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/*
* Copyright (C) 1999-2001, International Business Machines Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/17/99 aliu Creation.
**********************************************************************
*/
#ifndef TRANSLIT_H
#define TRANSLIT_H
#include "unicode/unistr.h"
#include "unicode/parseerr.h"
#include "unicode/utrans.h" // UTransPosition, UTransDirection
U_NAMESPACE_BEGIN
class Replaceable;
class UnicodeFilter;
class UnicodeSet;
class TransliterationRuleData;
class U_I18N_API UVector;
class CompoundTransliterator;
class TransliteratorParser;
class NormalizationTransliterator;
/**
* <code>Transliterator</code> 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 <em>translate</em> Russian to English!
* Transliteration, unlike translation, operates on characters, without
* reference to the meanings of words and sentences.
*
* <p>Although script conversion is its most common use, a
* transliterator can actually perform a more general class of tasks.
* In fact, <code>Transliterator</code> 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 <code>Transliterator</code>.
*
* <p><b>Transliterators are stateless</b>
*
* <p><code>Transliterator</code> objects are <em>stateless</em>; they
* retain no information between calls to
* <code>transliterate()</code>. (However, this does <em>not</em>
* 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
* <code>Transliterator</code> objects are stateless, the source text
* itself embodies all the needed information, and delayed operation
* allows arbitrary complexity.
*
* <p><b>Batch transliteration</b>
*
* <p>The simplest way to perform transliteration is all at once, on a
* string of existing text. This is referred to as <em>batch</em>
* transliteration. For example, given a string <code>input</code>
* and a transliterator <code>t</code>, the call
*
* <blockquote><code>String result = t.transliterate(input);
* </code></blockquote>
*
* will transliterate it and return the result. Other methods allow
* the client to specify a substring to be transliterated and to use
* {@link Replaceable} objects instead of strings, in order to
* preserve out-of-band information (such as text styles).
*
* <p><b>Keyboard transliteration</b>
*
* <p>Somewhat more involved is <em>keyboard</em>, 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.
*
* <p>In keyboard transliteration, a <code>Replaceable</code> 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.
*
* <p>Consider the simple <code>RuleBasedTransliterator</code>:
*
* <blockquote><code>
* th&gt;{theta}<br>
* t&gt;{tau}
* </code></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><code>
* t&gt;|{tau}<br>
* {tau}h&gt;{theta}
* </code></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
* <code>transliterate()</code>. Typically, the cursor will
* be coincident with the insertion point, but in a case like the one
* above, it will precede the insertion point.
*
* <p>Keyboard transliteration methods maintain a set of three indices
* that are updated with each call to
* <code>transliterate()</code>, including the cursor, start,
* and limit. Since these indices are changed by the method, they are
* passed in an <code>int[]</code> array. The <code>START</code> 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 <code>CURSOR</code>). The
* <code>CURSOR</code> 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 <code>CURSOR</code> can also be
* explicitly set by rules in a <code>RuleBasedTransliterator</code>.
* Any characters before the <code>CURSOR</code> index are frozen;
* future keyboard transliteration calls within this input sequence
* will not change them. New text is inserted at the
* <code>LIMIT</code> index, which marks the end of the substring that
* the transliterator looks at.
*
* <p>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
* <code>finishTransliteration()</code> to complete any
* pending transliterations.
*
* <p><b>Inverses</b>
*
* <p>Pairs of transliterators may be inverses of one another. For
* example, if transliterator <b>A</b> transliterates characters by
* incrementing their Unicode value (so "abc" -> "def"), and
* transliterator <b>B</b> decrements character values, then <b>A</b>
* is an inverse of <b>B</b> and vice versa. If we compose <b>A</b>
* with <b>B</b> in a compound transliterator, the result is the
* indentity transliterator, that is, a transliterator that does not
* change its input text.
