YACC
美 
英
- 网络编译器(Yet Another Compiler Compiler)；另一个编译器；分析器
例句
Yacc is a grammar parser; it reads text and can be used to turn a sequence of words into a structured format for processing.
Yacc是一种语法分析器，它可以读取文本并用来将单词序列转换为便于处理的结构化的格式。
This means that if yacc would have to read two tokens before it knew which action to take, it would be unable to parse this grammar.
这就意味着，如果yacc在知道采取哪个动作之前，必须读取两个标记，那么它将无法解析该语法。
Here's a simple example of a program that can be written in a page of yacc and a half-page of lex code.
这里是一个简单的示例程序，只需要一页yacc代码和半页lex代码就可以编写完该程序。
In some cases, Yacc fails to produce a parser when given a set of specifications.
一些情况下，当给定一个规范集合时，Yacc生成词法分析器会失败。
Throughout these articles, the names "lex" and "yacc" will be used to include also flex and bison, the GNU versions of these utilities.
在这两篇文章的所有内容中，“lex”和“yacc”这两个名字所代表的也包括这些工具的GNU版本flex和bison。
Yacc allows you to refer to the components of an expression by symbolic names.
yacc允许您通过符号名引用表达式的组成部分。
This data type is a C union object, and is declared in the first section of a yacc file using a %union declaration.
这个数据类型是一个Cunion对象，在yacc文件的第一部分使用%union声明来定义。
The first section of a yacc file defines the objects that the parser will manipulate and generate.
yacc文件的第一部分定义了解析器将要处理和生成的对象。
Normally we would use the compiler generator tools lex and yacc to build that part of the program which recognizes an arithmetic expression.
一般说来，我们将要通过规定的编译工具和另外的某编译器来生成能计算这个算术运算的目标程式。
Lex and yacc are a matched pair of tools.
lex和yacc是一对配对工具。
Yacc provides a general tool for imposing structure on the input to a computer program.
Yacc提供了一个通用工具来识别程序输入的结构。
The general way this is done is to define a data type to contain objects that yacc will be manipulating.
通常解决此问题的方法是定义一个容纳yacc将要处理的对象的数据类型。
For instance, code in many programming languages can be read using lex and yacc.
例如，可以使用lex和yacc读取很多编程语言的代码。
Yacc is designed to work with the output of Lex, although you can write your own code to fill that gap.
yacc设计用来处理lex的输出，不过您也可以编写自己的代码来完成此任务。
Lex and yacc can be used to parse fairly simple and regular grammars.
lex和yacc可以用来解析相当简单和规则的语法。
One of the best things you can do to learn more about lex and yacc is to write a few toy programs.
为了深入学习lex和yacc，您最好去编写一些用来消遣的小程序。
Yacc takes sets of tokens and assembles them into higher-level constructs, analogous to sentences.
yacc接受成组的记号，并将它们装配为高层次的结构，类似于句子。
This is where yacc comes in: yacc lets you describe what you want to do with tokens. A yacc grammar tends to look sort of like this
这就是yacc要做的：yacc让您可以描述希望怎样处理记号。
Those tools we look at here do so, as does the popular compiler development tool YACC (and its variants).
我们在这里研究的工具是这样做的，流行的编译器开发工具YACC（及其变体）也是这样做的。
Yacc files, like lex files, come in sections separated by %% markers.
类似于lex文件，yacc文件也是由使用%%标志隔开的部分构成。
External DSLs build a new language grammar, requiring tools like lexx and yacc or Antlr.
外部DSLs可构建一个新语法，构建时需要使用lexx和yacc或Antlr等工具。
JavaCC, like YACC, is designed to speed the process of developing parser logic for languages.
JavaCC与YACC一样，是为加快语言解析器逻辑的开发过程而设计的。
Lex and yacc are very good at parsing reasonably simple file formats.
lex和yacc非常擅长解析相当简单的文件格式。
Yacc then generates a function to control the input process.
Yacc生成一个函数来控制输入过程。
Yacc: This tool is standard on most UNIX operating systems.
Yacc：这个工具是大多数UNIX操作系统的标准组件。
This grammar is ambiguous; yacc can't figure out what's going on.
该语法是不明确的；所以yacc无法指出接下来将做什么。
Lex and yacc are tools for building programs.
lex和yacc是编译程序的工具。
The biggest limitation is that yacc is limited to one token of lookahead.
最大的局限在于，yacc被限定为一个预读标记。
By using the lex and yacc tools, you can build a parsing engine that processes text according to specific rules.
通过使用lex和yacc工具，您可以构建一个分析引擎，根据特定的规则来处理文本。
What are lex and yacc, and why do people refer to them together?
lex和yacc是什么，为什么人们同时提及它们？
In this tutorial, you'll examine how to use lex and yacc, first to build a calculator.
在本教程中，首先您将研究如何使用lex和yacc来构建一个计算器。
Programs using yacc, but not lex, are rarer.
使用yacc而不使用lex的程序比较罕见。
In fact, while lex and yacc are almost always mentioned in the same breath, they can be used separately.
实际上，尽管lex和yacc几乎总是被同时提到，但是它们可以单独使用。
This is where the UNIX lex and yacc tools are useful.
在这种情况下，UNIXlex和yacc工具就很有用处了。
Most people never need to know what lex and yacc do.
大部分人永远不需要知道lex和yacc可以做什么。
One thing you'll find if you play around a bit is that lex and yacc can be confusing to troubleshoot.
如果稍加研究，您将发现lex和yacc可以用于问题诊断。
The code provided should work in all major versions, such as MKS yacc.
给出的代码应该适用于所有主流版本，比如MKSyacc。
While Yacc cannot handle all possible specifications, its power compares favorably with similar systems;
然而Yacc无法处理所有可能的规范，它的能力与类似的系统相比要好；
When yacc is run with the -d option, it generates a header file defining constants. Thus, our earlier lex example using
当使用-d选项来运行yacc时，它会生成一个定义常量的头文件。
Yacc would create a header file (called y. tab. h by default) containing a line something like
yacc将创建包含有类似下面一行的一个头文件（默认名为y.tab.h）
