{"id":1310,"date":"2015-09-20T17:06:53","date_gmt":"2015-09-20T09:06:53","guid":{"rendered":"http:\/\/coderbee.net\/?p=1310"},"modified":"2015-09-20T17:07:44","modified_gmt":"2015-09-20T09:07:44","slug":"%e3%80%8a%e6%b7%b1%e5%85%a5%e7%90%86%e8%a7%a3-scala%e3%80%8b%e7%ac%ac%e4%ba%94%e7%ab%a0-%e5%88%a9%e7%94%a8%e9%9a%90%e5%bc%8f%e8%bd%ac%e6%8d%a2%e7%bc%96%e5%86%99%e6%9b%b4%e6%9c%89%e8%a1%a8%e8%be%be","status":"publish","type":"post","link":"https:\/\/coderbee.net\/index.php\/scala\/20150920\/1310","title":{"rendered":"\u300a\u6df1\u5165\u7406\u89e3 Scala\u300b\u7b2c\u4e94\u7ae0 &#8212; \u5229\u7528\u9690\u5f0f\u8f6c\u6362\u7f16\u5199\u66f4\u6709\u8868\u8fbe\u529b"},"content":{"rendered":"<p>Scala \u7684\u9690\u5f0f\u8f6c\u6362\u7cfb\u7edf\u5b9a\u4e49\u4e86\u4e00\u5957\u5b9a\u4e49\u826f\u597d\u7684\u67e5\u627e\u673a\u5236\uff0c\u8ba9\u7f16\u8bd1\u5668\u80fd\u591f\u8c03\u6574\u4ee3\u7801\u3002Scala \u7f16\u8bd1\u5668\u53ef\u4ee5\u63a8\u5bfc\u4e0b\u9762\u4e24\u79cd\u60c5\u51b5\uff1a<\/p>\n<ul>\n<li>\u7f3a\u5c11\u53c2\u6570\u7684\u65b9\u6cd5\u8c03\u7528\u6216\u6784\u9020\u5668\u8c03\u7528\uff1b<\/li>\n<li>\u7f3a\u5c11\u4e86\u7684\u4ece\u4e00\u79cd\u7c7b\u578b\u5230\u53e6\u4e00\u79cd\u7c7b\u578b\u7684\u8f6c\u6362\u3002\uff08\u662f\u6307\u8c03\u7528\u67d0\u4e2a\u5bf9\u8c61\u4e0a\u4e0d\u5b58\u5728\u7684\u65b9\u6cd5\u65f6\uff0c\u9690\u5f0f\u8f6c\u6362\u81ea\u52a8\u628a\u5bf9\u8c61\u8f6c\u6362\u6210\u6709\u8be5\u65b9\u6cd5\u7684\u5bf9\u8c61\uff09<\/li>\n<\/ul>\n<h2>\u4ecb\u7ecd\u9690\u5f0f\u8f6c\u6362\u7cfb\u7edf<\/h2>\n<p>implicit \u5173\u952e\u5b57\u53ef\u901a\u8fc7\u4e24\u79cd\u65b9\u5f0f\u4f7f\u7528\uff1a1\u3001\u65b9\u6cd5\u6216\u53d8\u91cf\u5b9a\u4e49\uff1b2\u3001\u65b9\u6cd5\u53c2\u6570\u5217\u8868\u3002\u5982\u679c\u5173\u952e\u5b57\u7528\u5728\u53d8\u91cf\u6216\u65b9\u6cd5\u4e0a\uff0c\u7b49\u4e8e\u544a\u8bc9\u7f16\u8bd1\u5668\u5728\u9690\u5f0f\u89e3\u6790\uff08implicit resolution\uff09\u7684\u8fc7\u7a0b\u4e2d\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e9b\u65b9\u6cd5\u548c\u53d8\u91cf\u3002<\/p>\n<p>\u9690\u5f0f\u89e3\u6790\u662f\u6307\u7f16\u8bd1\u5668\u53d1\u73b0\u4ee3\u7801\u91cc\u7684\u7f3a\u5c11\u90e8\u5206\u4fe1\u606f\uff0c\u800c\u53bb\u67e5\u627e\u7f3a\u5c11\u4fe1\u606f\u7684\u8fc7\u7a0b\u3002<\/p>\n<p>implicit \u5173\u952e\u5b57\u7528\u5728\u65b9\u6cd5\u53c2\u6570\u5217\u8868\u7684\u5f00\u5934\uff0c\u662f\u544a\u8bc9\u7f16\u8bd1\u5668\u5e94\u5f53\u901a\u8fc7\u9690\u5f0f\u89e3\u6790\u6765\u786e\u5b9a\u6240\u6709\u7684\u53c2\u6570\u503c\u3002<\/p>\n<pre><code class=\"scala\">scala&gt; def findAnInt(implicit x: Int) = x\nfindAnInt: (implicit x: Int)Int\n\nscala&gt; findAnInt\n&lt;console&gt;:9: error: could not find implicit value for parameter x: Int\n              findAnInt\n              ^\n\nscala&gt; implicit val test = 5\ntest: Int = 5\n\nscala&gt; findAnInt\nres1: Int = 5\n\nscala&gt; def findTwoInt(implicit a: Int, b: Int) = a + b\nfindTwoInt: (implicit a: Int, implicit b: Int)Int\n\nscala&gt; findTwoInt  \/\/ implicit \u4f5c\u7528\u4e8e\u6574\u4e2a\u53c2\u6570\u5217\u8868\nres2: Int = 10\n\nscala&gt; implicit val test2 = 5\ntest2: Int = 5\n\nscala&gt; findTwoInt\n&lt;console&gt;:11: error: ambiguous implicit values:\n both value test of type =&gt; Int\n and value test2 of type =&gt; Int\n match expected type Int\n              findTwoInt\n              ^\n\nscala&gt; findTwoInt(2, 5)  \/\/ \u9690\u5f0f\u7684\u65b9\u6cd5\u53c2\u6570\u4ecd\u7136\u80fd\u591f\u663e\u5f0f\u7ed9\u51fa\nres4: Int = 7\n<\/code><\/pre>\n<p>\u9690\u5f0f\u7684\u65b9\u6cd5\u53c2\u6570\u4ecd\u7136\u80fd\u591f\u663e\u5f0f\u7ed9\u51fa\u3002<\/p>\n<p><!--more--><\/p>\n<h3>\u6807\u8bc6\u7b26<\/h3>\n<p>Scala \u5b9a\u4e49\u4e86\u672f\u8bed entity \u6765\u4ee3\u8868\u7c7b\u578b\u3001\u503c\u3001\u65b9\u6cd5\u6216\u7c7b\uff0c\u8fd9\u4e9b\u662f\u6784\u5efa\u7a0b\u5e8f\u7684\u57fa\u672c\u8981\u7d20\uff0c\u901a\u8fc7\u6807\u8bc6\u7b26\u6216\u540d\u5b57\u6765\u5f15\u7528\u5b83\u4eec\uff0c\u8fd9\u5728 Scala \u91cc\u79f0\u4e3a\u7ed1\u5b9a\u3002<\/p>\n<p>import \u8bed\u53e5\u53ef\u4ee5\u5728\u6e90\u4ee3\u7801\u7684\u4efb\u4f55\u4f4d\u7f6e\u4f7f\u7528\uff0c\u800c\u4e14\u53ea\u4f1a\u5728 import \u8bed\u53e5\u6240\u5728\u7684\u5c40\u90e8\u4f5c\u7528\u57df\u521b\u5efa\u7ed1\u5b9a\u3002<\/p>\n<p>Scala \u7684\u5bfc\u5165\u8bed\u53e5\u53ef\u4ee5\u7ed9\u5bfc\u5165\u7684\u5b9e\u4f53\u8d4b\u4e88\u4efb\u610f\u540d\u79f0\uff0c\u4f7f\u7528\u8bed\u6cd5\uff1a<code>{OriginBinding  =&gt;  newBinding}<\/code>\u3002\u5bfc\u5165\u8bed\u53e5\u8fd8\u53ef\u4ee5\u7528\u6765\u6539\u53d8\u5305\u672c\u8eab\u7684\u540d\u5b57\uff0c\u5982\uff1a <code>import java.