*
* The <code>Transliterator</code> method <code>getInverse()</code>
* returns a transliterator's inverse, if one exists, or
* <code>null</code> otherwise. However, the result of
* <code>getInverse()</code> usually will <em>not</em> be a true
* mathematical inverse. This is because true inverse transliterators
* are difficult to formulate. For example, consider two
* transliterators: <b>AB</b>, which transliterates the character 'A'
* to 'B', and <b>BA</b>, which transliterates 'B' to 'A'. It might
* seem that these are exact inverses, since
*
* <blockquote>"A" x <b>AB</b> -> "B"<br>
* "B" x <b>BA</b> -> "A"</blockquote>
*
* where 'x' represents transliteration. However,
*
* <blockquote>"ABCD" x <b>AB</b> -> "BBCD"<br>
* "BBCD" x <b>BA</b> -> "AACD"</blockquote>
*
* so <b>AB</b> composed with <b>BA</b> is not the
* identity. Nonetheless, <b>BA</b> may be usefully considered to be
* <b>AB</b>'s inverse, and it is on this basis that
* <b>AB</b><code>.getInverse()</code> could legitimately return
* <b>BA</b>.
*
* <p><b>IDs and display names</b>
*
* <p>A transliterator is designated by a short identifier string or
* <em>ID</em>. IDs follow the format <em>source-destination</em>,
* where <em>source</em> describes the entity being replaced, and
* <em>destination</em> describes the entity replacing
* <em>source</em>. 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.
*
* <p>In addition to programmatic IDs, transliterator objects have
* display names for presentation in user interfaces, returned by
* {@link #getDisplayName}.
*
* <p><b>Factory methods and registration</b>
*
* <p>In general, client code should use the factory method
* <code>getInstance()</code> to obtain an instance of a
* transliterator given its ID. Valid IDs may be enumerated using
* <code>getAvailableIDs()</code>. Since transliterators are mutable,
* multiple calls to <code>getInstance()</code> with the same ID will
* return distinct objects.
*
* <p>In addition to the system transliterators registered at startup,
* user transliterators may be registered by calling
* <code>registerInstance()</code> at run time. A registered instance
* acts a template; future calls to <tt>getInstance()</tt> with the ID
* of the registered object return clones of that object. Thus any
* object passed to <tt>registerInstance()</tt> must implement
* <tt>clone()</tt> propertly. To register a transliterator subclass
* without instantiating it (until it is needed), users may call
* <code>registerClass()</code>. In this case, the objects are
* instantiated by invoking the zero-argument public constructor of
* the class.
*
* <p><b>Subclassing</b>
*
* Subclasses must implement the abstract method
* <code>handleTransliterate()</code>. <p>Subclasses should override
* the <code>transliterate()</code> method taking a
* <code>Replaceable</code> and the <code>transliterate()</code>
* method taking a <code>String</code> and <code>StringBuffer</code>
* if the performance of these methods can be improved over the
* performance obtained by the default implementations in this class.
*
* @author Alan Liu
* @draft
*/
class U_I18N_API Transliterator {
private:
/**
* Programmatic name, e.g., "Latin-Arabic".
*/
UnicodeString ID;
/**
* This transliterator's filter. Any character for which
* <tt>filter.contains()</tt> returns <tt>false</tt> will not be
* altered by this transliterator. If <tt>filter</tt> is
* <tt>null</tt> then no filtering is applied.
*/
UnicodeFilter* filter;
int32_t maximumContextLength;
public:
/**
* A context integer or pointer for a factory function, passed by
* value.
*/
union Token {
int32_t integer;
void* pointer;
};
/**
* Return a token containing an integer.
*/
inline static Token integerToken(int32_t);
/**
* Return a token containing a pointer.
*/
inline static Token pointerToken(void*);
/**
* 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.
*/
typedef Transliterator* (*Factory)(const UnicodeString& ID, Token context);
protected:
/**
* Default constructor.
* @param ID the string identifier for this transliterator
* @param adoptedFilter the filter. Any character for which
* <tt>filter.contains()</tt> returns <tt>false</tt> will not be
* altered by this transliterator. If <tt>filter</tt> is
* <tt>null</tt> then no filtering is applied.
*/
Transliterator(const UnicodeString& ID, UnicodeFilter* adoptedFilter);
/**
* Copy constructor.
*/
Transliterator(const Transliterator&);
/**
* Assignment operator.
