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Transliterator Class Reference

Transliterator is an abstract class that transliterates text from one format to another. More...

#include <translit.h>

Inheritance diagram for Transliterator:

CompoundTransliterator HexToUnicodeTransliterator NullTransliterator RuleBasedTransliterator UnicodeToHexTransliterator

Public Types

typedef Transliterator *(* Factory )(const UnicodeString &ID, Token context)
 A function that creates and returns a Transliterator.

Public Member Functions

virtual ~Transliterator ()
 Destructor.
virtual Transliteratorclone () const
 Implements Cloneable.
virtual int32_t transliterate (Replaceable &text, int32_t start, int32_t limit) const
 Transliterates a segment of a string, with optional filtering.
virtual void transliterate (Replaceable &text) const
 Transliterates an entire string in place.
virtual void transliterate (Replaceable &text, UTransPosition &index, const UnicodeString &insertion, UErrorCode &status) const
 Transliterates the portion of the text buffer that can be transliterated unambiguosly after new text has been inserted, typically as a result of a keyboard event.
virtual void transliterate (Replaceable &text, UTransPosition &index, UChar32 insertion, UErrorCode &status) const
 Transliterates the portion of the text buffer that can be transliterated unambiguosly after a new character has been inserted, typically as a result of a keyboard event.
virtual void transliterate (Replaceable &text, UTransPosition &index, UErrorCode &status) const
 Transliterates the portion of the text buffer that can be transliterated unambiguosly.
virtual void finishTransliteration (Replaceable &text, UTransPosition &index) const
 Finishes any pending transliterations that were waiting for more characters.
int32_t getMaximumContextLength (void) const
 Returns the length of the longest context required by this transliterator.
virtual const UnicodeStringgetID (void) const
 Returns a programmatic identifier for this transliterator.
const UnicodeFiltergetFilter (void) const
 Returns the filter used by this transliterator, or NULL if this transliterator uses no filter.
UnicodeFilterorphanFilter (void)
 Returns the filter used by this transliterator, or NULL if this transliterator uses no filter.
void adoptFilter (UnicodeFilter *adoptedFilter)
 Changes the filter used by this transliterator.
TransliteratorcreateInverse (UErrorCode &status) const
 Returns this transliterator's inverse.
virtual UnicodeStringtoRules (UnicodeString &result, UBool escapeUnprintable) const
 Create a rule string that can be passed to createFromRules() to recreate this transliterator.
virtual UClassID getDynamicClassID (void) const
 Returns a unique class ID polymorphically.

Static Public Member Functions

Token integerToken (int32_t)
 Return a token containing an integer.
Token pointerToken (void *)
 Return a token containing a pointer.
UnicodeStringgetDisplayName (const UnicodeString &ID, UnicodeString &result)
 Returns a name for this transliterator that is appropriate for display to the user in the default locale.
UnicodeStringgetDisplayName (const UnicodeString &ID, const Locale &inLocale, UnicodeString &result)
 Returns a name for this transliterator that is appropriate for display to the user in the given locale.
TransliteratorcreateInstance (const UnicodeString &ID, UTransDirection dir, UParseError &parseError, UErrorCode &status)
 Returns a Transliterator object given its ID.
TransliteratorcreateInstance (const UnicodeString &ID, UTransDirection dir, UErrorCode &status)
 Returns a Transliterator object given its ID.
TransliteratorcreateFromRules (const UnicodeString &ID, const UnicodeString &rules, UTransDirection dir, UParseError &parseError, UErrorCode &status)
 Returns a Transliterator object constructed from the given rule string.
void registerFactory (const UnicodeString &id, Factory factory, Token context)
 Registers a factory function that creates transliterators of a given ID.
void registerInstance (Transliterator *adoptedObj)
 Registers a instance obj of a subclass of Transliterator with the system.
void unregister (const UnicodeString &ID)
 Unregisters a transliterator or class.
int32_t countAvailableIDs (void)
 Return the number of IDs currently registered with the system.
const UnicodeStringgetAvailableID (int32_t index)
 Return the index-th available ID.
int32_t countAvailableSources (void)
 Return the number of registered source specifiers.
UnicodeStringgetAvailableSource (int32_t index, UnicodeString &result)
 Return a registered source specifier.
int32_t countAvailableTargets (const UnicodeString &source)
 Return the number of registered target specifiers for a given source specifier.
UnicodeStringgetAvailableTarget (int32_t index, const UnicodeString &source, UnicodeString &result)
 Return a registered target specifier for a given source.
int32_t countAvailableVariants (const UnicodeString &source, const UnicodeString &target)
 Return the number of registered variant specifiers for a given source-target pair.
UnicodeStringgetAvailableVariant (int32_t index, const UnicodeString &source, const UnicodeString &target, UnicodeString &result)
 Return a registered variant specifier for a given source-target pair.
UClassID getStaticClassID (void)
 Return the class ID for this class.

