javascript - 如何读取Javascript文件(How to read a Javascript file)

Question

I have a file a /path/to/my_js_functions.js that contains a Javascript function my_js_functions() , amongst other functions.(我有一个/path/to/my_js_functions.js文件，其中包含Javascript函数my_js_functions（）和其他函数。)

How can I go about reading the function myJsFunction as a String in C++ ?(如何在C ++中将函数myJsFunction读取为字符串？) I am looking for a way to get the whole function and only that function, and then contain it in a char *jsFunction .(我正在寻找一种方法来获取整个函数和仅该函数，然后将其包含在char *jsFunction 。) function myJsFunction(stringParam) { return stringParam // The function returns a stringParam from the parameter } function anotherJsFunction(stringParam) { return stringParam // Another function } Thank you all in advance.(谢谢大家。)   ask by Program-Me-Rev translate from so

Answer 1

To do this you need to read your javascript code file and parse it.(为此，您需要阅读并解析JavaScript代码文件。)

It is highly to use some parser library to do that like cashew , esprima-cpp .(使用某些解析器库来完成诸如腰果 ， esprima-cpp之类的操作非常重要 。) I never used that before I never used any of this before, So I can't comment on that.(我以前从未使用过它，所以我无法对此发表评论。) But here is some quick code for parser.(但是这里有一些用于解析器的快速代码。) You can start with this build on this to make it more robust.(您可以从此基础上开始，使其更强大。) main.cpp(main.cpp) #include <fstream> #include <iostream> #include <streambuf> #include <string> #include <vector> std::string getFunction(const std::string &fileData, const std::string &name) { std::string ret; std::size_t start = 0; while (true) { const auto fNameStart = fileData.find(name, start); if (fNameStart != std::string::npos) { auto fStart = fileData.find_last_not_of(" ",fNameStart-1); if(fStart == std::string::npos){ ret = "No Function Defination"; break; } else { fStart = fStart-7; if(fileData.substr(fStart,8) == "function"){ int openBraceCount = 0, closeBraceCount = 0; std::size_t fEnd = fNameStart + name.size(); fEnd = fileData.find_first_of("{}", fEnd); while (fEnd != std::string::npos) { if (fileData.at(fEnd) == '{') { openBraceCount++; } else { closeBraceCount++; } if (openBraceCount == closeBraceCount) { ret = fileData.substr(fStart, fEnd - fStart+1); break; } fEnd++; fEnd = fileData.find_first_of("{}", fEnd); } if(!ret.empty()){ break; } else if(openBraceCount != closeBraceCount){ ret = "Function Parse Error"; break; } } else{ start = fNameStart + name.size(); } } } else { ret = "No Function Defination"; break; } } return ret; } int main(int argc, char **argv) { const std::string jsPath = "module.js"; const std::vector<std::string> vecFuncNames{"funcA", "funcB", "funcC", "funcD", "funcE"}; std::ifstream fs(jsPath); if (fs.is_open()) { std::string fileData((std::istreambuf_iterator<char>(fs)), std::istreambuf_iterator<char>()); for (auto &name : vecFuncNames) { std::cout << name << " " << getFunction(fileData, name) << std::endl; } } return 0; } module.js(module.js) function funcA ( ){ funcC(); console.log(" Hello");funcB(); }function funcC(){funcB();console.log("Hello");funcA();} function funcB(a, b, c){ funcA(); setTimeout(function(){ alert("Hello"); }, 3000);funcC(); } funcD(); function funcE(){{{{}}}