cmm.java

使用JAVA写的CMM语言的解释器(词法分析部分)

                      ID.offer("Com");
                         output.append("\n"+"特殊符号： /");
                         state =done;
                     }else{
                       char b = getNext();
                       if(b=='*'){ 
                          state=note;
                          goon=true;
                          state =note;
                       }else{
                           output.append("\n"+"特殊符号： /");
                           tokens.offer(a);
                      ID.offer("Com");
                           state =done;
                           backup();
                       }  
                     }
                   }else if (a=='='){
                            if(!finish){
                      char b = getNext();
                   if(b=='='){
                      
                      tokens.offer("==");
                      ID.offer("FZ");
                   output.append("\n"+"特殊符号： ==");
                   state=done;
                   }else{
                         
                      tokens.offer(a);
                      ID.offer("Com");
                         output.append("\n"+"特殊符号： =");
                         state=done;
                   backup();
                   }
                     }else{
                                tokens.offer(a);
                      ID.offer("Com");
                output.append("\n"+"特殊符号： =");
                         state=done;
                     }                                   
                   }else if (Character.isDigit(a)){
                       if(finish){
                           tokens.offer(a);
                           ID.offer("Com");
                           output.append("\n"+"num： "+a);
                           state=done;
                       }
                       else
                   state = num;
                   }else if(a=='<'){
                          if(!finish){
                            char b = getNext();
                   if(b=='>'){
                                tokens.offer("<>");
                      ID.offer("PD");
                   output.append("\n"+"特殊符号： <>");
                   state=done;
                   }else{
                                tokens.offer(a);
                      ID.offer("PD");
                         output.append("\n"+"特殊符号： <");
                         state=done;
                   backup();
                   }
                     }else{
                              tokens.offer(a);
                      ID.offer("PD");
                 output.append("\n"+"特殊符号： <");
                         state=done;
                     }                                    
                   }else if(Character.isLetter(a)){
                     if(!finish){
                     state=id;
                     }else{
                      tokens.offer(a);
                      ID.offer("ID");
                     output.append("\n"+"标示符： "+a);
                     state=done;
                     }
                   }else{
                      errorA= true;
                    output.append("\n"+"错误  未知符号："+a);
                         state=done;                   
                   }
                   break;
               case 1:
                    break;
               case 2:
                    if(a=='*'&&finish==false){
                        char b = getNext();
                        if(b=='/'){                        
                        state=done;
                        output.append("\n"+"注释");
                        }         
                        break;
                   }else if (a=='*'&&finish==true){
                        errorA=true;
                   state =done;
                   output.append("\n"+"错误：注释缺少*/");                  
                   }else if(finish){
                        errorA=true;
                    state =done;
                    output.append("\n"+"错误：注释缺少*/");
                   }else if(a=='\n')
                   {
                         tokens.offer(a);
                         ID.offer("FG");
                               col++;  
                               output.append("\n"+"第"+col+"行："+line[col-1]);                   
                     
                      
                   }
                   break;
               case 3:
                    break;
               case 4:
                   if (a==' '||a=='\n'||a=='+'||a=='-'||a=='*'||a=='/'||a=='('||a==')'||a==';'||a=='='||a=='<'||a=='{'||a=='}'||a=='['||a==']'||a=='\r'){
                     backup();
                     end=pos;
                     currentToken=inPut.substring(begin,end);
                     errorA=true;
                     output.append("\n"+"错误： 非法符号"+currentToken);
                     state=done;
                      if(a=='\r'||a=='\n')
                            pos++ ;                   
                    }else if(finish){
                        end=pos;
                        currentToken=inPut.substring(begin,end);
                        errorA=true;
                        output.append("\n"+"错误： 非法符号"+currentToken);
                        state=done;
                    }
                    break;
               case 5:                   
                   if(Character.isDigit(a)&&finish==false){                   
                   }else{
                       if (a==' '||a=='\n'||a=='+'||a=='-'||a=='*'||a=='/'||a=='('||a==')'||a==';'||a=='='||a=='<'||a=='{'||a=='}'||a=='['||a==']'||a=='\r'){
                        backup(); 
                        end=pos;
                        currentToken=inPut.substring(begin,end);
                        if(currentToken.endsWith(".")){
                        currentToken=inPut.substring(begin,end-1);
                        backup();
                        }
                        tokens.offer(currentToken);
                         ID.offer("DIG");
                        output.append("\n"+"num:  "+currentToken);
                         state=done;
                         