*/
Transliterator& operator=(const Transliterator&);
/**
* Internal factory method.
*/
static Transliterator* createInstance(const UnicodeString& ID,
UTransDirection dir,
int32_t idSplitPoint,
Transliterator *adoptedSplitTrans,
UParseError& parseError,
UErrorCode& status);
/**
* Internal parsing method.
*/
static void parseCompoundID(const UnicodeString& ID,
UnicodeString& regenID,
UTransDirection dir,
int32_t idSplitPoint,
Transliterator *adoptedSplitTrans,
UVector& result,
int32_t& splitTransIndex,
UnicodeSet*& compoundFilter,
UParseError& parseError,
UErrorCode& status);
/**
* Internal parsing method for subclasses.
*/
static Transliterator* parseID(const UnicodeString& ID,
UnicodeString& regenID,
int32_t& pos,
UBool& sawDelimiter,
UnicodeSet*& compoundFilter,
UTransDirection dir,
UParseError& parseError,
UBool create,
UErrorCode& status);
/**
* Internal parsing method for parseID.
*/
static UBool parseIDBounds(const UnicodeString& ID,
int32_t pos,
UBool withinParens,
int32_t& limit,
int32_t& setStart,
int32_t& setLimit,
int32_t& revStart,
UnicodeSet*& filter);
static void skipSpaces(const UnicodeString& str,
int32_t& pos);
friend class TransliteratorParser; // for parseID()
public:
/**
* Destructor.
* @draft
*/
virtual ~Transliterator();
/**
* 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 <tt>registerInstance()<tt>
* 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 #registerInstance
* @draft
*/
virtual Transliterator* clone() const { return 0; }
/**
* Transliterates a segment of a string, with optional filtering.
*
* @param text the string to be transliterated
* @param start the beginning index, inclusive; <code>0 <= start
* <= limit</code>.
* @param limit the ending index, exclusive; <code>start <= limit
* <= text.length()</code>.
* @param filter the filter. Any character for which
* <tt>filter.contains()</tt> returns <tt>false</tt> will not be
* altered by this transliterator. If <tt>filter</tt> is
* <tt>null</tt> then no filtering is applied.
* @return The new limit index. The text previously occupying <code>[start,
* limit)</code> has been transliterated, possibly to a string of a different
* length, at <code>[start, </code><em>new-limit</em><code>)</code>, where
* <em>new-limit</em> is the return value.
* @draft
*/
virtual int32_t transliterate(Replaceable& text,
int32_t start, int32_t limit) const;
/**
* Transliterates an entire string in place. Convenience method.
* @param text the string to be transliterated
* @draft
*/
virtual void transliterate(Replaceable& text) 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. The new text in
* <code>insertion</code> will be inserted into <code>text</code>
* at <code>index.limit</code>, advancing
* <code>index.limit</code> by <code>insertion.length()</code>.
* Then the transliterator will try to transliterate characters of
* <code>text</code> between <code>index.cursor</code> and
* <code>index.limit</code>. Characters before
* <code>index.cursor</code> will not be changed.
*
* <p>Upon return, values in <code>index</code> will be updated.
* <code>index.start</code> will be advanced to the first
* character that future calls to this method will read.
* <code>index.cursor</code> and <code>index.limit</code> will
* be adjusted to delimit the range of text that future calls to
* this method may change.
*
* <p>Typical usage of this method begins with an initial call
* with <code>index.start</code> and <code>index.limit</code>
* set to indicate the portion of <code>text</code> to be
* transliterated, and <code>index.cursor == index.start</code>.
* Thereafter, <code>index</code> can be used without
* modification in future calls, provided that all changes to
* <code>text</code> are made via this method.
*
* <p>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 {@link
* #finishTransliteration} after the last call to this
* method has been made.
*
* @param text the buffer holding transliterated and untransliterated text
* @param index an array of three integers.
*
* <ul><li><code>index.start</code>: the beginning index,
* inclusive; <code>0 <= index.start <= index.limit</code>.
*
* <li><code>index.limit</code>: the ending index, exclusive;
* <code>index.start <= index.limit <= text.length()</code>.
