《编译原理》课程设计院系信息科学与技术学院专业软件工程年级 2011级学号 20112723姓名林苾湲西南交通大学信息科学与技术学院2013年 12月目录课程设计1 词法分析器 (2)1.1 设计题目 (2)1.2 设计容 (2)1.3 设计目的 (2)1.4 设计环境 (2)1.5 需求分析 (2)1.6 概要设计 (2)1.7 详细设计 (4)1.8 编程调试 (5)1.9 测试 (11)1.10 结束语 (13)课程设计2 赋值语句的解释程序设计 (14)2.1 设计题目 (14)2.2 设计容 (14)2.3 设计目的 (14)2.4 设计环境 (14)2.5 需求分析 (15)2.6 概要设计 (16)2.7 详细设计 (16)2.8 编程调试 (24)2.9 测试 (24)2.10 结束语 (25)课程设计一词法分析器设计一、设计题目手工设计c语言的词法分析器（可以是c语言的子集）。

二、设计容处理c语言源程序，过滤掉无用符号，判断源程序中单词的合法性，并分解出正确的单词，以二元组形式存放在文件中。

三、设计目的了解高级语言单词的分类，了解状态图以及如何表示并识别单词规则，掌握状态图到识别程序的编程。

四、设计环境该课程设计包括的硬件和软件条件如下：4.1.硬件（1）Intel Core Duo CPU P8700（2）存4G4.2.软件（1）Window 7 32位操作系统（2）Microsoft Visual Studio c#开发平台4.3.编程语言C#语言五、需求分析5.1.源程序的预处理：源程序中，存在许多编辑用的符号，他们对程序逻辑功能无任何影响。

