| /** |
| * @test |
| * @bug 7070134 |
| * @summary Hotspot crashes with sigsegv from PorterStemmer |
| * |
| * @run shell Test7070134.sh |
| */ |
| |
| /* |
| |
| Porter stemmer in Java. The original paper is in |
| |
| Porter, 1980, An algorithm for suffix stripping, Program, Vol. 14, |
| no. 3, pp 130-137, |
| |
| http://www.tartarus.org/~martin/PorterStemmer |
| |
| The software is completely free for any purpose, unless notes at the head |
| of the program text indicates otherwise (which is rare). In any case, |
| the notes about licensing are never more restrictive than the BSD License. |
| |
| In every case where the software is not written by me (Martin Porter), |
| this licensing arrangement has been endorsed by the contributor, and it is |
| therefore unnecessary to ask the contributor again to confirm it. |
| |
| I have not asked any contributors (or their employers, if they have them) |
| for proofs that they have the right to distribute their software in this way. |
| |
| History: |
| |
| Release 1 |
| |
| Bug 1 (reported by Gonzalo Parra 16/10/99) fixed as marked below. |
| The words 'aed', 'eed', 'oed' leave k at 'a' for step 3, and b[k-1] |
| is then out outside the bounds of b. |
| |
| Release 2 |
| |
| Similarly, |
| |
| Bug 2 (reported by Steve Dyrdahl 22/2/00) fixed as marked below. |
| 'ion' by itself leaves j = -1 in the test for 'ion' in step 5, and |
| b[j] is then outside the bounds of b. |
| |
| Release 3 |
| |
| Considerably revised 4/9/00 in the light of many helpful suggestions |
| from Brian Goetz of Quiotix Corporation (brian@quiotix.com). |
| |
| Release 4 |
| |
| */ |
| |
| import java.io.*; |
| |
| /** |
| * Stemmer, implementing the Porter Stemming Algorithm |
| * |
| * The Stemmer class transforms a word into its root form. The input |
| * word can be provided a character at time (by calling add()), or at once |
| * by calling one of the various stem(something) methods. |
| */ |
| |
| class Stemmer |
| { private char[] b; |
| private int i, /* offset into b */ |
| i_end, /* offset to end of stemmed word */ |
| j, k; |
| private static final int INC = 50; |
| /* unit of size whereby b is increased */ |
| public Stemmer() |
| { b = new char[INC]; |
| i = 0; |
| i_end = 0; |
| } |
| |
| /** |
| * Add a character to the word being stemmed. When you are finished |
| * adding characters, you can call stem(void) to stem the word. |
| */ |
| |
| public void add(char ch) |
| { if (i == b.length) |
| { char[] new_b = new char[i+INC]; |
| for (int c = 0; c < i; c++) new_b[c] = b[c]; |
| b = new_b; |
| } |
| b[i++] = ch; |
| } |
| |
| |
| /** Adds wLen characters to the word being stemmed contained in a portion |
| * of a char[] array. This is like repeated calls of add(char ch), but |
| * faster. |
| */ |
| |
| public void add(char[] w, int wLen) |
| { if (i+wLen >= b.length) |
| { char[] new_b = new char[i+wLen+INC]; |
| for (int c = 0; c < i; c++) new_b[c] = b[c]; |
| b = new_b; |
| } |
| for (int c = 0; c < wLen; c++) b[i++] = w[c]; |
| } |
| |
| /** |
| * After a word has been stemmed, it can be retrieved by toString(), |
| * or a reference to the internal buffer can be retrieved by getResultBuffer |
| * and getResultLength (which is generally more efficient.) |
| */ |
| public String toString() { return new String(b,0,i_end); } |
| |
| /** |
| * Returns the length of the word resulting from the stemming process. |
| */ |
| public int getResultLength() { return i_end; } |
| |
| /** |
| * Returns a reference to a character buffer containing the results of |
| * the stemming process. You also need to consult getResultLength() |
| * to determine the length of the result. |
| */ |
| public char[] getResultBuffer() { return b; } |
| |
| /* cons(i) is true <=> b[i] is a consonant. */ |
| |
| private final boolean cons(int i) |
| { switch (b[i]) |
| { case 'a': case 'e': case 'i': case 'o': case 'u': return false; |
| case 'y': return (i==0) ? true : !cons(i-1); |
| default: return true; |
| } |
| } |
| |
| /* m() measures the number of consonant sequences between 0 and j. if c is |
| a consonant sequence and v a vowel sequence, and <..> indicates arbitrary |
| presence, |
