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1 /* |
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2 ********************************************************************** |
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3 * Copyright (c) 2002-2008, International Business Machines |
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4 * Corporation and others. All Rights Reserved. |
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5 ********************************************************************** |
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6 */ |
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7 #ifndef USETITER_H |
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8 #define USETITER_H |
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9 |
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10 #include "unicode/utypes.h" |
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11 #include "unicode/uobject.h" |
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12 #include "unicode/unistr.h" |
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13 |
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14 /** |
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15 * \file |
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16 * \brief C++ API: UnicodeSetIterator iterates over the contents of a UnicodeSet. |
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17 */ |
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18 |
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19 U_NAMESPACE_BEGIN |
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20 |
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21 class UnicodeSet; |
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22 class UnicodeString; |
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23 |
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24 /** |
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25 * |
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26 * UnicodeSetIterator iterates over the contents of a UnicodeSet. It |
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27 * iterates over either code points or code point ranges. After all |
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28 * code points or ranges have been returned, it returns the |
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29 * multicharacter strings of the UnicodeSet, if any. |
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30 * |
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31 * This class is not intended to be subclassed. Consider any fields |
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32 * or methods declared as "protected" to be private. The use of |
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33 * protected in this class is an artifact of history. |
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34 * |
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35 * <p>To iterate over code points and strings, use a loop like this: |
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36 * <pre> |
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37 * UnicodeSetIterator it(set); |
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38 * while (it.next()) { |
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39 * processItem(it.getString()); |
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40 * } |
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41 * </pre> |
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42 * <p>Each item in the set is accessed as a string. Set elements |
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43 * consisting of single code points are returned as strings containing |
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44 * just the one code point. |
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45 * |
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46 * <p>To iterate over code point ranges, instead of individual code points, |
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47 * use a loop like this: |
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48 * <pre> |
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49 * UnicodeSetIterator it(set); |
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50 * while (it.nextRange()) { |
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51 * if (it.isString()) { |
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52 * processString(it.getString()); |
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53 * } else { |
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54 * processCodepointRange(it.getCodepoint(), it.getCodepointEnd()); |
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55 * } |
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56 * } |
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57 * </pre> |
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58 * @author M. Davis |
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59 * @stable ICU 2.4 |
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60 */ |
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61 class U_COMMON_API UnicodeSetIterator : public UObject { |
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62 |
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63 protected: |
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64 |
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65 /** |
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66 * Value of <tt>codepoint</tt> if the iterator points to a string. |
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67 * If <tt>codepoint == IS_STRING</tt>, then examine |
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68 * <tt>string</tt> for the current iteration result. |
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69 * @stable ICU 2.4 |
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70 */ |
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71 enum { IS_STRING = -1 }; |
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72 |
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73 /** |
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74 * Current code point, or the special value <tt>IS_STRING</tt>, if |
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75 * the iterator points to a string. |
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76 * @stable ICU 2.4 |
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77 */ |
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78 UChar32 codepoint; |
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79 |
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80 /** |
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81 * When iterating over ranges using <tt>nextRange()</tt>, |
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82 * <tt>codepointEnd</tt> contains the inclusive end of the |
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83 * iteration range, if <tt>codepoint != IS_STRING</tt>. If |
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84 * iterating over code points using <tt>next()</tt>, or if |
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85 * <tt>codepoint == IS_STRING</tt>, then the value of |
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86 * <tt>codepointEnd</tt> is undefined. |
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87 * @stable ICU 2.4 |
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88 */ |
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89 UChar32 codepointEnd; |
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90 |
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91 /** |
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92 * If <tt>codepoint == IS_STRING</tt>, then <tt>string</tt> points |
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93 * to the current string. If <tt>codepoint != IS_STRING</tt>, the |
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94 * value of <tt>string</tt> is undefined. |
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95 * @stable ICU 2.4 |
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96 */ |
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97 const UnicodeString* string; |
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98 |
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99 public: |
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100 |
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101 /** |
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102 * Create an iterator over the given set. The iterator is valid |
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103 * only so long as <tt>set</tt> is valid. |
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104 * @param set set to iterate over |
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105 * @stable ICU 2.4 |
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106 */ |
