创建前面示例中这样的复杂表达式要求彻底理解运算符优先级的规则。
Creating complex expressions such as the one in the preceding example requires a thorough understanding of the rules of operator precedence.
初始查询中的XMLEXISTS谓词被转换为一个复杂表达式，可以通过编号Q 1引用。
The XMLEXISTS predicate in the original query got converted into a complex expression that can be referred to using the number Q1.
本文不介绍用于动态选择Web服务的其他选项(例如确定最低执行成本或最佳质量的复杂表达式)。
Other options for dynamically selecting Web services (such as complex expressions that determine least execution cost or the best quality) are not covered here.
表达式可以简单到就是一个变量（如清单2 所示）或者是一个方法调用（例如getList()），亦或是包含布尔逻辑或三目运算符的复杂表达式。
This expression can be as simple as a variable (as shown in Listing 2) or a method call (like getList()), or a complex expression that involves boolean logic or a ternary operator.
基本搜索允许您使用+和-，但不能使用布尔运算符或更复杂的表达式。
Basic Search allows you to use + and - but you can not use Boolean operators or more complex expressions.
但是，一旦正式描述它的某种语言和语法变得复杂，那么语言中的有效表达式数量将迅速增加。
Once a language and the grammar that formally describes it becomes complex, however, the number of valid expressions in the language grows rapidly.
但是，这里经常有人提问这样一个问题：如何编写查询表达式才能从任何复杂的DOM中获取正确的节点？
It is here, though, that a common question is asked: How do you write the query expression to get the correct node from an arbitrarily complex DOM?
坦白地说，XML不是一种多么复杂的语法，因此认为可以自己通过正则表达式或其他特殊方法来解析的想法是可以理解的。
Granted, XML is not a very complex syntax so you can be forgiven for thinking that you can hack your way with regular expressions or other ad-hoc means.
好，说完了这一点，我们就可以讲些复杂些的话题了，例如，假设我看到了这个表达式。
Right, having done that, we can certainly get to more complicated things, so for example, suppose I look at that expression.
在开始编写更复杂的更新时，您可能会犯一些错误，DB 2可能会拒绝您的更新表达式。
As you start to craft more complex updates, you may make some mistakes and encounter situations where DB2 rejects your update expressions.
但不幸的是，简单的正则表达式并不满足于处理复杂的模式和符号。
Unfortunately, simple regular expressions are unable to cope with complex patterns and symbols.
您可以连接表1中显示的元素(以及其他操作符)并加以组合使用，从而构建(非常)复杂的正则表达式。
You can string together the primitives in Table 1 (and other operators) and use them in combination to build (very) complex regular expressions.
提供变量、表达式和控制流，以促进更复杂的决策制定。
Supplies variables, expressions, and control flow to facilitate more complicated decision making.
on 子句中的过滤器能够包含复杂查询或者简单表达式。
The filters in the on clause can contain complex queries or simple expressions.
在清单5中，Condition元素是用于创建作为可嵌套条件的复杂逻辑表达式。
In Listing 5, the condition element is used to create complex logical expressions as conditions can be nested.
XQuerywhere子句可以包含任意复杂的嵌套表达式，甚至可以包含函数调用。
The XQuery where clause can consist of nested expressions of arbitrary complexity that can even include function calls.
如果需要执行更为复杂的XPath表达式且需要对文档进行完全控制，那么就可以选用DOM。
If you need to perform more complex XPath expressions and need full control of the document, DOM is an option.
使用像sed和Perl这样功能强大的工具，以及神奇的正则表达式，您可以直接通过UNIX命令行轻松地完成复杂的文本处理任务。
Using powerful tools like sed and Perl, and the magic of regular expressions, you can easily do complex text processing tasks directly on the UNIX command line.
不过，与复杂的XML文档打过交道的人都知道，详细的XQuery表达式很容易变得笨拙而难以理解。
However, anyone who works with complex XML documents inevitably finds that detailed XQuery expressions can quickly become awkward and hard to understand.
Struts2OGNL表达式减小了编写复杂代码、将单级表单beans转换为多级域对象的难度。
Struts 2 OGNL expressions reduce the difficulty of writing complex code to transform single-level form beans to multi-level domain objects.
在Struts2中，HTML输入字段名称可以生成为ognl表达式，后者有助于消除操作类中的复杂编码。
In Struts 2, the HTML input field names could be generated as OGNL expressions, which in turn helps eliminate complex coding in the action class.
简单的答复是，Python会根据需要将表达式中的所有操作数转换为最复杂的操作数的类型。
The simple answer is that Python converts all operands in an expression to the type of the most complex operand, as necessary.
tcpdump和tcpflow工具有大量的选项，包括创建复杂过滤表达式的能力。
The tcpdump and tcpflow tools give you a huge number of options, including the ability to create complex filter expressions.
此外，在InternetExplorer7和Internet Explorer 8中运行具有多个复杂Xpath表达式的测试用例可能会太慢了。
Additionally, it might be too slow to run test cases that have multiple, complicated Xpath - expressions in Internet Explorer 7 and Internet Explorer 8.
让我们忽略较复杂的选项，只关注正则表达式的基本语法。
Let's ignore the more complex options and just look at the basic syntax of a regular expression. Here are some examples.
新的方式更加复杂，但可以在Aggregation Widgets 下拉列表中得到一个不错的聚合，还为参数和表达式提供了漂亮的文本框。
The new way is a bit more complex, but the result is that you get a nice aggregation in the drop-down list of the Aggregation widget, with nice text boxes for the parameters and expressions.
if语句(以及本文后面讨论的elif子句和while循环)中的表达式可以很复杂。
The expression used in the if statement (and in the elif clause and the while loop discussed later in this article) can be as complex as necessary.
SystemT 结合了字典和正则表达式技术，以及使用上下文和语法的复杂模式识别，达到行业领先的准确率。
SystemT combines both dictionaries and regular expressions techniques, along with sophisticated pattern recognition using context and syntax to achieve industry-leading accuracy rates.
对于初学者的一个最好的建议就是：首先学习最基本的正则表达式(参阅资料部分，或“perldocperlre ”参考手册)，稍后才进一步学习那些复杂的高级特性。
The best advice for the beginner is: learn the basics of regular expressions (see Resources or the "perldoc perlre" manual page), but stay away from the advanced features for a little while.
正则表达式支持有可能并且通常会无法识别或不能处理复杂查询，而正则grep 却可以轻松处理。
Regular-expression support is minimal at best and can often be unrecognized or unprocessable for complex queries that regular grep can handle easily.
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