/*
**********************************************************************
* Copyright (C) 1999-2008, 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/utypes.h"
/**
* \file
* \brief C++ API: Tranforms text from one format to another.
*/
#if !UCONFIG_NO_TRANSLITERATION
#include "unicode/uobject.h"
#include "unicode/unistr.h"
#include "unicode/parseerr.h"
#include "unicode/utrans.h" // UTransPosition, UTransDirection
#include "unicode/strenum.h"
U_NAMESPACE_BEGIN
class UnicodeFilter;
class UnicodeSet;
class CompoundTransliterator;
class TransliteratorParser;
class NormalizationTransliterator;
class TransliteratorIDParser;
/**
*
* <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.) This 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
*
* \htmlonly<blockquote>\endhtmlonly<code>String result = t.transliterate(input);
* </code>\htmlonly</blockquote>\endhtmlonly
*
* 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>:
*
* \htmlonly<blockquote>\endhtmlonly<code>
* th>{theta}<br>
* t>{tau}
* </code>\htmlonly</blockquote>\endhtmlonly
*
* 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:
*
* \htmlonly<blockquote>\endhtmlonly<code>
* t>|{tau}<br>
* {tau}h>{theta}
* </code>\htmlonly</blockquote>\endhtmlonly
*
* 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
*
* \htmlonly<blockquote>\endhtmlonly"A" x <b>AB</b> -> "B"<br>
* "B" x <b>BA</b> -> "A"\htmlonly</blockquote>\endhtmlonly
*
* where 'x' represents transliteration. However,
*
* \htmlonly<blockquote>\endhtmlonly"ABCD" x <b>AB</b> -> "BBCD"<br>
* "BBCD" x <b>BA</b> -> "AACD"\htmlonly</blockquote>\endhtmlonly
*
* 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
* {@link #createInstance } 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 {@link #createInstance } 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 {@link #createInstance } 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
* {@link #registerFactory }. 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
* @stable ICU 2.0
*/
class U_I18N_API Transliterator : public UObject {
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.
* @stable ICU 2.4
*/
union Token {
/**
* This token, interpreted as a 32-bit integer.
* @stable ICU 2.4
*/
int32_t integer;
/**
* This token, interpreted as a native pointer.
* @stable ICU 2.4
*/
void* pointer;
};
/**
* Return a token containing an integer.
* @return a token containing an integer.
* @internal
*/
inline static Token integerToken(int32_t);
/**
* Return a token containing a pointer.
* @return a token containing a pointer.
* @internal
*/
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.
* @param ID the string identifier for this transliterator
* @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.
* @stable ICU 2.4
*/
typedef Transliterator* (U_EXPORT2 *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.
* @stable ICU 2.4
*/
Transliterator(const UnicodeString& ID, UnicodeFilter* adoptedFilter);
/**
* Copy constructor.
* @stable ICU 2.4
*/
Transliterator(const Transliterator&);
/**
* Assignment operator.
* @stable ICU 2.4
*/
Transliterator& operator=(const Transliterator&);
/**
* Create a transliterator from a basic ID. This is an ID
* containing only the forward direction source, target, and
* variant.
* @param id a basic ID of the form S-T or S-T/V.
* @param canon canonical ID to assign to the object, or
* NULL to leave the ID unchanged
* @return a newly created Transliterator or null if the ID is
* invalid.
* @stable ICU 2.4
*/
static Transliterator* createBasicInstance(const UnicodeString& id,
const UnicodeString* canon);
friend class TransliteratorParser; // for parseID()
friend class TransliteratorIDParser; // for createBasicInstance()
friend class TransliteratorAlias; // for setID()
public:
/**
* Destructor.
* @stable ICU 2.0
*/
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.
*
* @return a copy of the object.
* @see #registerInstance
* @stable ICU 2.0
*/
virtual Transliterator* clone() const;
/**
* 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>.
* @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. If the input offsets are out of bounds,
* the returned value is -1 and the input string remains unchanged.
* @stable ICU 2.0
*/
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
* @stable ICU 2.0
*/
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.
* @param status Output param to filled in with a success or an error.
* @see #handleTransliterate
* @exception IllegalArgumentException if <code>index</code>
* is invalid
* @see UTransPosition
* @stable ICU 2.0
*/
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.
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers.
* @param insertion text to be inserted and possibly
* transliterated into the translation buffer at
* <code>index.limit</code>.
* @param status Output param to filled in with a success or an error.