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107 UnicodeSetIterator(const UnicodeSet& set); |
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108 |
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109 /** |
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110 * Create an iterator over nothing. <tt>next()</tt> and |
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111 * <tt>nextRange()</tt> return false. This is a convenience |
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112 * constructor allowing the target to be set later. |
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113 * @stable ICU 2.4 |
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114 */ |
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115 UnicodeSetIterator(); |
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116 |
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117 /** |
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118 * Destructor. |
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119 * @stable ICU 2.4 |
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120 */ |
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121 virtual ~UnicodeSetIterator(); |
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122 |
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123 /** |
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124 * Returns true if the current element is a string. If so, the |
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125 * caller can retrieve it with <tt>getString()</tt>. If this |
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126 * method returns false, the current element is a code point or |
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127 * code point range, depending on whether <tt>next()</tt> or |
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128 * <tt>nextRange()</tt> was called. |
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129 * Elements of types string and codepoint can both be retrieved |
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130 * with the function <tt>getString()</tt>. |
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131 * Elements of type codepoint can also be retrieved with |
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132 * <tt>getCodepoint()</tt>. |
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133 * For ranges, <tt>getCodepoint()</tt> returns the starting codepoint |
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134 * of the range, and <tt>getCodepointEnd()</tt> returns the end |
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135 * of the range. |
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136 * @stable ICU 2.4 |
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137 */ |
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138 inline UBool isString() const; |
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139 |
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140 /** |
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141 * Returns the current code point, if <tt>isString()</tt> returned |
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142 * false. Otherwise returns an undefined result. |
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143 * @stable ICU 2.4 |
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144 */ |
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145 inline UChar32 getCodepoint() const; |
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146 |
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147 /** |
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148 * Returns the end of the current code point range, if |
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149 * <tt>isString()</tt> returned false and <tt>nextRange()</tt> was |
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150 * called. Otherwise returns an undefined result. |
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151 * @stable ICU 2.4 |
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152 */ |
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153 inline UChar32 getCodepointEnd() const; |
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154 |
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155 /** |
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156 * Returns the current string, if <tt>isString()</tt> returned |
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157 * true. If the current iteration item is a code point, a UnicodeString |
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158 * containing that single code point is returned. |
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159 * |
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160 * Ownership of the returned string remains with the iterator. |
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161 * The string is guaranteed to remain valid only until the iterator is |
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162 * advanced to the next item, or until the iterator is deleted. |
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163 * |
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164 * @stable ICU 2.4 |
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165 */ |
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166 const UnicodeString& getString(); |
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167 |
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168 /** |
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169 * Advances the iteration position to the next element in the set, |
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170 * which can be either a single code point or a string. |
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171 * If there are no more elements in the set, return false. |
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172 * |
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173 * <p> |
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174 * If <tt>isString() == TRUE</tt>, the value is a |
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175 * string, otherwise the value is a |
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176 * single code point. Elements of either type can be retrieved |
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177 * with the function <tt>getString()</tt>, while elements of |
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178 * consisting of a single code point can be retrieved with |
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179 * <tt>getCodepoint()</tt> |
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180 * |
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181 * <p>The order of iteration is all code points in sorted order, |
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182 * followed by all strings sorted order. Do not mix |
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183 * calls to <tt>next()</tt> and <tt>nextRange()</tt> without |
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184 * calling <tt>reset()</tt> between them. The results of doing so |
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185 * are undefined. |
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186 * |
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187 * @return true if there was another element in the set. |
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188 * @stable ICU 2.4 |
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189 */ |
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190 UBool next(); |
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191 |
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192 /** |
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193 * Returns the next element in the set, either a code point range |
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194 * or a string. If there are no more elements in the set, return |
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195 * false. If <tt>isString() == TRUE</tt>, the value is a |
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196 * string and can be accessed with <tt>getString()</tt>. Otherwise the value is a |
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197 * range of one or more code points from <tt>getCodepoint()</tt> to |
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198 * <tt>getCodepointeEnd()</tt> inclusive. |
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199 * |
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200 * <p>The order of iteration is all code points ranges in sorted |
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201 * order, followed by all strings sorted order. Ranges are |
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202 * disjoint and non-contiguous. The value returned from <tt>getString()</tt> |
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203 * is undefined unless <tt>isString() == TRUE</tt>. Do not mix calls to |
