Файловый менеджер - Редактировать - /opt/alt/alt-nodejs20/root/usr/share/doc/alt-nodejs20-libicu-doc/caniter_8h_source.html
Назад
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.8.14"/> <meta name="viewport" content="width=device-width, initial-scale=1"/> <title>ICU 78.3: common/unicode/caniter.h Source File</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="dynsections.js"></script> <link href="search/search.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="search/searchdata.js"></script> <script type="text/javascript" src="search/search.js"></script> <link href="doxygen.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="top"><!-- do not remove this div, it is closed by doxygen! --> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td id="projectalign" style="padding-left: 0.5em;"> <div id="projectname">ICU 78.3  <span id="projectnumber">78.3</span> </div> </td> </tr> </tbody> </table> </div> <!-- end header part --> <!-- Generated by Doxygen 1.8.14 --> <script type="text/javascript"> /* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ var searchBox = new SearchBox("searchBox", "search",false,'Search'); /* @license-end */ </script> <script type="text/javascript" src="menudata.js"></script> <script type="text/javascript" src="menu.js"></script> <script type="text/javascript"> /* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */ $(function() { initMenu('',true,false,'search.php','Search'); $(document).ready(function() { init_search(); }); }); /* @license-end */</script> <div id="main-nav"></div> <!-- window showing the filter options --> <div id="MSearchSelectWindow" onmouseover="return searchBox.OnSearchSelectShow()" onmouseout="return searchBox.OnSearchSelectHide()" onkeydown="return searchBox.OnSearchSelectKey(event)"> </div> <!-- iframe showing the search results (closed by default) --> <div id="MSearchResultsWindow"> <iframe src="javascript:void(0)" frameborder="0" name="MSearchResults" id="MSearchResults"> </iframe> </div> <div id="nav-path" class="navpath"> <ul> <li class="navelem"><a class="el" href="dir_bdd9a5d540de89e9fe90efdfc6973a4f.html">common</a></li><li class="navelem"><a class="el" href="dir_f59c6450ff718ff1b085cfd1c36acbd7.html">unicode</a></li> </ul> </div> </div><!-- top --> <div class="header"> <div class="headertitle"> <div class="title">caniter.h</div> </div> </div><!--header--> <div class="contents"> <a href="caniter_8h.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">// © 2016 and later: Unicode, Inc. and others.</span></div><div class="line"><a name="l00002"></a><span class="lineno"> 2</span> <span class="comment">// License & terms of use: http://www.unicode.org/copyright.html</span></div><div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment">/*</span></div><div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment"> *******************************************************************************</span></div><div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment"> * Copyright (C) 1996-2014, International Business Machines Corporation and</span></div><div class="line"><a name="l00006"></a><span class="lineno"> 6</span> <span class="comment"> * others. All Rights Reserved.</span></div><div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="comment"> *******************************************************************************</span></div><div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment"> */</span></div><div class="line"><a name="l00009"></a><span class="lineno"> 9</span> </div><div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="preprocessor">#ifndef CANITER_H</span></div><div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="preprocessor">#define CANITER_H</span></div><div class="line"><a name="l00012"></a><span class="lineno"> 12</span> </div><div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="preprocessor">#include "<a class="code" href="utypes_8h.html">unicode/utypes.h</a>"</span></div><div class="line"><a name="l00014"></a><span class="lineno"> 14</span> </div><div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="preprocessor">#if U_SHOW_CPLUSPLUS_API</span></div><div class="line"><a name="l00016"></a><span class="lineno"> 16</span> </div><div class="line"><a name="l00017"></a><span class="lineno"> 17</span> <span class="preprocessor">#if !UCONFIG_NO_NORMALIZATION</span></div><div class="line"><a