (ends("ement")) break;
kvn@3038 329 if (ends("ment")) break;
kvn@3038 330 /* element etc. not stripped before the m */
kvn@3038 331 if (ends("ent")) break; return;
kvn@3038 332 case 'o': if (ends("ion") && j >= 0 && (b[j] == 's' || b[j] == 't')) break;
kvn@3038 333 /* j >= 0 fixes Bug 2 */
kvn@3038 334 if (ends("ou")) break; return;
kvn@3038 335 /* takes care of -ous */
kvn@3038 336 case 's': if (ends("ism")) break; return;
kvn@3038 337 case 't': if (ends("ate")) break;
kvn@3038 338 if (ends("iti")) break; return;
kvn@3038 339 case 'u': if (ends("ous")) break; return;
kvn@3038 340 case 'v': if (ends("ive")) break; return;
kvn@3038 341 case 'z': if (ends("ize")) break; return;
kvn@3038 342 default: return;
kvn@3038 343 }
kvn@3038 344 if (m() > 1) k = j;
kvn@3038 345 }
kvn@3038 346
kvn@3038 347 /* step6() removes a final -e if m() > 1. */
kvn@3038 348
kvn@3038 349 private final void step6()
kvn@3038 350 { j = k;
kvn@3038 351 if (b[k] == 'e')
kvn@3038 352 { int a = m();
kvn@3038 353 if (a > 1 || a == 1 && !cvc(k-1)) k--;
kvn@3038 354 }
kvn@3038 355 if (b[k] == 'l' && doublec(k) && m() > 1) k--;
kvn@3038 356 }
kvn@3038 357
kvn@3038 358 /** Stem the word placed into the Stemmer buffer through calls to add().
kvn@3038 359 * Returns true if the stemming process resulted in a word different
kvn@3038 360 * from the input. You can retrieve the result with
kvn@3038 361 * getResultLength()/getResultBuffer() or toString().
kvn@3038 362 */
kvn@3038 363 public void stem()
kvn@3038 364 { k = i - 1;
kvn@3038 365 if (k > 1) { step1(); step2(); step3(); step4(); step5(); step6(); }
kvn@3038 366 i_end = k+1; i = 0;
kvn@3038 367 }
kvn@3038 368
kvn@3038 369 /** Test program for demonstrating the Stemmer. It reads text from a
kvn@3038 370 * a list of files, stems each word, and writes the result to standard
kvn@3038 371 * output. Note that the word stemmed is expected to be in lower case:
kvn@3038 372 * forcing lower case must be done outside the Stemmer class.
kvn@3038 373 * Usage: Stemmer file-name file-name ...
kvn@3038 374 */
kvn@3038 375 public static void main(String[] args)
kvn@3038 376 {
kvn@3038 377 char[] w = new char[501];
kvn@3038 378 Stemmer s = new Stemmer();
kvn@3038 379 for (int i = 0; i < args.length; i++)
kvn@3038 380 try
kvn@3038 381 {
kvn@3038 382 FileInputStream in = new FileInputStream(args[i]);
kvn@3038 383
kvn@3038 384 try
kvn@3038 385 { while(true)
kvn@3038 386
kvn@3038 387 { int ch = in.read();
kvn@3038 388 if (Character.isLetter((char) ch))
kvn@3038 389 {
kvn@3038 390 int j = 0;
kvn@3038 391 while(true)
kvn@3038 392 { ch = Character.toLowerCase((char) ch);
kvn@3038 393 w[j] = (char) ch;
kvn@3038 394 if (j < 500) j++;
kvn@3038 395 ch = in.read();
kvn@3038 396 if (!Character.isLetter((char) ch))
kvn@3038 397 {
kvn@3038 398 /* to test add(char ch) */
kvn@3038 399 for (int c = 0; c < j; c++) s.add(w[c]);
kvn@3038 400
kvn@3038 401 /* or, to test add(char[] w, int j) */
kvn@3038 402 /* s.add(w, j); */
kvn@3038 403
kvn@3038 404 s.stem();
kvn@3038 405 { String u;
kvn@3038 406
kvn@3038 407 /* and now, to test toString() : */
kvn@3038 408 u = s.toString();
kvn@3038 409
kvn@3038 410 /* to test getResultBuffer(), getResultLength() : */
kvn@3038 411 /* u = new String(s.getResultBuffer(), 0, s.getResultLength()); */
kvn@3038 412
kvn@3038 413 System.out.print(u);
kvn@3038 414 }
kvn@3038 415 break;
kvn@3038 416 }
kvn@3038 417 }
kvn@3038 418 }
kvn@3038 419 if (ch < 0) break;
kvn@3038 420 System.out.print((char)ch);
kvn@3038 421 }
kvn@3038 422 }
kvn@3038 423 catch (IOException e)
kvn@3038 424 { System.out.println("error reading " + args[i]);
kvn@3038 425 break;
kvn@3038 426 }
kvn@3038 427 }
kvn@3038 428 catch (FileNotFoundException e)
kvn@3038 429 { System.out.println("file " + args[i] + " not found");
kvn@3038 430 break;
kvn@3038 431 }
kvn@3038 432 }
kvn@3038 433 }

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