icu::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 icu::UnicodeFilter:

icu::UnicodeFunctor icu::UnicodeMatcher icu::UObject icu::UMemory icu::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.

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 icu::UnicodeFilter::~UnicodeFilter (  )  [virtual]

Destructor.

Stable:
ICU 2.0


Member Function Documentation

virtual UBool icu::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 icu::UnicodeSet.

static UClassID icu::UnicodeFilter::getStaticClassID (  )  [static]

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

Stable:
ICU 2.2

Reimplemented from icu::UnicodeFunctor.

Reimplemented in icu::UnicodeSet.

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

Implement UnicodeMatcher API.

Stable:
ICU 2.4

Implements icu::UnicodeMatcher.

Reimplemented in icu::UnicodeSet.

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

UnicodeFunctor API.

Nothing to do.

Stable:
ICU 2.4

Implements icu::UnicodeFunctor.

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

UnicodeFunctor API.

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

Stable:
ICU 2.4

Reimplemented from icu::UnicodeFunctor.


The documentation for this class was generated from the following file:
Generated on 25 Nov 2014 for ICU 50.1.2 by  doxygen 1.4.7