c ++：外部声明和填充地图 [英] c++: declaring and populating map externally
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问题描述
所以我一直在试图整理我的代码很多，并且想知道是否有办法声明我的地图，并将其填充在其他文件，甚至其他功能。
So i've been trying to tidy my code a lot and was wondering if there was a way to declare my map's and also populate them within other files, or even other functions.
这是我的代码到目前为止:(这使用内置的tokeniser，我没有代码，但基本上地图存储输入机器代码的二进制文件，并将根据输入输出指令和c指令）
Here is my code thus far: (this uses an inbuilt tokeniser which i dont have the code for, but basically the maps store the binary for the input machine-code, and will output a-instructions and c-instructions depending on the input)
代码：
//将Hack程序集转换为二进制
// convert Hack assembly into binary
#include <iostream>
#include "tokens.h"
#include <bitset>
#include <cctype>
#include <string>
#include <map>
using namespace std ;
bool isNumber(string s){
for (size_t n = 0; n < s.length(); n++){
if (!(isdigit(s[n]))){
return false;
} else {
return true;
}
}
}
int main(){
// Declaring lookup tables (want to make this global [seperate file])
std::map<std::string, std::string> compTable;
std::map<std::string, std::string> destTable;
std::map<std::string, std::string> jumpTable;
// Inserting table data (want to make this global [seperate file])
// Jump Table Data
jumpTable.insert(pair<string, string> ("NULL", "000"));
jumpTable.insert(pair<string, string> ("JGT", "001"));
jumpTable.insert(pair<string, string> ("JEQ", "010"));
jumpTable.insert(pair<string, string> ("JGE", "011"));
jumpTable.insert(pair<string, string> ("JLT", "100"));
jumpTable.insert(pair<string, string> ("JNE", "101"));
jumpTable.insert(pair<string, string> ("JLE", "110"));
jumpTable.insert(pair<string, string> ("JMP", "111"));
// Dest Table Data
destTable.insert(pair<string, string> ("NULL", "000"));
destTable.insert(pair<string, string> ("M", "001"));
destTable.insert(pair<string, string> ("D", "010"));
destTable.insert(pair<string, string> ("MD", "011"));
destTable.insert(pair<string, string> ("A", "100"));
destTable.insert(pair<string, string> ("AM", "101"));
destTable.insert(pair<string, string> ("AD", "110"));
destTable.insert(pair<string, string> ("AMD", "111"));
// Comp Table Data
// When a=1
compTable.insert(pair<string, string> ("0", "1110101010"));
compTable.insert(pair<string, string> ("1", "1110111111"));
compTable.insert(pair<string, string> ("-1", "1110111010"));
compTable.insert(pair<string, string> ("D", "1110001100"));
compTable.insert(pair<string, string> ("A", "1110110000"));
compTable.insert(pair<string, string> ("!D", "1110001101"));
compTable.insert(pair<string, string> ("!A", "1110110001"));
compTable.insert(pair<string, string> ("-D", "1110001111"));
compTable.insert(pair<string, string> ("-A", "1110110011"));
compTable.insert(pair<string, string> ("D+1", "1110011111"));
compTable.insert(pair<string, string> ("A+1", "1110110111"));
compTable.insert(pair<string, string> ("D-1", "1110001110"));
compTable.insert(pair<string, string> ("A-1", "1110110010"));
compTable.insert(pair<string, string> ("D+A", "1110000010"));
compTable.insert(pair<string, string> ("D-A", "1110010011"));
compTable.insert(pair<string, string> ("A-D", "1110000111"));
compTable.insert(pair<string, string> ("D&A", "1110000000"));
compTable.insert(pair<string, string> ("D|A", "1110010101"));
// when a=0
compTable.insert(pair<string, string> ("M", "1111110000"));
compTable.insert(pair<string, string> ("!M", "1111110001"));
compTable.insert(pair<string, string> ("-M", "1111110011"));
compTable.insert(pair<string, string> ("M+1", "1111110111"));
compTable.insert(pair<string, string> ("M-1", "1111110010"));
compTable.insert(pair<string, string> ("D+M", "1111000010"));