Protected Member Functions

 Transliterator (const UnicodeString &ID, UnicodeFilter *adoptedFilter)
 Default constructor.
 Transliterator (const Transliterator &)
 Copy constructor.
Transliteratoroperator= (const Transliterator &)
 Assignment operator.
virtual void handleTransliterate (Replaceable &text, UTransPosition &pos, UBool incremental) const =0
 Abstract method that concrete subclasses define to implement keyboard transliteration.
virtual void filteredTransliterate (Replaceable &text, UTransPosition &index, UBool incremental) const
 Transliterate a substring of text, as specified by index, taking filters into account.
void setMaximumContextLength (int32_t maxContextLength)
 Method for subclasses to use to set the maximum context length.
void setID (const UnicodeString &id)
 Set the ID of this transliterators.

Static Protected Member Functions

TransliteratorcreateBasicInstance (const UnicodeString &id, const UnicodeString *canon)
 Create a transliterator from a basic ID.
void _registerFactory (const UnicodeString &id, Factory factory, Token context)
void _registerSpecialInverse (const UnicodeString &target, const UnicodeString &inverseTarget, UBool bidirectional)
 Register two targets as being inverses of one another.

Friends

class TransliteratorParser
class TransliteratorIDParser
class CompoundTransliterator

Detailed Description

Transliterator is an abstract class that transliterates text from one format to another.

The most common kind of transliterator is a script, or alphabet, transliterator. For example, a Russian to Latin transliterator changes Russian text written in Cyrillic characters to phonetically equivalent Latin characters. It does not translate Russian to English! Transliteration, unlike translation, operates on characters, without reference to the meanings of words and sentences.

Although script conversion is its most common use, a transliterator can actually perform a more general class of tasks. In fact, Transliterator defines a very general API which specifies only that a segment of the input text is replaced by new text. The particulars of this conversion are determined entirely by subclasses of Transliterator.

Transliterators are stateless

Transliterator objects are stateless; they retain no information between calls to transliterate(). (However, this does not mean that threads may share transliterators without synchronizing them. Transliterators are not immutable, so they must be synchronized when shared between threads.) This1 might seem to limit the complexity of the transliteration operation. In practice, subclasses perform complex transliterations by delaying the replacement of text until it is known that no other replacements are possible. In other words, although the Transliterator objects are stateless, the source text itself embodies all the needed information, and delayed operation allows arbitrary complexity.

Batch transliteration

The simplest way to perform transliteration is all at once, on a string of existing text. This is referred to as batch transliteration. For example, given a string input and a transliterator t, the call

<blockquote>String result = t.transliterate(input); </blockquote>

will transliterate it and return the result. Other methods allow the client to specify a substring to be transliterated and to use Replaceable objects instead of strings, in order to preserve out-of-band information (such as text styles).

Keyboard transliteration

Somewhat more involved is keyboard, or incremental transliteration. This is the transliteration of text that is arriving from some source (typically the user's keyboard) one character at a time, or in some other piecemeal fashion.