{io  =&gt;  jio}<\/code> \u3002<\/p>\n<p>\u7ed1\u5b9a\u5141\u8bb8\u6211\u4eec\u5728\u7279\u5b9a\u7684\u4f5c\u7528\u57df\u91cc\u7ed9\u5b83\u4eec\u547d\u540d\u3002<\/p>\n<h3>\u4f5c\u7528\u57df\u548c\u7ed1\u5b9a<\/h3>\n<p>\u4f5c\u7528\u57df\u662f\u4e00\u4e2a\u8bcd\u6cd5\u8fb9\u754c\uff0c\u800c\u7ed1\u5b9a\u4f4d\u4e8e\u5176\u4e2d\u3002\u4f5c\u7528\u57df\u53ef\u4ee5\u662f\u4efb\u4f55\u4e1c\u897f\uff0c\u4ece\u7c7b\u7684\u5b9e\u4f53\uff08body of a class\uff09\u5230\u65b9\u6cd5\u4f53\u5230\u533f\u540d\u4ee3\u7801\u5757\u90fd\u53ef\u4ee5\u662f\u4f5c\u7528\u57df\u3002\u4e00\u4e2a\u901a\u7528\u89c4\u5219\u662f\u5f53\u7528 <code>{}<\/code> \u7684\u65f6\u5019\u5c31\u521b\u5efa\u4e86\u4e00\u4e2a\u4f5c\u7528\u57df\u3002\u4f5c\u7528\u57df\u662f\u53ef\u4ee5\u5d4c\u5957\u7684\u3002<\/p>\n<p>\u540c\u4f5c\u7528\u57df\u5185\u7684\u9ad8\u4f18\u5148\u7ea7\u7ed1\u5b9a\u906e\u6321\uff08shadow\uff09\u4f4e\u4f18\u5148\u7ea7\u7ed1\u5b9a\uff0c\u9ad8\u4f18\u5148\u7ea7\u6216\u540c\u4f18\u5148\u7ea7\u7ed1\u5b9a\u906e\u6321\u5916\u90e8\u4f5c\u7528\u57df\u7684\u7ed1\u5b9a\u3002<\/p>\n<p>Scala \u5bf9\u7ed1\u5b9a\u5b9a\u4e49\u6765\u5982\u4e0b\u4f18\u5148\u7ea7\uff1a<\/p>\n<ol>\n<li>\u672c\u5730\u7684\u3001\u7ee7\u627f\u7684\uff0c\u6216\u8005\u901a\u8fc7\u5b9a\u4e49\u6240\u5728\u7684\u6e90\u4ee3\u7801\u6587\u4ef6\u7684 package \u8bed\u53e5\u6240\u5f15\u5165\u7684\u5b9a\u4e49\u548c\u58f0\u660e\u5177\u6709\u6700\u9ad8\u4f18\u5148\u7ea7\u3002<\/li>\n<li>\u663e\u5f0f\u5bfc\u5165\u7684\u5177\u6709\u6b21\u9ad8\u4f18\u5148\u7ea7\u3002<\/li>\n<li>\u901a\u914d\u7b26\u5bfc\u5165\u7684\u5177\u6709\u66f4\u6b21\u4e00\u7ea7\u7684\u4f18\u5148\u7ea7\u3002<\/li>\n<li>\u7531\u975e\u5b9a\u4e49\u6240\u5728\u7684\u6e90\u6587\u4ef6\u91cc\u7684 package \u8bed\u53e5\u5f15\u5165\u7684\u5b9a\u4e49\u4f18\u5148\u7ea7\u6700\u4f4e\u3002<\/li>\n<\/ol>\n<p>\u901a\u914d\u5bfc\u5165\u7684\u4f18\u5148\u7ea7\u9ad8\u4e8e\u540c\u5305\u4e0d\u540c\u6e90\u6587\u4ef6\u7684\u7ed1\u5b9a\u4f18\u5148\u7ea7\u3002<\/p>\n<h3>\u9690\u5f0f\u89e3\u6790<\/h3>\n<p>Scala \u8bed\u8a00\u89c4\u8303\u5b9a\u4e49\u4ee5\u4e0b\u4e24\u79cd\u67e5\u627e\u6807\u8bb0\u4e3a implicit \u7684\u5b9e\u4f53\u7684\u89c4\u5219\uff1a<\/p>\n<ul>\n<li>\u9690\u5f0f\u5b9e\u4f53\u5728\u67e5\u627e\u53d1\u751f\u7684\u5730\u70b9\u53ef\u89c1\uff0c\u5e76\u4e14\u6ca1\u6709\u4efb\u4f55\u524d\u7f00\uff0c\u6bd4\u5982\u4e0d\u80fd\u662f <code>foo.x<\/code>\uff0c\u53ea\u80fd\u662f <code>x<\/code>\u3002<\/li>\n<li>\u5982\u679c\u6309\u7167\u524d\u4e00\u6761\u89c4\u5219\u6ca1\u6709\u627e\u5230\u9690\u5f0f\u5b9e\u4f53\uff0c\u90a3\u4e48\u4f1a\u5728\u9690\u5f0f   \u53c2\u6570\u7684\u7c7b\u578b  \u7684\u9690\u5f0f\u4f5c\u7528\u57df\u91cc\u5305\u542b\u7684\u6240\u6709\u9690\u5f0f\u5b9e\u4f53\u91cc\u67e5\u627e\u3002<\/li>\n<\/ul>\n<p>\u5bf9\u4e8e\u89c4\u5219\u4e8c\uff0c\u7f16\u8bd1\u5668\u4f1a\u5728\u5176\u76ee\u6807\u7c7b\u578b\u7684 <strong>\u9690\u5f0f\u4f5c\u7528\u57df<\/strong> \u91cc\u9762\u7684\u4efb\u4f55\u5bf9\u8c61\u91cc\u67e5\u627e\u5b9a\u4e49\u4e8e\u5176\u4e2d\u7684\u9690\u5f0f\u5b9e\u4f53\u3002\u4e00\u4e2a\u7c7b\u578b\u7684\u9690\u5f0f\u4f5c\u7528\u57df\u662f\u6307\u4e0e\u8be5\u7c7b\u578b\u76f8\u5173\u8054\u7684\u5168\u90e8\u4f34\u6a21\u5757\u3002\u5982\u679c\u4e00\u7ec4\u7c7b\u578b\u4e0e T \u76f8\u5173\u8054\uff0c\u5728\u9690\u5f0f\u89e3\u6790\u7684\u65f6\u5019\u6240\u6709\u8fd9\u4e9b\u7c7b\u578b\u7684\u4f34\u751f\u5bf9\u8c61\u90fd\u4f1a\u88ab\u641c\u7d22\u3002<\/p>\n<p>Scala \u8bed\u8a00\u89c4\u8303\u91cc\u5b9a\u4e49\u7684\u201d\u5173\u8054\u201c\u662f\u6307\u7c7b\u578b T \u7684\u67d0\u90e8\u5206\u7684\u4efb\u4f55\u4e00\u4e2a\u57fa\u7c7b\u3002<strong>\u7c7b\u578b T \u7684\u67d0\u90e8\u5206<\/strong>\u5b9a\u4e49\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>T \u7684\u5168\u90e8\u5b50\u7c7b\u578b\uff08subtype\uff09\u90fd\u662f T \u7684\u90e8\u5206\u3002\u5982\u679c T \u5b9a\u4e49\u4e3a <code>A with B with C<\/code>\uff0c\u90a3\u4e48 A\u3001B\u3001C \u90fd\u662f T \u7684\u90e8\u5206\uff0c\u5728 T \u7684\u9690\u5f0f\u89e3\u6790\u8fc7\u7a0b\u4e2d\uff0c\u5b83\u4eec\u7684\u4f34\u751f\u5bf9\u8c61\u4f1a\u88ab\u641c\u7d22\u3002<\/li>\n<li>\u5982\u679c T \u662f\u53c2\u6570\u5316\u7c7b\u578b\uff0c\u90a3\u4e48\u6240\u6709\u7c7b\u578b\u53c2\u6570\u548c\u7c7b\u578b\u53c2\u6570\u7684<strong>\u90e8\u5206<\/strong>\u90fd\u7b97\u4f5c T \u7684\u90e8\u5206\u3002\u6bd4\u5982\u5bf9 <code>List[String]<\/code> \u7684\u9690\u5f0f\u641c\u7d22\u4f1a\u641c\u7d22 List \u7684\u4f34\u751f\u5bf9\u8c61\u548c String \u7684\u4f34\u751f\u5bf9\u8c61\u3002<\/li>\n<li>\u5982\u679c T \u662f\u4e00\u4e2a\u5355\u4f8b\u7c7b\u578b <code>p.T<\/code>\uff0c\u90a3\u4e48\u7c7b\u578b p \u7684\u90e8\u5206\u4e5f\u5305\u542b\u5728 T \u7684\u90e8\u5206\u91cc\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u7c7b\u578b T \u4f4d\u4e8e\u67d0\u4e2a\u5bf9\u8c61\u5185\uff0c\u90a3\u4e48\u90a3\u4e2a\u5bf9\u8c61\u4e5f\u4f1a\u88ab\u641c\u7d22\u3002<\/li>\n<li>\u5982\u679c T \u662f\u4e2a\u7c7b\u578b\u6ce8\u5165 <code>S#T<\/code>\uff0c\u90a3\u4e48 S \u7684\u90e8\u5206\u4e5f\u5305\u542b\u5728 T \u7684\u90e8\u5206\u91cc\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u7c7b\u578b T \u4f4d\u4e8e\u67d0\u4e2a\u7c7b\u578b\u6216\u7279\u8d28\u91cc\uff0c\u90a3\u4e48\u90a3\u4e2a\u7c7b\u578b\u6216\u7279\u8d28\u7684\u4f34\u751f\u5bf9\u8c61\u4e5f\u4f1a\u88ab\u641c\u7d22\u3002<\/li>\n<\/ul>\n<h3>\u901a\u8fc7\u7c7b\u578b\u53c2\u6570\u83b7\u5f97\u9690\u5f0f\u4f5c\u7528\u57df<\/h3>\n<pre><code class=\"scala\">object holder {\n    trait Foo\n    object Foo {\n        implicit val list = List(new Foo{})\n    }\n}\n\n\nprintln(implicitly[List[holder.Foo]])\n<\/code><\/pre>\n<p>implicitly \u7684\u51fd\u6570\u5b9a\u4e49\u4e3a <code>def implicitly[T](implicit arg: T): T<\/code>\uff0c\u7528\u4e8e\u5728\u5f53\u524d\u4f5c\u7528\u57df\u91cc\u67e5\u627e\u6307\u5b9a\u7c7b\u578b\u3002<\/p>\n<p>\u7c7b\u578b\u7279\u8d28\u53c8\u79f0\u4e3a \u7c7b\u578b\u7c7b\uff08type class\uff09\uff1a\u7528\u7c7b\u578b\u53c2\u6570\u6765\u63cf\u8ff0\u901a\u7528\u63a5\u53e3\uff0c\u4ee5\u4fbf\u80fd\u4e3a\u4efb\u610f\u7c7b\u578b\u521b\u5efa\uff08\u63a5\u53e3\u7684\uff09\u5b9e\u73b0\u3002<\/p>\n<p>\u5305\u5bf9\u8c61\uff08package object\uff09\u5c31\u662f\u7528 <code>package object<\/code> \u8bed\u6cd5\u5b9a\u4e49\u7684\u5bf9\u8c61\uff0c\u5728 Scala \u91cc\uff0c\u4e00\u822c\u7ea6\u5b9a\u628a\u5305\u5bf9\u8c61\u653e\u5728\u4e0e\u5305\u540d\u5bf9\u5e94\u7684\u76ee\u5f55\u4e0b\u7684 package.scala \u6587\u4ef6\u91cc\u3002<\/p>\n<p>\u4efb\u4f55\u5b9a\u4e49\u5728\u67d0\u4e2a\u5305\u91cc\u7684\u7c7b\u90fd\u7b97\u4f5c\u8be5\u5305\u7684\u5d4c\u5957\u7c7b\u3002\u4efb\u4f55\u5b9a\u4e49\u5728\u5305\u5bf9\u8c61\u91cc\u7684\u9690\u5f0f\u7ed1\u5b9a\u5bf9\u4e8e\u5b9a\u4e49\u5728\u8be5\u5305\u91cc\u7684\u6240\u6709\u7c7b\u578b\u90fd\u53ef\u89c1\u3002<\/p>\n<h2>\u9690\u5f0f\u89c6\u56fe\uff1a\u5f3a\u5316\u5df2\u5b58\u5728\u7684\u7c7b<\/h2>\n<p>\u9690\u5f0f\u89c6\u56fe\u662f\u6307\u4e00\u79cd\u628a\u7c7b\u578b\u81ea\u52a8\u8f6c\u6362\u5230\u53e6\u4e00\u79cd\u7c7b\u578b\uff0c\u4ee5\u7b26\u5408\u8868\u8fbe\u5f0f\u7684\u8981\u6c42\u3002\u9690\u5f0f\u89c6\u56fe\u5b9a\u4e49\u4e00\u822c\u7528\u5982\u4e0b\u5f62\u5f0f\uff1a<code>implicit