[翻译]High Performance JavaScript(018)
String Trimming 字符串修剪
Removing leading and trailing whitespace from a string is a simple but common task. Although ECMAScript 5 adds a native string trim method (and you should therefore start to see this method in upcoming browsers), JavaScript has not historically included it. For the current browser crop, it's still necessary to implement a trim method yourself or rely on a library that includes it.
去除字符串首尾的空格是一个简单而常见的任务。虽然ECMAScript 5添加了原生字符串修剪函数（你应该可以在即将出现的浏览器中看到它们），到目前为止JavaScript还没有包含它。对当前的浏览器而言，有必要自己实现一个修剪函数，或者依靠一个包含此功能的库。
Trimming strings is not a common performance bottleneck, but it serves as a decent case study for regex optimization since there are a variety of ways to implement it.
修剪字符串不是一个常见的性能瓶颈，但作为学习正则表达式优化的例子有多种实现方法。
Trimming with Regular Expressions 用正则表达式修剪
Regular expressions allow you to implement a trim method with very little code, which is important for JavaScript libraries that focus on file size. Probably the best all-around solution is to use two substitutions—one to remove leading whitespace and another to remove trailing whitespace. This keeps things simple and fast, especially with long strings.
正则表达式允许你用很少的代码实现一个修剪函数，这对JavaScript关心文件大小的库来说十分重要。可能最好的全面解决方案是使用两个子表达式：一个用于去除头部空格，另一个用于去除尾部空格。这样处理简单而迅速，特别是处理长字符串时。
if (!String.prototype.trim) {
String.prototype.trim = function() {
return this.replace(/^\s+/, "").replace(/\s+$/, "");
}
}
// test the new method...
// tab (\t) and line feed (\n) characters are
// included in the leading whitespace.
var str = " \t\n test string ".trim();
alert(str == "tes
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本文主要是出于有朋友使用我原来写的autocomplete的JS控件。当数据量大的时候，会出现效率极其慢的情况，我在这段时间做出的一些测试也及一些经验，与大家分享，如果有错的地方，还请指出。
经过测试，我们会发现如下的情况或者说的结论，如果您的测试结果与我的不符，请说明原因，以便相互学习。
1）当一个较大的HTML字� ......
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玩PHP、Delphi、Java基本上都有对象，习惯这种思路后上手任何语言都想靠OO思路，这绝不是在赶时髦，而是把相关代码进行内聚的确可以体会到维护的方便！
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funct ......
Recursion Patterns 递归模式
When you run into a call stack size limit, your first step should be to identify any instances of recursion in the code. To that end, there are two recursive patterns to be aware of. The first is the straightforward recursive pattern represented ......
A Note on Benchmarking 测试基准说明
Because a regex's performance can be wildly different depending on the text it's applied to, there's no straightforward way to benchmark regexes against each other. For the best result, you need to benchmark your regexes on test strings o ......
