Check in the pristine copy of ICU 4.6...

icu46/source/i18n/unicode/coleitr.h

+/*
+ ******************************************************************************
+ *   Copyright (C) 1997-2008, International Business Machines
+ *   Corporation and others.  All Rights Reserved.
+ ******************************************************************************
+ */
+
+/**
+ * \file 
+ * \brief C++ API: Collation Element Iterator.
+ */
+
+/**
+* File coleitr.h
+*
+* 
+*
+* Created by: Helena Shih
+*
+* Modification History:
+*
+*  Date       Name        Description
+*
+*  8/18/97    helena      Added internal API documentation.
+* 08/03/98    erm         Synched with 1.2 version CollationElementIterator.java
+* 12/10/99    aliu        Ported Thai collation support from Java.
+* 01/25/01    swquek      Modified into a C++ wrapper calling C APIs (ucoliter.h)
+* 02/19/01    swquek      Removed CollationElementsIterator() since it is 
+*                         private constructor and no calls are made to it
+*/
+
+#ifndef COLEITR_H
+#define COLEITR_H
+
+#include "unicode/utypes.h"
+
+ 
+#if !UCONFIG_NO_COLLATION
+
+#include "unicode/uobject.h"
+#include "unicode/tblcoll.h"
+#include "unicode/ucoleitr.h"
+
+/** 
+ * The UCollationElements struct.
+ * For usage in C programs.
+ * @stable ICU 2.0
+ */
+typedef struct UCollationElements UCollationElements;
+
+U_NAMESPACE_BEGIN
+
+/**
+* The CollationElementIterator class is used as an iterator to walk through     
+* each character of an international string. Use the iterator to return the
+* ordering priority of the positioned character. The ordering priority of a 
+* character, which we refer to as a key, defines how a character is collated in 
+* the given collation object.
+* For example, consider the following in Spanish:
+* <pre>
+*        "ca" -> the first key is key('c') and second key is key('a').
+*        "cha" -> the first key is key('ch') and second key is key('a').</pre>
+* And in German,
+* <pre> \htmlonly       "&#x00E6;b"-> the first key is key('a'), the second key is key('e'), and
+*        the third key is key('b'). \endhtmlonly </pre>
+* The key of a character, is an integer composed of primary order(short),
+* secondary order(char), and tertiary order(char). Java strictly defines the 
+* size and signedness of its primitive data types. Therefore, the static
+* functions primaryOrder(), secondaryOrder(), and tertiaryOrder() return 
+* int32_t to ensure the correctness of the key value.
+* <p>Example of the iterator usage: (without error checking)
+* <pre>
+* \code
+*   void CollationElementIterator_Example()
+*   {
+*       UnicodeString str = "This is a test";
+*       UErrorCode success = U_ZERO_ERROR;
+*       RuleBasedCollator* rbc =
+*           (RuleBasedCollator*) RuleBasedCollator::createInstance(success);
+*       CollationElementIterator* c =
+*           rbc->createCollationElementIterator( str );
+*       int32_t order = c->next(success);
+*       c->reset();
+*       order = c->previous(success);
+*       delete c;
+*       delete rbc;
+*   }
+* \endcode
+* </pre>
+* <p>
+* CollationElementIterator::next returns the collation order of the next
+* character based on the comparison level of the collator. 
+* CollationElementIterator::previous returns the collation order of the 
+* previous character based on the comparison level of the collator. 
+* The Collation Element Iterator moves only in one direction between calls to
+* CollationElementIterator::reset. That is, CollationElementIterator::next() 
+* and CollationElementIterator::previous can not be inter-used. Whenever 
+* CollationElementIterator::previous is to be called after 
+* CollationElementIterator::next() or vice versa, 
+* CollationElementIterator::reset has to be called first to reset the status, 
+* shifting pointers to either the end or the start of the string. Hence at the 
+* next call of CollationElementIterator::previous or 
+* CollationElementIterator::next(), the first or last collation order will be 
+* returned. 
+* If a change of direction is done without a CollationElementIterator::reset(), 
+* the result is undefined.
+* The result of a forward iterate (CollationElementIterator::next) and 
+* reversed result of the backward iterate (CollationElementIterator::previous) 
+* on the same string are equivalent, if collation orders with the value 
+* UCOL_IGNORABLE are ignored.