| |
| <c><v> gives 0 |
| <c>vc<v> gives 1 |
| <c>vcvc<v> gives 2 |
| <c>vcvcvc<v> gives 3 |
| .... |
| */ |
| |
| private final int m() |
| { int n = 0; |
| int i = 0; |
| while(true) |
| { if (i > j) return n; |
| if (! cons(i)) break; i++; |
| } |
| i++; |
| while(true) |
| { while(true) |
| { if (i > j) return n; |
| if (cons(i)) break; |
| i++; |
| } |
| i++; |
| n++; |
| while(true) |
| { if (i > j) return n; |
| if (! cons(i)) break; |
| i++; |
| } |
| i++; |
| } |
| } |
| |
| /* vowelinstem() is true <=> 0,...j contains a vowel */ |
| |
| private final boolean vowelinstem() |
| { int i; for (i = 0; i <= j; i++) if (! cons(i)) return true; |
| return false; |
| } |
| |
| /* doublec(j) is true <=> j,(j-1) contain a double consonant. */ |
| |
| private final boolean doublec(int j) |
| { if (j < 1) return false; |
| if (b[j] != b[j-1]) return false; |
| return cons(j); |
| } |
| |
| /* cvc(i) is true <=> i-2,i-1,i has the form consonant - vowel - consonant |
| and also if the second c is not w,x or y. this is used when trying to |
| restore an e at the end of a short word. e.g. |
| |
| cav(e), lov(e), hop(e), crim(e), but |
| snow, box, tray. |
| |
| */ |
| |
| private final boolean cvc(int i) |
| { if (i < 2 || !cons(i) || cons(i-1) || !cons(i-2)) return false; |
| { int ch = b[i]; |
| if (ch == 'w' || ch == 'x' || ch == 'y') return false; |
| } |
| return true; |
| } |
| |
| private final boolean ends(String s) |
| { int l = s.length(); |
| int o = k-l+1; |
| if (o < 0) return false; |
| for (int i = 0; i < l; i++) if (b[o+i] != s.charAt(i)) return false; |
| j = k-l; |
| return true; |
| } |
| |
| /* setto(s) sets (j+1),...k to the characters in the string s, readjusting |
| k. */ |
| |
| private final void setto(String s) |
| { int l = s.length(); |
| int o = j+1; |
| for (int i = 0; i < l; i++) b[o+i] = s.charAt(i); |
| k = j+l; |
| } |
| |
| /* r(s) is used further down. */ |
| |
| private final void r(String s) { if (m() > 0) setto(s); } |
| |
| /* step1() gets rid of plurals and -ed or -ing. e.g. |
| |
| caresses -> caress |
| ponies -> poni |
| ties -> ti |
| caress -> caress |
| cats -> cat |
| |
| feed -> feed |
| agreed -> agree |
| disabled -> disable |
| |
| matting -> mat |
| mating -> mate |
| meeting -> meet |
| milling -> mill |
| messing -> mess |
| |
| meetings -> meet |
| |
| */ |
| |
| private final void step1() |
| { if (b[k] == 's') |
| { if (ends("sses")) k -= 2; else |
| if (ends("ies")) setto("i"); else |
| if (b[k-1] != 's') k--; |
| } |
| if (ends("eed")) { if (m() > 0) k--; } else |
| if ((ends("ed") || ends("ing")) && vowelinstem()) |
| { k = j; |
| if (ends("at")) setto("ate"); else |
| if (ends("bl")) setto("ble"); else |
| if (ends("iz")) setto("ize"); else |
| if (doublec(k)) |
| { k--; |
| { int ch = b[k]; |
| if (ch == 'l' || ch == 's' || ch == 'z') k++; |
| } |
| } |
| else if (m() == 1 && cvc(k)) setto("e"); |
| } |
| } |
| |
| /* step2() turns terminal y to i when there is another vowel in the stem. */ |
| |
| private final void step2() { if (ends("y") && vowelinstem()) b[k] = 'i'; } |
| |
| /* step3() maps double suffices to single ones. so -ization ( = -ize plus |
| -ation) maps to -ize etc. note that the string before the suffix must give |
| m() > 0. */ |
| |
| private final void step3() { if (k == 0) return; /* For Bug 1 */ switch (b[k-1]) |
| { |
| case 'a': if (ends("ational")) { r("ate"); break; } |
| if (ends("tional")) { r("tion"); break; } |
| break; |
| case 'c': if (ends("enci")) { r("ence"); break; } |
| if (ends("anci")) { r("ance"); break; } |
| break; |
| case 'e': if (ends("izer")) { r("ize"); break; } |
| break; |
| case 'l': if (ends("bli")) { r("ble"); break; } |
| if (ends("alli")) { r("al"); break; } |
| if (ends("entli")) { r("ent"); break; } |
| if (ends("eli")) { r("e"); break; } |
| if (ends("ousli")) { r("ous"); break; } |
| break; |
| case 'o': if (ends("ization")) { r("ize"); break; } |
| if (ends("ation")) { r("ate"); break; } |
| if (ends("ator")) { r("ate"); break; } |
| break; |
| case 's': if (ends("alism")) { r("al"); break; } |
| if (ends("iveness")) { r("ive"); break; } |
| if (ends("fulness")) { r("ful"); break; } |
