不需懂得太多就可以理解扩展文法，在对付大项目时，这对您非常有帮助。
You don't need to know much to understand and extend the grammar, which can be very helpful when you're tackling large projects.
RecDescent的缺点是：由于它使用可扩展文法规则并且实时地进行记载和解析，所以比较慢。
The downside of Parse: : RecDescent is that it is moderately slow because it USES extensible grammar rules and on-the-fly lexing and parsing.
扩展文法处理（extend-grammarprocess）规则：这个 process 规则可以由一个查询或定义组成。
The extend-grammar process rule: The process rule can consist of a query or a definition.
扩展文法定义（extend-grammardefinition）规则：该可扩展文法的核心是 definition 规则。
The extend-grammar definition rule: The heart of this extensible grammar is the definition rule.
扩展文法查询(extend - grammar query)规则：这个query规则由do_you _ know产品组成，后跟一个名称或恰当的名称。
The extend-grammar query rules: The query rule consists of a do_you_know production, followed by a name or a proper name.
扩展并不是文法必需的特性，因此它们的语法不象该语言的其它构造那样得到良好定义。
Extensions are not a required feature of the grammar and, thus, their syntax is not as well defined as the other constructs of the language.
先从分析一般数控代码格式入手，然后用扩展巴科斯范式表达从中提取的文法规则，使后续对译码模块的研究建立在编译原理的基础上。
It begins with analyzing common CNC code format and then expresses its grammar with EBNF, so continuous research of coding module is established on compiler principle.
本文介绍用于识别手写印刷体汉字的二维扩展属性文法方法中文法归约阶段的工作。
The work on grammar reductions in Two-Dimensional Extended Attribute Grammars is presented for the recognition of hand-printed Chinese characters.
对虚拟表示模型进行了扩展，使VDM页面能够灵活地支持模块化设计，并给出了相应扩充语义标记的形式文法。
Through Extending Virtual Description Model, VDM web pages can support modular design, and bring forward relevant extended semantic tag format grammar.
对虚拟表示模型进行了扩展，使VDM页面能够灵活地支持模块化设计，并给出了相应扩充语义标记的形式文法。
Through Extending Virtual Description Model, VDM web pages can support modular design, and bring forward relevant extended semantic tag format grammar.
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