--- /dev/null
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.lucene.analysis.compound.hyphenation;
+
+import java.io.File;
+import java.io.Serializable;
+import java.net.MalformedURLException;
+import java.util.ArrayList;
+import java.util.HashMap;
+
+import org.xml.sax.InputSource;
+
+/**
+ * This tree structure stores the hyphenation patterns in an efficient way for
+ * fast lookup. It provides the provides the method to hyphenate a word.
+ *
+ * This class has been taken from the Apache FOP project (http://xmlgraphics.apache.org/fop/). They have been slightly modified.
+ */
+public class HyphenationTree extends TernaryTree implements PatternConsumer,
+ Serializable {
+
+ private static final long serialVersionUID = -7842107987915665573L;
+
+ /**
+ * value space: stores the interletter values
+ */
+ protected ByteVector vspace;
+
+ /**
+ * This map stores hyphenation exceptions
+ */
+ protected HashMap<String,ArrayList<Object>> stoplist;
+
+ /**
+ * This map stores the character classes
+ */
+ protected TernaryTree classmap;
+
+ /**
+ * Temporary map to store interletter values on pattern loading.
+ */
+ private transient TernaryTree ivalues;
+
+ public HyphenationTree() {
+ stoplist = new HashMap<String,ArrayList<Object>>(23); // usually a small table
+ classmap = new TernaryTree();
+ vspace = new ByteVector();
+ vspace.alloc(1); // this reserves index 0, which we don't use
+ }
+
+ /**
+ * Packs the values by storing them in 4 bits, two values into a byte Values
+ * range is from 0 to 9. We use zero as terminator, so we'll add 1 to the
+ * value.
+ *
+ * @param values a string of digits from '0' to '9' representing the
+ * interletter values.
+ * @return the index into the vspace array where the packed values are stored.
+ */
+ protected int packValues(String values) {
+ int i, n = values.length();
+ int m = (n & 1) == 1 ? (n >> 1) + 2 : (n >> 1) + 1;
+ int offset = vspace.alloc(m);
+ byte[] va = vspace.getArray();
+ for (i = 0; i < n; i++) {
+ int j = i >> 1;
+ byte v = (byte) ((values.charAt(i) - '0' + 1) & 0x0f);
+ if ((i & 1) == 1) {
+ va[j + offset] = (byte) (va[j + offset] | v);
+ } else {
+ va[j + offset] = (byte) (v << 4); // big endian
+ }
+ }
+ va[m - 1 + offset] = 0; // terminator
+ return offset;
+ }
+
+ protected String unpackValues(int k) {
+ StringBuilder buf = new StringBuilder();
+ byte v = vspace.get(k++);
+ while (v != 0) {
+ char c = (char) ((v >>> 4) - 1 + '0');
+ buf.append(c);
+ c = (char) (v & 0x0f);
+ if (c == 0) {
+ break;
+ }
+ c = (char) (c - 1 + '0');
+ buf.append(c);
+ v = vspace.get(k++);
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Read hyphenation patterns from an XML file.
+ *
+ * @param f the filename
+ * @throws HyphenationException In case the parsing fails
+ */
+ public void loadPatterns(File f) throws HyphenationException {
+ try {
+ InputSource src = new InputSource(f.toURL().toExternalForm());
+ loadPatterns(src);
+ } catch (MalformedURLException e) {
+ throw new HyphenationException("Error converting the File '" + f
+ + "' to a URL: " + e.getMessage());
+ }
+ }
+
+ /**
+ * Read hyphenation patterns from an XML file.
+ *
+ * @param source the InputSource for the file
+ * @throws HyphenationException In case the parsing fails
+ */
+ public void loadPatterns(InputSource source) throws HyphenationException {
+ PatternParser pp = new PatternParser(this);
+ ivalues = new TernaryTree();
+
+ pp.parse(source);
+
+ // patterns/values should be now in the tree
+ // let's optimize a bit
+ trimToSize();
+ vspace.trimToSize();
+ classmap.trimToSize();
+
+ // get rid of the auxiliary map
+ ivalues = null;
+ }
+
+ public String findPattern(String pat) {
+ int k = super.find(pat);
+ if (k >= 0) {
+ return unpackValues(k);
+ }
+ return "";
+ }
+
+ /**
+ * String compare, returns 0 if equal or t is a substring of s
+ */
+ protected int hstrcmp(char[] s, int si, char[] t, int ti) {
+ for (; s[si] == t[ti]; si++, ti++) {
+ if (s[si] == 0) {
+ return 0;
+ }
+ }
+ if (t[ti] == 0) {
+ return 0;
+ }
+ return s[si] - t[ti];
+ }
+
+ protected byte[] getValues(int k) {
+ StringBuilder buf = new StringBuilder();
+ byte v = vspace.get(k++);
+ while (v != 0) {
+ char c = (char) ((v >>> 4) - 1);
+ buf.append(c);
+ c = (char) (v & 0x0f);
+ if (c == 0) {
+ break;
+ }
+ c = (char) (c - 1);
+ buf.append(c);
+ v = vspace.get(k++);
+ }
+ byte[] res = new byte[buf.length()];
+ for (int i = 0; i < res.length; i++) {
+ res[i] = (byte) buf.charAt(i);
+ }
+ return res;
+ }
+
+ /**
+ * <p>
+ * Search for all possible partial matches of word starting at index an update
+ * interletter values. In other words, it does something like:
+ * </p>
+ * <code>
+ * for(i=0; i<patterns.length; i++) {
+ * if ( word.substring(index).startsWidth(patterns[i]) )
+ * update_interletter_values(patterns[i]);
+ * }
+ * </code>
+ * <p>
+ * But it is done in an efficient way since the patterns are stored in a
+ * ternary tree. In fact, this is the whole purpose of having the tree: doing
+ * this search without having to test every single pattern. The number of
+ * patterns for languages such as English range from 4000 to 10000. Thus,
+ * doing thousands of string comparisons for each word to hyphenate would be
+ * really slow without the tree. The tradeoff is memory, but using a ternary
+ * tree instead of a trie, almost halves the the memory used by Lout or TeX.