* @see #transliterate(Replaceable&, UTransPosition&, const UnicodeString&, UErrorCode&) const
* @stable ICU 2.0
*/
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&, UTransPosition&, const UnicodeString&, UErrorCode&) const }
* for details.
* @param text the buffer holding transliterated and
* untransliterated text
* @param index an array of three integers. See {@link
* #transliterate(Replaceable&, UTransPosition&, const UnicodeString&, UErrorCode&) const }.
* @param status Output param to filled in with a success or an error.
* @see #transliterate(Replaceable, int[], String)
* @stable ICU 2.0
*/
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 }
* @stable ICU 2.0
*/
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.
* @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>.
* @param status Output param to filled in with a success or an error.
*/
void _transliterate(Replaceable& text,
UTransPosition& index,
const UnicodeString* insertion,
UErrorCode &status) const;
protected:
/**
* Abstract method that concrete subclasses define to implement
* their transliteration algorithm. This method handles both
* incremental and non-incremental transliteration. Let
* <code>originalStart</code> refer to the value of
* <code>pos.start</code> upon entry.
*
* <ul>
* <li>If <code>incremental</code> is false, then this method
* should transliterate all characters between
* <code>pos.start</code> and <code>pos.limit</code>. Upon return
* <code>pos.start</code> must == <code> pos.limit</code>.</li>
*
* <li>If <code>incremental</code> is true, then this method
* should transliterate all characters between
* <code>pos.start</code> and <code>pos.limit</code> that can be
* unambiguously transliterated, regardless of future insertions
* of text at <code>pos.limit</code>. Upon return,
* <code>pos.start</code> should be in the range
* [<code>originalStart</code>, <code>pos.limit</code>).
* <code>pos.start</code> should be positioned such that
* characters [<code>originalStart</code>, <code>
* pos.start</code>) will not be changed in the future by this
* transliterator and characters [<code>pos.start</code>,
* <code>pos.limit</code>) are unchanged.</li>
* </ul>
*
* <p>Implementations of this method should also obey the
* following invariants:</p>
*
* <ul>
* <li> <code>pos.limit</code> and <code>pos.contextLimit</code>
* should be updated to reflect changes in length of the text
* between <code>pos.start</code> and <code>pos.limit</code>. The
* difference <code> pos.contextLimit - pos.limit</code> should
* not change.</li>
*
* <li><code>pos.contextStart</code> should not change.</li>
*
* <li>Upon return, neither <code>pos.start</code> nor
* <code>pos.limit</code> should be less than
* <code>originalStart</code>.</li>
*
* <li>Text before <code>originalStart</code> and text after
* <code>pos.limit</code> should not change.</li>
*
* <li>Text before <code>pos.contextStart</code> and text after
* <code> pos.contextLimit</code> should be ignored.</li>
* </ul>
*
* <p>Subclasses may safely assume that all characters in
* [<code>pos.start</code>, <code>pos.limit</code>) are filtered.
* In other words, the filter has already been applied by the time
* this method is called. See
* <code>filteredTransliterate()</code>.
*
* <p>This method is <b>not</b> for public consumption. Calling
* this method directly will transliterate
* [<code>pos.start</code>, <code>pos.limit</code>) without
* applying the filter. End user code should call <code>
* transliterate()</code> instead of this method. Subclass code
* and wrapping transliterators should call
* <code>filteredTransliterate()</code> instead of this method.<p>
*
* @param text the buffer holding transliterated and
* untransliterated text
*
* @param pos the indices indicating the start, limit, context
* start, and context limit of the text.
*
* @param incremental if true, assume more text may be inserted at
* <code>pos.limit</code> and act accordingly. Otherwise,
* transliterate all text between <code>pos.start</code> and
* <code>pos.limit</code> and move <code>pos.start</code> up to
* <code>pos.limit</code>.
*
* @see #transliterate
* @stable ICU 2.4
*/
virtual void handleTransliterate(Replaceable& text,
UTransPosition& pos,
UBool incremental) const = 0;
public:
/**
* 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.
* @param text the text to be transliterated
* @param index the position indices
* @param incremental if TRUE, then assume more characters may be inserted
* at index.limit, and postpone processing to accomodate future incoming
* characters
* @stable ICU 2.4
*/
virtual void filteredTransliterate(Replaceable& text,
UTransPosition& index,
UBool incremental) const;
private:
/**
* Top-level transliteration method, handling filtering, incremental and
* non-incremental transliteration, and rollback. All transliteration
* public API methods eventually call this method with a rollback argument
* of TRUE. Other entities may call this method but rollback should be
* FALSE.
