CharacterIterator

class U_COMMON_API CharacterIterator

Abstract class defining a protcol for accessing characters in a text-storage object

Inheritance:

Public Fields
static const UChar DONE: Value returned by most of CharacterIterator's functions when the iterator has reached the limits of its iteration

Public Methods
virtual ~CharacterIterator(): Destructor
virtual bool_t operator==(const CharacterIterator& that) const: Returns true when both iterators refer to the same character in the same character-storage object
bool_t operator!=(const CharacterIterator& that) const: Returns true when the iterators refer to different text-storage objects, or to different characters in the same text-storage object
virtual CharacterIterator* clone(void) const: Returns a pointer to a new CharacterIterator of the same concrete class as this one, and referring to the same character in the same text-storage object as this one
virtual int32_t hashCode(void) const: Generates a hash code for this iterator
virtual UChar first(void): Sets the iterator to refer to the first character in its iteration range, and returns that character,
virtual UChar last(void): Sets the iterator to refer to the last character in its iteration range, and returns that character
virtual UChar setIndex(UTextOffset position): Sets the iterator to refer to the "position"-th character in the text-storage object the iterator refers to, and returns that character
virtual UChar current(void) const: Returns the character the iterator currently refers to
virtual UChar next(void): Advances to the next character in the iteration range (toward last()), and returns that character
virtual UChar previous(void): Advances to the previous character in the iteration rance (toward first()), and returns that character
virtual UTextOffset startIndex(void) const: Returns the numeric index in the underlying text-storage object of the character returned by first()
virtual UTextOffset endIndex(void) const: Returns the numeric index in the underlying text-storage object of the position immediately BEYOND the character returned by last()
virtual UTextOffset getIndex(void) const: Returns the numeric index in the underlying text-storage object of the character the iterator currently refers to (i
virtual void getText(UnicodeString& result): Copies the text under iteration into the UnicodeString referred to by "result"
virtual UClassID getDynamicClassID(void) const: Returns a UClassID for this CharacterIterator ("poor man's RTTI")

Documentation

Abstract class defining a protcol for accessing characters in a text-storage object.

Examples:

Function processing characters, in this example simple output

.   void processChar( UChar c )
.   {
.       cout << " " << c;
.   }

Traverse the text from start to finish

 
.   void traverseForward(CharacterIterator& iter)
.   {
.       for(UChar c = iter.first(); c != CharacterIterator.DONE; c = iter.next()) {
.           processChar(c);
.       }
.   }

Traverse the text backwards, from end to start

.   void traverseBackward(CharacterIterator& iter)
.   {
.       for(UChar c = iter.last(); c != CharacterIterator.DONE; c = iter.previous()) {
.           processChar(c);
.       }
.   }

Traverse both forward and backward from a given position in the text. Calls to notBoundary() in this example represents some additional stopping criteria.

.   void traverseOut(CharacterIterator& iter, UTextOffset pos)
.   {
.       UChar c;
.       for (c = iter.setIndex(pos);
.       c != CharacterIterator.DONE && (Unicode::isLetter(c) || Unicode::isDigit(c));
.           c = iter.next()) {}
.       UTextOffset end = iter.getIndex();
.       for (c = iter.setIndex(pos);
.           c != CharacterIterator.DONE && (Unicode::isLetter(c) || Unicode::isDigit(c));
.           c = iter.previous()) {}
.       UTextOffset start = iter.getIndex() + 1;
.   
.       cout << "start: " << start << " end: " << end << endl;
.       for (c = iter.setIndex(start); iter.getIndex() < end; c = iter.next() ) {
.           processChar(c);
.       }
.    }

Creating a StringCharacterIteratorand calling the test functions

.    void CharacterIterator_Example( void )
.    {
.        cout << endl << "===== CharacterIterator_Example: =====" << endl;
.        UnicodeString text("Ein kleiner Satz.");
.        StringCharacterIterator iterator(text);
.        cout << "----- traverseForward: -----------" << endl;
.        traverseForward( iterator );
.        cout << endl << endl << "----- traverseBackward: ----------" << endl;
.        traverseBackward( iterator );
.        cout << endl << endl << "----- traverseOut: ---------------" << endl;
.        traverseOut( iterator, 7 );
.        cout << endl << endl << "-----" << endl;
.    }

static const UChar DONE

Value returned by most of CharacterIterator's functions when the iterator has reached the limits of its iteration.

virtual ~CharacterIterator()

Destructor.

virtual bool_t operator==(const CharacterIterator& that) const

Returns true when both iterators refer to the same character in the same character-storage object.

bool_t operator!=(const CharacterIterator& that) const

Returns true when the iterators refer to different text-storage objects, or to different characters in the same text-storage object.

virtual CharacterIterator* clone(void) const

Returns a pointer to a new CharacterIterator of the same concrete class as this one, and referring to the same character in the same text-storage object as this one. The caller is responsible for deleting the new clone.

virtual int32_t hashCode(void) const