In keyboard transliteration, a Replaceable buffer stores the text. As text is inserted, as much as possible is transliterated on the fly. This means a GUI that displays the contents of the buffer may show text being modified as each new character arrives.

Consider the simple RuleBasedTransliterator:

<blockquote> th>{theta}
t>{tau}
</blockquote>

When the user types 't', nothing will happen, since the transliterator is waiting to see if the next character is 'h'. To remedy this, we introduce the notion of a cursor, marked by a '|' in the output string:

<blockquote> t>|{tau}
{tau}h>{theta}
</blockquote>

Now when the user types 't', tau appears, and if the next character is 'h', the tau changes to a theta. This is accomplished by maintaining a cursor position (independent of the insertion point, and invisible in the GUI) across calls to transliterate(). Typically, the cursor will be coincident with the insertion point, but in a case like the one above, it will precede the insertion point.

Keyboard transliteration methods maintain a set of three indices that are updated with each call to transliterate(), including the cursor, start, and limit. Since these indices are changed by the method, they are passed in an int[] array. The START index marks the beginning of the substring that the transliterator will look at. It is advanced as text becomes committed (but it is not the committed index; that's the CURSOR). The CURSOR index, described above, marks the point at which the transliterator last stopped, either because it reached the end, or because it required more characters to disambiguate between possible inputs. The CURSOR can also be explicitly set by rules in a RuleBasedTransliterator. Any characters before the CURSOR index are frozen; future keyboard transliteration calls within this input sequence will not change them. New text is inserted at the LIMIT index, which marks the end of the substring that the transliterator looks at.

Because keyboard transliteration assumes that more characters are to arrive, it is conservative in its operation. It only transliterates when it can do so unambiguously. Otherwise it waits for more characters to arrive. When the client code knows that no more characters are forthcoming, perhaps because the user has performed some input termination operation, then it should call finishTransliteration() to complete any pending transliterations.

Inverses

Pairs of transliterators may be inverses of one another. For example, if transliterator A transliterates characters by incrementing their Unicode value (so "abc" -> "def"), and transliterator B decrements character values, then A is an inverse of B and vice versa. If we compose A with B in a compound transliterator, the result is the indentity transliterator, that is, a transliterator that does not change its input text.

The Transliterator method getInverse() returns a transliterator's inverse, if one exists, or null otherwise. However, the result of getInverse() usually will not be a true mathematical inverse. This is because true inverse transliterators are difficult to formulate. For example, consider two transliterators: AB, which transliterates the character 'A' to 'B', and BA, which transliterates 'B' to 'A'. It might seem that these are exact inverses, since

<blockquote>"A" x AB -> "B"
"B" x BA -> "A"</blockquote>

where 'x' represents transliteration. However,

<blockquote>"ABCD" x AB -> "BBCD"
"BBCD" x BA -> "AACD"</blockquote>

so AB composed with BA is not the identity. Nonetheless, BA may be usefully considered to be AB's inverse, and it is on this basis that AB.getInverse() could legitimately return BA.

IDs and display names

A transliterator is designated by a short identifier string or ID. IDs follow the format source-destination, where source describes the entity being replaced, and destination describes the entity replacing source. The entities may be the names of scripts, particular sequences of characters, or whatever else it is that the transliterator converts to or from. For example, a transliterator from Russian to Latin might be named "Russian-Latin". A transliterator from keyboard escape sequences to Latin-1 characters might be named "KeyboardEscape-Latin1". By convention, system entity names are in English, with the initial letters of words capitalized; user entity names may follow any format so long as they do not contain dashes.

In addition to programmatic IDs, transliterator objects have display names for presentation in user interfaces, returned by getDisplayName.

Factory methods and registration

In general, client code should use the factory method getInstance() to obtain an instance of a transliterator given its ID. Valid IDs may be enumerated using getAvailableIDs(). Since transliterators are mutable, multiple calls to getInstance() with the same ID will return distinct objects.