例如：回车，换行，多余空白符，注释行等。

在词法分析之前，首先要先剔除掉这些符号，使得词法分析更为简单。

5.2.单词符号的识别并判断单词的合法性：将每个单词符号进行不同类别的划分。

单词符号可以划分成5中。

(1)标识符：用户自己定义的名字，常量名，变量名和过程名。

(2)常数：各种类型的常数。

(3) 保留字（关键字）：如if、else、while、int、float等。

(4) 运算符：如+、-、*、<、>、=等。

(5)界符：如逗号、分号、括号等。

5.3.将所有合法的单词符号转化为便于计算机处理的二元组形式：（单词分类号，单词自身值）；以图形化界面显示出来。

5.4.可选择性地将结果保存到文件中。

六、概要设计6.1．数据类型6.1.1.单词的分类：本词法分析器演示的是C语言的一个子集，故字符集如下：(1)标识符：以字母开头的字母数字串。

(2)整数或浮点型(3)保留字：auto, break, case, char, const, continue, default, do, double, else, enum, extern, float, for, goto, if, int, long, register, return, short, signed, sizeof, static, struct, switch, typedef, union, unsigned, void, volatile, while(4)运算符：+、-、*、/、%、>、<、=、!=、==、<=、>=、++、--、!、&、&&、||；(5)界符：[ ] { } ( ) : ; ‘ “ # ,6.1.2.单词二元组：（单词分类号，单词自身值）表6.1单词分类表单词分类号 标识符1 常数2 保留字3 界符4 运算符56.2图6.1 词法分析器的结构6.3．部分单词的正规式与状态转换图图6.2部分单词的状态转换图源程序 输入缓冲区预处理子程序扫描缓冲区1 扫描缓冲区2 词法分析子程序调用 数据 返回—单词6.4．功能模块表6.2 词法分析器的C#程序过程或函数功能表七、详细设计7.1．总体流程图图7.1程序总体流程图7.2．主要分支选择算法介绍7.2.1case0情况算法图7.2 部分分支流程图八、编程调试8.1主要源代码//逻辑操作类与函数using System;using System.Collections.Generic;using System.Text;using System.IO;namespace TokenAnalysis {struct TokenNode {public string type;public string token;}class TokenAnalysis {int cPosition = 0;int lPosition = 0;int ignorWs = 0;int recordWs = 1;FileInfo output;string source;string[] kwList = { "auto", "break", "case", "char", "const", "continue", "default", "do", "double", "else","enum", "extern", "float", "for", "goto", "if", "int", "long", "register","return", "short", "signed", "sizeof", "static", "struct", "switch", "typedef", "union", "unsigned", "void", "volatile", "while","printf","scanf","end","main"};int Error = -2;int Normal = -1;int statue = -1;bool isComment = false;List<TokenNode> resultTokenNodes = new List<TokenNode>();public List<TokenNode> GetTokens() {TokenNode node2Add = new TokenNode();int cp = 0;//current positionint lp = 0;//last positionstring aCopy = source;int length = aCopy.Length;aCopy = aCopy.Trim();while( cp < aCopy.Length ) {//ID or KeyWordsnode2Add = this.GetToken( ignorWs, aCopy, ref cp, ref lp ); if( node2Add.type == "cmtLeft" ) {isComment = true;}if( node2Add.type == "cmtRight" ) {isComment = false;}if( !isComment && node2Add.type != "cmtRight" ) {resultTokenNodes.Add( node2Add );}}return resultTokenNodes;}public TokenNode GetToken() {if( cPosition < source.Length ) {TokenNode token = this.GetToken( ignorWs, source, ref cPosition, ref lPosition );return token;}else {TokenNode token = new TokenNode();token.token = "Error";return token;}}private TokenNode GetToken( int type, string aCopy, ref int cp, ref int lp ) {TokenNode token = new TokenNode();string tempToken;string tempType;if( type == ignorWs ) {if( Char.IsLetter( aCopy[ cp ] ) ) {cp++;while( cp < aCopy.Length &&( Char.IsLetterOrDigit( aCopy[ cp ] ) ||aCopy[ cp ] == '_' ) ) {cp++;}tempToken = aCopy.Substring( lp, cp - lp );tempType = "1 or 3";tempType = GetTokenType( tempToken, tempType );token.token = tempToken;token.type = tempType;lp = cp = NoWs( aCopy, cp );}//Numelse if( Char.IsDigit( aCopy[ cp ] ) ) {cp++;while( cp < aCopy.Length && ( ( Char.IsDigit( aCopy[ cp ] ) ) || ( aCopy[ cp ] == '.' && Char.IsDigit( aCopy[ cp + 1 ] ) ) ) ) {cp++;}tempToken = aCopy.Substring( lp, cp - lp );tempType = "2";token.token = tempToken;token.type = tempType;lp = cp = NoWs( aCopy, cp );}//Borderelse if( aCopy[ cp ] == '(' || aCopy[ cp ] == ')' || aCopy[ cp ] == '{' ||aCopy[ cp ] == '}' || aCopy[ cp ] == '[' || aCopy[ cp ] == ']' ||aCopy[ cp ] == ',' || aCopy[ cp ] == ';' || aCopy[ cp ] == '"' ||aCopy[ cp ] == '\'' || aCopy[ cp ] == '\\' ) {cp++;tempToken = aCopy.Substring( lp, cp - lp );tempType = "4";token.token = tempToken;token.type = tempType;lp = cp = NoWs( aCopy, cp );}//Operation and otherelse {if( cp < aCopy.Length ) {cp++;}switch( aCopy[ cp - 1 ] ) {case '+':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' || aCopy[ cp ] == '+' ) { cp++;}break;case '-':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' || aCopy[ cp ] == '-' ||aCopy[ cp ] == '>' ) {cp++;}break;case '*':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' || aCopy[ cp ] == '/' ) { cp++;}break;case '/':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' || aCopy[ cp ] == '*' ) { cp++;}break;case '=':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' ) {cp++;}break;case '>':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' ) {cp++;}break;case '<':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' ) {cp++;}break;case '!':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '=' ) {cp++;}else {statue = Error;}break;case '|':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '|' ) {cp++;}else {statue = Error;}break;case '&':cp = NoWs( aCopy, cp );if( aCopy[ cp ] == '&' ) {cp++;}else {statue = Error;}break;default:statue = Error;break;}tempToken = aCopy.Substring( lp, cp - lp );tempToken = tempToken.Replace( " ", "" );tempType = "5";tempType = GetTokenType( tempToken, tempType );token.token = tempToken;token.type = tempType;lp = cp = NoWs( aCopy, cp );}}return token;}public void GetInput( string get ) {//source = "for( int i = 0; i < array -> length; i++ ) /* cmt */"; source = get;}private int NoWs( string aCopy, int cp ) {if( cp < aCopy.Length ) {while( Char.IsWhiteSpace( aCopy[ cp ] ) ) {cp++;}}return cp;}private string GetTokenType( string tk2anls, string iniType ) {if( iniType == "1 or 3" ) {foreach( string kw in kwList ) {if( tk2anls == kw ) {return "3";}}return "1";}if( iniType == "5" ) {if( tk2anls == "/*" ) {return "cmtLeft";}if( tk2anls == "*/" ) {return "cmtRight";}return iniType;}return "UnknownTpye";}public void OutPut( string fileName ) {FileInfo outFile = new FileInfo( fileName );StreamWriter fw = outFile.AppendText();foreach( TokenNode tkNode in resultTokenNodes ) {string show = string.Format( "{0,-25}{1,-40}", tkNode.token, tkNode.type );System.Console.WriteLine( show );fw.WriteLine( show );}fw.Close();}public void OutPut() {FileInfo outFile = new FileInfo( "result.txt" );StreamWriter fw = outFile.AppendText();foreach( TokenNode tkNode in resultTokenNodes ) {string show = string.Format( "{0,-25}{1,-40}", tkNode.token, tkNode.type );System.Console.WriteLine( show );fw.WriteLine( show );}fw.Close();}public List<string> GetResult() {List<string> res = new List<string>();foreach( TokenNode tkNode in resultTokenNodes ) {string show = string.Format( "{0,-25}{1,-40}", tkNode.token, tkNode.type );res.Add( show );}return res;}}}//前台控制类与函数namespace TokenAnalysis_FormApp{public partial class Form1 : Form{public Form1(){InitializeComponent();}private void btnAnalysis_Click(object sender, EventArgs e){TokenAnalysis.TokenAnalysis ta = new TokenAnalysis.TokenAnalysis();ta.GetInput(rtxtInput.Text);ta.GetTokens();List< string > res = ta.GetResult();lstResult.Items.Clear();lstResult.Items.AddRange(res.ToArray());}private void btnExit_Click(object sender, EventArgs e){Application.Exit();}private void 保存SToolStripButton_Click(object sender, EventArgs e) {saveFileDialog1.Title = "保存分析结果";saveFileDialog1.Filter = "文本文件|*.txt";if( ( saveFileDialog1.ShowDialog() ) == DialogResult.OK ) {if( saveFileDialog1.FileName != null ) {FileInfo outFile = new FileInfo( saveFileDialog1.FileName );StreamWriter fw = outFile.AppendText();foreach( string tkString in lstResult.Items ) {fw.WriteLine( tkString );}fw.Close();}}}private void btnsave_Click(object sender, EventArgs e){saveFileDialog1.Title = "保存分析结果";saveFileDialog1.Filter = "文本文件|*.txt";if ((saveFileDialog1.ShowDialog()) == DialogResult.OK){if (saveFileDialog1.FileName != null){FileInfo outFile = new FileInfo(saveFileDialog1.FileName);StreamWriter fw = outFile.AppendText();foreach (string tkString in lstResult.Items){fw.WriteLine(tkString);}fw.Close();}}}}}8.2调试调试过程中存在保存不了输出结果的问题。