编译原理经典算法的可视化实现 编译原理经典算法的可视化实现

摘要

在计算机教学中，编译原理这门课程在计算机科学中占有非常重要的地位，每个计算机专业的同学都需要学习它。而通过学习编译原理，能更好的了解高级程序语言的运行机制，并能编写出更加高效的程序。但是编译原理中的算法比较抽象，学习起来困难，而本系统能够动态演示编译原理中的词法分析阶段和语法分析阶段的LL(1)文法，而词法分析器将输出每个单词对应的二元组，这将有利于我们对词法分析器的理解，而LL(1)文法的动态演示使我们能够更好的理解并运用LL(1)文法中的各种算法。所以这种算法可视化技术能加深人们对程序行为的理解和认识，准确地了解和分析程序执行过程所反映的逻辑含义和功能。

本程序是在vs2012平台下用C#语言实现的。本程序界面简洁，能实现词法分析器的可视化和LL(1)文法的演示。

关键词：词法分析;LL(1)文法;可视化技术

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编译原理经典算法的可视化实现

THE VISUAL IMPLEMENTATION of CLASSIC ALGORITHM

of COMPILATION PRINCIPLE

Abstract

In the computer course,Compilation principle plays a very important role in computer science, each student who learns computer science has to learn it. Through the study of these principles, we can be more easy to understand the operation mechanism of various high-level language, and we can produce more efficient code. But the compilation principle is abstract, it’s very difficult to learn it. The system can dynamic demo the compilation principle of lexical analysis and LL (1) of grammar grammar analysis phase, and the lexical analyzer will output each word two tuples, which will help us to analysis of lexical understanding, LL (1) dynamic demo grammar enables us to better understand and use the LL (1) algorithms in the grammar. So this kind of algorithm visualization technology can help people to understand program behavior, understand the reflection accuratly and analysis of program execution logic meaning and function.

This procedure is used C# language under vs2012 platform. The program’s interface is simple, and it achieves visual of lexical analyzer and the demo of LL(1) algorithms.

Key words: lexical analysis; LL (1); visualization technology

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编译原理经典算法的可视化实现 目录

1 绪 论…………………………………………………………………………………………………………………….1

1.1背景 .................................................................................................................. 1 1.2本课题研究的目的和意义 .............................................................................. 1 1.3国内外研究现状 .............................................................................................. 2 1.4主要工作 .......................................................................................................... 2 1.5 本系统的设计思想 ......................................................................................... 2 2 词法分析概述……………………………………………………………………………………………….…….4

2.1 词法分析器的作用 ......................................................................................... 4 2.2词法分析中的问题 .......................................................................................... 5 2.3 词法分析中的术语 ......................................................................................... 5 2.4 词法错误 ......................................................................................................... 7 2.5 词法分析生成工具 ......................................................................................... 8 3 词法分析器动态演示的设计与实现…………………………………………………………..…….10

3.1 词法分析器描述语言 ................................................................................... 10

3.1.1 Lex说明………………………………………………………………………………………………………..10 3.1.2 超前扫描操作………………………………………………………………………….………………….11 3.1.3 Lex编程………………………………………………………………………………………………………..12 3.2词法分析器动态演示的事件实现 ................................................................ 12 4 语法分析……………………………………………………………………………………………….…….…….17

4.1 语法分析的基本概念 ................................................................................... 17 4.2 语法分析的任务 ........................................................................................... 17 4.3 语法分析基础 ............................................................................................... 17 5 LL(1)文法可视化的设计与实现………………………………………………………………………23

5.1 程序界面的实现 ......................................... ...23 5.2 程序关键功能的实现。 ....................................... 25

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编译原理经典算法的可视化实现 5.2.1 FIRST和FOLLOW………………………………………………………………………………..……25 5.2.2 预测分析表的构造 .................................. ...27

致谢…………………………………………………………………………………………………………………………29 参考文献………………………………………………………………………………………………………………….30 附录………………………………………………………………………………………………………………………….31 附件1 开题报告 附件2 译文及原文影印件

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