com.ibm.icu.impl

Class CharTrie

java.lang.Object

com.ibm.icu.impl.Trie

com.ibm.icu.impl.CharTrie

public class CharTrie
extends Trie

Trie implementation which stores data in char, 16 bits.

Since:

release 2.1, Jan 01 2002

See Also:

Trie

Nested Class Summary

Nested classes/interfaces inherited from class com.ibm.icu.impl.Trie

Trie.DataManipulate

Field Summary

Fields inherited from class com.ibm.icu.impl.Trie

BMP_INDEX_LENGTH, DATA_BLOCK_LENGTH, HEADER_LENGTH_, HEADER_OPTIONS_DATA_IS_32_BIT_, HEADER_OPTIONS_INDEX_SHIFT_, HEADER_OPTIONS_LATIN1_IS_LINEAR_MASK_, HEADER_SIGNATURE_, INDEX_STAGE_1_SHIFT_, INDEX_STAGE_2_SHIFT_, INDEX_STAGE_3_MASK_, LEAD_INDEX_OFFSET_, m_dataLength_, m_dataManipulate_, m_dataOffset_, m_index_, SURROGATE_BLOCK_BITS, SURROGATE_BLOCK_COUNT, SURROGATE_MASK_

Constructor Summary

Constructors

Constructor and Description
CharTrie(ByteBuffer bytes, Trie.DataManipulate dataManipulate) Creates a new Trie with the settings for the trie data.
CharTrie(int initialValue, int leadUnitValue, Trie.DataManipulate dataManipulate) Make a dummy CharTrie.

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) Checks if the argument Trie has the same data as this Trie
char	getBMPValue(char ch) Get the value associated with the BMP code point.
char	getCodePointValue(int ch) Gets the value associated with the codepoint.
protected int	getInitialValue() Gets the default initial value
char	getLatin1LinearValue(char ch) Gets the latin 1 fast path value.
char	getLeadValue(char ch) Gets the value to the data which this lead surrogate character points to.
protected int	getSurrogateOffset(char lead, char trail) Gets the offset to the data which the surrogate pair points to.
char	getSurrogateValue(char lead, char trail) Get the value associated with a pair of surrogates.
char	getTrailValue(int leadvalue, char trail) Get a value from a folding offset (from the value of a lead surrogate) and a trail surrogate.
protected int	getValue(int index) Gets the value at the argument index.
int	hashCode() Returns an integer hash code for this object.
protected void	unserialize(ByteBuffer bytes) Parses the byte buffer and stores its trie content into a index and data array

Methods inherited from class com.ibm.icu.impl.Trie

getBMPOffset, getCodePointOffset, getLeadOffset, getRawOffset, getSerializedDataSize, isCharTrie, isIntTrie, isLatin1Linear

Methods inherited from class java.lang.Object

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

Constructor Detail

CharTrie

public CharTrie(ByteBuffer bytes,
                Trie.DataManipulate dataManipulate)

Creates a new Trie with the settings for the trie data.

Unserialize the 32-bit-aligned input buffer and use the data for the trie.

Parameters:

bytes - data of an ICU data file, containing the trie

dataManipulate - object which provides methods to parse the char data

CharTrie

public CharTrie(int initialValue,
                int leadUnitValue,
                Trie.DataManipulate dataManipulate)

Make a dummy CharTrie. A dummy trie is an empty runtime trie, used when a real data trie cannot be loaded. The trie always returns the initialValue, or the leadUnitValue for lead surrogate code points. The Latin-1 part is always set up to be linear.

Parameters:

initialValue - the initial value that is set for all code points

leadUnitValue - the value for lead surrogate code _units_ that do not have associated supplementary data

dataManipulate - object which provides methods to parse the char data

Method Detail

getCodePointValue

public final char getCodePointValue(int ch)

Gets the value associated with the codepoint. If no value is associated with the codepoint, a default value will be returned.

Parameters:

ch - codepoint

Returns:

offset to data

getLeadValue

public final char getLeadValue(char ch)

Gets the value to the data which this lead surrogate character points to. Returned data may contain folding offset information for the next trailing surrogate character. This method does not guarantee correct results for trail surrogates.

Parameters:

ch - lead surrogate character

Returns:

data value

getBMPValue

public final char getBMPValue(char ch)

Get the value associated with the BMP code point. Lead surrogate code points are treated as normal code points, with unfolded values that may differ from getLeadValue() results.

Parameters:

ch - the input BMP code point

Returns:

trie data value associated with the BMP codepoint

getSurrogateValue

public final char getSurrogateValue(char lead,
                                    char trail)

Get the value associated with a pair of surrogates.

Parameters:

lead - a lead surrogate

trail - a trail surrogate

getTrailValue

public final char getTrailValue(int leadvalue,
                                char trail)

Get a value from a folding offset (from the value of a lead surrogate) and a trail surrogate.

If the

Parameters:

leadvalue - value associated with the lead surrogate which contains the folding offset

trail - surrogate

Returns:

trie data value associated with the trail character

getLatin1LinearValue

public final char getLatin1LinearValue(char ch)

Gets the latin 1 fast path value.

Note this only works if latin 1 characters have their own linear array.

Parameters:

ch - latin 1 characters

Returns:

value associated with latin character

equals

public boolean equals(Object other)

Checks if the argument Trie has the same data as this Trie

Overrides:

equals in class Trie

Parameters:

other - Trie to check

Returns:

true if the argument Trie has the same data as this Trie, false otherwise

See Also:

Object.hashCode()

hashCode

public int hashCode()

Description copied from class: Object

Returns an integer hash code for this object. By contract, any two objects for which Object.equals(java.lang.Object) returns true must return the same hash code value. This means that subclasses of Object usually override both methods or neither method.

Note that hash values must not change over time unless information used in equals comparisons also changes.

See Writing a correct hashCode method if you intend implementing your own hashCode method.

Overrides:

hashCode in class Trie

Returns:

this object's hash code.

See Also:

Object.equals(java.lang.Object)

unserialize

protected final void unserialize(ByteBuffer bytes)

Parses the byte buffer and stores its trie content into a index and data array

Overrides:

unserialize in class Trie

Parameters:

bytes - buffer containing trie data

getSurrogateOffset

protected final int getSurrogateOffset(char lead,
                                       char trail)

Gets the offset to the data which the surrogate pair points to.

Specified by:

getSurrogateOffset in class Trie

Parameters:

lead - lead surrogate

trail - trailing surrogate

Returns:

offset to data

getValue

protected final int getValue(int index)

Gets the value at the argument index. For use internally in TrieIterator.

Specified by:

getValue in class Trie

Parameters:

index - value at index will be retrieved

Returns:

32 bit value

See Also:

TrieIterator

getInitialValue

protected final int getInitialValue()

Gets the default initial value

Specified by:

getInitialValue in class Trie

Returns:

32 bit value