*
* <p>If this transliterator has a filter, break up the input text into runs
* of unfiltered characters. Pass each run to
* <subclass>.handleTransliterate().
*
* <p>In incremental mode, if rollback is TRUE, perform a special
* incremental procedure in which several passes are made over the input
* text, adding one character at a time, and committing successful
* transliterations as they occur. Unsuccessful transliterations are rolled
* back and retried with additional characters to give correct results.
*
* @param text the text to be transliterated
* @param index the position indices
* @param incremental if TRUE, then assume more characters may be inserted
* at index.limit, and postpone processing to accomodate future incoming
* characters
* @param rollback if TRUE and if incremental is TRUE, then perform special
* incremental processing, as described above, and undo partial
* transliterations where necessary. If incremental is FALSE then this
* parameter is ignored.
*/
virtual void filteredTransliterate(Replaceable& text,
UTransPosition& index,
UBool incremental,
UBool rollback) const;
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
* @stable ICU 2.0
*/
int32_t getMaximumContextLength(void) const;
protected:
/**
* Method for subclasses to use to set the maximum context length.
* @param maxContextLength the new value to be set.
* @see #getMaximumContextLength
* @stable ICU 2.4
*/
void setMaximumContextLength(int32_t maxContextLength);
public:
/**
* Returns a programmatic identifier for this transliterator.
* If this identifier is passed to <code>createInstance()</code>, it
* will return this object, if it has been registered.
* @return a programmatic identifier for this transliterator.
* @see #registerInstance
* @see #registerFactory
* @see #getAvailableIDs
* @stable ICU 2.0
*/
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 } for details.
* @param ID the string identifier for this transliterator
* @param result Output param to receive the display name
* @return A reference to 'result'.
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 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 ID the string identifier for this transliterator
* @param inLocale the Locale in which the display name should be
* localized.
* @param result Output param to receive the display name
* @return A reference to 'result'.
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 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.
* @return the filter used by this transliterator, or <tt>NULL</tt>
* if this transliterator uses no filter.
* @stable ICU 2.0
*/
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>.
* @return the filter used by this transliterator, or <tt>NULL</tt> if this
* transliterator uses no filter.
* @stable ICU 2.4
*/
UnicodeFilter* orphanFilter(void);
/**
* 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.
* @param adoptedFilter the new filter to be adopted.
* @stable ICU 2.0
*/
void adoptFilter(UnicodeFilter* adoptedFilter);
/**
* 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>createInstance("B-A")</code>, or <code>null</code> if that
* call fails.
*
* <p>Subclasses with knowledge of their inverse may wish to
* override this method.
*
* @param status Output param to filled in with a success or an error.
* @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
* @stable ICU 2.0
*/
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>
* @param dir either FORWARD or REVERSE.
* @param parseError Struct to recieve information on position
* of error if an error is encountered
* @param status Output param to filled in with a success or an error.
* @return A <code>Transliterator</code> object with the given ID
* @see #registerInstance
* @see #getAvailableIDs
* @see #getID
* @stable ICU 2.0
*/
static Transliterator* U_EXPORT2 createInstance(const UnicodeString& ID,
UTransDirection dir,
UParseError& parseError,
UErrorCode& status);
/**
* 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>
* @param dir either FORWARD or REVERSE.
* @param status Output param to filled in with a success or an error.
* @return A <code>Transliterator</code> object with the given ID
* @stable ICU 2.0
*/
static Transliterator* U_EXPORT2 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.
* @param ID the id for the transliterator.
* @param rules rules, separated by ';'
* @param dir either FORWARD or REVERSE.
* @param parseError Struct to recieve information on position
* of error if an error is encountered
* @param status Output param set to success/failure code.
* @stable ICU 2.0
*/
static Transliterator* U_EXPORT2 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.
* @stable ICU 2.0
*/
virtual UnicodeString& toRules(UnicodeString& result,
UBool escapeUnprintable) const;
/**
* Return the number of elements that make up this transliterator.
* For example, if the transliterator "NFD;Jamo-Latin;Latin-Greek"
* were created, the return value of this method would be 3.
*
* <p>If this transliterator is not composed of other
* transliterators, then this method returns 1.
* @return the number of transliterators that compose this
* transliterator, or 1 if this transliterator is not composed of
* multiple transliterators
* @stable ICU 3.0
*/
int32_t countElements() const;
/**
* Return an element that makes up this transliterator. For
* example, if the transliterator "NFD;Jamo-Latin;Latin-Greek"
* were created, the return value of this method would be one
* of the three transliterator objects that make up that
* transliterator: [NFD, Jamo-Latin, Latin-Greek].