* <code>insertion</code> is inserted at
* <code>index.limit</code>.
*
* <li><code>index.cursor</code>: the next character to be
* considered for transliteration; <code>index.start <=
* index.cursor <= index.limit</code>. Characters before
* <code>index.cursor</code> will not be changed by future calls
* to this method.</ul>
*
* @param insertion text to be inserted and possibly
* transliterated into the translation buffer at
* <code>index.limit</code>. If <code>null</code> then no text
* is inserted.
* @see #handleTransliterate
* @exception IllegalArgumentException if <code>index</code>
* is invalid
* @draft
*/
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 a new character has been
* inserted, typically as a result of a keyboard event. This is a
* convenience method; see {@link
* #transliterate(Replaceable, int[], String)} for details.
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers. See {@link
* #transliterate(Replaceable, int[], String)}.
* @param insertion text to be inserted and possibly
* transliterated into the translation buffer at
* <code>index.limit</code>.
* @see #transliterate(Replaceable, int[], String)
* @draft
*/
virtual void transliterate(Replaceable& text, UTransPosition& index,
UChar32 insertion,
UErrorCode& status) const;
/**
* Transliterates the portion of the text buffer that can be
* transliterated unambiguosly. This is a convenience method; see
* {@link #transliterate(Replaceable, int[], String)} for
* details.
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers. See {@link
* #transliterate(Replaceable, int[], String)}.
* @see #transliterate(Replaceable, int[], String)
* @draft
*/
virtual void transliterate(Replaceable& text, UTransPosition& index,
UErrorCode& status) const;
/**
* 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
* <code>transliterate()</code>.
* @param text the buffer holding transliterated and
* untransliterated text.
* @param index the array of indices previously passed to {@link
* #transliterate}
* @draft
*/
virtual void finishTransliteration(Replaceable& text,
UTransPosition& index) const;
private:
/**
* This internal method does incremental transliteration. If the
* 'insertion' is non-null then we append it to 'text' before
* proceeding. This method calls through to the pure virtual
* framework method handleTransliterate() to do the actual
* work.
*/
void _transliterate(Replaceable& text,
UTransPosition& index,
const UnicodeString* insertion,
UErrorCode &status) const;
protected:
/**
* Abstract method that concrete subclasses define to implement
* keyboard transliteration. This method should transliterate all
* characters between <code>index.cursor</code> and
* <code>index.limit</code> that can be unambiguously
* transliterated, regardless of future insertions of text at
* <code>index.limit</code>. <code>index.cursor</code> should
* be advanced past committed characters (those that will not
* change in future calls to this method).
* <code>index.limit</code> should be updated to reflect text
* replacements that shorten or lengthen the text between
* <code>index.cursor</code> and <code>index.limit</code>. Upon
* return, neither <code>index.cursor</code> nor
* <code>index.limit</code> should be less than the initial value
* of <code>index.cursor</code>. <code>index.start</code>
* should <em>not</em> be changed.
*
* <p>Subclasses may safely assume that all characters in
* [index.start, index.limit) are unfiltered. In other words, the
* filter has already been applied by the time this method is
* called. See filteredTransliterate().
*
* <p>This method is <b>not</b> for public consumption. Calling
* this method directly will transliterate [index.start,
* index.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().
*
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers. See {@link
* #transliterate(Replaceable, int[], String)}.
* @see #transliterate
*/
virtual void handleTransliterate(Replaceable& text,
UTransPosition& index,
UBool incremental) const = 0;
/**
* Core transliteration method called by all other methods in
* Tranliterator. This method splits up the input text into
* segments of unfiltered text and passes those to
* handleTransliterate(). For most subclasses this is convenient
* and efficient. Subclasses that can more efficiently handle the
* filter logic on their own (rare) can override
* filteredTransliterate(). Such subclasses must still implement
* handleTransliterate() but they can do so with an empty body,
* since filteredTransliterate() is the only method that calls
* handleTransliterate().
