循环外的语句重复 c++

问：

我尝试从用户的输入中读取令牌，就像编译器一样。 标记化工作正常，但是在输出所有令牌时，我想在它们全部发出后换行。

这是我的代码：

#include <iostream>
#include <map>
#include <vector>
//import for using std::getline()
#include <string>

//DIGITs
const std::string DIGITS = "0123456789";
const std::string WHITESPACE = " \t\n\r";

//TOKENS
const std::string TT_INT = "INT";
const std::string TT_FLOAT = "FLOAT";
const std::string TT_PLUS = "PLUS";
const std::string TT_MINUS = "MINUS";
const std::string TT_MUL = "MUL";
const std::string TT_DIV = "DIV";
const std::string TT_LPAREN = "LPAREN";
const std::string TT_RPAREN = "RPAREN";

const std::string TT_INVALID_NUMBER = "INVALID_NUMBER_LITERAL";

class Token{
    public: 
        std::string type;
        std::string value;
    
    void repr(){
        std::cout << type << ":" << "value" << "\n";
    }
};

class Lexer{
    public:
        std::string text;
        int position = -1;
        std::string current_char;
    
    void advance(){
        this->position += 1;
        this->current_char = this->text[this->position];
    }

    void make_digit(std::string *type, std::string *value){
        //if its number or floating point
        std::string digit = "";
        int is_float = 0;
        while(DIGITS.find(this->current_char) != std::string::npos || this->current_char == "."){
            digit += this->current_char;
            if(this->current_char == "."){
                is_float += 1;
            }
            this->advance();
        }
        *value = digit;
        if(is_float == 0){
            *type = TT_INT;
        } else if((0 < is_float) && (is_float < 2)){
            *type = TT_FLOAT;
        } else {
            *type = TT_INVALID_NUMBER;
        }
    }    

    std::vector<std::string> make_tokens(){
        std::vector<std::string> tokens;
        this->advance();

        while (!(this->text.length() <= this->position))
        {
            if(WHITESPACE.find(this->current_char) != std::string::npos){
                //dont add a token
                this->advance();
            } else if(DIGITS.find(this->current_char) != std::string::npos){
                std::string type;
                std::string value;
                this->make_digit(&type, &value);
                tokens.push_back(type);
                tokens.push_back(value);
            } else if(this->current_char == "+"){
                tokens.push_back(TT_PLUS);
                tokens.push_back(this->current_char);
                this->advance();
            } else if(this->current_char == "-"){
                tokens.push_back(TT_MINUS);
                tokens.push_back(this->current_char);
                this->advance();
            } else if(this->current_char == "*"){
                tokens.push_back(TT_MUL);
                tokens.push_back(this->current_char);
                this->advance();
            } else if(this->current_char == "/"){
                tokens.push_back(TT_DIV);
                tokens.push_back(this->current_char);
                this->advance();
            } else if(this->current_char == "("){
                tokens.push_back(TT_LPAREN);
                tokens.push_back(this->current_char);
                this->advance();
            } else if(this->current_char == ")"){
                tokens.push_back(TT_RPAREN);
                tokens.push_back(this->current_char);
                this->advance();
            } else {
                //nothing
                this->advance();
            }
        }             
        return tokens;  
    }

};

int main(){
    //previous: true
    while(std::getline(std::cin, input)){
        std::string input;
        //previous: std::cin >> input;
        //fix
        std::getline(std::cin, input);
        Lexer mylexer;
        mylexer.text = input;
        int x = 0;
        std::vector<std::string> output = mylexer.make_tokens();
        for (int i = 0; i < output.size(); i += 2){
            std::cout << output.at(i) << ":" << output.at(i + 1) << std::endl;
        }
        std::cout << "\n";
    }
};

输入 1 + 2 时

我的期望

1 + 2
INT:1
PLUS:+
INT:2

here is the cursor

我得到了什么

1 + 2
INT:1

PLUS:+

INT:2

here is the cursor

当删除末尾的换行符时，我得到了这个，但是当输入第二个输入行时，它全部在一起，没有空行，这不是我想要的

1 + 2
INT:1
PLUS:+
INT:2
here is the cursor

但我希望它看起来像这样

1 + 2
INT:1
PLUS:+
INT:2

3 + 4
INT:3
PLUS:+
INT:4

谁能解释一下这种奇怪的行为是什么？ 我错过了什么吗？请注意，我没有太多的C++经验。 我在Windows上使用clang-cl.exe进行编译。我也想知道使用 MSYS2 g++ 编译时throw_bad_array_new_lengthv错误是什么意思.exe