*
* <p>If this transliterator is not composed of other
* transliterators, then this method will return a reference to
* this transliterator when given the index 0.
* @param index a value from 0..countElements()-1 indicating the
* transliterator to return
* @param ec input-output error code
* @return one of the transliterators that makes up this
* transliterator, if this transliterator is made up of multiple
* transliterators, otherwise a reference to this object if given
* an index of 0
* @stable ICU 3.0
*/
const Transliterator& getElement(int32_t index, UErrorCode& ec) const;
/**
* Returns the set of all characters that may be modified in the
* input text by this Transliterator. This incorporates this
* object's current filter; if the filter is changed, the return
* value of this function will change. The default implementation
* returns an empty set. Some subclasses may override {@link
* #handleGetSourceSet } to return a more precise result. The
* return result is approximate in any case and is intended for
* use by tests, tools, or utilities.
* @param result receives result set; previous contents lost
* @return a reference to result
* @see #getTargetSet
* @see #handleGetSourceSet
* @stable ICU 2.4
*/
UnicodeSet& getSourceSet(UnicodeSet& result) const;
/**
* Framework method that returns the set of all characters that
* may be modified in the input text by this Transliterator,
* ignoring the effect of this object's filter. The base class
* implementation returns the empty set. Subclasses that wish to
* implement this should override this method.
* @return the set of characters that this transliterator may
* modify. The set may be modified, so subclasses should return a
* newly-created object.
* @param result receives result set; previous contents lost
* @see #getSourceSet
* @see #getTargetSet
* @stable ICU 2.4
*/
virtual void handleGetSourceSet(UnicodeSet& result) const;
/**
* Returns the set of all characters that may be generated as
* replacement text by this transliterator. The default
* implementation returns the empty set. Some subclasses may
* override this method to return a more precise result. The
* return result is approximate in any case and is intended for
* use by tests, tools, or utilities requiring such
* meta-information.
* @param result receives result set; previous contents lost
* @return a reference to result
* @see #getTargetSet
* @stable ICU 2.4
*/
virtual UnicodeSet& getTargetSet(UnicodeSet& result) 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.
* @stable ICU 2.0
*/
static void U_EXPORT2 registerFactory(const UnicodeString& id,
Factory factory,
Token context);
/**
* Registers an 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 adoptedObj an instance of subclass of
* <code>Transliterator</code> that defines <tt>clone()</tt>
* @see #createInstance
* @see #registerFactory
* @see #unregister
* @stable ICU 2.0
*/
static void U_EXPORT2 registerInstance(Transliterator* adoptedObj);
/**
* Registers an ID string as an alias of another ID string.
* That is, after calling this function, <tt>createInstance(aliasID)</tt>
* will return the same thing as <tt>createInstance(realID)</tt>.
* This is generally used to create shorter, more mnemonic aliases
* for long compound IDs.
*
* @param aliasID The new ID being registered.
* @param realID The ID that the new ID is to be an alias for.
* This can be a compound ID and can include filters and should
* refer to transliterators that have already been registered with
* the framework, although this isn't checked.
* @stable ICU 3.6
*/
static void U_EXPORT2 registerAlias(const UnicodeString& aliasID,
const UnicodeString& realID);
protected:
/**
* @internal
* @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);
/**
* @internal
*/
static void _registerInstance(Transliterator* adoptedObj);
/**
* @internal
*/
static void _registerAlias(const UnicodeString& aliasID, const UnicodeString& realID);
/**
* Register two targets as being inverses of one another. For
* example, calling registerSpecialInverse("NFC", "NFD", true) causes
* Transliterator to form the following inverse relationships:
*
* <pre>NFC => NFD
* Any-NFC => Any-NFD
* NFD => NFC
* Any-NFD => Any-NFC</pre>
*
* (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.
*
* <p>The relationship is symmetrical; registering (a, b) is
* equivalent to registering (b, a).
*
* <p>The relevant IDs must still be registered separately as
* factories or classes.
*
* <p>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.
*
* @param target the target against which to register the inverse
* @param inverseTarget the inverse of target, that is
* Any-target.getInverse() => Any-inverseTarget
* @param bidirectional if true, register the reverse relation
* as well, that is, Any-inverseTarget.getInverse() => Any-target
* @internal
*/
static void _registerSpecialInverse(const UnicodeString& target,
const UnicodeString& inverseTarget,
UBool bidirectional);
public:
/**
* 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.
