ComposedCharIter
is an iterator class that returns all of the precomposed characters defined in the Unicode standard, along with their decomposed forms.
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#include <compitr.h>
Public Types | |
enum | { DONE = 0xffff } |
Constant that indicates the iteration has completed. More... | |
Public Methods | |
ComposedCharIter () | |
Construct a new ComposedCharIter . More... | |
ComposedCharIter (UBool compat, int32_t options) | |
Constructs a non-default ComposedCharIter with optional behavior. More... | |
UBool | hasNext (void) const |
Determines whether there any precomposed Unicode characters not yet returned by. More... | |
UChar | next (void) |
Returns the next precomposed Unicode character. More... | |
void | getDecomposition (UnicodeString& result) const |
Returns the Unicode decomposition of the current character. More... |
ComposedCharIter
is an iterator class that returns all of the precomposed characters defined in the Unicode standard, along with their decomposed forms.
This is often useful when building data tables (e.g. collation tables) which need to treat composed and decomposed characters equivalently.
For example, imagine that you have built a collation table with ordering rules for the Normalizer#DECOMP forms of all characters used in a particular language. When you process input text using this table, the text must first be decomposed so that it matches the form used in the table. This can impose a performance penalty that may be unacceptable in some situations.
You can avoid this problem by ensuring that the collation table contains rules for both the decomposed and composed versions of each character. To do so, use a ComposedCharIter
to iterate through all of the composed characters in Unicode. If the decomposition for that character consists solely of characters that are listed in your ruleset, you can add a new rule for the composed character that makes it equivalent to its decomposition sequence.
Note that ComposedCharIter
iterates over a static table of the composed characters in Unicode. If you want to iterate over the composed characters in a particular string, use Normalizer instead.
When constructing a ComposedCharIter
there is one optional feature that you can enable or disable:
ComposedCharIter
is currently based on version 2.1.8 of the Unicode Standard. It will be updated as later versions of Unicode are released.
Definition at line 58 of file compitr.h.
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Constant that indicates the iteration has completed.
#next returns this value when there are no more composed characters over which to iterate. This value is equal to |
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Construct a new The iterator will return all Unicode characters with canonical decompositions, including Korean Hangul characters. |
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Constructs a non-default
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Returns the Unicode decomposition of the current character. This method returns the decomposition of the precomposed character most recently returned by #next. The resulting decomposition is affected by the settings of the options passed to the constructor. Normalizer#COMPATIBILITY and Normalizer#NO_HANGUL options passed to the constructor. |
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Determines whether there any precomposed Unicode characters not yet returned by. |
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Returns the next precomposed Unicode character.
Repeated calls to |