main.cpp

课程作业

#include <iostream>
#include <string>
#include <fstream>
#include <stdio.h>
  
  //define the ReservedWords total num.
  #define MAXRESERVED 10
  //define the specialSymbols total num
  #define MAXSPECIALSYMBOLS 24
  
  using namespace std;
  
  // define StateType,5 states.
  typedef enum {
  
  START,INCOMMENT,INNUM,INID,INCL,QUOTE,DONE
  } StateType;
  
  typedef enum {
      
      IF,ELSE,INT,RETURN,VOID,WHILE,USING, NAMESPACE, STD,COUT,/* reserved words */
     
      ID,NUM,PRECOMPILE,HEADFILE, QUOTATION,/* multicharacter tokens */
      
      PLUS,MINUS,MTPLUS,DEVIDE,EQ,ASSIGN,LT,MT,TIMES,LXKH,RXKH,LZKH,
	  RZKH,LDKH,RDKH,SEMI,LE,ME,NOTEQ,FH,LZS,RZS,ZS,RM,LM,QUOTES,/* special symbols */
	  
	  ENDFILE,UNKNOWN,ERROR/*stateToken */
  } TokenType;
  
  static struct {
	  char* str;
      TokenType tt;
  } specialSymbols[MAXSPECIALSYMBOLS] = { {"+",PLUS},{"-",MINUS},{"*",MTPLUS},{"/",DEVIDE},{"<",LT},{"<=",LE},{">",MT},
             {">=",ME},{"==",EQ},{"!=",NOTEQ},{"=",ASSIGN},{",",SEMI},{";",FH},{"(",LXKH},
  {")",RXKH},{"[",LZKH},{"]",RZKH},{"{",LDKH},{"}",RDKH},{"/*",LZS},{"*/",RZS},{"<<",LM},{">>",RM},{"\"",QUOTES}
             };
  static struct {
	  char* str;
      TokenType tt;
  } reservedWords[MAXRESERVED] = {{"if",IF},{"else",ELSE}, {"int",INT},
  {"return",RETURN},{"void",VOID},{"while",WHILE},{"cout",COUT},
  {"using",USING},{"namespace",NAMESPACE},{"std",STD}};
  
  //judge if is digit.
  bool isDigit(char c) {
  
  	string digit = "0123456789";
  
  	for(int i = 0;i < digit.size();i++) {
  
     	if(digit[i] == c) {
    
      	return true;
     }
  }
  
  return false;
  }
  
  //judge if is a letter.
  bool isLetter(char c) {
  
  string alpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
  
  for(int i = 0;i < alpha.size();i++) {
  
     if(alpha[i] == c) {
    
      return true;
     }
  } 
  
  return false;
  }
  
  //judge if is ReseredWords,if is return the reservedWords,if is not it is a ID.
  TokenType isReservedWords(string str) {
  	
  	for(int i = 0;i < MAXRESERVED;i++) { 
  		
  		if(str == reservedWords[i].str) {
    
      return reservedWords[i].tt;
     } 
  }
  
  return ID;
  }
  
  //output to the outf filestream.
  void outputFile(ofstream& outf,TokenType tt,string str) {
  
  	for(int i = 0;i < MAXRESERVED;i++) {
  
     	if(reservedWords[i].str == str) {
  
      	tt = reservedWords[i].tt;
      	outf << "ReservedWords: " << str<<endl;
     	}
  	}
  
  	for(int j=0;j<MAXSPECIALSYMBOLS;j++) {
  
     	if(specialSymbols[j].tt == tt) {
    
      	outf << "Special Symbol: " << str <<endl;
     	}
  	}
	if(tt == PRECOMPILE){
		outf << "PRECOMPILE: " << str << endl;
	}


	if(tt == HEADFILE){
		outf << "HEADFILE: " << str << endl;
	}
	if(tt == QUOTATION){
		outf << "QUOTATION: " << str << endl;
	}
  