In addition to the system transliterators registered at startup, user transliterators may be registered by calling registerInstance() at run time. A registered instance acts a template; future calls to getInstance() with the ID of the registered object return clones of that object. Thus any object passed to registerInstance() must implement clone() propertly. To register a transliterator subclass without instantiating it (until it is needed), users may call registerClass(). In this case, the objects are instantiated by invoking the zero-argument public constructor of the class.

Subclassing

Subclasses must implement the abstract method handleTransliterate().

Subclasses should override the transliterate() method taking a Replaceable and the transliterate() method taking a String and StringBuffer if the performance of these methods can be improved over the performance obtained by the default implementations in this class.

Author:
Alan Liu


Member Typedef Documentation

typedef Transliterator*(* Transliterator::Factory)(const UnicodeString &ID, Token context)
 

A function that creates and returns a Transliterator.

When invoked, it will be passed the ID string that is being instantiated, together with the context pointer that was passed in when the factory function was first registered. Many factory functions will ignore both parameters, however, functions that are registered to more than one ID may use the ID or the context parameter to parameterize the transliterator they create.


Constructor & Destructor Documentation

Transliterator::Transliterator const UnicodeString ID,
UnicodeFilter adoptedFilter
[protected]
 

Default constructor.

Parameters:
ID the string identifier for this transliterator
adoptedFilter the filter. Any character for which filter.contains() returns false will not be altered by this transliterator. If filter is null then no filtering is applied.

virtual Transliterator::~Transliterator  )  [virtual]
 

Destructor.


Member Function Documentation

void Transliterator::_registerFactory const UnicodeString id,
Factory  factory,
Token  context
[static, protected]
 

For internal use only.

void Transliterator::_registerSpecialInverse const UnicodeString target,
const UnicodeString inverseTarget,
UBool  bidirectional
[static, protected]
 

Register two targets as being inverses of one another.

For example, calling registerSpecialInverse("NFC", "NFD", true) causes Transliterator to form the following inverse relationships:

NFC => NFD
 Any-NFC => Any-NFD
 NFD => NFC
 Any-NFD => Any-NFC

(Without the special inverse registration, the inverse of NFC would be NFC-Any.) Note that NFD is shorthand for Any-NFD, but that the presence or absence of "Any-" is preserved.

The relationship is symmetrical; registering (a, b) is equivalent to registering (b, a).

The relevant IDs must still be registered separately as factories or classes.

Only the targets are specified. Special inverses always have the form Any-Target1 <=> Any-Target2. The target should have canonical casing (the casing desired to be produced when an inverse is formed) and should contain no whitespace or other extraneous characters.

Parameters:
target the target against which to register the inverse
inverseTarget the inverse of target, that is Any-target.getInverse() => Any-inverseTarget
bidirectional if true, register the reverse relation as well, that is, Any-inverseTarget.getInverse() => Any-target

For internal use only.

void Transliterator::adoptFilter UnicodeFilter adoptedFilter  ) 
 

Changes the filter used by this transliterator.

If the filter is set to null then no filtering will occur.

Callers must take care if a transliterator is in use by multiple threads. The filter should not be changed by one thread while another thread may be transliterating. ICU 2.0

virtual Transliterator* Transliterator::clone void   )  const [inline, virtual]
 

Implements Cloneable.

All subclasses are encouraged to implement this method if it is possible and reasonable to do so. Subclasses that are to be registered with the system using registerInstance() are required to implement this method. If a subclass does not implement clone() properly and is registered with the system using registerInstance(), then the default clone() implementation will return null, and calls to createInstance() will fail.

See also:
registerInstance

Reimplemented in CompoundTransliterator, HexToUnicodeTransliterator, NullTransliterator, RuleBasedTransliterator, and UnicodeToHexTransliterator.

int32_t Transliterator::countAvailableIDs void   )  [static]
 

Return the number of IDs currently registered with the system.

