| <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <!-- NewPage --> |
| <html lang="zh"> |
| <head> |
| <!-- Generated by javadoc --> |
| <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> |
| <title>Extensions (Apache Calcite calcite API)</title> |
| <link rel="stylesheet" type="text/css" href="../../../../stylesheet.css" title="Style"> |
| <script type="text/javascript" src="../../../../script.js"></script> |
| </head> |
| <body> |
| <script type="text/javascript"><!-- |
| try { |
| if (location.href.indexOf('is-external=true') == -1) { |
| parent.document.title="Extensions (Apache Calcite calcite API)"; |
| } |
| } |
| catch(err) { |
| } |
| //--> |
| var methods = {"i0":9,"i1":9}; |
| var tabs = {65535:["t0","所有方法"],1:["t1","静态方法"],8:["t4","具体方法"]}; |
| var altColor = "altColor"; |
| var rowColor = "rowColor"; |
| var tableTab = "tableTab"; |
| var activeTableTab = "activeTableTab"; |
| </script> |
| <noscript> |
| <div>您的浏览器已禁用 JavaScript。</div> |
| </noscript> |
| <!-- ========= START OF TOP NAVBAR ======= --> |
| <div class="topNav"><a name="navbar.top"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.top" title="跳过导航链接">跳过导航链接</a></div> |
| <a name="navbar.top.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="导航"> |
| <li><a href="../../../../overview-summary.html">概览</a></li> |
| <li><a href="package-summary.html">程序包</a></li> |
| <li class="navBarCell1Rev">类</li> |
| <li><a href="package-tree.html">树</a></li> |
| <li><a href="../../../../deprecated-list.html">已过时</a></li> |
| <li><a href="../../../../index-all.html">索引</a></li> |
| <li><a href="../../../../help-doc.html">帮助</a></li> |
| </ul> |
| <div class="aboutLanguage"><b>Apache Calcite</b></div> |
| </div> |
| <div class="subNav"> |
| <ul class="navList"> |
| <li><a href="../../../../org/apache/calcite/linq4j/ExtendedOrderedQueryable.html" title="org.apache.calcite.linq4j中的接口"><span class="typeNameLink">上一个类</span></a></li> |
| <li><a href="../../../../org/apache/calcite/linq4j/Grouping.html" title="org.apache.calcite.linq4j中的接口"><span class="typeNameLink">下一个类</span></a></li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../../index.html?org/apache/calcite/linq4j/Extensions.html" target="_top">框架</a></li> |
| <li><a href="Extensions.html" target="_top">无框架</a></li> |
| </ul> |
| <ul class="navList" id="allclasses_navbar_top"> |
| <li><a href="../../../../allclasses-noframe.html">所有类</a></li> |
| </ul> |
| <div> |
| <script type="text/javascript"><!-- |
| allClassesLink = document.getElementById("allclasses_navbar_top"); |
| if(window==top) { |
| allClassesLink.style.display = "block"; |
| } |
| else { |
| allClassesLink.style.display = "none"; |
| } |
| //--> |
| </script> |
| </div> |
| <div> |
| <ul class="subNavList"> |
| <li>概要: </li> |
| <li>嵌套 | </li> |
| <li>字段 | </li> |
| <li>构造器 | </li> |
| <li><a href="#method.summary">方法</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>详细资料: </li> |
| <li>字段 | </li> |
| <li>构造器 | </li> |
| <li><a href="#method.detail">方法</a></li> |
| </ul> |
| </div> |
| <a name="skip.navbar.top"> |
| <!-- --> |
| </a></div> |
| <!-- ========= END OF TOP NAVBAR ========= --> |
| <!-- ======== START OF CLASS DATA ======== --> |
| <div class="header"> |
| <div class="subTitle">org.apache.calcite.linq4j</div> |
| <h2 title="类 Extensions" class="title">类 Extensions</h2> |
| </div> |
| <div class="contentContainer"> |
| <ul class="inheritance"> |
| <li><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true" title="java.lang中的类或接口">java.lang.Object</a></li> |
| <li> |
| <ul class="inheritance"> |
| <li>org.apache.calcite.linq4j.Extensions</li> |
| </ul> |
| </li> |
| </ul> |
| <div class="description"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <hr> |
| <br> |
| <pre>public abstract class <span class="typeNameLabel">Extensions</span> |
| extends <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true" title="java.lang中的类或接口">Object</a></pre> |
| <div class="block">Contains what, in LINQ.NET, would be extension methods. |
| |
| <h2>Notes on mapping from LINQ.NET to Java</h2> |
| |
| <p>We have preserved most of the API. But we've changed a few things, so that |
| the API is more typical Java API:</p> |
| |