*/
virtual void filteredTransliterate(Replaceable& text,
UTransPosition& index,
UBool incremental) const;
friend class CompoundTransliterator; // for filteredTransliterate
public:
/**
* Returns the length of the longest context required by this transliterator.
* This is <em>preceding</em> context. The default implementation supplied
* by <code>Transliterator</code> 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)".
*
* @return The maximum number of preceding context characters this
* transliterator needs to examine
* @draft
*/
int32_t getMaximumContextLength(void) const;
protected:
/**
* Method for subclasses to use to set the maximum context length.
* @see #getMaximumContextLength
*/
void setMaximumContextLength(int32_t maxContextLength);
public:
/**
* Returns a programmatic identifier for this transliterator.
* If this identifier is passed to <code>getInstance()</code>, it
* will return this object, if it has been registered.
* @see #registerInstance
* @see #registerClass
* @see #getAvailableIDs
* @draft
*/
virtual const UnicodeString& getID(void) const;
/**
* Returns a name for this transliterator that is appropriate for
* display to the user in the default locale. See {@link
* #getDisplayName(Locale)} for details.
* @draft
*/
static UnicodeString& getDisplayName(const UnicodeString& ID,
UnicodeString& result);
/**
* 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
* <code>java.text</code> package.
*
* <p>If no localized names exist in the system resource bundles,
* a name is synthesized using a localized
* <code>MessageFormat</code> 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.
* @param inLocale the Locale in which the display name should be
* localized.
* @see java.text.MessageFormat
* @draft
*/
static UnicodeString& getDisplayName(const UnicodeString& ID,
const Locale& inLocale,
UnicodeString& result);
/**
* Returns the filter used by this transliterator, or <tt>NULL</tt>
* if this transliterator uses no filter.
* @draft
*/
const UnicodeFilter* getFilter(void) const;
/**
* Returns the filter used by this transliterator, or <tt>NULL</tt> if this
* transliterator uses no filter. The caller must eventually delete the
* result. After this call, this transliterator's filter is set to
* <tt>NULL</tt>.
*/
UnicodeFilter* orphanFilter(void);
#ifdef U_USE_DEPRECATED_TRANSLITERATOR_API
/**
* Changes the filter used by this transliterator. If the filter
* is set to <tt>null</tt> then no filtering will occur.
*
* <p>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.
*
* @deprecated This method will be made NON-VIRTUAL in Aug 2002.
*/
virtual void adoptFilter(UnicodeFilter* adoptedFilter);
#else
/**
* Changes the filter used by this transliterator. If the filter
* is set to <tt>null</tt> then no filtering will occur.
*
* <p>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.
* @draft
*/
void adoptFilter(UnicodeFilter* adoptedFilter);
#endif
/**
* 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 <code>getID()</code>
* returns "A-B", then this method will return the result of
* <code>getInstance("B-A")</code>, or <code>null</code> if that
* call fails.
*
* <p>This method does not take filtering into account. The
* returned transliterator will have no filter.
*
* <p>Subclasses with knowledge of their inverse may wish to
* override this method.
*
* @return a transliterator that is an inverse, not necessarily
* exact, of this transliterator, or <code>null</code> if no such
* transliterator is registered.
* @see #registerInstance
* @draft
*/
Transliterator* createInverse(UErrorCode& status) const;
/**
* Returns a <code>Transliterator</code> object given its ID.
* The ID must be either a system transliterator ID or a ID registered
* using <code>registerInstance()</code>.
*
* @param ID a valid ID, as enumerated by <code>getAvailableIDs()</code>
* @return A <code>Transliterator</code> object with the given ID
* @exception IllegalArgumentException if the given ID is invalid.
* @see #registerInstance
* @see #getAvailableIDs
* @see #getID
* @draft
*/
static Transliterator* createInstance(const UnicodeString& ID,
UTransDirection dir,
UParseError& parseError,
UErrorCode& status);
static Transliterator* createInstance(const UnicodeString& ID,
UTransDirection dir,
UErrorCode& status);
/**
* Returns a <code>Transliterator</code> 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.
