com.ibm.icu.text
Class FilteredNormalizer2

java.lang.Object
  com.ibm.icu.text.Normalizer2
      com.ibm.icu.text.FilteredNormalizer2

public class FilteredNormalizer2
extends Normalizer2

Normalization filtered by a UnicodeSet. Normalizes portions of the text contained in the filter set and leaves portions not contained in the filter set unchanged. Filtering is done via UnicodeSet.span(..., UnicodeSet.SpanCondition.SIMPLE). Not-in-the-filter text is treated as "is normalized" and "quick check yes". This class implements all of (and only) the Normalizer2 API. An instance of this class is unmodifiable/immutable.

Author:

Markus W. Scherer

Status:

Stable ICU 4.4.

Nested Class Summary

Nested classes/interfaces inherited from class com.ibm.icu.text.Normalizer2

Normalizer2.Mode

Constructor Summary

FilteredNormalizer2(Normalizer2 n2, UnicodeSet filterSet)
Constructs a filtered normalizer wrapping any Normalizer2 instance and a filter set.

Method Summary

StringBuilder	append(StringBuilder first, CharSequence second) Appends the second string to the first string (merging them at the boundary) and returns the first string.
String	getDecomposition(int c) Gets the decomposition mapping of c.
boolean	hasBoundaryAfter(int c) Tests if the character always has a normalization boundary after it, regardless of context.
boolean	hasBoundaryBefore(int c) Tests if the character always has a normalization boundary before it, regardless of context.
boolean	isInert(int c) Tests if the character is normalization-inert.
boolean	isNormalized(CharSequence s) Tests if the string is normalized.
Appendable	normalize(CharSequence src, Appendable dest) Writes the normalized form of the source string to the destination Appendable and returns the destination Appendable.
StringBuilder	normalize(CharSequence src, StringBuilder dest) Writes the normalized form of the source string to the destination string (replacing its contents) and returns the destination string.
StringBuilder	normalizeSecondAndAppend(StringBuilder first, CharSequence second) Appends the normalized form of the second string to the first string (merging them at the boundary) and returns the first string.
Normalizer.QuickCheckResult	quickCheck(CharSequence s) Tests if the string is normalized.
int	spanQuickCheckYes(CharSequence s) Returns the end of the normalized substring of the input string.

Methods inherited from class com.ibm.icu.text.Normalizer2

getInstance, normalize

Methods inherited from class java.lang.Object

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

Constructor Detail

FilteredNormalizer2

public FilteredNormalizer2(Normalizer2 n2,
                           UnicodeSet filterSet)

Constructs a filtered normalizer wrapping any Normalizer2 instance and a filter set. Both are aliased and must not be modified or deleted while this object is used. The filter set should be frozen; otherwise the performance will suffer greatly.

Parameters:

n2 - wrapped Normalizer2 instance

filterSet - UnicodeSet which determines the characters to be normalized

Status:

Stable ICU 4.4.

Method Detail

normalize

public StringBuilder normalize(CharSequence src,
                               StringBuilder dest)

Writes the normalized form of the source string to the destination string (replacing its contents) and returns the destination string. The source and destination strings must be different objects.

Specified by:

normalize in class Normalizer2

Parameters:

src - source string

dest - destination string; its contents is replaced with normalized src

Returns:

dest

Status:

Stable ICU 4.4.

normalize

public Appendable normalize(CharSequence src,
                            Appendable dest)

Writes the normalized form of the source string to the destination Appendable and returns the destination Appendable. The source and destination strings must be different objects.

Specified by:

normalize in class Normalizer2

Parameters:

src - source string

dest - destination Appendable; gets normalized src appended

Returns:

dest

Status:

Draft ICU 4.6.

normalizeSecondAndAppend

public StringBuilder normalizeSecondAndAppend(StringBuilder first,
                                              CharSequence second)

Appends the normalized form of the second string to the first string (merging them at the boundary) and returns the first string. The result is normalized if the first string was normalized. The first and second strings must be different objects.