| <ul> |
| |
| <li>Java method names start with a lower-case letter.</li> |
| |
| <li>A few methods became keywords when their first letter was converted |
| to lower case; hence |
| <a href="../../../../org/apache/calcite/linq4j/tree/Expressions.html#break_-org.apache.calcite.linq4j.tree.LabelTarget-"><code>Expressions.break_(org.apache.calcite.linq4j.tree.LabelTarget)</code></a></li> |
| |
| <li>We created a Java interface <a href="../../../../org/apache/calcite/linq4j/Enumerable.html" title="org.apache.calcite.linq4j中的接口"><code>Enumerable</code></a>, similar to LINQ.NET's |
| IEnumerable. IEnumerable is built into C#, and that gives it |
| advantages: the standard collections implement it, and you can use |
| any IEnumerable in a foreach loop. We made the Java |
| <code>Enumerable</code> extend <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html?is-external=true" title="java.lang中的类或接口"><code>Iterable</code></a>, |
| so that it can be used in for-each loops. But the standard |
| collections still don't implement it. A few methods that take an |
| IEnumerable in LINQ.NET take an Iterable in LINQ4J.</li> |
| |
| <li>LINQ.NET's Dictionary interface maps to Map in Java; |
| hence, the LINQ.NET <code>ToDictionary</code> methods become |
| <code>toMap</code>.</li> |
| |
| <li>LINQ.NET's decimal type changes to BigDecimal. (A little bit unnatural, |
| since decimal is primitive and BigDecimal is not.)</li> |
| |
| <li>There is no Nullable in Java. Therefore we distinguish between methods |
| that return, say, Long (which may be null) and long. See for example |
| <a href="../../../../org/apache/calcite/linq4j/function/NullableLongFunction1.html" title="org.apache.calcite.linq4j.function中的接口"><code>NullableLongFunction1</code></a> and |
| <a href="../../../../org/apache/calcite/linq4j/function/LongFunction1.html" title="org.apache.calcite.linq4j.function中的接口"><code>LongFunction1</code></a>, and the |
| variants of <a href="../../../../org/apache/calcite/linq4j/ExtendedEnumerable.html#sum-org.apache.calcite.linq4j.function.BigDecimalFunction1-"><code>ExtendedEnumerable.sum(org.apache.calcite.linq4j.function.BigDecimalFunction1<TSource>)</code></a> that call them. |
| |
| <li>Java erases type parameters from argument types before resolving |
| overloading. Therefore similar methods have the same erasure. Methods |
| <code>averageDouble</code>, |
| <code>averageInteger</code>, |
| <code>groupByK</code>, |
| <code>selectN</code>, |
| <code>selectManyN</code>, |
| <code>skipWhileN</code>, |
| <code>sumBigDecimal</code>, |
| <code>sumNullableBigDecimal</code>, |
| <code>whereN</code> |
| have been renamed from <code>average</code>, <code>groupBy</code>, <code>max</code>, |
| <code>min</code>, <code>select</code>, <code>selectMany</code>, <code>skipWhile</code> and |
| <code>where</code> to prevent ambiguity.</li> |
| |
| <li>.NET allows <i>extension methods</i> — static methods that then |
| become, via compiler magic, a method of any object whose type is the |
| same as the first parameter of the extension method. In LINQ.NET, the |
| <code>IQueryable</code> and <code>IEnumerable</code> interfaces have many such methods. |
| In Java, those methods need to be explicitly added to the interface, and will |
| need to be implemented by every class that implements that interface. |
| We can help by implementing the methods as static methods, and by |
| providing an abstract base class that implements the extension methods |
| in the interface. Hence <a href="../../../../org/apache/calcite/linq4j/AbstractEnumerable.html" title="org.apache.calcite.linq4j中的类"><code>AbstractEnumerable</code></a> and |
| <a href="../../../../org/apache/calcite/linq4j/AbstractQueryable.html" title="org.apache.calcite.linq4j中的类"><code>AbstractQueryable</code></a> call methods in <a href="../../../../org/apache/calcite/linq4j/Extensions.html" title="org.apache.calcite.linq4j中的类"><code>Extensions</code></a>.</li> |
| |
| <li>.NET Func becomes <a href="../../../../org/apache/calcite/linq4j/function/Function0.html" title="org.apache.calcite.linq4j.function中的接口"><code>Function0</code></a>, |
| <a href="../../../../org/apache/calcite/linq4j/function/Function1.html" title="org.apache.calcite.linq4j.function中的接口"><code>Function1</code></a>, |
