A specialized Map/Symbol table - like data structure that can be used for both checking whether a word (passed in as a char array) exists in certain set of words AND getting that word as a String. It is reasonably efficient both time and speed-wise, at least for certain use cases; specifically, if there is no existing key to use, it is more efficient way to get to a shared copy of that String The general usage pattern is expected to be such that most checks are positive, ie. that the word indeed is contained in the structure.

Although this is an efficient data struct for specific set of usage patterns, one restriction is that the full set of words to include has to be known before constructing the instnace. Also, the size of the set is limited to total word content of about 20k characters.

Todo

Should document the internal data structure...

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	WordResolver.Builder

Field Summary

Modifier and Type	Field and Description
pack-priv static final char	CHAR_NULL
public static final int	MAX_WORDS Maximum number of words (Strings) an instance can contain
pack-priv final char[]	mData Compressed presentation of the word set.
pack-priv static final int	MIN_BINARY_SEARCH This is actually just a guess; but in general linear search should be faster for short sequences (definitely for 4 or less; maybe up to 8 or less?)
pack-priv final String[]	mWords Array of actual words returned resolved for matches.
pack-priv static final int	NEGATIVE_OFFSET Offset added to numbers to mark 'negative' numbers.

Access	Constructor and Description
pack-priv	WordResolver(String[] words, char[] index)

Method Summary

Modifier and Type	Method and Description
public static WordResolver	Returns: WordResolver constructed for given set of words, if the word set size is not too big; null to indicate "too big" instance. constructInstance(TreeSet<String> wordSet) Tries to construct an instance given ordered set of words.
public String	Returns: (Shared) string instance of the word, if it exists in the word set; null if not. find(char[] Character array that contains the word to find str, final int Index of the first character of the word start, final int Index following the last character of the word, so that `end - start` equals word length (similar to the way `String.substring()` has). end)
public String	Returns: (Shared) string instance of the word, if it exists in the word set; null if not. find(String str)
private String	findFromOne(char[] str, final int start, final int end)
public int	Returns: Number of words contained size()
public String	toString() Overrides java.lang.Object.toString. Returns a string representation of the object.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

Field Detail

CHAR_NULL	back to summary
pack-priv static final char CHAR_NULL

MAX_WORDS	back to summary
public static final int MAX_WORDS Maximum number of words (Strings) an instance can contain

mData	back to summary
pack-priv final char[] mData Compressed presentation of the word set.

MIN_BINARY_SEARCH	back to summary
pack-priv static final int MIN_BINARY_SEARCH This is actually just a guess; but in general linear search should be faster for short sequences (definitely for 4 or less; maybe up to 8 or less?)

mWords	back to summary
pack-priv final String[] mWords Array of actual words returned resolved for matches.

NEGATIVE_OFFSET	back to summary
pack-priv static final int NEGATIVE_OFFSET Offset added to numbers to mark 'negative' numbers. Asymmetric, since range of negative markers needed is smaller than positive numbers...

WordResolver	back to summary
pack-priv WordResolver(String[] words, char[] index)

Method Detail

constructInstance back to summary

constructInstance	back to summary
public static WordResolver constructInstance(TreeSet<String> wordSet) Tries to construct an instance given ordered set of words. Note currently maximum number of words that can be contained is limited to `MAX_WORDS`; additionally, maximum length of all such words can not exceed roughly 28000 characters. Returns:WordResolver WordResolver constructed for given set of words, if the word set size is not too big; null to indicate "too big" instance.

public static WordResolver constructInstance(TreeSet<String> wordSet)

Tries to construct an instance given ordered set of words.

Note

currently maximum number of words that can be contained is limited to MAX_WORDS; additionally, maximum length of all such words can not exceed roughly 28000 characters.

Returns:WordResolver: WordResolver constructed for given set of words, if the word set size is not too big; null to indicate "too big" instance.

find back to summary

find	back to summary
public String find(char[] str, final int start, final int end) Parameters str:char[] Character array that contains the word to find start:int Index of the first character of the word end:int Index following the last character of the word, so that `end - start` equals word length (similar to the way `String.substring()` has). Returns:String (Shared) string instance of the word, if it exists in the word set; null if not. Annotations @SuppressWarnings:cast

public String find(char[] str, final int start, final int end)

Parameters

str:char[]: Character array that contains the word to find
start:int: Index of the first character of the word
end:int: Index following the last character of the word, so that end - start equals word length (similar to the way String.substring() has).

Returns:String

(Shared) string instance of the word, if it exists in the word set; null if not.

Annotations

@SuppressWarnings:cast

find	back to summary
public String find(String str) Returns:String (Shared) string instance of the word, if it exists in the word set; null if not. Annotations @SuppressWarnings:cast

findFromOne	back to summary
private String findFromOne(char[] str, final int start, final int end)

size	back to summary
public int size() Returns:int Number of words contained

toString back to summary

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Doc from java.lang.Object.toString. Returns a string representation of the object. Satisfying this method's contract implies a non-`null` result must be returned. Returns:String a string representation of the object Annotations @Override

public String toString()

Overrides java.lang.Object.toString.

Doc from java.lang.Object.toString.

Returns a string representation of the object. Satisfying this method's contract implies a non-null result must be returned.

Returns:String

a string representation of the object

Annotations

@Override

com.ctc.wstx.util back to summary

private final Class WordResolver.Builder

Class Inheritance

extends Object

java.lang.Object
com.ctc.wstx.util.WordResolver.Builder

Field Summary

Modifier and Type	Field and Description
pack-priv char[]	mData
pack-priv int	mSize Number of characters currently used from mData
pack-priv final String[]	mWords

Constructor Summary

Access	Constructor and Description
public	Builder(TreeSet<String> wordSet)

Method Summary

Modifier and Type	Method and Description
public WordResolver	Returns: Raw character data that contains compressed structure of the word set construct()
private void	constructBranch(int Index of the character in words to consider for this round charIndex, int Index of the first word to be processed start, int Index of the word after last word to be processed (so that number of words is `end - start - 1` end) Method that is called recursively to build the data representation for a branch, ie.
private char[]	expand(int needSpace)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

mData	back to summary
pack-priv char[] mData

mSize	back to summary
pack-priv int mSize Number of characters currently used from mData

mWords	back to summary
pack-priv final String[] mWords

Constructor Detail

Builder	back to summary
public Builder(TreeSet<String> wordSet)

Method Detail

construct	back to summary
public WordResolver construct() Returns:WordResolver Raw character data that contains compressed structure of the word set

constructBranch back to summary

constructBranch	back to summary
private void constructBranch(int charIndex, int start, int end) Method that is called recursively to build the data representation for a branch, ie. part of word set tree that still has more than one ending Parameters charIndex:int Index of the character in words to consider for this round start:int Index of the first word to be processed end:int Index of the word after last word to be processed (so that number of words is `end - start - 1` Annotations @SuppressWarnings:cast

private void constructBranch(int charIndex, int start, int end)

Method that is called recursively to build the data representation for a branch, ie. part of word set tree that still has more than one ending

Parameters

charIndex:int: Index of the character in words to consider for this round
start:int: Index of the first word to be processed
end:int: Index of the word after last word to be processed (so that number of words is end - start - 1

Annotations

@SuppressWarnings:cast

expand	back to summary
private char[] expand(int needSpace)

public final Class WordResolver

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private final Class WordResolver.Builder

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail