| /* |
| ********************************************************************** |
| * Copyright (C) 1999-2004, 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" |
| |
| #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.) 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 |
| * |
| * \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() |
| |
| 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 { 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>. |
| * @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; 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 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 |
| * 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; |
| |
| /** |
| * 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; |
| |
| friend class CompoundTransliterator; // for filteredTransliterate() |
| friend class AnyTransliterator; // for filteredTransliterate() |
| |
| 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 |
| * @draft 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 |
| * @draft 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 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 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); |
| |
| 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); |
| |
| /** |
| * 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. |
| * @draft 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(void); |
| |
| 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 |
| ID.getTerminatedBuffer(); |
| } |
| |
| 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 |