| <a href="../../../../org/apache/calcite/linq4j/function/Function2.html" title="org.apache.calcite.linq4j.function中的接口"><code>Function2</code></a>, depending |
| on the number of arguments to the function, because Java types cannot be |
| overloaded based on the number of type parameters.</li> |
| |
| <li>Types map as follows: |
| <code>Int32</code> → <code>int</code> or <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Integer.html?is-external=true" title="java.lang中的类或接口"><code>Integer</code></a>, |
| <code>Int64</code> → <code>long</code> or <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Long.html?is-external=true" title="java.lang中的类或接口"><code>Long</code></a>, |
| <code>bool</code> → <code>boolean</code> or <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Boolean.html?is-external=true" title="java.lang中的类或接口"><code>Boolean</code></a>, |
| <code>Dictionary</code> → <a href="https://docs.oracle.com/javase/8/docs/api/java/util/Map.html?is-external=true" title="java.util中的类或接口"><code>Map</code></a>, |
| <code>Lookup</code> → <a href="https://docs.oracle.com/javase/8/docs/api/java/util/Map.html?is-external=true" title="java.util中的类或接口"><code>Map</code></a> whose value type is an <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Iterable.html?is-external=true" title="java.lang中的类或接口"><code>Iterable</code></a>, |
| </li> |
| |
| <li>Function types that accept primitive types in LINQ.NET have become |
| boxed types in LINQ4J. For example, a predicate function |
| <code>Func&lt;T, bool&gt;</code> becomes <code>Func1&lt;T, Boolean&gt;</code>. |
| It would be wrong to infer that the function is allowed to return null.</li> |
| |
| </ul></div> |
| </li> |
| </ul> |
| </div> |
| <div class="summary"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- ========== METHOD SUMMARY =========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="method.summary"> |
| <!-- --> |
| </a> |
| <h3>方法概要</h3> |
| <table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="方法概要表, 列表方法和解释"> |
| <caption><span id="t0" class="activeTableTab"><span>所有方法</span><span class="tabEnd"> </span></span><span id="t1" class="tableTab"><span><a href="javascript:show(1);">静态方法</a></span><span class="tabEnd"> </span></span><span id="t4" class="tableTab"><span><a href="javascript:show(8);">具体方法</a></span><span class="tabEnd"> </span></span></caption> |
| <tr> |
| <th class="colFirst" scope="col">限定符和类型</th> |
| <th class="colLast" scope="col">方法和说明</th> |
| </tr> |
| <tr id="i0" class="altColor"> |
| <td class="colFirst"><code>static <T> <a href="../../../../org/apache/calcite/linq4j/Queryable.html" title="org.apache.calcite.linq4j中的接口">Queryable</a><T></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../org/apache/calcite/linq4j/Extensions.html#asQueryable-org.apache.calcite.linq4j.DefaultEnumerable-">asQueryable</a></span>(<a href="../../../../org/apache/calcite/linq4j/DefaultEnumerable.html" title="org.apache.calcite.linq4j中的类">DefaultEnumerable</a><T> source)</code> </td> |
| </tr> |
| <tr id="i1" class="rowColor"> |
| <td class="colFirst"><code>static <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/RuntimeException.html?is-external=true" title="java.lang中的类或接口">RuntimeException</a></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../org/apache/calcite/linq4j/Extensions.html#todo--">todo</a></span>()</code> </td> |
| </tr> |
| </table> |
| <ul class="blockList"> |
| <li class="blockList"><a name="methods.inherited.from.class.java.lang.Object"> |
| <!-- --> |
| </a> |
| <h3>从类继承的方法 java.lang.<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true" title="java.lang中的类或接口">Object</a></h3> |