name="l00018"></a><span class="lineno"> 18</span> </div><div class="line"><a name="l00019"></a><span class="lineno"> 19</span> <span class="preprocessor">#include "<a class="code" href="uobject_8h.html">unicode/uobject.h</a>"</span></div><div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="preprocessor">#include "<a class="code" href="unistr_8h.html">unicode/unistr.h</a>"</span></div><div class="line"><a name="l00021"></a><span class="lineno"> 21</span> </div><div class="line"><a name="l00031"></a><span class="lineno"> 31</span> <span class="preprocessor">#ifndef CANITER_SKIP_ZEROES</span></div><div class="line"><a name="l00032"></a><span class="lineno"><a class="line" href="caniter_8h.html#acce620fe9bc17fed20e14e1597a8a0b8"> 32</a></span> <span class="preprocessor">#define CANITER_SKIP_ZEROES true</span></div><div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00034"></a><span class="lineno"> 34</span> </div><div class="line"><a name="l00035"></a><span class="lineno"> 35</span> U_NAMESPACE_BEGIN</div><div class="line"><a name="l00036"></a><span class="lineno"> 36</span> </div><div class="line"><a name="l00037"></a><span class="lineno"> 37</span> <span class="keyword">class </span>Hashtable;</div><div class="line"><a name="l00038"></a><span class="lineno"> 38</span> <span class="keyword">class </span>Normalizer2;</div><div class="line"><a name="l00039"></a><span class="lineno"> 39</span> <span class="keyword">class </span>Normalizer2Impl;</div><div class="line"><a name="l00040"></a><span class="lineno"> 40</span> </div><div class="line"><a name="l00076"></a><span class="lineno"><a class="line" href="classicu_1_1CanonicalIterator.html"> 76</a></span> <span class="keyword">class </span><a class="code" href="utypes_8h.html#a559955ec3bc692657c5d8b1c6de8e334">U_COMMON_API</a> <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a> final : <span class="keyword">public</span> <a class="code" href="classicu_1_1UObject.html">UObject</a> {</div><div class="line"><a name="l00077"></a><span class="lineno"> 77</span> <span class="keyword">public</span>:</div><div class="line"><a name="l00084"></a><span class="lineno"> 84</span>  <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>(<span class="keyword">const</span> <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> &source, <a class="code" href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a> &status);</div><div class="line"><a name="l00085"></a><span class="lineno"> 85</span> </div><div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  <span class="keyword">virtual</span> ~<a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>();</div><div class="line"><a name="l00091"></a><span class="lineno"> 91</span> </div><div class="line"><a name="l00097"></a><span class="lineno"> 97</span>  <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> getSource();</div><div class="line"><a name="l00098"></a><span class="lineno"> 98</span> </div><div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  <span class="keywordtype">void</span> reset();</div><div class="line"><a name="l00104"></a><span class="lineno"> 104</span> </div><div class="line"><a name="l00112"></a><span class="lineno"> 112</span>  <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> next();</div><div class="line"><a name="l00113"></a><span class="lineno"> 113</span> </div><div class="line"><a name="l00121"></a><span class="lineno"> 121</span>  <span class="keywordtype">void</span> setSource(<span class="keyword">const</span> <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> &newSource, <a class="code" href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a> &status);</div><div class="line"><a name="l00122"></a><span class="lineno"> 122</span> </div><div class="line"><a name="l00123"></a><span class="lineno"> 123</span> <span class="preprocessor">#ifndef U_HIDE_INTERNAL_API</span></div><div class="line"><a name="l00124"></a><span class="lineno"> 124</span> </div><div class="line"><a name="l00134"></a><span class="lineno"> 134</span>  <span class="keyword">static</span> <span class="keywordtype">void</span> U_EXPORT2 permute(<a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> &source, <a class="code" href="umachine_8h.html#a349ef00011f20ccd1d3b424445681aa5">UBool</a> skipZeros, Hashtable *result, <a class="code" href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a> &status, int32_t