+* Character based on the comparison level of the collator.  A collation order 
+* consists of primary order, secondary order and tertiary order.  The data 
+* type of the collation order is <strong>t_int32</strong>. 
+*
+* Note, CollationElementIterator should not be subclassed.
+* @see     Collator
+* @see     RuleBasedCollator
+* @version 1.8 Jan 16 2001
+*/
+class U_I18N_API CollationElementIterator : public UObject {
+public: 
+
+    // CollationElementIterator public data member ------------------------------
+
+    enum {
+        /**
+         * NULLORDER indicates that an error has occured while processing
+         * @stable ICU 2.0
+         */
+        NULLORDER = (int32_t)0xffffffff
+    };
+
+    // CollationElementIterator public constructor/destructor -------------------
+
+    /**
+    * Copy constructor.
+    *
+    * @param other    the object to be copied from
+    * @stable ICU 2.0
+    */
+    CollationElementIterator(const CollationElementIterator& other);
+
+    /** 
+    * Destructor
+    * @stable ICU 2.0
+    */
+    virtual ~CollationElementIterator();
+
+    // CollationElementIterator public methods ----------------------------------
+
+    /**
+    * Returns true if "other" is the same as "this"
+    *
+    * @param other    the object to be compared
+    * @return         true if "other" is the same as "this"
+    * @stable ICU 2.0
+    */
+    UBool operator==(const CollationElementIterator& other) const;
+
+    /**
+    * Returns true if "other" is not the same as "this".
+    *
+    * @param other    the object to be compared
+    * @return         true if "other" is not the same as "this"
+    * @stable ICU 2.0
+    */
+    UBool operator!=(const CollationElementIterator& other) const;
+
+    /**
+    * Resets the cursor to the beginning of the string.
+    * @stable ICU 2.0
+    */
+    void reset(void);
+
+    /**
+    * Gets the ordering priority of the next character in the string.
+    * @param status the error code status.
+    * @return the next character's ordering. otherwise returns NULLORDER if an 
+    *         error has occured or if the end of string has been reached
+    * @stable ICU 2.0
+    */
+    int32_t next(UErrorCode& status);
+
+    /**
+    * Get the ordering priority of the previous collation element in the string.
+    * @param status the error code status.
+    * @return the previous element's ordering. otherwise returns NULLORDER if an 
+    *         error has occured or if the start of string has been reached
+    * @stable ICU 2.0
+    */
+    int32_t previous(UErrorCode& status);
+
+    /**
+    * Gets the primary order of a collation order.
+    * @param order the collation order
+    * @return the primary order of a collation order.
+    * @stable ICU 2.0
+    */
+    static inline int32_t primaryOrder(int32_t order);
+
+    /**
+    * Gets the secondary order of a collation order.
+    * @param order the collation order
+    * @return the secondary order of a collation order.
+    * @stable ICU 2.0
+    */
+    static inline int32_t secondaryOrder(int32_t order);
+
+    /**
+    * Gets the tertiary order of a collation order.
+    * @param order the collation order
+    * @return the tertiary order of a collation order.
+    * @stable ICU 2.0
+    */
+    static inline int32_t tertiaryOrder(int32_t order);
+
+    /**
+    * Return the maximum length of any expansion sequences that end with the 
+    * specified comparison order.
+    * @param order a collation order returned by previous or next.
+    * @return maximum size of the expansion sequences ending with the collation 
+    *         element or 1 if collation element does not occur at the end of any 
+    *         expansion sequence
+    * @stable ICU 2.0
+    */
+    int32_t getMaxExpansion(int32_t order) const;
+
+    /**
+    * Gets the comparison order in the desired strength. Ignore the other
+    * differences.
+    * @param order The order value
+    * @stable ICU 2.0
+    */
+    int32_t strengthOrder(int32_t order) const;
+
+    /**
+    * Sets the source string.
+    * @param str the source string.
+    * @param status the error code status.
+    * @stable ICU 2.0
+    */
+    void setText(const UnicodeString& str, UErrorCode& status);
+
+    /**
+    * Sets the source string.
+    * @param str the source character iterator.
+    * @param status the error code status.
+    * @stable ICU 2.0
+    */
+    void setText(CharacterIterator& str, UErrorCode& status);
+
+    /**
+    * Checks if a comparison order is ignorable.
+    * @param order the collation order.
+    * @return TRUE if a character is ignorable, FALSE otherwise.
