编译语言-语法分析器的设计.docx

实验三 语法分析器的设计一、 实验内容设计、编写和调试构造LR（0）项目集规范簇或实现基于LR分析表对给定的符号串进行LR分析的程序。以下两个内容任选其中一项：（1） 对于给定的文法，实现构造识别该文法全部活前缀DFA的程序。（2） 对于给定的LR分析表和符号串，设计程序以实现所输入符号串是否为合法符号串。要求用JAVA语言编程。（可参考实验指导书P149至P156）二、 程序代码AnalysisOfGrammer.javapackage analysis;import javax.swing.*;import javax.swing.table.DefaultTableModel;import java.awt.*;import java.awt.event.*;import java.io.*;import java.util.LinkedList;public class AnalysisOfGrammer extends JAppletprivate JFileChooser jfc = new JFileChooser(new File(.);private JButton jbt1 = new JButton(打开文法文件);private JButton jbt2 = new JButton(构造LR规范簇);private JButton jbt3 = new JButton(构造LR分析表);private JButton jbt4 = new JButton(清空);private JButton jbt5 = new JButton(退出);private JLabel jl1 = new JLabel(LR(0)项目集规范簇);private JLabel jl2 = new JLabel(LR(0)分析表);private JPanel p3 = new JPanel();private JTextArea jta1 = new JTextArea();private String grammer = new String50;private int count = 0;private LinkedList list = new LinkedList();private Object content = new Object1004;int num1 = 0;String cache = new String50100;int location = new int50;int back = 0;public void clear1()grammer = null;public void clear2()num1 = 0;list = null;content = null;cache = null;location = null;back = 0;public AnalysisOfGrammer()JPanel p1 = new JPanel();p1.setLayout(new GridLayout(1,5);p1.add(jbt1);p1.add(jbt2);p1.add(jbt3);p1.add(jbt4);p1.add(jbt5);add(p1,BorderLayout.NORTH);JPanel p4 = new JPanel();p4.setLayout(new GridLayout(1,2);JPanel p2 = new JPanel();p2.setLayout(new BorderLayout();p2.add(new JLabel(文法为：),BorderLayout.NORTH);p2.add(new JScrollPane(jta1),BorderLayout.CENTER);p4.add(p2);p4.add(p3);add(p4,BorderLayout.CENTER);jbt1.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e)jta1.setText();open(););jbt2.addActionListener(new ActionListener()public void actionPerformed(ActionEvent e)if(jta1.getText().equals()JOptionPane.showMessageDialog(null, 请打开文法文件！);elseDNF();list.get(1).setNextState(接受态);for(int k = 0 ; k +grammer0.substring(0, 1);flagnum1 = createI(start);/初态集建立locationnum1 = getleng(cachenum1);while(back = num1)if(c locationback & flagback = 0)num1+;list.get(back).setNextState(list.get(back).getNextState()+S+num1+ );flagnum1 = createI(cachebackc);locationnum1 = getleng(cachenum1);c+;elseback+;c = 0;public int createI(String t)/生成状态集int end = 0;String s = addPoint(t);String head = findNext(s);String state = S+num1;String nextsign=;String nextstate=;boolean gra = new booleancount;int c = 1;int loop = 0;for(int k = 0 ; cachek0 != null; k+)if(cachek0.equals(s)loop = k;end = 2;break;if(end = 2)/更改后继状态String old = list.get(back).getNextState();String sta = S+num1;String renew = ;int staleng = sta.length(); for(int k = 0 ; k old.length()-staleng+1; k+ )if(old.substring(k,k+staleng).matches(sta)|old.equals(归约)num1-;renew = old.substring(0,k-1)+S+loop+old.substring(k+staleng+1, old.length()+ ;list.get(back).setNextState(renew);break;else if(old.equals(归约)num1-;renew = old.substring(0,k-1)+S+loop+old.substring(k+staleng+1, old.length()+ ;list.get(back).setNextState(renew);break;return end;cachenum10 = s;String set = cachenum10 + ;if(num1 list.size()nextsign=list.get(num1).getNextSign();nextstate=list.get(num1).getNextState();set = list.get(num1).getProjectSet()+cachenum10 + ;if(findNext(s).equals(#)set = s;nextsign = #;nextstate = 归约;ViablePrefixe o = new ViablePrefixe(state,set,nextsign,nextstate);list.add(o);return 1;elsewhile(true)int i = 0;for(; i = count & head.equals(findNext(s).substring(0,1) break;else if(i = count)head = grammer0.substring(0,1);/while循环结束int cc = 0; /设置下一状态的值String nextS = new String50;for(int i = 0 ; cachenum1i!=null; i+)int j = 0;boolean f = false;for(; nextSj!=null;j+)if(findNext(cachenum1i).equals(nextSj)f = true; break;/for j 的循环结束,查找有无相同的后继符号，f作为标记，相同的符号跳过，不同的记录下来,放在nestS里if(f != true)nextScc+ = findNext(cachenum1j);nextsign = nextsign+findNext(cachenum1j)+ ;/for i 循环结束ViablePrefixe o = new ViablePrefixe(state,set,nextsign,nextstate);list.add(o);return end;public int show(String s, String grammer)/文法的拆分函数，显示在界面上，返回值是文法的条数boolean lastSign = false;/上一符号为nint flag1 = 0;/上一符号位置int count = 0;String str = s.substring(flag1, flag1+3);for(int i = 0 ; i s.length() ; i+)if(s.substring(i, i+1).equals(|)if(lastSign)grammercount+ = str + s.substring(flag1, i);elsegrammercount+ = s.substring(flag1, i);flag1 = i + 1;lastSign = true;else if(s.substring(i, i+1).equals(n)if(lastSign)grammercount+ = str + s.substring(flag1, i);elsegrammercount+ = s.substring(flag1, i);flag1 = i+1;if(flag1+3 s.length()str = s.substring(flag1, flag1+3);lastSign = false;else if(s.substring(i, i+1).equals(r)if(lastSign)grammercount+ = str + s.substring(flag1, i);elsegrammercount+ = s.substring(flag1, i);i+;flag1 = i+1;if(flag1+3 s.length()str = s.substring(flag1, flag1+3);lastSign = false;return count;private void open()/打开文件String s =;if(jfc.showOpenDialog(this) = JFileChooser.APPROVE_OPTION)s = open(jfc.getSelectedFile();count = show(s,grammer);for(int i = 0 ; grammeri!=null ; i+)jta1.append(grammeri);jta1.append(n);private String open(File file)/打开文件String content1 = ;tryBufferedInputStream in = new BufferedInputStream(new FileInputStream(file);byte b = new bytein.available();in.read(b,0,b.length);content1 = new String(b,0,b.length);in.close();catch(IOException ex)jta1.setText(Error opening + file.getName();return content1;private static String addPoint(String m)/在文法中添加.String t=;int i;for(i = 0 ; i m.length()-1)t = m.substring(0,3)+.+m.substring(3,m.length();return t;private static String findNext(String m)/返回.后的字母String c = #;for(int i = 0 ; i m.length()-1 ; i+)if(m.substring(i,i+1).equals(.)c = m.substring(i+1,i+2);return c;ViablePrefixe.javapackage analysis;public class ViablePrefixe /活前缀类private String state = ;/状态private String projectSet = ;/项目private String nextSign = ;/后继符号private String nextState = ;/后继状态public ViablePrefixe(String state,String projectSet,String nextSign,String nextState)this.state = state;jectSet = projectSet;this.nextSign = nextSign;this.nextState = nextState;public ViablePrefixe(String state,String projectSet,String nextSign)this.state = state;jectSet = projectS