*
* @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 #registerFactory
* @stable ICU 2.0
*/
static void U_EXPORT2 unregister(const UnicodeString& ID);
public:
/**
* Return a StringEnumeration over the IDs available at the time of the
* call, including user-registered IDs.
* @param ec input-output error code
* @return a newly-created StringEnumeration over the transliterators
* available at the time of the call. The caller should delete this object
* when done using it.
* @stable ICU 3.0
*/
static StringEnumeration* U_EXPORT2 getAvailableIDs(UErrorCode& ec);
/**
* Return the number of registered source specifiers.
* @return the number of registered source specifiers.
* @stable ICU 2.0
*/
static int32_t U_EXPORT2 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
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 getAvailableSource(int32_t index,
UnicodeString& result);
/**
* Return the number of registered target specifiers for a given
* source specifier.
* @param source the given source specifier.
* @return the number of registered target specifiers for a given
* source specifier.
* @stable ICU 2.0
*/
static int32_t U_EXPORT2 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
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 getAvailableTarget(int32_t index,
const UnicodeString& source,
UnicodeString& result);
/**
* Return the number of registered variant specifiers for a given
* source-target pair.
* @param source the source specifiers.
* @param target the target specifiers.
* @stable ICU 2.0
*/
static int32_t U_EXPORT2 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
* @stable ICU 2.0
*/
static UnicodeString& U_EXPORT2 getAvailableVariant(int32_t index,
const UnicodeString& source,
const UnicodeString& target,
UnicodeString& result);
protected:
/**
* Non-mutexed internal method
* @internal
*/
static int32_t _countAvailableSources(void);
/**
* Non-mutexed internal method
* @internal
*/
static UnicodeString& _getAvailableSource(int32_t index,
UnicodeString& result);
/**
* Non-mutexed internal method
* @internal
*/
static int32_t _countAvailableTargets(const UnicodeString& source);
/**
* Non-mutexed internal method
* @internal
*/
static UnicodeString& _getAvailableTarget(int32_t index,
const UnicodeString& source,
UnicodeString& result);
/**
* Non-mutexed internal method
* @internal
*/
static int32_t _countAvailableVariants(const UnicodeString& source,
const UnicodeString& target);
/**
* Non-mutexed internal method
* @internal
*/
static UnicodeString& _getAvailableVariant(int32_t index,
const UnicodeString& source,
const UnicodeString& target,
UnicodeString& result);
protected:
/**
* Set the ID of this transliterators. Subclasses shouldn't do
* this, unless the underlying script behavior has changed.
* @param id the new id t to be set.
* @stable ICU 2.4
*/
void setID(const UnicodeString& id);
public:
/**
* Return the class ID for this class. This is useful only for
* comparing to a return value from getDynamicClassID().
* Note that Transliterator is an abstract base class, and therefor
* no fully constructed object will have a dynamic
* UCLassID that equals the UClassID returned from
* TRansliterator::getStaticClassID().
* @return The class ID for class Transliterator.
* @stable ICU 2.0
*/
static UClassID U_EXPORT2 getStaticClassID(void);
/**
* 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 must use the
* UOBJECT_DEFINE_RTTI_IMPLEMENTATION macro from
* uobject.h to provide the RTTI functions.
*
* @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.
* @stable ICU 2.0
*/
virtual UClassID getDynamicClassID(void) const = 0;
private:
static UBool initializeRegistry(UErrorCode &status);
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.
* @return the number of IDs currently registered with the system.
* @obsolete ICU 3.4 use getAvailableIDs() instead
*/
static int32_t U_EXPORT2 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.
* @param index the given ID index.
* @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.
* @obsolete ICU 3.4 use getAvailableIDs() instead; this function
* is not thread safe, since it returns a reference to storage that
* may become invalid if another thread calls unregister
*/
static const UnicodeString& U_EXPORT2 getAvailableID(int32_t index);
};
inline int32_t Transliterator::getMaximumContextLength(void) const {
return maximumContextLength;
}
inline void Transliterator::setID(const UnicodeString& id) {
ID = id;
// NUL-terminate the ID string, which is a non-aliased copy.
ID.append((UChar)0);
ID.truncate(ID.length()-1);
}
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;
}
U_NAMESPACE_END
#endif /* #if !UCONFIG_NO_TRANSLITERATION */
#endif