Specified by:

normalizeSecondAndAppend in class Normalizer2

Parameters:

first - string, should be normalized

second - string, will be normalized

Returns:

first

Status:

Stable ICU 4.4.

append

public StringBuilder append(StringBuilder first,
                            CharSequence second)

Appends the second string to the first string (merging them at the boundary) and returns the first string. The result is normalized if both the strings were normalized. The first and second strings must be different objects.

Specified by:

append in class Normalizer2

Parameters:

first - string, should be normalized

second - string, should be normalized

Returns:

first

Status:

Stable ICU 4.4.

getDecomposition

public String getDecomposition(int c)

Gets the decomposition mapping of c. Roughly equivalent to normalizing the String form of c on a DECOMPOSE Normalizer2 instance, but much faster, and except that this function returns null if c does not have a decomposition mapping in this instance's data. This function is independent of the mode of the Normalizer2.

Specified by:

getDecomposition in class Normalizer2

Parameters:

c - code point

Returns:

c's decomposition mapping, if any; otherwise null

Status:

Draft ICU 4.6.

isNormalized

public boolean isNormalized(CharSequence s)

Tests if the string is normalized. Internally, in cases where the quickCheck() method would return "maybe" (which is only possible for the two COMPOSE modes) this method resolves to "yes" or "no" to provide a definitive result, at the cost of doing more work in those cases.

Specified by:

isNormalized in class Normalizer2

Parameters:

s - input string

Returns:

true if s is normalized

Status:

Stable ICU 4.4.

quickCheck

public Normalizer.QuickCheckResult quickCheck(CharSequence s)

Tests if the string is normalized. For the two COMPOSE modes, the result could be "maybe" in cases that would take a little more work to resolve definitively. Use spanQuickCheckYes() and normalizeSecondAndAppend() for a faster combination of quick check + normalization, to avoid re-checking the "yes" prefix.

Specified by:

quickCheck in class Normalizer2

Parameters:

s - input string

Returns:

the quick check result

Status:

Stable ICU 4.4.

spanQuickCheckYes

public int spanQuickCheckYes(CharSequence s)

Returns the end of the normalized substring of the input string. In other words, with end=spanQuickCheckYes(s); the substring s.subSequence(0, end) will pass the quick check with a "yes" result.

The returned end index is usually one or more characters before the "no" or "maybe" character: The end index is at a normalization boundary. (See the class documentation for more about normalization boundaries.)

When the goal is a normalized string and most input strings are expected to be normalized already, then call this method, and if it returns a prefix shorter than the input string, copy that prefix and use normalizeSecondAndAppend() for the remainder.

Specified by:

spanQuickCheckYes in class Normalizer2

Parameters:

s - input string

Returns:

"yes" span end index

Status:

Stable ICU 4.4.

hasBoundaryBefore

public boolean hasBoundaryBefore(int c)

Tests if the character always has a normalization boundary before it, regardless of context. If true, then the character does not normalization-interact with preceding characters. In other words, a string containing this character can be normalized by processing portions before this character and starting from this character independently. This is used for iterative normalization. See the class documentation for details.

Specified by:

hasBoundaryBefore in class Normalizer2

Parameters:

c - character to test

Returns:

true if c has a normalization boundary before it

Status:

Stable ICU 4.4.

hasBoundaryAfter

public boolean hasBoundaryAfter(int c)

Tests if the character always has a normalization boundary after it, regardless of context. If true, then the character does not normalization-interact with following characters. In other words, a string containing this character can be normalized by processing portions up to this character and after this character independently. This is used for iterative normalization. See the class documentation for details.

Note that this operation may be significantly slower than hasBoundaryBefore().

Specified by:

hasBoundaryAfter in class Normalizer2

Parameters:

c - character to test

Returns:

true if c has a normalization boundary after it

Status:

Stable ICU 4.4.

isInert

public boolean isInert(int c)

Tests if the character is normalization-inert. If true, then the character does not change, nor normalization-interact with preceding or following characters. In other words, a string containing this character can be normalized by processing portions before this character and after this character independently. This is used for iterative normalization. See the class documentation for details.

Note that this operation may be significantly slower than hasBoundaryBefore().

Specified by:

isInert in class Normalizer2

Parameters:

c - character to test

Returns:

true if c is normalization-inert

Status:

Stable ICU 4.4.