com.lowagie.text.pdf.hyphenation

## Class HyphenationTree

- java.lang.Object
- - com.lowagie.text.pdf.hyphenation.TernaryTree
  - - com.lowagie.text.pdf.hyphenation.HyphenationTree

All Implemented Interfaces:
  PatternConsumer, java.io.Serializable, java.lang.Cloneable

    public class HyphenationTree
    extends TernaryTree
    implements PatternConsumer

This tree structure stores the hyphenation patterns in an efficient way for fast lookup. It provides the provides the method to hyphenate a word.

Author:
  Carlos Villegas <cav@uniscope.co.jp>
See Also:
  Serialized Form

### Nested Class Summary

### Nested classes/interfaces inherited from class com.lowagie.text.pdf.hyphenation.TernaryTree

`TernaryTree.Iterator`

### Field Summary

Fields
`protected TernaryTree` `classmap` This map stores the character classes
`private TernaryTree` `ivalues` Temporary map to store interletter values on pattern loading.
`private static long` `serialVersionUID`
`protected java.util.HashMap` `stoplist` This map stores hyphenation exceptions
`protected ByteVector` `vspace` value space: stores the interletter values

### Fields inherited from class com.lowagie.text.pdf.hyphenation.TernaryTree

`BLOCK_SIZE, eq, freenode, hi, kv, length, lo, root, sc`

### Constructor Summary

Constructors
Constructor and Description
`HyphenationTree()`

### Method Summary

Methods
`void` `addClass(java.lang.String chargroup)` Add a character class to the tree.
`void` `addException(java.lang.String word, java.util.ArrayList hyphenatedword)` Add an exception to the tree.
`void` `addPattern(java.lang.String pattern, java.lang.String ivalue)` Add a pattern to the tree.
`java.lang.String` `findPattern(java.lang.String pat)`
`protected byte[]` `getValues(int k)`
`protected int` `hstrcmp(char[] s, int si, char[] t, int ti)` String compare, returns 0 if equal or t is a substring of s
`Hyphenation` `hyphenate(char[] w, int offset, int len, int remainCharCount, int pushCharCount)` Hyphenate word and return an array of hyphenation points.
`Hyphenation` `hyphenate(java.lang.String word, int remainCharCount, int pushCharCount)` Hyphenate word and return a Hyphenation object.
`void` `loadSimplePatterns(java.io.InputStream stream)`
`protected int` `packValues(java.lang.String values)` Packs the values by storing them in 4 bits, two values into a byte Values range is from 0 to 9.
`void` `printStats()`
`protected void` `searchPatterns(char[] word, int index, byte[] il)` Search for all possible partial matches of word starting at index an update interletter values.
`protected java.lang.String` `unpackValues(int k)`

### Methods inherited from class com.lowagie.text.pdf.hyphenation.TernaryTree

`balance, clone, find, find, init, insert, insert, insertBalanced, keys, knows, size, strcmp, strcmp, strcpy, strlen, strlen, trimToSize`

### Methods inherited from class java.lang.Object

`equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Field Detail

#### serialVersionUID

    private static final long serialVersionUID

See Also:
  Constant Field Values

#### vspace

    protected ByteVector vspace

value space: stores the interletter values

#### stoplist

    protected java.util.HashMap stoplist

This map stores hyphenation exceptions

#### classmap

    protected TernaryTree classmap

This map stores the character classes

#### ivalues

    private transient TernaryTree ivalues

Temporary map to store interletter values on pattern loading.

### Constructor Detail

#### HyphenationTree

    public HyphenationTree()

### Method Detail

#### packValues

    protected int packValues(java.lang.String values)

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.

Parameters:
  `values` - a string of digits from '0' to '9' representing the interletter values.
Returns:
  the index into the vspace array where the packed values are stored.

#### unpackValues

    protected java.lang.String unpackValues(int k)

#### loadSimplePatterns

    public void loadSimplePatterns(java.io.InputStream stream)

#### findPattern

    public java.lang.String findPattern(java.lang.String pat)

#### hstrcmp

    protected int hstrcmp(char[] s,
              int si,
              char[] t,
              int ti)

String compare, returns 0 if equal or t is a substring of s

#### getValues

    protected byte[] getValues(int k)

#### searchPatterns

    protected void searchPatterns(char[] word,
                      int index,
                      byte[] il)

Search for all possible partial matches of word starting at index an update interletter values. In other words, it does something like:

`for(i=0; i<patterns.length; i++) { if ( word.substring(index).startsWidth(patterns[i]) ) update_interletter_values(patterns[i]); }`

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

Parameters:
  `word` - null terminated word to match
  `index` - start index from word
  `il` - interletter values array to update

#### hyphenate

    public Hyphenation hyphenate(java.lang.String word,
                        int remainCharCount,
                        int pushCharCount)

Hyphenate word and return a Hyphenation object.

Parameters:
  `word` - the word to be hyphenated
  `remainCharCount` - Minimum number of characters allowed before the hyphenation point.
  `pushCharCount` - Minimum number of characters allowed after the hyphenation point.
Returns:
  a `Hyphenation` object representing the hyphenated word or null if word is not hyphenated.

#### hyphenate

    public Hyphenation hyphenate(char[] w,
                        int offset,
                        int len,
                        int remainCharCount,
                        int pushCharCount)

Hyphenate word and return an array of hyphenation points.

Parameters:
  `w` - char array that contains the word
  `offset` - Offset to first character in word
  `len` - Length of word
  `remainCharCount` - Minimum number of characters allowed before the hyphenation point.
  `pushCharCount` - Minimum number of characters allowed after the hyphenation point.
Returns:
  a `Hyphenation` object representing the hyphenated word or null if word is not hyphenated.

#### addClass

    public void addClass(java.lang.String chargroup)

Add a character class to the tree. It is used by `SimplePatternParser` 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.

Specified by:
  `addClass` in interface `PatternConsumer`
Parameters:
  `chargroup` - character group

#### addException

    public void addException(java.lang.String word,
                    java.util.ArrayList hyphenatedword)

Add an exception to the tree. It is used by `SimplePatternParser` class as callback to store the hyphenation exceptions.

Specified by:
  `addException` in interface `PatternConsumer`
Parameters:
  `word` - normalized word
  `hyphenatedword` - a vector of alternating strings and `hyphen` objects.

#### addPattern

    public void addPattern(java.lang.String pattern,
                  java.lang.String ivalue)

Add a pattern to the tree. Mainly, to be used by `SimplePatternParser` class as callback to add a pattern to the tree.

Specified by:
  `addPattern` in interface `PatternConsumer`
Parameters:
  `pattern` - the hyphenation pattern
  `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').

#### printStats

    public void printStats()

Overrides:
  `printStats` in class `TernaryTree`