com.ibm.icu.text

Class RuleBasedBreakIterator_New

Implemented Interfaces:
Cloneable

public class RuleBasedBreakIterator_New
extends RuleBasedBreakIterator

Rule Based Break Iterator implementation. This is a port of the C++ class RuleBasedBreakIterator from ICU4C. A note on future plans: Once a new DictionaryBasedBreakIterator implementation is completed, the archaic implementation class RuleBasedBreakIterator_Old can be completely removed, and this class can be renamed to be simply RuleBasedBreakIterator.

Field Summary

static boolean
fTrace
Debugging flag.

Fields inherited from class com.ibm.icu.text.RuleBasedBreakIterator

WORD_IDEO, WORD_IDEO_LIMIT, WORD_KANA, WORD_KANA_LIMIT, WORD_LETTER, WORD_LETTER_LIMIT, WORD_NONE, WORD_NONE_LIMIT, WORD_NUMBER, WORD_NUMBER_LIMIT

Fields inherited from class com.ibm.icu.text.BreakIterator

DONE, KIND_CHARACTER, KIND_LINE, KIND_SENTENCE, KIND_TITLE, KIND_WORD

Method Summary

protected static void
checkOffset(int offset, CharacterIterator text)
Throw IllegalArgumentException unless begin <= offset <32end.
Object
clone()
Clones this iterator.
int
current()
Returns the current iteration position.
void
dump()
Dump the contents of the state table and character classes for this break iterator.
boolean
equals(Object that)
Returns true if both BreakIterators are of the same class, have the same rules, and iterate over the same text.
int
first()
Sets the current iteration position to the beginning of the text.
int
following(int offset)
Sets the iterator to refer to the first boundary position following the specified position.
static RuleBasedBreakIterator
getInstanceFromCompiledRules(InputStream is)
Create a break iterator from a precompiled set of rules.
int
getRuleStatus()
Return the status tag from the break rule that determined the most recently returned break position.
int
getRuleStatusVec(int[] fillInArray)
Get the status (tag) values from the break rule(s) that determined the most recently returned break position.
CharacterIterator
getText()
Return a CharacterIterator over the text being analyzed.
int
hashCode()
Compute a hashcode for this BreakIterator
boolean
isBoundary(int offset)
Returns true if the specfied position is a boundary position.
int
last()
Sets the current iteration position to the end of the text.
int
next()
Advances the iterator to the next boundary position.
int
next(int n)
Advances the iterator either forward or backward the specified number of steps.
int
preceding(int offset)
Sets the iterator to refer to the last boundary position before the specified position.
int
previous()
Moves the iterator backwards, to the last boundary preceding this one.
void
setText(CharacterIterator newText)
Set the iterator to analyze a new piece of text.
String
toString()
Returns the description (rules) used to create this iterator.

Methods inherited from class com.ibm.icu.text.RuleBasedBreakIterator

clone, current, equals, first, following, getInstanceFromCompiledRules, getRuleStatus, getRuleStatusVec, getText, hashCode, isBoundary, last, next, next, preceding, previous, setText, toString

Methods inherited from class com.ibm.icu.text.BreakIterator

clone, current, first, following, getAvailableLocales, getAvailableULocales, getCharacterInstance, getCharacterInstance, getCharacterInstance, getLineInstance, getLineInstance, getLineInstance, getLocale, getSentenceInstance, getSentenceInstance, getSentenceInstance, getText, getTitleInstance, getTitleInstance, getTitleInstance, getWordInstance, getWordInstance, getWordInstance, isBoundary, last, next, next, preceding, previous, registerInstance, registerInstance, setText, setText, unregister

Field Details

fTrace

public static boolean fTrace
Debugging flag. Trace operation of state machine when true.

Method Details

checkOffset

protected static final void checkOffset(int offset,
                                        CharacterIterator text)
Throw IllegalArgumentException unless begin <= offset <32end.

clone

public Object clone()
Clones this iterator.
Overrides:
clone in interface RuleBasedBreakIterator
Returns:
A newly-constructed RuleBasedBreakIterator with the same behavior as this one.

current

public int current()
Returns the current iteration position.
Overrides:
current in interface RuleBasedBreakIterator
Returns:
The current iteration position.

dump

public void dump()
Dump the contents of the state table and character classes for this break iterator. For debugging only.

equals

public boolean equals(Object that)
Returns true if both BreakIterators are of the same class, have the same rules, and iterate over the same text.
Overrides:
equals in interface RuleBasedBreakIterator

first

public int first()
Sets the current iteration position to the beginning of the text. (i.e., the CharacterIterator's starting offset).
Overrides:
first in interface RuleBasedBreakIterator
Returns:
The offset of the beginning of the text.