compTable.insert(pair<string, string> ("D-M", "1111010011"));
compTable.insert(pair<string, string> ("M-D", "1111000111"));
compTable.insert(pair<string, string> ("D&M", "1111000000"));
compTable.insert(pair<string, string> ("D|M", "1111010101"));
// Declaring Variables
string temp;
string tempValue;
int skipLine = 0;
int tokenCounter = 0;
// create a new assembler tokeniser then read the first token
tokens *tokeniser = new tokens(getchar) ;
std::string token = tokeniser->next_token() ;
while ( token != "?" ) // stop at EOF, "?" denotes EOF
{
if(tokenCounter > 0) {
cout << endl;
}
if(skipLine == 1) {
cout << endl;
}
skipLine = 0;
if(token == "address"){
string adrsStr = tokeniser->token_value();
if(isNumber(adrsStr)==true){
int adrs = stoi(adrsStr);
cout << bitset<16>(adrs);
}
}
if(token == "comp" || token == "dest" || token == "dest-comp?" || token == "null"){
tempValue = tokeniser->token_value();
temp = token;
token = tokeniser->next_token() ;
if(token == "equals"){
token = tokeniser->next_token() ;
if(temp == "null") {
std::cout << compTable.find(tokeniser->token_value())->second;
std::cout << destTable.find("NULL")->second;
std::cout << jumpTable.find("NULL")->second;
}else if(temp == "dest" || temp == "dest-comp?"){
if (token == "comp" || token == "dest-comp?"){
std::cout << compTable.find(tokeniser->token_value())->second;
std::cout << destTable.find(tempValue)->second;
std::cout << jumpTable.find("NULL")->second;
}
}
}else if(token == "semi") {
std::cout << compTable.find(tempValue)->second;
std::cout << destTable.find("NULL")->second;
token = tokeniser->next_token() ;
if (token == "jump"){
std::cout << jumpTable.find(tokeniser->token_value())->second;
} else if(token == "null") {
std::cout <<jumpTable.find("NULL")->second;
}
}else if (token != "equal" || token != "semi"){
std::cout << compTable.find(tempValue)->second;
std::cout << destTable.find("NULL")->second;
std::cout << jumpTable.find("NULL")->second;
if (token!= "semi" || token!="equals"){
skipLine=1;
continue;
}
}
}
tokenCounter++;
token = tokeniser->next_token() ;
}
cout << endl;
/*cout << jumpTable.find("NULL")->second << endl;
cout << compTable.find("A")->second << endl;
cout << destTable.find("A")->second << endl;*/
return 0 ;
}
地图的首选格式将包含一个create（）函数，它将用于在外部声明地图和一个insert（）函数来填充地图
The preferred format for the map would contain a create() function which will be used to declare the maps externally and an insert() function to populate the map
这是可能吗？
推荐答案
如何做老式的方式？通过使用 extern 并提供 main（）应该调用的函数，执行所有插入。
How about doing it the old fashioned way? By using extern and providing a function that main() should call, that performs all the insertions.
我写了一个例子，基于这个，你可以编写你的代码（我不能这样做，因为我没有你的标记头）。
I wrote an example, based on this, based on which you could write your code (that I am not able to do so because I don't have the token header of yours).
main.cpp
#include <iostream>
#include <map>
#include "myMap.h"
std::map<char,int> mymap;
int main ()
{
myMapInsertions(mymap);
std::cout << "mymap contains:\n";
for (std::map<char,int>::iterator it=mymap.begin(); it!=mymap.end(); ++it)
std::cout << it->first << " => " << it->second << '\n';
return 0;
}
myMap.h
#ifndef MYMAP_H_
#define MYMAP_H_
#include <map>
extern std::map<char,int> mymap;
void myMapInsertions(std::map<char,int>& mymap);
#endif // MYMAP_H_
myMap.cpp
myMap.cpp
#include "myMap.h"
void myMapInsertions(std::map<char,int>& mymap)
{
mymap.insert ( std::pair<char,int>('a',100) );
mymap.insert ( std::pair<char,int>('z',200) );
}
编译如下：
g ++-Wall main.cpp myMap.cpp -o main
g++ -Wall main.cpp myMap.cpp -o main
请阅读有关extern关键字的信息：什么时候在C ++中使用extern？ / a>？
Read about the extern keyword here: When to use extern in C++?
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