  	if(tt == ZS) {
  
     	outf << "ZS: " << str << endl; 
  	}
  
  	if(tt == ID) {
  
     	outf<<"ID: "<< str <<endl;
  	}
  
  	if(tt == NUM) {
  
     	outf<<"NUM: "<< atoi(str.c_str()) <<endl;
  	}
  
  	if(tt == ERROR) {
  
     	outf << "ERROR: " << str << endl;
  	}
  
	  if(tt == UNKNOWN) {
	  
	     outf << "UNKNOWN Symbol: " << str << endl;
	  }
	 }
  
  // get the token,有穷自动机的实现
  void getToken(ifstream& inf,ofstream& outf,int& lineno) {
  
	  TokenType tt; 
	  StateType state = START; 
	  string str = "";
	  
	  static int flag = 1;
	  
	  while(state != DONE) {
	     
	     char c = inf.get(); 
	  
	     if(flag == 1) {
	    
	      outf << "-------------------------------------------" << endl;
	      outf << "In the line " << lineno << " : " <<endl;
	      flag = 0;   
	     }
	    
	     switch(state) {
	  
	      case START: if(isLetter(c)) {    
	         
	          state = INID;
	          str += c;
	         } 
			  else if(isDigit(c)) {    
	      
	          state = INNUM;
	          str += c;
	         } 
			 else if(c == '\t' || c == ' ') {
	         
	         } 
			 else if(c == '\n') {
	        
	          //output the line number
	          lineno = lineno + 1;
	          outf << "-------------------------------------------" << endl;
	          outf << "In the line " << lineno << " : " <<endl; 
	         } 
			 else if(c == '/' && inf.peek() == '*') {
	       
	          str = str + c;
	          c = inf.get();
	          str = str + c;       
	          state = INCOMMENT;
	         } 
			 else if(c== '#')
			 {
				 str += c;
				 state = INCL;
			 }
			 else if(c == '\"'){
				 tt = QUOTES;
				 str+=c;
				 outputFile(outf,tt,str);
				 str="";
				 state = QUOTE;
			 }
			 else {
	  
	          state = DONE;
	          str += c;
	          //judge is special symbols,if is not ,output UNKNOWN
	          switch(c) { 
			  case EOF: tt = ENDFILE;break;              
	          case '+': tt = PLUS;break; 
	          case '-': tt = MINUS;break;
	          case '*': tt = MTPLUS;break;
	          case '/': tt = DEVIDE;break;
	          case ';': tt = FH;break;
	          case '(': tt = LXKH;break;
	          case ')': tt = RXKH;break;
			  
	           case '=': //judge if is '=='
	                 if(inf.peek() == '=') {
	         
	              c = inf.get();
	              tt = EQ; 
	              str+=c;
	              //judge if is '='
	              } else {
	           
	               tt = ASSIGN;
	              } break;           
	           case '<': //judge if is '<='
	                 if(inf.peek() == '=') {
	  
	              c = inf.get();
	              tt = LE;str+=c;
	              //judge if is '<'
					 } else if(inf.peek() == '<'){
						 c = inf.get();
						 tt = LM;
						 str+=c;
					 }
					 else{
	              tt = LT;            
	              }break;
	           case '>': //judge if is '>='
	              if(inf.peek() == '=') {
	              
	              c = inf.get();
	              tt = ME;            
	              str+=c;
	              //judge if is '>'
	              } else if(inf.peek() == '>'){
						 c = inf.get();
						 tt = RM;
						 str+=c;
					 }
					 else{         
	              tt = MT;           
	              } break;
	           case ',': tt = SEMI;break;        
	           case '[': tt = LZKH;break;
	           case ']': tt = RXKH;break;
	           case '{': tt = LDKH;break;
	           case '}': tt = RDKH;break;
	           case '!': c = inf.get();            
	              if(c == '=') {
	               
