编译原理实验1

#include <iostream>
#include<string>
#include<fstream>
#include<iomanip>
#define _for(i, a, b) for(int i = a; i<b; i++)
using namespace std;
string kw[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 fj[8] = { ",", ";", "(", ")", "[", "]", "{", "}" };
string as[4] = {"+", "-", "*", "/"};
string rs[6] = {">", "<", ">=", "<=", "<>"};
int nm[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
char ch;

bool iskw(string s) {//是否为关键字
	_for(i, 0, 12) {
		if (s == kw[i])
			return true;
		}
	return false;
}
bool isfj(string s) {//是否为分界符
	_for(i, 0, 8) 
		if (s == fj[i])
			return true;
		return false;
}
bool isas(string s) {//是否为算术运算符
	_for(i, 0, 4) {
		if (s == as[i]) {
			return true;
		}
		return false;
	}
}
bool isrs(string s) {//是否为关系运算符
	_for(i, 0, 6) {
		if (s == rs[i]) {
			return true;
		}
		return false;
	}
}
bool isnum(char ch) {//是否为数字
		if (ch <= '9'&&ch >= '0')
			return true;
		else
			return false;
}
bool isle(char ch) {//是否为字母
	if ((ch <= 'z'&&ch >= 'a') || (ch <= 'Z'&&ch >= 'A'))
		return true;
	else
	return false;
}

void scanf(ifstream &in){
	int line = 0;
	int row = 1;
	string s = "";
	while (in.get(ch)) {//读取
		if (ch == '\n') {//换行则行加一
			row++;
			line = 0;
		}
		else if(ch == ' '){}
		else if (isle(ch)){//首字符为字母
			s = "";
			while (isle(ch) || isnum(ch)){//挨个读取字符赋给S
				s = s + ch;
				ch = in.get();
			}
			in.seekg(-1, ios::cur);
			if (iskw(s)){//如果为关键字输出
				line++;
				cout.setf(ios::right, ios::adjustfield);
				cout << s << "\t" << setw(20) << "(1," << s << ")" << "\t" << setw(12) << "关键字" << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
			else//为标识符
			{
				line++;
				cout.setf(ios::right, ios::adjustfield);
				cout << s << "\t" << setw(20) << "(2," << s << ")" << "\t"  << setw(20) << "标识符" << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
		}
		else if (isnum(ch)) {//首字符为数字
			string s = "";
			while (isnum(ch)){
				s = s + ch;
				ch = in.get();
			}
			line++;
			if (isle(ch)){//数字后面有字母则错误
				s += ch;
				cout << s << "\t" << setw(20) << "error" << "\t" << setw(20) << "error" ;
				cout << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
			else//否则为常数
			{
				in.seekg(-1, ios::cur);
				cout << s << "\t" << setw(20) <<"(6," << s << ")" << "\t" << setw(18);
				cout << "常数" << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
		}
		else {//首字符既不是字母也不是数字
			string s = "";
			s = s + ch;
			if (isas(s)) {
				line++;
				cout.setf(ios::right, ios::adjustfield);
				cout << s << "\t" << setw(20) << "(3," << s << ")" << "\t" << setw(24)<< "算术运算符" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
			else if (isfj(s)) {
				line++;
				cout << s << "\t" << setw(20) <<"(2," << s << ")" << "\t" << setw(20);
				cout << "分界符" << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
			else if (isrs(s)) {
				line++;
				switch (ch){
				case '=':
					ch = in.get();
					if (ch == '='){
						s += ch;
						cout << s << "\t" << setw(20) << "(4," << s << ")" << "\t" << setw(20);
						cout << "关系运算符" << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
					}
					else{
						cout << s << "\t" << setw(20) << "error" << "\t" << setw(20) << "error" ;
						cout << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
						in.seekg(-1, ios::cur);
					}
					break;
				case '<':
					ch = in.get();
					if (ch == '='){
						s += ch;
						cout << s << "\t" << setw(20) << "(4," << s << ")" << "\t" << setw(20);
						cout << "关系运算符" << "\t" << setw(20) << "(" << row << "," << line;
						cout << ")" << "\n";
					}
					else{
						cout << s << "\t" << setw(20) << "(4," << s << ")" << "\t" << setw(20);
						cout << "关系运算符" << "\t" << setw(20) << "(" << row << "," << line;
						cout << ")" << "\n";
						in.seekg(-1, ios::cur);
					}
					break;
				case '>':
					ch = in.get();
					if (ch == '='){
						s += ch;
						cout << s << "\t" << setw(20) << "(4," << s << ")" << "\t" << setw(20);
						cout <<"关系运算符" << "\t" << setw(20) << "(" << row << "," << line;
						cout << ")" << "\n";
					}
					else{
						cout << s << "\t" << setw(20) << "(4," << s << ")" << "\t" << setw(20) << ">" << "\t" << setw(20) << "(" << row << "," << line<< ")" << "\n";
						in.seekg(-1, ios::cur);
					}
					break;
				default:
					cout << s << "\t" << setw(20) << "error" << "\t" << setw(20) << "error" ;
					cout << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
				}
			}
			else{
				line++;
				cout << s << "\t" << setw(22) << "error" << "\t" << setw(19) << "error" ;
				cout << "\t" << setw(20) << "(" << row << "," << line << ")" << "\n";
			}
			}
			}
		}
int main(){
	ifstream in;
	in.open("./test.txt");
	scanf(in);
	in.close();
	getchar();
	return 0;
}