ICU-990 add toRules API to RuleBasedTransliterator

X-SVN-Rev: 4964

icu4c/source/i18n/unicode/rbt.h

@@ -375,6 +375,57 @@ public:
     virtual void handleTransliterate(Replaceable& text, UTransPosition& offsets,
                                      UBool isIncremental) const;
 
+    /**
+     * Return a representation of this transliterator as source rules.
+     * These rules will produce an equivalent transliterator if used
+     * to construct a new transliterator.
+     * @param result the string to receive the rules.  Previous
+     * contents will be deleted.
+     * @param escapeUnprintable if TRUE then convert unprintable
+     * character to their hex escape representations, \uxxxx or
+     * \Uxxxxxxxx.  Unprintable characters are those other than
+     * U+000A, U+0020..U+007E.
+     */
+    virtual UnicodeString& toRules(UnicodeString& result,
+                                   UBool escapeUnprintable) const;
+
+    /**
+     * Return the class ID for this class.  This is useful only for
+     * comparing to a return value from getDynamicClassID().  For example:
+     * <pre>
+     * .      Base* polymorphic_pointer = createPolymorphicObject();
+     * .      if (polymorphic_pointer->getDynamicClassID() ==
+     * .          Derived::getStaticClassID()) ...
+     * </pre>
+     * @return          The class ID for all objects of this class.
+     * @stable
+     */
+    static UClassID getStaticClassID(void) { return (UClassID)&fgClassID; }
+
+    /**
+     * Returns a unique class ID <b>polymorphically</b>.  This method
+     * is to implement a simple version of RTTI, since not all C++
+     * compilers support genuine RTTI.  Polymorphic operator==() and
+     * clone() methods call this method.
+     * 
+     * <p>Concrete subclasses of Transliterator that wish clients to
+     * be able to identify them should implement getDynamicClassID()
+     * and also a static method and data member:
+     * 
+     * <pre>
+     * static UClassID getStaticClassID() { return (UClassID)&fgClassID; }
+     * static char fgClassID;
+     * </pre>
+     *
+     * Subclasses that do not implement this method will have a
+     * dynamic class ID of Transliterator::getStatisClassID().
+     *
+     * @return The class ID for this object. All objects of a given
+     * class have the same class ID.  Objects of other classes have
+     * different class IDs.
+     */
+    virtual UClassID getDynamicClassID(void) const { return getStaticClassID(); };
+
     /**
      * Parse error codes generated by RuleBasedTransliterator.
      * See parseerr.h.
@@ -405,6 +456,11 @@ public:
 
 private:
 
+    /**
+     * Class identifier for RuleBasedTransliterator.
+     */
+    static char fgClassID;
+
     void _construct(const UnicodeString& rules,
                     UTransDirection direction,
                     UErrorCode& status,