+ * It's also faster than using a hash table
+ * </p>
+ *
+ * @param word null terminated word to match
+ * @param index start index from word
+ * @param il interletter values array to update
+ */
+ protected void searchPatterns(char[] word, int index, byte[] il) {
+ byte[] values;
+ int i = index;
+ char p, q;
+ char sp = word[i];
+ p = root;
+
+ while (p > 0 && p < sc.length) {
+ if (sc[p] == 0xFFFF) {
+ if (hstrcmp(word, i, kv.getArray(), lo[p]) == 0) {
+ values = getValues(eq[p]); // data pointer is in eq[]
+ int j = index;
+ for (int k = 0; k < values.length; k++) {
+ if (j < il.length && values[k] > il[j]) {
+ il[j] = values[k];
+ }
+ j++;
+ }
+ }
+ return;
+ }
+ int d = sp - sc[p];
+ if (d == 0) {
+ if (sp == 0) {
+ break;
+ }
+ sp = word[++i];
+ p = eq[p];
+ q = p;
+
+ // look for a pattern ending at this position by searching for
+ // the null char ( splitchar == 0 )
+ while (q > 0 && q < sc.length) {
+ if (sc[q] == 0xFFFF) { // stop at compressed branch
+ break;
+ }
+ if (sc[q] == 0) {
+ values = getValues(eq[q]);
+ int j = index;
+ for (int k = 0; k < values.length; k++) {
+ if (j < il.length && values[k] > il[j]) {
+ il[j] = values[k];
+ }
+ j++;
+ }
+ break;
+ } else {
+ q = lo[q];
+
+ /**
+ * actually the code should be: q = sc[q] < 0 ? hi[q] : lo[q]; but
+ * java chars are unsigned
+ */
+ }
+ }
+ } else {
+ p = d < 0 ? lo[p] : hi[p];
+ }
+ }
+ }
+
+ /**
+ * Hyphenate word and return a Hyphenation object.
+ *
+ * @param word the word to be hyphenated
+ * @param remainCharCount Minimum number of characters allowed before the
+ * hyphenation point.
+ * @param pushCharCount Minimum number of characters allowed after the
+ * hyphenation point.
+ * @return a {@link Hyphenation Hyphenation} object representing the
+ * hyphenated word or null if word is not hyphenated.
+ */
+ public Hyphenation hyphenate(String word, int remainCharCount,
+ int pushCharCount) {
+ char[] w = word.toCharArray();
+ return hyphenate(w, 0, w.length, remainCharCount, pushCharCount);
+ }
+
+ /**
+ * w = "****nnllllllnnn*****", where n is a non-letter, l is a letter, all n
+ * may be absent, the first n is at offset, the first l is at offset +
+ * iIgnoreAtBeginning; word = ".llllll.'\0'***", where all l in w are copied
+ * into word. In the first part of the routine len = w.length, in the second
+ * part of the routine len = word.length. Three indices are used: index(w),
+ * the index in w, index(word), the index in word, letterindex(word), the
+ * index in the letter part of word. The following relations exist: index(w) =
+ * offset + i - 1 index(word) = i - iIgnoreAtBeginning letterindex(word) =
+ * index(word) - 1 (see first loop). It follows that: index(w) - index(word) =
+ * offset - 1 + iIgnoreAtBeginning index(w) = letterindex(word) + offset +
+ * iIgnoreAtBeginning
+ */
+
+ /**
+ * Hyphenate word and return an array of hyphenation points.
+ *
+ * @param w char array that contains the word
+ * @param offset Offset to first character in word
+ * @param len Length of word
+ * @param remainCharCount Minimum number of characters allowed before the
+ * hyphenation point.
+ * @param pushCharCount Minimum number of characters allowed after the
+ * hyphenation point.
+ * @return a {@link Hyphenation Hyphenation} object representing the
+ * hyphenated word or null if word is not hyphenated.