	              tt = NOTEQ;
	              str+=c;            
	              } else { 
	               
	              inf.putback(c);
	              tt=UNKNOWN;                      
	              } break;
	           default: tt = UNKNOWN;break;
	          }
	         } break;       
	      case INCOMMENT: 
			  if(c=='\n')lineno=lineno+1;
	          if(c == '*' && inf.peek() == '/') { 
	           str = str + c;
	           c = inf.get();        
	           state = DONE;tt=ZS;       
	          } else if(inf.eof()) { 
	           tt = ERROR;
	           state = DONE;
	          } str = str + c;break;
	         
	      case INNUM: if(!isDigit(c)) {
	          
	          // if is letter,it is error
	          if(isLetter(c)) {
	          
	           str = str + c;
	  
	           if(inf.peek() == ' ' || inf.peek() == '\t' || inf.peek() == '\n') {
	          
	            tt = ERROR;state = DONE;
	            break; 
	           }
	          //else correct            
	          } else {
	          
	           inf.putback(c);
	           tt=NUM;
	           state = DONE;        
	          } 
	         
	          break;
	         } str += c;break;
	  
	      case INID: 
			  if(!isLetter(c)) 
			  {
	        
				//if is digit, it is error
				if(isDigit(c)) {
					str = str + c;
					if(inf.peek() == ' ' || inf.peek() == '\t' || inf.peek() == '\n') 
					{
						tt = ERROR;state = DONE;break; 
					}
				} 
				else 
				{
					inf.putback(c);
					tt=ID;state = DONE;
				}      
				break;
			  }
			  str += c;break;

		  case INCL:
			  if(isLetter(c))
			  {
				  str+=c;
				  break;
			  }
			  else{

				  if(str=="#include"){
					  tt = PRECOMPILE;
					  outputFile(outf,tt,str);

					  str="";
				  }
				  else if(str[0]=='#'){
					  tt=ERROR;
					  state = DONE;
					  break;
				  }
				  if(c==' ')
					  break;
				  if(c=='<'){
					  tt = LT;
					  outputFile(outf,tt,"<");
					  break;
				  }
				  if(c=='>'){
					  tt = HEADFILE;
					  outputFile(outf,tt,str);

					  str="";

					  tt = MT;
					  outputFile(outf,tt,">");
					  state=START;
					  break;
				  }
				  break;
					  
			  }
		  case QUOTE:
			  if(c=='\"'){
				  if(str==""){
					tt = QUOTES;
					  outputFile(outf,tt,"\"");
					  state=DONE;
					  break;
				  }
				  else if(str[str.size()-1]=='\\'){
					  str+=c;
					  break;
				  }
				  else{
					  tt = QUOTATION;
					  outputFile(outf,tt,str);
					  state=DONE;
					  break;
				  }
			  }
			  else{
				  str+=c;
				  break;
			  }

				
	  
	      case DONE:break;
	  
	      default:     
	       state = DONE;
	       tt = ERROR;
	       break;
	     }  
	  }
	  
	  // if is done output to the file the message.
	  if(state == DONE){
	  
	     outputFile(outf,tt,str);
	  }  
  }
  
  int main(int argc, char* argv[]) {
  
  char *filename = NULL;
  char *output = NULL;

  int include=3;
  
  //check the parameter needed.
  if ( argc == 2 )
       
     filename = argv[1];
      else {
       
     cerr << "Usage: " << argv[0] << " [-n] file" << endl;
          return EXIT_FAILURE;
      }
      
  ofstream outf("output.txt");
  ifstream inf(argv[1]);
  
  //if inf is error,output the error message.
  if ( !inf ) {
  
     cerr << "cannot open " << filename << " for input" << endl;
     return EXIT_FAILURE;
  }
  
  int lineno = 1;
  
  while(true){
  
     getToken(inf,outf,lineno);
  
     if(inf == NULL) {
  
      outf << "END OF FILE!" << endl;
      break;
     }
  }
  
  // file stream close
  inf.close();
  outf.close();
  return 0;
  }
  ///:~