yacc允许您通过符号名引用表达式的组成部分。
Yacc allows you to refer to the components of an expression by symbolic names.
因此，流开发人员不应该使用变量引用表达式映射到名称列可能为 NULL 的路由决策。
Therefore flow developers should not use routing decisions in which variable reference expressions map onto name columns whose values may be NULL.
如果检索到的列值为SQLNULL，那么不会给此类值分配任何XPath变量引用表达式。
In the case where a retrieved column has a value of SQL NULL, then no XPath variable reference expression is assigned to such a value.
请注意，这里有一个将被选中表达式所有出现的地方都替换成新变量的引用的选项。
Notice that there is an option to replace all occurrences of the selected expression with references to the new variable.
如果一个度量引用其他度量，那么在为它产生SQL表达式时，不能使用聚合函数来为嵌套的度量产生SQL表达式。
When generating SQL expressions for measures that reference other measures, the aggregation function might not be used to form the SQL expression for the nested measures.
基于卡片的表单中的字段可以像表格中的单元格一样引用，可以包含数据，也可以包含能在运行时确定数据的表达式。
The fields in the card-based forms can be referenced like cells in a spreadsheet and can contain either data or an expression that determines the data at run-time.
如果一个值绑定表达式引用的模型数据不再可用，或者在组件树被恢复之前发生了更改，那么组件树的一些部分将被撤销。
If model data referenced by a value binding expression is no longer available or has changed prior to the component tree being restored, it can result in portions of the tree being dropped.
上面的表达式将产生和前面的反向引用同样的效果，但通过使用命名组，这将明显地更便于阅读。
The above expression will create the same effect as the previous back reference example, but by instead using named groups. It is also significantly easier to read.
然后表达式中对变量的引用可以静态绑定到本地堆栈框架或一列全局变量的特定槽上。
References to variables within an expression can then be statically bound to a particular slot in either the local stack frame or the list of global variables.
除了简化元素嵌入，紧凑表达式也提供一种引用和重用策略表达式的方法。
Besides simplifying element nesting, compact expression also provides a way to reference and reuse policy expressions.
对于外部策略表达式，引用的UR i属性通常提供外部策略的真实url。
For external policy expressions, the reference's URI attribute normally gives the actual URL of the external policy.
当要使用多个反向引用时，正则表达式很快就会变得令人迷惑而且很难去理解。
When using multiple back references, a regular expression can quickly become confusing and hard to understand.
在第一次引用时，默认表达式将为全局变量计算一个值。
The default expression calculates a value to assign to the global variable the first time it is referenced.
这意味着通过引用正则表达式(或者甚至是一段代码)，变量会拒绝将其值设置为某些恶意的值或完全无意义值的尝试。
This means that a variable may reject attempts to set its value to something malicious or simply nonsensical by referring to a regular expression (or even a piece of code).
LIKE谓词有一个新特性，允许使用列引用作为模式表达式。
There is also a new feature for the LIKE predicate that makes it possible to use a column reference as pattern expression.
最后，我们看到第二个子表达式，它除了有由方括号组成的“不引用”运算符外，还有一个加号。
Finally, we get the second child subexpression, which other than the "don't refer" operator consists of some stuff in square brackets, and a plus sign.
在这个特殊的例子中，方法引用比lambda表达式更清晰地表达了我们的意图，但它们的概念是一样的。
In this particular example, a method reference is a clearer expression of what we mean than a lambda expression, but the idea is the same.
我们先给出为一个度量产生SQL表达式的示例，这个度量没有引用其他任何度量。
Let's first start with an example of generating the SQL expression for a measure that does not reference any other measures.
可以通过实例文档填充表单，实例文档是从表单元素上的XPath表达式引用的。
You can populate the form through an instance document, which you reference from XPath expressions on the form elements.
Spring附带了一个变量解析器实现类，允许您在JSF表达式中引用 Spring托管Bean。
Spring comes with a variable resolver implementation class that lets you reference Spring managed beans in JSF expressions.
节点中指定的条件可以使用ESQL引用或XPath表达式。
The condition specified in the node can use an ESQL reference or XPath expression.
最重要的一点是XPath表达式只能引用名称空间前缀限定的元素和属性名。
Foremost among them is that XPath expressions can only reference namespace-qualified element and attribute names by the use of namespace prefixes.
最后，触发器的setvalue操作引用其index属性中的相同value元素，index属性可以使用XPath表达式。
Finally, the setvalue action tied to the trigger references that same value element in its index attribute, which can take an XPath expression.
对于DatabaseRoute节点，始终是结果集第一行中的指定列值被引用，并用于这些xpath路由表达式。
For the DatabaseRoute node it is always the named column values located in the first row within the result set that are referenced and acted upon in these XPath routing expressions.
比方说，表达式中的变量引用将导致错误，即使元素确实位于变量有效的模板中。
For example, a variable reference in the expression results in an error even though the element is positioned in a template where the variable is in scope. Some key differences are.
第一个“非引用”子表达式只表示“查找类似于http或ftp或其它值的字符串”。
The first of these "non-reference" child subexpressions just says "match something that looks like HTTP or that looks like FTP or...".
X Forms表单元素使用的数据模型引用实际上是XPath表达式，因此可用XPath表达式来引用模型中的任何元素。
The data model references used by the XForms form elements are actually XPath expressions, so you can use them to refer to any element in the model.
这说明，该函数必须在一个涉及比较操作并且引用了索引扩展hash _ index的搜索方法“equals”的表达式中使用。
It says that the function must be used in an expression involving the comparison operation and that the search method "equals" of the index extension hash_index is referred to.
这两个XPath表达式由树节点引用的com . icl . saxon . expr . Expression对象表示。
The two XPath expressions are represented by com.icl.saxon.expr.Expression objects referenced from the nodes of the tree.
内部类以及lambda表达式一个局限性是——它们只引用来自它们的词法作用域的最终(final)局部变量。
One limitation of inner classes - and lambda expressions too - is that they can only refer to final local variables from their lexical scope.
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