To retrieve the actual IDs, call getAvailableID(i) with i from 0 to countAvailableIDs() - 1.

int32_t Transliterator::countAvailableSources void   )  [static]
 

Return the number of registered source specifiers.

ICU 2.0

int32_t Transliterator::countAvailableTargets const UnicodeString source  )  [static]
 

Return the number of registered target specifiers for a given source specifier.

ICU 2.0

int32_t Transliterator::countAvailableVariants const UnicodeString source,
const UnicodeString target
[static]
 

Return the number of registered variant specifiers for a given source-target pair.

ICU 2.0

Transliterator* Transliterator::createBasicInstance const UnicodeString id,
const UnicodeString canon
[static, protected]
 

Create a transliterator from a basic ID.

This is an ID containing only the forward direction source, target, and variant.

Parameters:
id a basic ID of the form S-T or S-T/V.
canon canonical ID to assign to the object, or NULL to leave the ID unchanged
Returns:
a newly created Transliterator or null if the ID is invalid.

Transliterator* Transliterator::createFromRules const UnicodeString ID,
const UnicodeString rules,
UTransDirection  dir,
UParseError parseError,
UErrorCode status
[static]
 

Returns a Transliterator object constructed from the given rule string.

This will be a RuleBasedTransliterator, if the rule string contains only rules, or a CompoundTransliterator, if it contains ID blocks, or a NullTransliterator, if it contains ID blocks which parse as empty for the given direction. ICU 2.0

Transliterator* Transliterator::createInstance const UnicodeString ID,
UTransDirection  dir,
UErrorCode status
[static]
 

Returns a Transliterator object given its ID.

The ID must be either a system transliterator ID or a ID registered using registerInstance(). ICU 2.0

Transliterator* Transliterator::createInstance const UnicodeString ID,
UTransDirection  dir,
UParseError parseError,
UErrorCode status
[static]
 

Returns a Transliterator object given its ID.

The ID must be either a system transliterator ID or a ID registered using registerInstance().

Parameters:
ID a valid ID, as enumerated by getAvailableIDs()
Returns:
A Transliterator object with the given ID
See also:
registerInstance

#getAvailableIDs

getID ICU 2.0

Transliterator* Transliterator::createInverse UErrorCode status  )  const
 

Returns this transliterator's inverse.

See the class documentation for details. This implementation simply inverts the two entities in the ID and attempts to retrieve the resulting transliterator. That is, if getID() returns "A-B", then this method will return the result of getInstance("B-A"), or null if that call fails.

Subclasses with knowledge of their inverse may wish to override this method.

Returns:
a transliterator that is an inverse, not necessarily exact, of this transliterator, or null if no such transliterator is registered.
See also:
registerInstance

virtual void Transliterator::filteredTransliterate Replaceable text,
UTransPosition index,
UBool  incremental
const [protected, virtual]
 

Transliterate a substring of text, as specified by index, taking filters into account.

This method is for subclasses that need to delegate to another transliterator, such as CompoundTransliterator.

Parameters:
text the text to be transliterated
index the position indices
incremental if TRUE, then assume more characters may be inserted at index.limit, and postpone processing to accomodate future incoming characters

virtual void Transliterator::finishTransliteration Replaceable text,
UTransPosition index
const [virtual]
 

Finishes any pending transliterations that were waiting for more characters.

Clients should call this method as the last call after a sequence of one or more calls to transliterate().

Parameters:
text the buffer holding transliterated and untransliterated text.
index the array of indices previously passed to transliterate

const UnicodeString& Transliterator::getAvailableID int32_t  index  )  [static]
 

Return the index-th available ID.

index must be between 0 and countAvailableIDs() - 1, inclusive. If index is out of range, the result of getAvailableID(0) is returned.

UnicodeString& Transliterator::getAvailableSource int32_t  index,
UnicodeString result
[static]
 

Return a registered source specifier.