                       }else if (Character.isDigit(a)&&finish==true){                       
                        end=pos;                        
                        currentToken=inPut.substring(begin,end);
                        tokens.offer(currentToken);
                         ID.offer("DIG");
                        output.append("\n"+"num:  "+currentToken);
                        state=done;
                       }
                       else if(a=='.'){                       
                           if(!decimal&&!finish){                           
                           decimal=true;
                           }
                           else if(decimal){                                
                              end=pos-1;                     
                               currentToken=inPut.substring(begin,end);
                               tokens.offer(currentToken);
                         ID.offer("DIG");
                           output.append("\n"+"num:  "+currentToken);
                           backup();
                           state = done;
                           }  if(!decimal&&finish){
                           end=pos;
                           currentToken=inPut.substring(begin,end-1);
                           backup();
                           tokens.offer(currentToken);
                         ID.offer("DIG");
                            output.append("\n"+"num:  "+currentToken);
                             state = done;
                             finish=false;
                           }                                                          
                       }else{
                           if(finish){
                            end=pos;
                        currentToken=inPut.substring(begin,end);
                        errorA =true;
                        output.append("\n"+"错误： 非法符号"+currentToken);
                        state=done;
                           }else{
                           state=error;
                           }
                       }                                                                                       
                   }                                                                                                               
                    break;
               case 6:
                
                   if(Character.isLetter(a)||a=='_'||Character.isDigit(a)){
                       if(finish){
                           end=pos;
                           currentToken=inPut.substring(begin,end);
                           if(currentToken.endsWith("_")){
                               errorA = true;
                             output.append("\n"+"非法标示符（不能以_结尾）:  "+currentToken);
                             state = done;                            
                           }else{                          
                           isKW(currentToken);
                           state = done;
                           }
                       }
                   }  else if (a==' '||a=='\n'||a=='+'||a=='-'||a=='*'||a=='/'||a=='('||a==')'||a==';'||a=='='||a=='<'||a=='{'||a=='}'||a=='['||a==']'||a=='\r'){
                        
                        backup();                                                   
                        end=pos;
                        currentToken=inPut.substring(begin,end);
                        if(currentToken.endsWith("_")){
                            errorA = true;
                             output.append("\n"+"非法标示符（不能以_结尾）:  "+currentToken);
                             state = done;                               
                           }else{            
                           
                           isKW(currentToken);
                           state = done;
                           }                      
                  }else{
                  state=error;                 
                  }
                    break;
               case 7:
                    break;          
           }     
    }            
    }   
    
  
    public static void main(String[] args) {
        new Cmm();
    }
    public void actionPerformed(ActionEvent e) {
        if(e.getActionCommand()=="open"){            
        int returnVal = fileChooser.showOpenDialog(this);
			if (returnVal == JFileChooser.APPROVE_OPTION) {
				File file = fileChooser.getSelectedFile();
				try {
					BufferedReader bufferedreader = new BufferedReader(
							new FileReader(file));                                    
                                        String s1= bufferedreader.readLine();
					for (String s2 = bufferedreader.readLine(); s2 != null; s2 = bufferedreader
							.readLine()) {
						s1=s1+"\n"+s2;
					}
                                         input.setText(s1);
                                         output.setText("");					
				} catch (FileNotFoundException abc) {
                                   output.setText("文件不存在");
				} catch (IOException io) {
                                     output.setText("文件格式错误");
				}				
			} else {
			}
    }else if (e.getActionCommand()=="clean"){
    input.setText("");
    output.setText("");    
    }else if (e.getActionCommand()=="analyse"){
            errorA = false;
            read();
    }
    }
}