def &lt;myConversionName&gt;  (&lt;argumentName&gt;:  OriginalType):  ViewType<\/code> \u3002\u5728\u9700\u8981\u7684\u65f6\u5019\uff0c\u5982\u679c\u9690\u5f0f\u4f5c\u7528\u57df\u91cc\u5b58\u5728\u8fd9\u4e2a\u5b9a\u4e49\uff0c\u5b83\u4f1a\u9690\u5f0f\u5730\u628a OriginalType \u7c7b\u578b\u7684\u503c\u8f6c\u6362\u4e3a ViewType \u7c7b\u578b\u7684\u503c\u3002<\/p>\n<p>\u9690\u5f0f\u89c6\u56fe\u7528\u5728\u4ee5\u4e0b\u4e24\u79cd\u573a\u5408\uff1a<\/p>\n<ul>\n<li>\u5982\u679c\u8868\u8fbe\u5f0f\u4e0d\u7b26\u5408\u7f16\u8bd1\u5668\u8981\u6c42\u7684\u7c7b\u578b\uff0c\u7f16\u8bd1\u5668\u4f1a\u67e5\u627e\u80fd\u4f7f\u4e4b\u7b26\u5408\u7c7b\u578b\u8981\u6c42\u7684\u9690\u5f0f\u89c6\u56fe\u3002<\/li>\n<li>\u7ed9\u5b9a\u4e00\u4e2a <code>e.t<\/code> \uff0c\u8fd9\u91cc\u7684\u9009\u62e9\u662f\u6307\u6210\u5458\u53d8\u91cf\u8bbf\u95ee\uff0c\u5982\u679c e \u7684\u7c7b\u578b\u91cc\u5e76\u6ca1\u6709\u6210\u5458 t\uff0c\u5219\u7f16\u8bd1\u5668\u4f1a\u67e5\u627e\u80fd\u5e94\u7528\u5230 e \u7c7b\u578b\u5e76\u4e14\u8fd4\u56de\u7c7b\u578b\u5305\u542b\u6210\u5458\u53d8\u91cf t \u7684\u9690\u5f0f\u89c6\u56fe\u3002<\/li>\n<\/ul>\n<p>\u9690\u5f0f\u89c6\u56fe\u6240\u4f7f\u7528\u7684\u4f5c\u7528\u57df\u4e0e\u9690\u5f0f\u53c2\u6570\u76f8\u540c\u3002\u4f46\u662f\u5f53\u7f16\u8bd1\u5668\u67e5\u627e\u5173\u8054\u7c7b\u578b\u65f6\uff0c\u4f1a\u4f7f\u7528\u8f6c\u6362\u7684\u201d\u6e90\u7c7b\u578b\u201c\u800c\u4e0d\u662f\u201d\u76ee\u6807\u7c7b\u578b\u201c\u3002<\/p>\n<p>\u9690\u5f0f\u89c6\u56fe\u8fd9\u79cd\u673a\u5236\u4f7f\u5f97\u5224\u65ad\u540c\u4e2a\u7c7b\u578b\u7684\u591a\u4e2a\u9690\u5f0f\u89c6\u56fe\u4e4b\u95f4\u662f\u5426\u5b58\u5728\u547d\u540d\u51b2\u7a81\u53d8\u5f97\u975e\u5e38\u56f0\u96be\uff0c\u4e5f\u53ef\u80fd\u4f1a\u6709 HotSpot \u4f18\u5316\u5668\u65e0\u6cd5\u6539\u5584\u6027\u80fd\u5f00\u9500\u3002<\/p>\n<h2>\u9690\u5f0f\u53c2\u6570\u7ed3\u5408\u9ed8\u8ba4\u53c2\u6570<\/h2>\n<p>\u5f53\u672a\u63d0\u4f9b\u53c2\u6570\uff0c\u4e14\u901a\u8fc7\u9690\u5f0f\u89e3\u6790\u65e0\u6cd5\u627e\u5230\u9690\u5f0f\u503c\u7684\u65f6\u5019\uff0c\u7f16\u8bd1\u5668\u5c31\u4f1a\u4f7f\u7528\u9ed8\u8ba4\u53c2\u6570\u3002<\/p>\n<h2>\u9650\u5236\u9690\u5f0f\u7cfb\u7edf\u7684\u4f5c\u7528\u57df<\/h2>\n<p>\u5728\u5e94\u7528\u9690\u5f0f\u7cfb\u7edf\u65f6\u6700\u91cd\u8981\u7684\u4e00\u70b9\u662f\u786e\u4fdd\u7a0b\u5e8f\u5458\u7406\u89e3\u4e00\u5757\u4ee3\u7801\u91cc\u53d1\u751f\u4e86\u4ec0\u4e48\uff0c\u8981\u505a\u5230\u8fd9\u70b9\u5c31\u5fc5\u987b\u7f29\u5c0f\u7a0b\u5e8f\u5458\u67e5\u627e\u53ef\u7528\u9690\u5f0f\u503c\u7684\u65f6\u5019\u9700\u8981\u770b\u7684\u4ee3\u7801\u8303\u56f4\u3002<\/p>\n<p>\u9690\u5f0f\u7ed1\u5b9a\u53ef\u80fd\u6240\u5904\u7684\u4f4d\u7f6e\uff1a<\/p>\n<ul>\n<li>\u6240\u6709\u5173\u8054\u7684\u4f34\u751f\u5bf9\u8c61\uff0c\u5305\u62ec\u5305\u5bf9\u8c61\uff1b<\/li>\n<li>scala.Predef \u5bf9\u8c61\uff1b<\/li>\n<li>\u4f5c\u7528\u57df\u91cc\u6240\u6709\u5bfc\u5165\u8bed\u53e5\u3002<\/li>\n<\/ul>\n<p>\u4f34\u751f\u5bf9\u8c61\u548c\u5305\u5bf9\u8c61\u5e94\u5f53\u89c6\u4f5c\u4e00\u4e2a\u7c7b\u7684 API \u7684\u4e00\u90e8\u5206\u3002<\/p>\n<p>\u5728\u5b9a\u4e49\u671f\u671b\u88ab\u663e\u5f0f\u5bfc\u5165\u7684\u9690\u5f0f\u89c6\u56fe\u6216\u9690\u5f0f\u53c2\u6570\u65f6\uff0c\u9700\u8981\u786e\u4fdd\u4ee5\u4e0b\u51e0\u70b9\uff1a<\/p>\n<ul>\n<li>\u9690\u5f0f\u89c6\u56fe\u6216\u53c2\u6570\u4e0e\u5176\u4ed6\u9690\u5f0f\u503c\u6ca1\u6709\u51b2\u7a81\uff1b<\/li>\n<li>\u9690\u5f0f\u89c6\u56fe\u6216\u53c2\u6570\u7684\u540d\u5b57\u4e0d\u548c <code>scala.Predef<\/code> \u5bf9\u8c61\u91cc\u7684\u4efb\u4f55\u4e1c\u897f\u51b2\u7a81\u3002<\/li>\n<li>\u9690\u5f0f\u89c6\u56fe\u6216\u53c2\u6570\u662f\u201d\u53ef\u53d1\u73b0\u7684\u201c\uff0c\u662f\u6307\u5e93\u6216\u6a21\u5757\u7684\u7528\u6237\u80fd\u591f\u627e\u5230\u9690\u5f0f\u8f6c\u6362\u7684\u4f4d\u7f6e\u548c\u5224\u7b49\u5176\u7528\u6cd5\u3002<\/li>\n<\/ul>\n<p>\u5728 Scala \u793e\u533a\u4e2d\uff0c\u901a\u5e38\u7684\u505a\u6cd5\u662f\u628a\u53ef\u5bfc\u5165\u9690\u5f0f\u8f6c\u6362\u9650\u5236\u5728\u4ee5\u4e0b\u4e24\u4e2a\u4f4d\u7f6e\u4e4b\u4e00\uff1a<\/p>\n<ul>\n<li>\u5305\u5bf9\u8c61\uff1b<\/li>\n<li>\u5e26 implicits \u540e\u7f00\u7684\u5355\u4f8b\u5bf9\u8c61\u3002<\/li>\n<\/ul>\n<h2>\u5c0f\u7ed3<\/h2>\n<p>Scala \u652f\u6301\u4e24\u79cd\u5f62\u5f0f\u7684\u9690\u5f0f\u8f6c\u6362\uff1a\u9690\u5f0f\u503c\u548c\u9690\u5f0f\u89c6\u56fe\u3002\u9690\u5f0f\u503c\u53ef\u4ee5\u7528\u4e8e\u7ed9\u65b9\u6cd5\u63d0\u4f9b\u53c2\u6570\uff1b\u9690\u5f0f\u89c6\u56fe\u53ef\u4ee5\u7528\u4e8e\u7c7b\u578b\u4e4b\u95f4\u8f6c\u6362\uff0c\u6216\u4f7f\u9488\u5bf9\u67d0\u7c7b\u578b\u7684\u65b9\u6cd5\u8c03\u7528\u6210\u529f\u3002\u9690\u5f0f\u503c\u548c\u9690\u5f0f\u89c6\u56fe\u90fd\u4f7f\u7528\u76f8\u540c\u7684\u9690\u5f0f\u89e3\u6790\u673a\u5236\u3002<\/p>\n<p>\u9690\u5f0f\u89e3\u6790\u91c7\u7528\u4e00\u79cd\u4e24\u9636\u6bb5\u8fc7\u7a0b\uff1a\u7b2c\u4e00\u9636\u6bb5\u5728\u5f53\u524d\u4f5c\u7528\u57df\u91cc\u67e5\u627e\u4e0d\u5e26\u524d\u7f00\u7684\u9690\u5f0f\u8f6c\u6362\uff1b\u7b2c\u4e8c\u9636\u6bb5\u5728\u5173\u8054\u5bf9\u8c61\u7684\u4f34\u751f\u5bf9\u8c61\u91cc\u8fdb\u884c\u67e5\u627e\u3002<\/p>\n<hr\/>\n<p>\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u5fae\u4fe1\u516c\u4f17\u53f7: <strong>coderbee\u7b14\u8bb0<\/strong>\uff0c\u53ef\u4ee5\u66f4\u53ca\u65f6\u56de\u590d\u4f60\u7684\u8ba8\u8bba\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"258\" height=\"258\" src=\"https:\/\/coderbee.net\/wp-content\/uploads\/2019\/01\/coderbee-note.jpg\" class=\"alignnone size-full wp-image-1707\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Scala \u7684\u9690\u5f0f\u8f6c\u6362\u7cfb\u7edf\u5b9a\u4e49\u4e86\u4e00\u5957\u5b9a\u4e49\u826f\u597d\u7684\u67e5\u627e\u673a\u5236\uff0c\u8ba9\u7f16\u8bd1\u5668\u80fd\u591f\u8c03\u6574\u4ee3\u7801\u3002S &hellip; <a href=\"https:\/\/coderbee.net\/index.php\/scala\/20150920\/1310\">\u7ee7\u7eed\u9605\u8bfb <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[181],"tags":[234,227],"_links":{"self":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1310"}],"collection":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/comments?post=1310"}],"version-history":[{"count":3,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1310\/revisions"}],"predecessor-version":[{"id":1313,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/1310\/revisions\/1313"}],"wp:attachment":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/media?parent=1310"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/categories?post=1310"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/tags?post=1310"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}