| if (ends("ousness")) { r("ous"); break; } |
| break; |
| case 't': if (ends("aliti")) { r("al"); break; } |
| if (ends("iviti")) { r("ive"); break; } |
| if (ends("biliti")) { r("ble"); break; } |
| break; |
| case 'g': if (ends("logi")) { r("log"); break; } |
| } } |
| |
| /* step4() deals with -ic-, -full, -ness etc. similar strategy to step3. */ |
| |
| private final void step4() { switch (b[k]) |
| { |
| case 'e': if (ends("icate")) { r("ic"); break; } |
| if (ends("ative")) { r(""); break; } |
| if (ends("alize")) { r("al"); break; } |
| break; |
| case 'i': if (ends("iciti")) { r("ic"); break; } |
| break; |
| case 'l': if (ends("ical")) { r("ic"); break; } |
| if (ends("ful")) { r(""); break; } |
| break; |
| case 's': if (ends("ness")) { r(""); break; } |
| break; |
| } } |
| |
| /* step5() takes off -ant, -ence etc., in context <c>vcvc<v>. */ |
| |
| private final void step5() |
| { if (k == 0) return; /* for Bug 1 */ switch (b[k-1]) |
| { case 'a': if (ends("al")) break; return; |
| case 'c': if (ends("ance")) break; |
| if (ends("ence")) break; return; |
| case 'e': if (ends("er")) break; return; |
| case 'i': if (ends("ic")) break; return; |
| case 'l': if (ends("able")) break; |
| if (ends("ible")) break; return; |
| case 'n': if (ends("ant")) break; |
| if (ends("ement")) break; |
| if (ends("ment")) break; |
| /* element etc. not stripped before the m */ |
| if (ends("ent")) break; return; |
| case 'o': if (ends("ion") && j >= 0 && (b[j] == 's' || b[j] == 't')) break; |
| /* j >= 0 fixes Bug 2 */ |
| if (ends("ou")) break; return; |
| /* takes care of -ous */ |
| case 's': if (ends("ism")) break; return; |
| case 't': if (ends("ate")) break; |
| if (ends("iti")) break; return; |
| case 'u': if (ends("ous")) break; return; |
| case 'v': if (ends("ive")) break; return; |
| case 'z': if (ends("ize")) break; return; |
| default: return; |
| } |
| if (m() > 1) k = j; |
| } |
| |
| /* step6() removes a final -e if m() > 1. */ |
| |
| private final void step6() |
| { j = k; |
| if (b[k] == 'e') |
| { int a = m(); |
| if (a > 1 || a == 1 && !cvc(k-1)) k--; |
| } |
| if (b[k] == 'l' && doublec(k) && m() > 1) k--; |
| } |
| |
| /** Stem the word placed into the Stemmer buffer through calls to add(). |
| * Returns true if the stemming process resulted in a word different |
| * from the input. You can retrieve the result with |
| * getResultLength()/getResultBuffer() or toString(). |
| */ |
| public void stem() |
| { k = i - 1; |
| if (k > 1) { step1(); step2(); step3(); step4(); step5(); step6(); } |
| i_end = k+1; i = 0; |
| } |
| |
| /** Test program for demonstrating the Stemmer. It reads text from a |
| * a list of files, stems each word, and writes the result to standard |
| * output. Note that the word stemmed is expected to be in lower case: |
| * forcing lower case must be done outside the Stemmer class. |
| * Usage: Stemmer file-name file-name ... |
| */ |
| public static void main(String[] args) |
| { |
| char[] w = new char[501]; |
| Stemmer s = new Stemmer(); |
| for (int i = 0; i < args.length; i++) |
| try |
| { |
| FileInputStream in = new FileInputStream(args[i]); |
| |
| try |
| { while(true) |
| |
| { int ch = in.read(); |
| if (Character.isLetter((char) ch)) |
| { |
| int j = 0; |
| while(true) |
| { ch = Character.toLowerCase((char) ch); |
| w[j] = (char) ch; |
| if (j < 500) j++; |
| ch = in.read(); |
| if (!Character.isLetter((char) ch)) |
| { |
| /* to test add(char ch) */ |
| for (int c = 0; c < j; c++) s.add(w[c]); |
| |
| /* or, to test add(char[] w, int j) */ |
| /* s.add(w, j); */ |
| |
| s.stem(); |
| { String u; |
| |
| /* and now, to test toString() : */ |
| u = s.toString(); |
| |
| /* to test getResultBuffer(), getResultLength() : */ |
| /* u = new String(s.getResultBuffer(), 0, s.getResultLength()); */ |
| |
| System.out.print(u); |
| } |
| break; |
| } |
| } |
| } |
| if (ch < 0) break; |
| System.out.print((char)ch); |
| } |
| } |
| catch (IOException e) |
| { System.out.println("error reading " + args[i]); |
| break; |
| } |
| } |
| catch (FileNotFoundException e) |
| { System.out.println("file " + args[i] + " not found"); |
| break; |
| } |
| } |
| } |
