词法分析器用C#实现

设计界面如上图所示：代码如下：namespaceWindowsApplication1{publicpartialclassForm1:Form{publicForm1(){InitializeComponent();}stringStr=,text2=;privatevoid打开ToolStripMenuItem_Click(objectsender,EventArgse){stringFname=;openFileDialog1.Filter=文本文件(*.txt)|*.txt;openFileDialog1.Title=打开文件;openFileDialog1.RestoreDirectory=true;if(openFileDialog1.ShowDialog()==DialogResult.OK)Fname=openFileDialog1.FileName;richTextBox1.LoadFile(Fname,RichTextBoxStreamType.PlainText);Str=richTextBox1.Text;}privatevoid保存ToolStripMenuItem_Click(objectsender,EventArgse){stringFname=openFileDialog1.FileName;richTextBox1.SaveFile(Fname,RichTextBoxStreamType.PlainText);}privatevoid另存为ToolStripMenuItem_Click(objectsender,EventArgse){stringFname;saveFileDialog1.Filter=文本文件(*.txt)|*.txt;saveFileDialog1.Title=保存文件;saveFileDialog1.RestoreDirectory=true;saveFileDialog1.ShowDialog();Fname=saveFileDialog1.FileName;if(Fname!=)richTextBox1.SaveFile(Fname,RichTextBoxStreamType.PlainText);}privatevoid关闭ToolStripMenuItem_Click(objectsender,EventArgse){Application.Exit();}privatevoid字体ToolStripMenuItem_Click(objectsender,EventArgse){fontDialog1.ShowEffects=true;fontDialog1.Font=richTextBox1.SelectionFont;if(fontDialog1.ShowDialog()==DialogResult.OK)richTextBox1.SelectionFont=fontDialog1.Font;}privatevoid词法分析ToolStripMenuItem_Click(objectsender,EventArgse){Gets.LineNo=1;//初始化行号Gets.errors=0;//初始化错误个数Gets.text5=;stringtext1=richTextBox1.Text+'\0';Getsgetstring=newGets();text2=getstring.GetString(text1);richTextBox2.Text=*****************Token串生成表如下********************+\r\n+text2;textBox2.Text=getstring.ErrorN0();}privatevoidForm1_Load(objectsender,EventArgse){}privatevoid符号表ToolStripMenuItem_Click(objectsender,EventArgse){textBox2.Text=***********************符号表信息******************+\r\n;textBox2.Text+=Gets.text4;}privatevoid错误详细信息ToolStripMenuItem_Click(objectsender,EventArgse){textBox2.Text=Gets.text5;}}主要实现功能的代码如下：创建一个Gets类用来对输入的字符串进行扫描classGets{inti=0,j=0;//记录字符位置,token数组的位置publicstaticintLineNo=1;//行号stringtoken=;//记录识别出的单词stringtext2=;stringtext3=;//用来记录错误信息stringwrong=;//记录异常信息publicstaticinterrors=0;//错误字段的个数publicstaticstringtext5=;//记录错误的详细信息intflag1=0,flag2=0,flag3,flag4,flag5,flag6=0;//标记成对出现的界符publicstaticstringtext4=入口:单词名称长度类型种属值内存地址+\r\n;//用来记录符号表string[]m_KeyWords=newstring[32]{auto,double,int,struct,break,else,long,switch,case,enum,register,typedef,char,extern,return,union,const,float,short,unsigned,continue,for,signed,void,default,goto,sizeof,volatile,do,if,while,static};string[]m_operator=newstring[28]{+,-,*,/,%,,,=,=,==,-=,+=,*=,/=,//运算符!=,=,%=,&,&&,|,||,!,++,--,~,,,?:};string[]m_bound=newstring[15]{{,},[,],;,,,.,(,),:,\,#,,,\'};//界符publicstringGetString(stringstr)//读入字符串{stringspace=;//空格数if(str.Length==0)//判断字符串是否为空return;try{while(str[i]!='\0')//读入字符判断，空格、字母、数字、界符{if(str[i]==''||str[i]=='\t'||str[i]=='\r'){i++;//跳过无意义的字符}elseif(str[i]=='\n')//如果是换行符，则行号加1{LineNo++;i++;}elseif(isalpha(str[i]))//如果是字母{i=recog_id(str,i);for(j=0;jm_KeyWords.Length;j++){if(token.CompareTo(m_KeyWords[j])==0)break;}if(j=m_KeyWords.Length)//不是保留字{for(intm=0;m12-token.Length;m++)space=space+;text2=text2+LineNo.ToString()+:+token+space+标识符Token码75+\r\n;;text4=text4+LineNo.ToString()+:+token++token.Length+space+标识符++简单变量++未知++未知+\r\n;token=;space=;}if(jm_KeyWords.Length)//是保留字{for(intm=0;m12-token.Length;m++)space=space+;text2=text2+LineNo.ToString()+:+m_KeyWords[j]+space+保留字Token码+Convert.ToString(gettoken(token,1))+\r\n;;token=;space=;}}elseif(isdigit(str[i]))//如果是数字{i=recog_dig(str,i);for(intm=0;m12-token.Length;m++)space=space+;text2=text2+LineNo.ToString()+:+token+space+常量Token码76+\r\n;text4=text4+LineNo.ToString()+:+token++token.Length+space+整数++简单变量++未知++未知+\r\n;token=;space=;}elseif(isbound(str[i]))//识别界符{i=recog_bound(str,i);for(intm=0;m12-token.Length;m++)space=space+;text2=text2+LineNo.ToString()+:+token+space+界符Token码+Convert.ToString(gettoken(token,3))+\r\n;;token=;space=;}elseif(isoperator(str[i])){i=recog_Operator(str,i);for(intm=0;m12-token.Length;m++)space=space+;text2=text2+LineNo.ToString()+:+token+space+运算符Token码+Convert.ToString(gettoken(token,2))+\r\n;token=;space=;}else{error(0);i++;}}}catch(DivideByZeroExceptione1){wrong=e1.Message;}catch(IndexOutOfRangeExceptione2){wrong=e2.Message;}catch(Exceptione){wrong=e.Message;}returntext2;}publicboolisalpha(charch)//判断是否为字母{if((ch='a'&&ch='z')||(ch='A'&&ch='Z'))returntrue;elsereturnfalse;}publicboolisdigit(charch)//判断是否为数字{if(ch='0'&&ch='9')returntrue;elsereturnfalse;}publicboolissign(charch)//识别下划线{if(ch=='_')returntrue;elsereturnfalse;}publicboolisbound(charch)//判断是否为界符{for(intj=0;jm_bound.Length;j++)if(ch.CompareTo(m_bound[j][0])==0){returntrue;}returnfalse;}publicboolisoperator(charch){for(inti=0;im_operator.Length;i++)if(ch==m_operator[i][0]){returntrue;}returnfalse;}privateintrecog_Operator(stringstr,inti){charstate='0';stringsstr=;while(state!='2'){switch(state){case'0':sstr+=str[i];i++;state='1';break;case'1'://判断为双个运算符if(str.Substring(i-1,2)==++||str.Substring(i-1,2)==--||