depth=0);</div><div class="line"><a name="l00135"></a><span class="lineno"> 135</span> <span class="preprocessor">#endif </span><span class="comment">/* U_HIDE_INTERNAL_API */</span><span class="preprocessor"></span></div><div class="line"><a name="l00136"></a><span class="lineno"> 136</span> </div><div class="line"><a name="l00142"></a><span class="lineno"> 142</span>  <span class="keyword">static</span> <a class="code" href="uobject_8h.html#a22af10545208a455a6e884008df48e9f">UClassID</a> U_EXPORT2 getStaticClassID();</div><div class="line"><a name="l00143"></a><span class="lineno"> 143</span> </div><div class="line"><a name="l00149"></a><span class="lineno"> 149</span>  <span class="keyword">virtual</span> <a class="code" href="uobject_8h.html#a22af10545208a455a6e884008df48e9f">UClassID</a> <a class="code" href="classicu_1_1UObject.html#aca1169c4978c52ce2b76eda104e9a214">getDynamicClassID</a>() <span class="keyword">const override</span>;</div><div class="line"><a name="l00150"></a><span class="lineno"> 150</span> </div><div class="line"><a name="l00151"></a><span class="lineno"> 151</span> <span class="keyword">private</span>:</div><div class="line"><a name="l00152"></a><span class="lineno"> 152</span>  <span class="comment">// ===================== PRIVATES ==============================</span></div><div class="line"><a name="l00153"></a><span class="lineno"> 153</span>  <span class="comment">// private default constructor</span></div><div class="line"><a name="l00154"></a><span class="lineno"> 154</span>  <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>() = <span class="keyword">delete</span>;</div><div class="line"><a name="l00155"></a><span class="lineno"> 155</span> </div><div class="line"><a name="l00156"></a><span class="lineno"> 156</span> </div><div class="line"><a name="l00160"></a><span class="lineno"> 160</span>  <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>(<span class="keyword">const</span> <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>& other) = <span class="keyword">delete</span>;</div><div class="line"><a name="l00161"></a><span class="lineno"> 161</span> </div><div class="line"><a name="l00165"></a><span class="lineno"> 165</span>  <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>& operator=(<span class="keyword">const</span> <a class="code" href="classicu_1_1CanonicalIterator.html">CanonicalIterator</a>& other) = <span class="keyword">delete</span>;</div><div class="line"><a name="l00166"></a><span class="lineno"> 166</span> </div><div class="line"><a name="l00167"></a><span class="lineno"> 167</span>  <span class="comment">// fields</span></div><div class="line"><a name="l00168"></a><span class="lineno"> 168</span>  <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> source;</div><div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  <a class="code" href="umachine_8h.html#a349ef00011f20ccd1d3b424445681aa5">UBool</a> done;</div><div class="line"><a name="l00170"></a><span class="lineno"> 170</span> </div><div class="line"><a name="l00171"></a><span class="lineno"> 171</span>  <span class="comment">// 2 dimensional array holds the pieces of the string with</span></div><div class="line"><a name="l00172"></a><span class="lineno"> 172</span>  <span class="comment">// their different canonically equivalent representations</span></div><div class="line"><a name="l00173"></a><span class="lineno"> 173</span>  <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> **pieces;</div><div class="line"><a name="l00174"></a><span class="lineno"> 174</span>  int32_t pieces_length;</div><div class="line"><a name="l00175"></a><span class="lineno"> 175</span>  int32_t *pieces_lengths;</div><div class="line"><a name="l00176"></a><span class="lineno"> 176</span> </div><div class="line"><a name="l00177"></a><span class="lineno"> 177</span>  <span class="comment">// current is used in iterating to combine pieces</span></div><div class="line"><a name="l00178"></a><span class="lineno"> 178</span>  int32_t *current;</div><div class="line"><a name="l00179"></a><span class="lineno"> 179</span>  int32_t current_length;</div><div class="line"><a name="l00180"></a><span class="lineno"> 180</span> </div><div class="line"><a name="l00181"></a><span class="lineno"> 181</span>  <span class="comment">// transient fields</span></div><div class="line"><a name="l00182"></a><span class="lineno"> 182</span>  <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> buffer;</div><div class="line"><a name="l00183"></a><span class="lineno"> 183</span> </div><div class="line"><a name="l00184"></a><span class="lineno"> 184</span>  <span class="keyword">const</span> <a class="code" href="classicu_1_1Normalizer2.html">Normalizer2</a> *nfd;</div><div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  <span class="keyword">const</span> Normalizer2Impl *nfcImpl;</div><div class="line"><a name="l00186"></a><span class="lineno"> 186</span> </div><div class="line"><a name="l00187"></a><span class="lineno"> 187</span>  <span class="comment">// we have a segment, in NFD. Find all the strings that are canonically equivalent to it.</span></div><div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> *getEquivalents(<span class="keyword">const</span> <a class="code" href="classicu_1_1UnicodeString.html">UnicodeString</a> &segment, int32_t &result_len, <a class="code" href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a> &status); <span class="comment">//private String[] getEquivalents(String segment)</span></div><div class="line"><a name="l00189"></a><span class="lineno"> 189</span> </div><div class="line"><a name="l00190"></a><span class="lineno"> 190</span>  <span class="comment">//Set getEquivalents2(String segment);</span></div><div class="line"><a name="l00191"></a><span class="lineno"> 191</span>  Hashtable *getEquivalents2(Hashtable *fillinResult, <span class="keyword">const</span> char16_t *segment, int32_t segLen, <a class="code" href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a> &status);</div><div class="line"><a name="l00192"></a><span class="lineno"> 192</span>  <span class="comment">//Hashtable *getEquivalents2(const UnicodeString &segment, int32_t segLen, UErrorCode &status);</span></div><div class="line"><a name="l00193"></a><span class="lineno"> 193</span> </div><div class="line"><a name="l00199"></a><span class="lineno"> 199</span>  <span class="comment">//Set extract(int comp, String segment, int segmentPos, StringBuffer buffer);</span></div><div class="line"><a name="l00200"></a><span class="lineno"> 200</span>  Hashtable *extract(Hashtable *fillinResult, <a class="code" href="umachine_8h.html#a09fff5c3b5a5b015324dc3ec3cf92809">UChar32</a> comp, <span class="keyword">const</span> char16_t *segment, int32_t segLen, int32_t segmentPos, <a class="code" href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a> &status);</div><div class="line"><a name="l00201"></a><span class="lineno"> 201</span>  <span class="comment">//Hashtable *extract(UChar32 comp, const UnicodeString &segment, int32_t segLen, int32_t segmentPos, UErrorCode &status);</span></div><div class="line"><a name="l00202"></a><span class="lineno"> 202</span> </div><div class="line"><a name="l00203"></a><span class="lineno"> 203</span>  <span class="keywordtype">void</span> cleanPieces();</div><div class="line"><a name="l00204"></a><span class="lineno"> 204</span> </div><div class="line"><a name="l00205"></a><span class="lineno"> 205</span> };</div><div class="line"><a name="l00206"></a><span class="lineno"> 206</span> </div><div class="line"><a name="l00207"></a><span class="lineno"> 207</span> U_NAMESPACE_END</div><div class="line"><a name="l00208"></a><span class="lineno"> 208</span> </div><div class="line"><a name="l00209"></a><span class="lineno"> 209</span> <span class="preprocessor">#endif </span><span class="comment">/* #if !UCONFIG_NO_NORMALIZATION */</span><span class="preprocessor"></span></div><div class="line"><a name="l00210"></a><span class="lineno"> 210</span> </div><div class="line"><a name="l00211"></a><span class="lineno"> 211</span> <span class="preprocessor">#endif </span><span class="comment">/* U_SHOW_CPLUSPLUS_API */</span><span class="preprocessor"></span></div><div class="line"><a name="l00212"></a><span class="lineno"> 212</span> </div><div class="line"><a name="l00213"></a><span class="lineno"> 213</span> <span class="preprocessor">#endif</span></div><div class="ttc" id="classicu_1_1CanonicalIterator_html"><div class="ttname"><a href="classicu_1_1CanonicalIterator.html">icu::CanonicalIterator</a></div><div class="ttdoc"> This class allows one to iterate through all the strings that are canonically equivalent to a given...