+ */
+ public Hyphenation hyphenate(char[] w, int offset, int len,
+ int remainCharCount, int pushCharCount) {
+ int i;
+ char[] word = new char[len + 3];
+
+ // normalize word
+ char[] c = new char[2];
+ int iIgnoreAtBeginning = 0;
+ int iLength = len;
+ boolean bEndOfLetters = false;
+ for (i = 1; i <= len; i++) {
+ c[0] = w[offset + i - 1];
+ int nc = classmap.find(c, 0);
+ if (nc < 0) { // found a non-letter character ...
+ if (i == (1 + iIgnoreAtBeginning)) {
+ // ... before any letter character
+ iIgnoreAtBeginning++;
+ } else {
+ // ... after a letter character
+ bEndOfLetters = true;
+ }
+ iLength--;
+ } else {
+ if (!bEndOfLetters) {
+ word[i - iIgnoreAtBeginning] = (char) nc;
+ } else {
+ return null;
+ }
+ }
+ }
+ len = iLength;
+ if (len < (remainCharCount + pushCharCount)) {
+ // word is too short to be hyphenated
+ return null;
+ }
+ int[] result = new int[len + 1];
+ int k = 0;
+
+ // check exception list first
+ String sw = new String(word, 1, len);
+ if (stoplist.containsKey(sw)) {
+ // assume only simple hyphens (Hyphen.pre="-", Hyphen.post = Hyphen.no =
+ // null)
+ ArrayList<Object> hw = stoplist.get(sw);
+ int j = 0;
+ for (i = 0; i < hw.size(); i++) {
+ Object o = hw.get(i);
+ // j = index(sw) = letterindex(word)?
+ // result[k] = corresponding index(w)
+ if (o instanceof String) {
+ j += ((String) o).length();
+ if (j >= remainCharCount && j < (len - pushCharCount)) {
+ result[k++] = j + iIgnoreAtBeginning;
+ }
+ }
+ }
+ } else {
+ // use algorithm to get hyphenation points
+ word[0] = '.'; // word start marker
+ word[len + 1] = '.'; // word end marker
+ word[len + 2] = 0; // null terminated
+ byte[] il = new byte[len + 3]; // initialized to zero
+ for (i = 0; i < len + 1; i++) {
+ searchPatterns(word, i, il);
+ }
+
+ // hyphenation points are located where interletter value is odd
+ // i is letterindex(word),
+ // i + 1 is index(word),
+ // result[k] = corresponding index(w)
+ for (i = 0; i < len; i++) {
+ if (((il[i + 1] & 1) == 1) && i >= remainCharCount
+ && i <= (len - pushCharCount)) {
+ result[k++] = i + iIgnoreAtBeginning;
+ }
+ }
+ }
+
+ if (k > 0) {
+ // trim result array
+ int[] res = new int[k+2];
+ System.arraycopy(result, 0, res, 1, k);
+ // We add the synthetical hyphenation points
+ // at the beginning and end of the word
+ res[0]=0;
+ res[k+1]=len;
+ return new Hyphenation(res);
+ } else {
+ return null;
+ }
+ }
+
+ /**
+ * Add a character class to the tree. It is used by
+ * {@link PatternParser PatternParser} as callback to add character classes.
+ * Character classes define the valid word characters for hyphenation. If a
+ * word contains a character not defined in any of the classes, it is not
+ * hyphenated. It also defines a way to normalize the characters in order to
+ * compare them with the stored patterns. Usually pattern files use only lower
+ * case characters, in this case a class for letter 'a', for example, should
+ * be defined as "aA", the first character being the normalization char.
+ */
+ public void addClass(String chargroup) {
+ if (chargroup.length() > 0) {
+ char equivChar = chargroup.charAt(0);
+ char[] key = new char[2];
+ key[1] = 0;
+ for (int i = 0; i < chargroup.length(); i++) {
+ key[0] = chargroup.charAt(i);
+ classmap.insert(key, 0, equivChar);
+ }
+ }
+ }
+
+ /**
+ * Add an exception to the tree. It is used by
+ * {@link PatternParser PatternParser} class as callback to store the
+ * hyphenation exceptions.
+ *
+ * @param word normalized word
+ * @param hyphenatedword a vector of alternating strings and
+ * {@link Hyphen hyphen} objects.
+ */
+ public void addException(String word, ArrayList<Object> hyphenatedword) {
+ stoplist.put(word, hyphenatedword);
+ }
+
+ /**
+ * Add a pattern to the tree. Mainly, to be used by
+ * {@link PatternParser PatternParser} class as callback to add a pattern to
+ * the tree.
+ *
+ * @param pattern the hyphenation pattern
+ * @param ivalue interletter weight values indicating the desirability and
+ * priority of hyphenating at a given point within the pattern. It
+ * should contain only digit characters. (i.e. '0' to '9').
+ */
+ public void addPattern(String pattern, String ivalue) {
+ int k = ivalues.find(ivalue);
+ if (k <= 0) {
+ k = packValues(ivalue);
+ ivalues.insert(ivalue, (char) k);
+ }
+ insert(pattern, (char) k);
+ }
+
+ @Override
+ public void printStats() {
+ System.out.println("Value space size = "
+ + Integer.toString(vspace.length()));
+ super.printStats();
+
+ }
+}
fnp / pylucene.git / blobdiff