| <code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#clone--" title="java.lang中的类或接口">clone</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#equals-java.lang.Object-" title="java.lang中的类或接口">equals</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#finalize--" title="java.lang中的类或接口">finalize</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#getClass--" title="java.lang中的类或接口">getClass</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#hashCode--" title="java.lang中的类或接口">hashCode</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#notify--" title="java.lang中的类或接口">notify</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#notifyAll--" title="java.lang中的类或接口">notifyAll</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#toString--" title="java.lang中的类或接口">toString</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#wait--" title="java.lang中的类或接口">wait</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#wait-long-" title="java.lang中的类或接口">wait</a>, <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html?is-external=true#wait-long-int-" title="java.lang中的类或接口">wait</a></code></li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </div> |
| <div class="details"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <!-- ============ METHOD DETAIL ========== --> |
| <ul class="blockList"> |
| <li class="blockList"><a name="method.detail"> |
| <!-- --> |
| </a> |
| <h3>方法详细资料</h3> |
| <a name="todo--"> |
| <!-- --> |
| </a> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <h4>todo</h4> |
| <pre>public static <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/RuntimeException.html?is-external=true" title="java.lang中的类或接口">RuntimeException</a> todo()</pre> |
| </li> |
| </ul> |
| <a name="asQueryable-org.apache.calcite.linq4j.DefaultEnumerable-"> |
| <!-- --> |
| </a> |
| <ul class="blockListLast"> |
| <li class="blockList"> |
| <h4>asQueryable</h4> |
| <pre>public static <T> <a href="../../../../org/apache/calcite/linq4j/Queryable.html" title="org.apache.calcite.linq4j中的接口">Queryable</a><T> asQueryable(<a href="../../../../org/apache/calcite/linq4j/DefaultEnumerable.html" title="org.apache.calcite.linq4j中的类">DefaultEnumerable</a><T> source)</pre> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| </div> |
| </div> |
| <!-- ========= END OF CLASS DATA ========= --> |
| <!-- ======= START OF BOTTOM NAVBAR ====== --> |
| <div class="bottomNav"><a name="navbar.bottom"> |
| <!-- --> |
| </a> |
| <div class="skipNav"><a href="#skip.navbar.bottom" title="跳过导航链接">跳过导航链接</a></div> |
| <a name="navbar.bottom.firstrow"> |
| <!-- --> |
| </a> |
| <ul class="navList" title="导航"> |
| <li><a href="../../../../overview-summary.html">概览</a></li> |
| <li><a href="package-summary.html">程序包</a></li> |
| <li class="navBarCell1Rev">类</li> |
| <li><a href="package-tree.html">树</a></li> |
| <li><a href="../../../../deprecated-list.html">已过时</a></li> |
| <li><a href="../../../../index-all.html">索引</a></li> |
| <li><a href="../../../../help-doc.html">帮助</a></li> |
| </ul> |
| <div class="aboutLanguage"><b>Apache Calcite</b></div> |
| </div> |
| <div class="subNav"> |
| <ul class="navList"> |
| <li><a href="../../../../org/apache/calcite/linq4j/ExtendedOrderedQueryable.html" title="org.apache.calcite.linq4j中的接口"><span class="typeNameLink">上一个类</span></a></li> |
| <li><a href="../../../../org/apache/calcite/linq4j/Grouping.html" title="org.apache.calcite.linq4j中的接口"><span class="typeNameLink">下一个类</span></a></li> |
| </ul> |
| <ul class="navList"> |
| <li><a href="../../../../index.html?org/apache/calcite/linq4j/Extensions.html" target="_top">框架</a></li> |
| <li><a href="Extensions.html" target="_top">无框架</a></li> |
| </ul> |
| <ul class="navList" id="allclasses_navbar_bottom"> |
| <li><a href="../../../../allclasses-noframe.html">所有类</a></li> |
| </ul> |
| <div> |
| <script type="text/javascript"><!-- |
| allClassesLink = document.getElementById("allclasses_navbar_bottom"); |
| if(window==top) { |
| allClassesLink.style.display = "block"; |
| } |
| else { |
| allClassesLink.style.display = "none"; |
| } |
| //--> |
| </script> |
| </div> |
| <div> |
| <ul class="subNavList"> |
| <li>概要: </li> |
| <li>嵌套 | </li> |
| <li>字段 | </li> |
| <li>构造器 | </li> |
| <li><a href="#method.summary">方法</a></li> |
| </ul> |
| <ul class="subNavList"> |
| <li>详细资料: </li> |
| <li>字段 | </li> |
| <li>构造器 | </li> |
| <li><a href="#method.detail">方法</a></li> |
| </ul> |
| </div> |
| <a name="skip.navbar.bottom"> |
| <!-- --> |
| </a></div> |
| <!-- ======== END OF BOTTOM NAVBAR ======= --> |
| <p class="legalCopy"><small>Copyright © 2012-2020 Apache Software Foundation. All Rights Reserved.</small></p> |
| </body> |
| </html> |