</div><div class="ttdef"><b>Definition:</b> <a href="caniter_8h_source.html#l00076">caniter.h:76</a></div></div> <div class="ttc" id="unistr_8h_html"><div class="ttname"><a href="unistr_8h.html">unistr.h</a></div><div class="ttdoc">C++ API: Unicode String. </div></div> <div class="ttc" id="uobject_8h_html_a22af10545208a455a6e884008df48e9f"><div class="ttname"><a href="uobject_8h.html#a22af10545208a455a6e884008df48e9f">UClassID</a></div><div class="ttdeci">void * UClassID</div><div class="ttdoc">UClassID is used to identify classes without using the compiler&#39;s RTTI. </div><div class="ttdef"><b>Definition:</b> <a href="uobject_8h_source.html#l00096">uobject.h:96</a></div></div> <div class="ttc" id="classicu_1_1Normalizer2_html"><div class="ttname"><a href="classicu_1_1Normalizer2.html">icu::Normalizer2</a></div><div class="ttdoc">Unicode normalization functionality for standard Unicode normalization or for using custom mapping ta...</div><div class="ttdef"><b>Definition:</b> <a href="normalizer2_8h_source.html#l00085">normalizer2.h:85</a></div></div> <div class="ttc" id="umachine_8h_html_a09fff5c3b5a5b015324dc3ec3cf92809"><div class="ttname"><a href="umachine_8h.html#a09fff5c3b5a5b015324dc3ec3cf92809">UChar32</a></div><div class="ttdeci">int32_t UChar32</div><div class="ttdoc">Define UChar32 as a type for single Unicode code points. </div><div class="ttdef"><b>Definition:</b> <a href="umachine_8h_source.html#l00449">umachine.h:449</a></div></div> <div class="ttc" id="classicu_1_1UObject_html_aca1169c4978c52ce2b76eda104e9a214"><div class="ttname"><a href="classicu_1_1UObject.html#aca1169c4978c52ce2b76eda104e9a214">icu::UObject::getDynamicClassID</a></div><div class="ttdeci">virtual UClassID getDynamicClassID() const</div><div class="ttdoc">ICU4C "poor man&#39;s RTTI", returns a UClassID for the actual ICU class. </div></div> <div class="ttc" id="uobject_8h_html"><div class="ttname"><a href="uobject_8h.html">uobject.h</a></div><div class="ttdoc">C++ API: Common ICU base class UObject. </div></div> <div class="ttc" id="utypes_8h_html_a3343c1c8a8377277046774691c98d78c"><div class="ttname"><a href="utypes_8h.html#a3343c1c8a8377277046774691c98d78c">UErrorCode</a></div><div class="ttdeci">UErrorCode</div><div class="ttdoc">Standard ICU4C error code type, a substitute for exceptions. </div><div class="ttdef"><b>Definition:</b> <a href="utypes_8h_source.html#l00509">utypes.h:509</a></div></div> <div class="ttc" id="utypes_8h_html"><div class="ttname"><a href="utypes_8h.html">utypes.h</a></div><div class="ttdoc">Basic definitions for ICU, for both C and C++ APIs. </div></div> <div class="ttc" id="utypes_8h_html_a559955ec3bc692657c5d8b1c6de8e334"><div class="ttname"><a href="utypes_8h.html#a559955ec3bc692657c5d8b1c6de8e334">U_COMMON_API</a></div><div class="ttdeci">#define U_COMMON_API</div><div class="ttdoc">Set to export library symbols from inside the common library, and to import them from outside...</div><div class="ttdef"><b>Definition:</b> <a href="utypes_8h_source.html#l00315">utypes.h:315</a></div></div> <div class="ttc" id="classicu_1_1UnicodeString_html"><div class="ttname"><a href="classicu_1_1UnicodeString.html">icu::UnicodeString</a></div><div class="ttdoc">UnicodeString is a string class that stores Unicode characters directly and provides similar function...</div><div class="ttdef"><b>Definition:</b> <a href="unistr_8h_source.html#l00302">unistr.h:302</a></div></div> <div class="ttc" id="classicu_1_1UObject_html"><div class="ttname"><a href="classicu_1_1UObject.html">icu::UObject</a></div><div class="ttdoc">UObject is the common ICU "boilerplate" class. </div><div class="ttdef"><b>Definition:</b> <a href="uobject_8h_source.html#l00222">uobject.h:222</a></div></div> <div class="ttc" id="umachine_8h_html_a349ef00011f20ccd1d3b424445681aa5"><div class="ttname"><a href="umachine_8h.html#a349ef00011f20ccd1d3b424445681aa5">UBool</a></div><div class="ttdeci">int8_t UBool</div><div class="ttdoc">The ICU boolean type, a signed-byte integer. </div><div class="ttdef"><b>Definition:</b> <a href="umachine_8h_source.html#l00269">umachine.h:269</a></div></div> </div><!-- fragment --></div><!-- contents --> <!-- start footer part --> <hr class="footer"/><address class="footer"><small> Generated by  <a href="http://www.doxygen.org/index.html"> <img class="footer" src="doxygen.png" alt="doxygen"/> </a> 1.8.14 </small></address> </body> </html>
| ver. 1.6 |
Github
|
.
| PHP 8.3.30 | Генерация страницы: 0 |
proxy
|
phpinfo
|
Настройка