Parameters:
index which specifier to return, from 0 to n-1, where n = countAvailableSources()
result fill-in paramter to receive the source specifier. If index is out of range, result will be empty.
Returns:
reference to result ICU 2.0

UnicodeString& Transliterator::getAvailableTarget int32_t  index,
const UnicodeString source,
UnicodeString result
[static]
 

Return a registered target specifier for a given source.

Parameters:
index which specifier to return, from 0 to n-1, where n = countAvailableTargets(source)
source the source specifier
result fill-in paramter to receive the target specifier. If source is invalid or if index is out of range, result will be empty.
Returns:
reference to result ICU 2.0

UnicodeString& Transliterator::getAvailableVariant int32_t  index,
const UnicodeString source,
const UnicodeString target,
UnicodeString result
[static]
 

Return a registered variant specifier for a given source-target pair.

Parameters:
index which specifier to return, from 0 to n-1, where n = countAvailableVariants(source, target)
source the source specifier
target the target specifier
result fill-in paramter to receive the variant specifier. If source is invalid or if target is invalid or if index is out of range, result will be empty.
Returns:
reference to result ICU 2.0

UnicodeString& Transliterator::getDisplayName const UnicodeString ID,
const Locale &  inLocale,
UnicodeString result
[static]
 

Returns a name for this transliterator that is appropriate for display to the user in the given locale.

This name is taken from the locale resource data in the standard manner of the java.text package.

If no localized names exist in the system resource bundles, a name is synthesized using a localized MessageFormat pattern from the resource data. The arguments to this pattern are an integer followed by one or two strings. The integer is the number of strings, either 1 or 2. The strings are formed by splitting the ID for this transliterator at the first '-'. If there is no '-', then the entire ID forms the only string.

Parameters:
inLocale the Locale in which the display name should be localized.
See also:
java.text.MessageFormat

UnicodeString& Transliterator::getDisplayName const UnicodeString ID,
UnicodeString result
[static]
 

Returns a name for this transliterator that is appropriate for display to the user in the default locale.

See getDisplayName(Locale) for details.

virtual UClassID Transliterator::getDynamicClassID void   )  const [inline, virtual]
 

Returns a unique class ID polymorphically.

This method is to implement a simple version of RTTI, since not all C++ compilers support genuine RTTI. Polymorphic operator==() and clone() methods call this method.

Concrete subclasses of Transliterator that wish clients to be able to identify them should implement getDynamicClassID() and also a static method and data member:

 static UClassID getStaticClassID() { return (UClassID) }
 static char fgClassID;
 

Subclasses that do not implement this method will have a dynamic class ID of Transliterator::getStatisClassID().

Returns:
The class ID for this object. All objects of a given class have the same class ID. Objects of other classes have different class IDs. ICU 2.0

Reimplemented in RuleBasedTransliterator.

const UnicodeFilter* Transliterator::getFilter void   )  const
 

Returns the filter used by this transliterator, or NULL if this transliterator uses no filter.

virtual const UnicodeString& Transliterator::getID void   )  const [virtual]
 

Returns a programmatic identifier for this transliterator.

If this identifier is passed to getInstance(), it will return this object, if it has been registered.

See also:
registerInstance

#registerClass

#getAvailableIDs

int32_t Transliterator::getMaximumContextLength void   )  const [inline]
 

Returns the length of the longest context required by this transliterator.

This is preceding context. The default implementation supplied by Transliterator returns zero; subclasses that use preceding context should override this method to return the correct value. For example, if a transliterator translates "ddd" (where d is any digit) to "555" when preceded by "(ddd)", then the preceding context length is 5, the length of "(ddd)".

Returns:
The maximum number of preceding context characters this transliterator needs to examine

UClassID Transliterator::getStaticClassID void   )  [inline, static]
 

Return the class ID for this class.

This is useful only for comparing to a return value from getDynamicClassID(). For example:

 .      Base* polymorphic_pointer = createPolymorphicObject();
 .      if (polymorphic_pointer->getDynamicClassID() ==
 .          Derived::getStaticClassID()) ...
 
