initial commit, 4.5 stable

thirdparty/icu4c/common/unicode/usetiter.h

@@ -0,0 +1,323 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+**********************************************************************
+* Copyright (c) 2002-2014, International Business Machines
+* Corporation and others.  All Rights Reserved.
+**********************************************************************
+*/
+#ifndef USETITER_H
+#define USETITER_H
+
+#include "unicode/utypes.h"
+
+#if U_SHOW_CPLUSPLUS_API
+
+#include "unicode/uobject.h"
+#include "unicode/unistr.h"
+
+/**
+ * \file 
+ * \brief C++ API: UnicodeSetIterator iterates over the contents of a UnicodeSet.
+ */
+
+U_NAMESPACE_BEGIN
+
+class UnicodeSet;
+class UnicodeString;
+
+/**
+ *
+ * UnicodeSetIterator iterates over the contents of a UnicodeSet.  It
+ * iterates over either code points or code point ranges.  After all
+ * code points or ranges have been returned, it returns the
+ * multicharacter strings of the UnicodeSet, if any.
+ *
+ * This class is not intended for public subclassing.
+ *
+ * <p>To iterate over code points and strings, use a loop like this:
+ * <pre>
+ * UnicodeSetIterator it(set);
+ * while (it.next()) {
+ *     processItem(it.getString());
+ * }
+ * </pre>
+ * <p>Each item in the set is accessed as a string.  Set elements
+ *    consisting of single code points are returned as strings containing
+ *    just the one code point.
+ *
+ * <p>To iterate over code point ranges, instead of individual code points,
+ *    use a loop like this:
+ * <pre>
+ * UnicodeSetIterator it(set);
+ * while (it.nextRange()) {
+ *   if (it.isString()) {
+ *     processString(it.getString());
+ *   } else {
+ *     processCodepointRange(it.getCodepoint(), it.getCodepointEnd());
+ *   }
+ * }
+ * </pre>
+ *
+ * To iterate over only the strings, start with <code>skipToStrings()</code>.
+ *
+ * @author M. Davis
+ * @stable ICU 2.4
+ */
+class U_COMMON_API UnicodeSetIterator final : public UObject {
+    /**
+     * Value of <tt>codepoint</tt> if the iterator points to a string.
+     * If <tt>codepoint == IS_STRING</tt>, then examine
+     * <tt>string</tt> for the current iteration result.
+     */
+    enum { IS_STRING = -1 };
+
+    /**
+     * Current code point, or the special value <tt>IS_STRING</tt>, if
+     * the iterator points to a string.
+     */
+    UChar32 codepoint;
+
+    /**
+     * When iterating over ranges using <tt>nextRange()</tt>,
+     * <tt>codepointEnd</tt> contains the inclusive end of the
+     * iteration range, if <tt>codepoint != IS_STRING</tt>.  If
+     * iterating over code points using <tt>next()</tt>, or if
+     * <tt>codepoint == IS_STRING</tt>, then the value of
+     * <tt>codepointEnd</tt> is undefined.
+     */
+    UChar32 codepointEnd;
+
+    /**
+     * If <tt>codepoint == IS_STRING</tt>, then <tt>string</tt> points
+     * to the current string.  If <tt>codepoint != IS_STRING</tt>, the
+     * value of <tt>string</tt> is undefined.
+     */
+    const UnicodeString* string;
+
+ public:
+
+    /**
+     * Create an iterator over the given set.  The iterator is valid
+     * only so long as <tt>set</tt> is valid.
+     * @param set set to iterate over
+     * @stable ICU 2.4
+     */
+    UnicodeSetIterator(const UnicodeSet& set);
+
+    /**
+     * Create an iterator over nothing.  <tt>next()</tt> and
+     * <tt>nextRange()</tt> return false. This is a convenience
+     * constructor allowing the target to be set later.
+     * @stable ICU 2.4
+     */
+    UnicodeSetIterator();
+
+    /**
+     * Destructor.
+     * @stable ICU 2.4
+     */
+    virtual ~UnicodeSetIterator();
+
+    /**
+     * Returns true if the current element is a string.  If so, the
+     * caller can retrieve it with <tt>getString()</tt>.  If this
+     * method returns false, the current element is a code point or
+     * code point range, depending on whether <tt>next()</tt> or
+     * <tt>nextRange()</tt> was called.
+     * Elements of types string and codepoint can both be retrieved
+     * with the function <tt>getString()</tt>.
+     * Elements of type codepoint can also be retrieved with
+     * <tt>getCodepoint()</tt>.
+     * For ranges, <tt>getCodepoint()</tt> returns the starting codepoint
+     * of the range, and <tt>getCodepointEnd()</tt> returns the end
+     * of the range.
+     * @stable ICU 2.4
+     */
+    inline UBool isString() const;
+
+    /**
+     * Returns the current code point, if <tt>isString()</tt> returned
+     * false.  Otherwise returns an undefined result.
+     * @stable ICU 2.4
+     */
+    inline UChar32 getCodepoint() const;
+
+    /**
+     * Returns the end of the current code point range, if
+     * <tt>isString()</tt> returned false and <tt>nextRange()</tt> was
+     * called.  Otherwise returns an undefined result.