following

public int following(int offset)
Sets the iterator to refer to the first boundary position following the specified position.
Overrides:
following in interface RuleBasedBreakIterator
Parameters:
offset - The position from which to begin searching for a break position.
Returns:
The position of the first break after the current position.

getInstanceFromCompiledRules

public static RuleBasedBreakIterator getInstanceFromCompiledRules(InputStream is)
            throws IOException
Create a break iterator from a precompiled set of rules.
Overrides:
getInstanceFromCompiledRules in interface RuleBasedBreakIterator

getRuleStatus

public int getRuleStatus()
Return the status tag from the break rule that determined the most recently returned break position. The values appear in the rule source within brackets, {123}, for example. For rules that do not specify a status, a default value of 0 is returned. If more than one rule applies, the numerically largest of the possible status values is returned.

Of the standard types of ICU break iterators, only the word break iterator provides status values. The values are defined in class RuleBasedBreakIterator, and allow distinguishing between words that contain alphabetic letters, "words" that appear to be numbers, punctuation and spaces, words containing ideographic characters, and more. Call getRuleStatus after obtaining a boundary position from next(), previous(), or any other break iterator functions that returns a boundary position.

Overrides:
getRuleStatus in interface RuleBasedBreakIterator
Returns:
the status from the break rule that determined the most recently returned break position.

getRuleStatusVec

public int getRuleStatusVec(int[] fillInArray)
Get the status (tag) values from the break rule(s) that determined the most recently returned break position. The values appear in the rule source within brackets, {123}, for example. The default status value for rules that do not explicitly provide one is zero.

The status values used by the standard ICU break rules are defined as public constants in class RuleBasedBreakIterator.

If the size of the output array is insufficient to hold the data, the output will be truncated to the available length. No exception will be thrown.

Overrides:
getRuleStatusVec in interface RuleBasedBreakIterator
Parameters:
fillInArray - an array to be filled in with the status values.
Returns:
The number of rule status values from rules that determined the most recent boundary returned by the break iterator. In the event that the array is too small, the return value is the total number of status values that were available, not the reduced number that were actually returned.

getText

public CharacterIterator getText()
Return a CharacterIterator over the text being analyzed. This version of this method returns the actual CharacterIterator we're using internally. Changing the state of this iterator can have undefined consequences. If you need to change it, clone it first.
Overrides:
getText in interface RuleBasedBreakIterator
Returns:
An iterator over the text being analyzed.

hashCode

public int hashCode()
Compute a hashcode for this BreakIterator
Overrides:
hashCode in interface RuleBasedBreakIterator
Returns:
A hash code

isBoundary

public boolean isBoundary(int offset)
Returns true if the specfied position is a boundary position. As a side effect, leaves the iterator pointing to the first boundary position at or after "offset".
Overrides:
isBoundary in interface RuleBasedBreakIterator
Parameters:
offset - the offset to check.
Returns:
True if "offset" is a boundary position.

last

public int last()
Sets the current iteration position to the end of the text. (i.e., the CharacterIterator's ending offset).
Overrides:
last in interface RuleBasedBreakIterator
Returns:
The text's past-the-end offset.

next

public int next()
Advances the iterator to the next boundary position.
Overrides:
next in interface RuleBasedBreakIterator
Returns:
The position of the first boundary after this one.

next

public int next(int n)
Advances the iterator either forward or backward the specified number of steps. Negative values move backward, and positive values move forward. This is equivalent to repeatedly calling next() or previous().
Overrides:
next in interface RuleBasedBreakIterator
Parameters:
n - The number of steps to move. The sign indicates the direction (negative is backwards, and positive is forwards).
Returns:
The character offset of the boundary position n boundaries away from the current one.

preceding

public int preceding(int offset)
Sets the iterator to refer to the last boundary position before the specified position.
Overrides:
preceding in interface RuleBasedBreakIterator
Parameters:
offset - The position to begin searching for a break from.
Returns:
The position of the last boundary before the starting position.

previous

public int previous()
Moves the iterator backwards, to the last boundary preceding this one.
Overrides:
previous in interface RuleBasedBreakIterator
Returns:
The position of the last boundary position preceding this one.

setText

public void setText(CharacterIterator newText)
Set the iterator to analyze a new piece of text. This function resets the current iteration position to the beginning of the text.
Overrides:
setText in interface RuleBasedBreakIterator
Parameters:
newText - An iterator over the text to analyze.

toString

public String toString()
Returns the description (rules) used to create this iterator. (In ICU4C, the same function is RuleBasedBreakIterator::getRules())
Overrides:
toString in interface RuleBasedBreakIterator

Copyright (c) 2006 IBM Corporation and others.