Returns:
The class ID for all objects of this class. ICU 2.0

Reimplemented in RuleBasedTransliterator.

virtual void Transliterator::handleTransliterate Replaceable text,
UTransPosition pos,
UBool  incremental
const [protected, pure virtual]
 

Abstract method that concrete subclasses define to implement keyboard transliteration.

This method should transliterate all characters between pos.start and pos.contextLimit that can be unambiguously transliterated, regardless of future insertions of text at pos.contextLimit. pos.start should be advanced past committed characters (those that will not change in future calls to this method). pos.contextLimit should be updated to reflect text replacements that shorten or lengthen the text between pos.start and pos.contextLimit. Upon return, neither pos.start nor pos.contextLimit should be less than the initial value of pos.start. pos.contextStart should not be changed.

Subclasses may safely assume that all characters in [pos.start, pos.limit) are unfiltered. In other words, the filter has already been applied by the time this method is called. See filteredTransliterate().

This method is not for public consumption. Calling this method directly will transliterate [pos.start, pos.limit) without applying the filter. End user code that wants to call this method should be calling transliterate(). Subclass code that wants to call this method should probably be calling filteredTransliterate().

If incremental is true, then upon return pos.start may be less than pos.limit, if some characters are unprocessed. If incremental is false, then pos.start should be equal to pos.limit.

Parameters:
text the buffer holding transliterated and untransliterated text
pos the start and limit of the text, the position of the cursor, and the start and limit of transliteration.
incremental if true, assume more text may be coming after pos.contextLimit. Otherwise, assume the text is complete.
See also:
transliterate

Implemented in CompoundTransliterator, HexToUnicodeTransliterator, NullTransliterator, RuleBasedTransliterator, and UnicodeToHexTransliterator.

UnicodeFilter* Transliterator::orphanFilter void   ) 
 

Returns the filter used by this transliterator, or NULL if this transliterator uses no filter.

The caller must eventually delete the result. After this call, this transliterator's filter is set to NULL.

void Transliterator::registerFactory const UnicodeString id,
Factory  factory,
Token  context
[static]
 

Registers a factory function that creates transliterators of a given ID.

Parameters:
id the ID being registered
factory a function pointer that will be copied and called later when the given ID is passed to createInstance()
context a context pointer that will be stored and later passed to the factory function when an ID matching the registration ID is being instantiated with this factory. ICU 2.0

void Transliterator::registerInstance Transliterator adoptedObj  )  [static]
 

Registers a instance obj of a subclass of Transliterator with the system.

When createInstance() is called with an ID string that is equal to obj->getID(), then obj->clone() is returned.

After this call the Transliterator class owns the adoptedObj and will delete it.

Parameters:
obj an instance of subclass of Transliterator that defines clone()
See also:
#getInstance

#registerClass

unregister

void Transliterator::setID const UnicodeString id  )  [inline, protected]
 

Set the ID of this transliterators.

Subclasses shouldn't do this, unless the underlying script behavior has changed.

void Transliterator::setMaximumContextLength int32_t  maxContextLength  )  [protected]
 

Method for subclasses to use to set the maximum context length.

See also:
getMaximumContextLength

virtual UnicodeString& Transliterator::toRules UnicodeString result,
UBool  escapeUnprintable
const [virtual]
 

Create a rule string that can be passed to createFromRules() to recreate this transliterator.

Parameters:
result the string to receive the rules. Previous contents will be deleted.
escapeUnprintable if TRUE then convert unprintable character to their hex escape representations, or . Unprintable characters are those other than U+000A, U+0020..U+007E. ICU 2.0

Reimplemented in CompoundTransliterator, and RuleBasedTransliterator.

virtual void Transliterator::transliterate Replaceable text,
UTransPosition index,
UErrorCode status
const [virtual]
 

Transliterates the portion of the text buffer that can be transliterated unambiguosly.