+    * @stable ICU 2.0
+    */
+    static inline UBool isIgnorable(int32_t order);
+
+    /**
+    * Gets the offset of the currently processed character in the source string.
+    * @return the offset of the character.
+    * @stable ICU 2.0
+    */
+    int32_t getOffset(void) const;
+
+    /**
+    * Sets the offset of the currently processed character in the source string.
+    * @param newOffset the new offset.
+    * @param status the error code status.
+    * @return the offset of the character.
+    * @stable ICU 2.0
+    */
+    void setOffset(int32_t newOffset, UErrorCode& status);
+
+    /**
+    * ICU "poor man's RTTI", returns a UClassID for the actual class.
+    *
+    * @stable ICU 2.2
+    */
+    virtual UClassID getDynamicClassID() const;
+
+    /**
+    * ICU "poor man's RTTI", returns a UClassID for this class.
+    *
+    * @stable ICU 2.2
+    */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+protected:
+  
+    // CollationElementIterator protected constructors --------------------------
+    /**
+    * @stable ICU 2.0
+    */
+    friend class RuleBasedCollator;
+
+    /**
+    * CollationElementIterator constructor. This takes the source string and the 
+    * collation object. The cursor will walk thru the source string based on the 
+    * predefined collation rules. If the source string is empty, NULLORDER will 
+    * be returned on the calls to next().
+    * @param sourceText    the source string.
+    * @param order         the collation object.
+    * @param status        the error code status.
+    * @stable ICU 2.0
+    */
+    CollationElementIterator(const UnicodeString& sourceText,
+        const RuleBasedCollator* order, UErrorCode& status);
+
+    /**
+    * CollationElementIterator constructor. This takes the source string and the 
+    * collation object.  The cursor will walk thru the source string based on the 
+    * predefined collation rules.  If the source string is empty, NULLORDER will 
+    * be returned on the calls to next().
+    * @param sourceText    the source string.
+    * @param order         the collation object.
+    * @param status        the error code status.
+    * @stable ICU 2.0
+    */
+    CollationElementIterator(const CharacterIterator& sourceText,
+        const RuleBasedCollator* order, UErrorCode& status);
+
+    // CollationElementIterator protected methods -------------------------------
+
+    /**
+    * Assignment operator
+    *
+    * @param other    the object to be copied
+    * @stable ICU 2.0
+    */
+    const CollationElementIterator&
+        operator=(const CollationElementIterator& other);
+
+private:
+    CollationElementIterator(); // default constructor not implemented
+
+    // CollationElementIterator private data members ----------------------------
+
+    /**
+    * Data wrapper for collation elements
+    */
+    UCollationElements *m_data_;
+
+    /**
+    * Indicates if m_data_ belongs to this object.
+    */
+    UBool isDataOwned_;
+
+};
+
+// CollationElementIterator inline method defination --------------------------
+
+/**
+* Get the primary order of a collation order.
+* @param order the collation order
+* @return the primary order of a collation order.
+*/
+inline int32_t CollationElementIterator::primaryOrder(int32_t order)
+{
+    order &= RuleBasedCollator::PRIMARYORDERMASK;
+    return (order >> RuleBasedCollator::PRIMARYORDERSHIFT);
+}
+
+/**
+* Get the secondary order of a collation order.
+* @param order the collation order
+* @return the secondary order of a collation order.
+*/
+inline int32_t CollationElementIterator::secondaryOrder(int32_t order)
+{
+    order = order & RuleBasedCollator::SECONDARYORDERMASK;
+    return (order >> RuleBasedCollator::SECONDARYORDERSHIFT);
+}
+
+/**
+* Get the tertiary order of a collation order.
+* @param order the collation order
+* @return the tertiary order of a collation order.
+*/
+inline int32_t CollationElementIterator::tertiaryOrder(int32_t order)
+{
+    return (order &= RuleBasedCollator::TERTIARYORDERMASK);
+}
+
+inline int32_t CollationElementIterator::getMaxExpansion(int32_t order) const
+{
+    return ucol_getMaxExpansion(m_data_, (uint32_t)order);
+}
+
+inline UBool CollationElementIterator::isIgnorable(int32_t order)
+{
+    return (primaryOrder(order) == RuleBasedCollator::PRIMIGNORABLE);
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_COLLATION */
+
+#endif