UnicodeFilter Class Reference

UnicodeFilter defines a protocol for selecting a subset of the full range (U+0000 to U+10FFFF) of Unicode characters. More...

#include <unifilt.h>

Inheritance diagram for UnicodeFilter:
UnicodeFunctor UnicodeMatcher UObject UMemory UnicodeSet

Public Member Functions

virtual ~UnicodeFilter ()
 Destructor.
virtual UBool contains (UChar32 c) const =0
 Returns true for characters that are in the selected subset.
virtual UnicodeMatchertoMatcher () const
 UnicodeFunctor API.
virtual UMatchDegree matches (const Replaceable &text, int32_t &offset, int32_t limit, UBool incremental)
 Implement UnicodeMatcher API.
virtual void setData (const TransliterationRuleData *)
 UnicodeFunctor API.
virtual UClassID getDynamicClassID () const =0
 ICU "poor man's RTTI", returns a UClassID for the actual class.

Static Public Member Functions

static UClassID getStaticClassID ()
 ICU "poor man's RTTI", returns a UClassID for this class.

Detailed Description

UnicodeFilter defines a protocol for selecting a subset of the full range (U+0000 to U+10FFFF) of Unicode characters.

Currently, filters are used in conjunction with classes like Transliterator to only process selected characters through a transformation.

Note: UnicodeFilter currently stubs out two pure virtual methods of its base class, UnicodeMatcher. These methods are toPattern() and matchesIndexValue(). This is done so that filter classes that are not actually used as matchers -- specifically, those in the UnicodeFilterLogic component, and those in tests -- can continue to work without defining these methods. As long as a filter is not used in an RBT during real transliteration, these methods will not be called. However, this breaks the UnicodeMatcher base class protocol, and it is not a correct solution.

In the future we may revisit the UnicodeMatcher / UnicodeFilter hierarchy and either redesign it, or simply remove the stubs in UnicodeFilter and force subclasses to implement the full UnicodeMatcher protocol.

See also:
UnicodeFilterLogic
Stable:
ICU 2.0

Definition at line 59 of file unifilt.h.


Constructor & Destructor Documentation

virtual UnicodeFilter::~UnicodeFilter (  )  [virtual]

Destructor.

Stable:
ICU 2.0

Member Function Documentation

virtual UBool UnicodeFilter::contains ( UChar32  c  )  const [pure virtual]

Returns true for characters that are in the selected subset.

In other words, if a character is to be filtered, then contains() returns false.

Stable:
ICU 2.0

Implemented in UnicodeSet.

virtual UClassID UnicodeFilter::getDynamicClassID (  )  const [pure virtual]

ICU "poor man's RTTI", returns a UClassID for the actual class.

Stable:
ICU 2.2

Implements UnicodeFunctor.

Implemented in UnicodeSet.

static UClassID UnicodeFilter::getStaticClassID (  )  [static]

ICU "poor man's RTTI", returns a UClassID for this class.

Stable:
ICU 2.2

Reimplemented from UnicodeFunctor.

Reimplemented in UnicodeSet.

virtual UMatchDegree UnicodeFilter::matches ( const Replaceable text,
int32_t &  offset,
int32_t  limit,
UBool  incremental 
) [virtual]

Implement UnicodeMatcher API.

Stable:
ICU 2.4

Implements UnicodeMatcher.

Reimplemented in UnicodeSet.

virtual void UnicodeFilter::setData ( const TransliterationRuleData *   )  [virtual]

UnicodeFunctor API.

Nothing to do.

Stable:
ICU 2.4

Implements UnicodeFunctor.

virtual UnicodeMatcher* UnicodeFilter::toMatcher (  )  const [virtual]

UnicodeFunctor API.

Cast 'this' to a UnicodeMatcher* pointer and return the pointer.

Stable:
ICU 2.4

Reimplemented from UnicodeFunctor.


The documentation for this class was generated from the following file:
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Generated on Sat Jan 23 15:17:45 2010 for ICU 4.3.4 by  doxygen 1.6.1