只是为了好玩(谁知道我以后可能会使用它),我用c ++写了一个配置文件解析器。它似乎并不困难,在我写作的时候看不出任何问题。但是,当我测试它时,配置解析器没有捕获任何东西。我已经完成了三次代码。有人能告诉我这个问题吗?
#include <istream> // for std::basic_stream<char> (aka std::string)
#include <string> // for std::basic_string<char> (aka std::string)
#include <map> // for std::map<t, t>
#include <cctype> // for character type testing, c style
std::map<std::string, std::string> configParser(std::istream &stream, const char &comment, const char &seperator) {
std::map<std::string, std::string> options; // to hold key, value pairs
std::string key, value; // so options[key] = value
bool seperatorFound; // for differentiating between key and value
while(stream) { // operate on the stream while its good
char current = stream.get(); // current will hold the next character returned from the stream
if(current == '\n') { // current is a newline
options[key] = value; // add the key, value pair as an option found
key = ""; // reset key
value = ""; // reset value
seperatorFound = false; // reset seperatorFound
continue; // jump back up to the top
}
else if(isspace(current)) { // current is one of: \r, \t, [SPACE]
continue; // eat the white space and jump back up to the top
}
else if(current == comment) { // current is a comment marker
getline(stream, key, '\n'); // eat the rest of the line. i use key since its alreay there
// no since in creating a string object to eat a line
key = ""; // reset key
continue; // jump back up to the top
}
else if(current == seperator) { // current is a seperator marker
seperatorFound = true; // update the seperator state
continue; // jump back up to the top
}
else { // current must be a symbol
if(!seperatorFound) { // haven't found the seperator yet. as a result, must be a key
key += current; // give key the next letter
continue; // jump back up to the top
}
// otherwise, it must be a value
value += current; // give value the next letter instead.
}
}
return options;
}
#include <iostream>
#include <sstream>
int main() {
std::map<std::string, std::string> options;
std::string line;
while(true) {
getline(std::cin, line);
std::istringstream stream(line);
options = configParser(stream, '#', ':');
for(auto iterator = options.begin(); iterator != options.end(); iterator++) {
std::cout<< iterator->first <<" : "<< iterator->second << std::endl;
}
std::cout<< std::endl << std::endl;
}
}
答案 0 :(得分:2)
你的解析器大多数都有效,但包装器没有。 getline不会捕获'\ n',并且您的解析器不会从没有'\ n'的行中捕获结果。
将您的main()简化为:
int main() {
std::map<std::string, std::string> options;
std::string line;
options = configParser(std::cin, '#', ':');
for(auto iterator = options.begin(); iterator != options.end(); iterator++) {
std::cout<< iterator->first <<" : "<< iterator->second << std::endl;
}
std::cout<< std::endl << std::endl;
}
它主要起作用。
答案 1 :(得分:1)
问题1:您的line
实际上并不包含换行符,因为getline
会丢弃它。可能的解决方案是:std::istringstream stream(line + '\n');
问题2: seperatorFound
未初始化。它应该初始化为false。
问题3:您应该在获得角色后检查流是否正常。也就是说,你应该这样做:
while(true) {
char current = stream.get();
if (!stream) break;