+     * @stable ICU 2.4
+     */
+    inline UChar32 getCodepointEnd() const;
+
+    /**
+     * Returns the current string, if <tt>isString()</tt> returned
+     * true.  If the current iteration item is a code point, a UnicodeString
+     * containing that single code point is returned.
+     *
+     * Ownership of the returned string remains with the iterator.
+     * The string is guaranteed to remain valid only until the iterator is
+     *   advanced to the next item, or until the iterator is deleted.
+     * 
+     * @stable ICU 2.4
+     */
+    const UnicodeString& getString();
+
+    /**
+     * Skips over the remaining code points/ranges, if any.
+     * A following call to next() or nextRange() will yield a string, if there is one.
+     * No-op if next() would return false, or if it would yield a string anyway.
+     *
+     * @return *this
+     * @stable ICU 70
+     * @see UnicodeSet#strings()
+     */
+    inline UnicodeSetIterator &skipToStrings() {
+        // Finish code point/range iteration.
+        range = endRange;
+        endElement = -1;
+        nextElement = 0;
+        return *this;
+    }
+
+    /**
+     * Advances the iteration position to the next element in the set, 
+     * which can be either a single code point or a string.  
+     * If there are no more elements in the set, return false.
+     *
+     * <p>
+     * If <tt>isString() == true</tt>, the value is a
+     * string, otherwise the value is a
+     * single code point.  Elements of either type can be retrieved
+     * with the function <tt>getString()</tt>, while elements of
+     * consisting of a single code point can be retrieved with
+     * <tt>getCodepoint()</tt>
+     *
+     * <p>The order of iteration is all code points in sorted order,
+     * followed by all strings sorted order.    Do not mix
+     * calls to <tt>next()</tt> and <tt>nextRange()</tt> without
+     * calling <tt>reset()</tt> between them.  The results of doing so
+     * are undefined.
+     *
+     * @return true if there was another element in the set.
+     * @stable ICU 2.4
+     */
+    UBool next();
+
+    /**
+     * Returns the next element in the set, either a code point range
+     * or a string.  If there are no more elements in the set, return
+     * false.  If <tt>isString() == true</tt>, the value is a
+     * string and can be accessed with <tt>getString()</tt>.  Otherwise the value is a
+     * range of one or more code points from <tt>getCodepoint()</tt> to
+     * <tt>getCodepointeEnd()</tt> inclusive.
+     *
+     * <p>The order of iteration is all code points ranges in sorted
+     * order, followed by all strings sorted order.  Ranges are
+     * disjoint and non-contiguous.  The value returned from <tt>getString()</tt>
+     * is undefined unless <tt>isString() == true</tt>.  Do not mix calls to
+     * <tt>next()</tt> and <tt>nextRange()</tt> without calling
+     * <tt>reset()</tt> between them.  The results of doing so are
+     * undefined.
+     *
+     * @return true if there was another element in the set.
+     * @stable ICU 2.4
+     */
+    UBool nextRange();
+
+    /**
+     * Sets this iterator to visit the elements of the given set and
+     * resets it to the start of that set.  The iterator is valid only
+     * so long as <tt>set</tt> is valid.
+     * @param set the set to iterate over.
+     * @stable ICU 2.4
+     */
+    void reset(const UnicodeSet& set);
+
+    /**
+     * Resets this iterator to the start of the set.
+     * @stable ICU 2.4
+     */
+    void reset();
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for this class.
+     *
+     * @stable ICU 2.4
+     */
+    static UClassID U_EXPORT2 getStaticClassID();
+
+    /**
+     * ICU "poor man's RTTI", returns a UClassID for the actual class.
+     *
+     * @stable ICU 2.4
+     */
+    virtual UClassID getDynamicClassID() const override;
+
+    // ======================= PRIVATES ===========================
+
+private:
+
+    // endElement and nextElements are really UChar32's, but we keep
+    // them as signed int32_t's so we can do comparisons with
+    // endElement set to -1.  Leave them as int32_t's.
+    /** The set
+     */
+    const UnicodeSet* set;
+    /** End range
+     */
+    int32_t endRange;
+    /** Range
+     */
+    int32_t range;
+    /** End element
+     */
+    int32_t endElement;
+    /** Next element
+     */
+    int32_t nextElement;
+    /** Next string
+     */
+    int32_t nextString;
+    /** String count
+     */
+    int32_t stringCount;
+
+    /**
+     *  Points to the string to use when the caller asks for a
+     *  string and the current iteration item is a code point, not a string.
+     */
+    UnicodeString *cpString;
+
+    /** Copy constructor. Disallowed.
+     */
+    UnicodeSetIterator(const UnicodeSetIterator&) = delete;
+
+    /** Assignment operator. Disallowed.
+     */
+    UnicodeSetIterator& operator=(const UnicodeSetIterator&) = delete;
+
+    /** Load range
+     */
+    void loadRange(int32_t range);
+};
+
+inline UBool UnicodeSetIterator::isString() const {
+    return codepoint < 0;
+}
+
+inline UChar32 UnicodeSetIterator::getCodepoint() const {
+    return codepoint;
+}
+
+inline UChar32 UnicodeSetIterator::getCodepointEnd() const {
+    return codepointEnd;
+}
+
+
+U_NAMESPACE_END
+
+#endif /* U_SHOW_CPLUSPLUS_API */
+
+#endif