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204 * <tt>next()</tt> and <tt>nextRange()</tt> without calling |
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205 * <tt>reset()</tt> between them. The results of doing so are |
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206 * undefined. |
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207 * |
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208 * @return true if there was another element in the set. |
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209 * @stable ICU 2.4 |
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210 */ |
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211 UBool nextRange(); |
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212 |
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213 /** |
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214 * Sets this iterator to visit the elements of the given set and |
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215 * resets it to the start of that set. The iterator is valid only |
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216 * so long as <tt>set</tt> is valid. |
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217 * @param set the set to iterate over. |
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218 * @stable ICU 2.4 |
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219 */ |
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220 void reset(const UnicodeSet& set); |
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221 |
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222 /** |
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223 * Resets this iterator to the start of the set. |
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224 * @stable ICU 2.4 |
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225 */ |
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226 void reset(); |
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227 |
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228 /** |
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229 * ICU "poor man's RTTI", returns a UClassID for this class. |
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230 * |
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231 * @stable ICU 2.4 |
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232 */ |
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233 static UClassID U_EXPORT2 getStaticClassID(); |
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234 |
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235 /** |
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236 * ICU "poor man's RTTI", returns a UClassID for the actual class. |
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237 * |
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238 * @stable ICU 2.4 |
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239 */ |
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240 virtual UClassID getDynamicClassID() const; |
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241 |
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242 // ======================= PRIVATES =========================== |
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243 |
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244 protected: |
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245 |
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246 // endElement and nextElements are really UChar32's, but we keep |
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247 // them as signed int32_t's so we can do comparisons with |
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248 // endElement set to -1. Leave them as int32_t's. |
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249 /** The set |
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250 * @stable ICU 2.4 |
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251 */ |
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252 const UnicodeSet* set; |
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253 /** End range |
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254 * @stable ICU 2.4 |
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255 */ |
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256 int32_t endRange; |
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257 /** Range |
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258 * @stable ICU 2.4 |
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259 */ |
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260 int32_t range; |
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261 /** End element |
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262 * @stable ICU 2.4 |
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263 */ |
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264 int32_t endElement; |
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265 /** Next element |
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266 * @stable ICU 2.4 |
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267 */ |
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268 int32_t nextElement; |
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269 //UBool abbreviated; |
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270 /** Next string |
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271 * @stable ICU 2.4 |
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272 */ |
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273 int32_t nextString; |
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274 /** String count |
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275 * @stable ICU 2.4 |
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276 */ |
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277 int32_t stringCount; |
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278 |
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279 /** |
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280 * Points to the string to use when the caller asks for a |
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281 * string and the current iteration item is a code point, not a string. |
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282 * @internal |
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283 */ |
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284 UnicodeString *cpString; |
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285 |
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286 /** Copy constructor. Disallowed. |
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287 * @stable ICU 2.4 |
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288 */ |
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289 UnicodeSetIterator(const UnicodeSetIterator&); // disallow |
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290 |
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291 /** Assignment operator. Disallowed. |
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292 * @stable ICU 2.4 |
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293 */ |
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294 UnicodeSetIterator& operator=(const UnicodeSetIterator&); // disallow |
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295 |
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296 /** Load range |
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297 * @stable ICU 2.4 |
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298 */ |
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299 virtual void loadRange(int32_t range); |
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300 |
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301 }; |
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302 |
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303 inline UBool UnicodeSetIterator::isString() const { |
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304 return codepoint == (UChar32)IS_STRING; |
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305 } |
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306 |
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307 inline UChar32 UnicodeSetIterator::getCodepoint() const { |
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308 return codepoint; |
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309 } |
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310 |
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311 inline UChar32 UnicodeSetIterator::getCodepointEnd() const { |
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312 return codepointEnd; |
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313 } |
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314 |
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315 |
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316 U_NAMESPACE_END |
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317 |
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318 #endif |