*/
static Transliterator* createFromRules(const UnicodeString& ID,
const UnicodeString& rules,
UTransDirection dir,
UParseError& parseError,
UErrorCode& status);
/**
* Create a rule string that can be passed to createFromRules()
* to recreate this transliterator.
* @param result the string to receive the rules. Previous
* contents will be deleted.
* @param escapeUnprintable if TRUE then convert unprintable
* character to their hex escape representations, \uxxxx or
* \Uxxxxxxxx. Unprintable characters are those other than
* U+000A, U+0020..U+007E.
*/
virtual UnicodeString& toRules(UnicodeString& result,
UBool escapeUnprintable) const;
public:
/**
* Registers a factory function that creates transliterators of
* a given ID.
* @param id the ID being registered
* @param factory a function pointer that will be copied and
* called later when the given ID is passed to createInstance()
* @param 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.
*/
static void registerFactory(const UnicodeString& id,
Factory factory,
Token context);
/**
* Registers a instance <tt>obj</tt> of a subclass of
* <code>Transliterator</code> with the system. When
* <tt>createInstance()</tt> is called with an ID string that is
* equal to <tt>obj->getID()</tt>, then <tt>obj->clone()</tt> is
* returned.
*
* After this call the Transliterator class owns the adoptedObj
* and will delete it.
*
* @param obj an instance of subclass of
* <code>Transliterator</code> that defines <tt>clone()</tt>
* @see #getInstance
* @see #registerClass
* @see #unregister
* @draft
*/
static void registerInstance(Transliterator* adoptedObj);
private:
friend class NormalizationTransliterator;
static void _registerFactory(const UnicodeString& id,
Factory factory,
Token context);
public:
/**
* Unregisters a transliterator or class. This may be either
* a system transliterator or a user transliterator or class.
*
* @param ID the ID of the transliterator or class
* @return the <code>Object</code> that was registered with
* <code>ID</code>, or <code>null</code> if none was
* @see #registerInstance
* @see #registerClass
* @draft
*/
static void unregister(const UnicodeString& ID);
public:
/**
* 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.
* @draft
*/
static int32_t countAvailableIDs(void);
/**
* 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.
* @draft
*/
static const UnicodeString& getAvailableID(int32_t index);
/**
* Return the number of registered source specifiers.
*/
static int32_t countAvailableSources(void);
/**
* Return a registered source specifier.
* @param index which specifier to return, from 0 to n-1, where
* n = countAvailableSources()
* @param result fill-in paramter to receive the source specifier.
* If index is out of range, result will be empty.
* @return reference to result
*/
static UnicodeString& getAvailableSource(int32_t index,
UnicodeString& result);
/**
* Return the number of registered target specifiers for a given
* source specifier.
*/
static int32_t countAvailableTargets(const UnicodeString& source);
/**
* Return a registered target specifier for a given source.
* @param index which specifier to return, from 0 to n-1, where
* n = countAvailableTargets(source)
* @param source the source specifier
* @param result fill-in paramter to receive the target specifier.
* If source is invalid or if index is out of range, result will
* be empty.
* @return reference to result
*/
static UnicodeString& getAvailableTarget(int32_t index,
const UnicodeString& source,
UnicodeString& result);
/**
* Return the number of registered variant specifiers for a given
* source-target pair.
*/
static int32_t countAvailableVariants(const UnicodeString& source,
const UnicodeString& target);
/**
* Return a registered variant specifier for a given source-target
* pair.
* @param index which specifier to return, from 0 to n-1, where
* n = countAvailableVariants(source, target)
* @param source the source specifier
* @param target the target specifier
* @param 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.
* @return reference to result
*/
static UnicodeString& getAvailableVariant(int32_t index,
const UnicodeString& source,
const UnicodeString& target,
UnicodeString& result);
/**
* Return the class ID for this class. This is useful only for
* comparing to a return value from getDynamicClassID(). For example:
* <pre>
* . Base* polymorphic_pointer = createPolymorphicObject();
* . if (polymorphic_pointer->getDynamicClassID() ==
* . Derived::getStaticClassID()) ...
* </pre>
* @return The class ID for all objects of this class.