This is a convenience method; see transliterate(Replaceable, int[], String) for details.

Parameters:
text the buffer holding transliterated and untransliterated text
index an array of three integers. See transliterate(Replaceable, int[], String).
See also:
transliterate(Replaceable, int[], String)

virtual void Transliterator::transliterate Replaceable text,
UTransPosition index,
UChar32  insertion,
UErrorCode status
const [virtual]
 

Transliterates the portion of the text buffer that can be transliterated unambiguosly after a new character has been inserted, typically as a result of a keyboard event.

This is a convenience method; see transliterate(Replaceable, int[], String) for details.

Parameters:
text the buffer holding transliterated and untransliterated text
index an array of three integers. See transliterate(Replaceable, int[], String).
insertion text to be inserted and possibly transliterated into the translation buffer at index.limit.
See also:
transliterate(Replaceable, int[], String)

virtual void Transliterator::transliterate Replaceable text,
UTransPosition index,
const UnicodeString insertion,
UErrorCode status
const [virtual]
 

Transliterates the portion of the text buffer that can be transliterated unambiguosly after new text has been inserted, typically as a result of a keyboard event.

The new text in insertion will be inserted into text at index.limit, advancing index.limit by insertion.length(). Then the transliterator will try to transliterate characters of text between index.cursor and index.limit. Characters before index.cursor will not be changed.

Upon return, values in index will be updated. index.start will be advanced to the first character that future calls to this method will read. index.cursor and index.limit will be adjusted to delimit the range of text that future calls to this method may change.

Typical usage of this method begins with an initial call with index.start and index.limit set to indicate the portion of text to be transliterated, and index.cursor == index.start. Thereafter, index can be used without modification in future calls, provided that all changes to text are made via this method.

This method assumes that future calls may be made that will insert new text into the buffer. As a result, it only performs unambiguous transliterations. After the last call to this method, there may be untransliterated text that is waiting for more input to resolve an ambiguity. In order to perform these pending transliterations, clients should call finishTransliteration after the last call to this method has been made.

Parameters:
text the buffer holding transliterated and untransliterated text
index an array of three integers.
  • index.start: the beginning index, inclusive; 0 <= index.start <= index.limit.

  • index.limit: the ending index, exclusive; index.start <= index.limit <= text.length(). insertion is inserted at index.limit.

  • index.cursor: the next character to be considered for transliteration; index.start <= index.cursor <= index.limit. Characters before index.cursor will not be changed by future calls to this method.

Parameters:
insertion text to be inserted and possibly transliterated into the translation buffer at index.limit. If null then no text is inserted.
See also:
handleTransliterate
Exceptions:
IllegalArgumentException if index is invalid
See also:
UTransPosition

virtual void Transliterator::transliterate Replaceable text  )  const [virtual]
 

Transliterates an entire string in place.

Convenience method.

Parameters:
text the string to be transliterated

virtual int32_t Transliterator::transliterate Replaceable text,
int32_t  start,
int32_t  limit
const [virtual]
 

Transliterates a segment of a string, with optional filtering.

Parameters:
text the string to be transliterated
start the beginning index, inclusive; 0 <= start <= limit.
limit the ending index, exclusive; start <= limit <= text.length().
Returns:
The new limit index. The text previously occupying [start, limit) has been transliterated, possibly to a string of a different length, at [start, new-limit), where new-limit is the return value. If the input offsets are out of bounds, the returned value is -1 and the input string remains unchanged.

void Transliterator::unregister const UnicodeString ID  )  [static]
 

Unregisters a transliterator or class.

This may be either a system transliterator or a user transliterator or class. Any attempt to construct an unregistered transliterator based on its ID will fail.

Parameters:
ID the ID of the transliterator or class
Returns:
the Object that was registered with ID, or null if none was
See also:
registerInstance

#registerClass


The documentation for this class was generated from the following file:
Generated on Wed Nov 17 21:02:08 2004 for ICU 2.1 by  doxygen 1.3.9.1