Class Trie

java.lang.Object
  |
  +--Trie

public class Trie

extends java.lang.Object

Warning this class serves as both a Trie and a Trie-node. These duties should probably be broken into separate classes. The current version suppots Joggle-lookup in addition to insertion/search so it exposes Nodes to client code

Limitation: supports wors up to 1024 characters long

Implements a trie for storing strings/string prefixes This trie stores only 26 characters per node, these characters are assumed to be lowercase. For uppercase or mixed case change the protected fields

• ALPH_SIZE which is the size of the alphabet (defaults to 26)

• FIRST is the first of ALPH_SIZE consecutive characters used in making the trie (defaults to 'a'

This trie supports adding Strings and C-style strings where a C-style string is a '\0' terminated array of char

See Also:

JoggleWordFinder

Field Summary

protected static int	ALPH_SIZE
protected static char	FIRST

Constructor Summary

Trie()
create a new emtpy Trie

Method Summary

void	addCString(char[] s)
void	addString(java.lang.String s) Add a string to the trie, subsequent calls of isWord(s) will return true
protected int	charToIndex(char ch)
Trie	childAt(char ch)
java.util.List	getWords() return a List of every word in the Trie
boolean	isWord()
boolean	isWord(java.lang.String s) determine if a word is in the trie

Methods inherited from class java.lang.Object

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

Field Detail

ALPH_SIZE

protected static int ALPH_SIZE

FIRST

protected static char FIRST

Constructor Detail

Trie

public Trie()

create a new emtpy Trie

Method Detail

addString

public void addString(java.lang.String s)

Add a string to the trie, subsequent calls of isWord(s) will return true

Parameters:

s - The string added to Trie

addCString

public void addCString(char[] s)

getWords

public java.util.List getWords()

return a List of every word in the Trie

isWord

public boolean isWord(java.lang.String s)

determine if a word is in the trie

Parameters:

s - The string searched for

Returns:

true iff s is in trie (rooted here)

isWord

public boolean isWord()

Returns:

true iff path from some root to this node is a word

childAt

public Trie childAt(char ch)

Parameters:

ch - Character used to index node (find child)

Returns:

Trie formed from this by indexing using ch

charToIndex

protected int charToIndex(char ch)