* @stable
*/
static UClassID getStaticClassID(void) { return (UClassID)&fgClassID; }
/**
* Returns a unique class ID <b>polymorphically</b>. 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.
*
* <p>Concrete subclasses of Transliterator that wish clients to
* be able to identify them should implement getDynamicClassID()
* and also a static method and data member:
*
* <pre>
* static UClassID getStaticClassID() { return (UClassID)&fgClassID; }
* static char fgClassID;
* </pre>
*
* Subclasses that do not implement this method will have a
* dynamic class ID of Transliterator::getStatisClassID().
*
* @return 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.
*/
virtual UClassID getDynamicClassID(void) const { return getStaticClassID(); };
private:
/**
* Class identifier for subclasses of Transliterator that do not
* define their class (anonymous subclasses).
*/
static const char fgClassID;
protected:
/**
* Set the ID of this transliterators. Subclasses shouldn't do
* this, unless the underlying script behavior has changed.
*/
void setID(const UnicodeString& id);
private:
static void initializeRegistry(void);
#ifdef U_USE_DEPRECATED_TRANSLITERATOR_API
public:
/**
* Returns a <code>Transliterator</code> object given its ID.
* The ID must be either a system transliterator ID or a ID registered
* using <code>registerInstance()</code>.
*
* @param ID a valid ID, as enumerated by <code>getAvailableIDs()</code>
* @return A <code>Transliterator</code> object with the given ID
* @exception IllegalArgumentException if the given ID is invalid.
* @see #registerInstance
* @see #getAvailableIDs
* @see #getID
* @deprecated Remove after Aug 2002 use factory mehod that takes UParseError
* and UErrorCode
*/
inline Transliterator* createInstance(const UnicodeString& ID,
UTransDirection dir=UTRANS_FORWARD,
UParseError* parseError=0);
/**
* 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 <code>getID()</code>
* returns "A-B", then this method will return the result of
* <code>getInstance("B-A")</code>, or <code>null</code> if that
* call fails.
*
* <p>This method does not take filtering into account. The
* returned transliterator will have no filter.
*
* <p>Subclasses with knowledge of their inverse may wish to
* override this method.
*
* @return a transliterator that is an inverse, not necessarily
* exact, of this transliterator, or <code>null</code> if no such
* transliterator is registered.
* @deprecated Remove after Aug 2002 use factory mehod that takes UErrorCode
*/
inline Transliterator* createInverse() const;
protected:
/**
* Method for subclasses to use to obtain a character in the given
* string, with filtering. If the character at the given offset
* is excluded by this transliterator's filter, then U+FFFE is returned.
*
* <p><b>Note:</b> Most subclasses that implement
* handleTransliterator() will <em>not</em> want to use this
* method, since characters they see are already filtered. Only
* subclasses with special requirements, such as those overriding
* filteredTransliterate(), should need this method.
*
* @deprecated the new architecture provides filtering at the top
* level. This method will be removed Aug 2002.
*/
UChar filteredCharAt(const Replaceable& text, int32_t i) const;
#endif
};
inline int32_t Transliterator::getMaximumContextLength(void) const {
return maximumContextLength;
}
inline void Transliterator::setID(const UnicodeString& id) {
ID = id;
}
inline Transliterator::Token Transliterator::integerToken(int32_t i) {
Token t;
t.integer = i;
return t;
}
inline Transliterator::Token Transliterator::pointerToken(void* p) {
Token t;
t.pointer = p;
return t;
}
/**
* Definitions for deprecated API
* @deprecated Remove after Aug 2002
*/
#ifdef U_USE_DEPRECATED_TRANSLITERATOR_API
inline Transliterator* Transliterator::createInstance(const UnicodeString& ID,
UTransDirection dir,
UParseError* parseError){
UErrorCode status = U_ZERO_ERROR;
UParseError error;
if(parseError == NULL){
parseError = &error;
}
return Transliterator::createInstance(ID,dir,*parseError,status);
}
inline Transliterator* Transliterator::createInverse() const{
UErrorCode status = U_ZERO_ERROR;
return createInverse(status);
}
#endif
U_NAMESPACE_END
#endif