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正如在主題中所述,我很難得到一個基本的文本處理器來編譯。以下代碼在基本部分中起作用。這意味着。當find_text()和match()函數被排除時,它將獲取一個文本文件並將其讀入一個Document類並使用print()輸出它。但是,當我包含上面提到的功能,並嘗試編譯它給出了大量的錯誤信息。在C++中獲取基本的文本處理器來編譯
此代碼來自Stroustrup「Programming:practice and principles using C++」第20章。在練習中,我應該獲取示例代碼部分以運行並繼續編寫match()函數。任何人都可以指出代碼中的錯誤?我正在使用Visual Studio 2013和2013年11月的CTP編譯器。是
#include <algorithm>
#include <string>
#include <vector>
#include <iostream>
#include<fstream>
#include<sstream>
#include <list>
using namespace std;
using Line = vector<char>; // a line is a vector of characters
//....................TEXT ITERATOR CLASS......................
class Text_iterator { // keep track of line and character position within a line
list<Line>::iterator ln;
Line::iterator pos;
public:
// start the iterator at line ll’s character position pp:
Text_iterator(list<Line>::iterator ll, Line::iterator pp)
:ln { ll }, pos { pp } { }
char& operator*() { return *pos; }
Text_iterator& operator++();
bool operator==(const Text_iterator& other) const {
return ln == other.ln && pos == other.pos;
}
bool operator!=(const Text_iterator& other) const {
return !(*this == other);
}
};
Text_iterator& Text_iterator::operator++() {
++pos; // proceed to next character
if (pos == (*ln).end()) {
++ln; // proceed to next line
pos = (*ln).begin(); // bad if ln==line.end(); so make sure it isn’t
}
return *this;
}
//....................DOCUMENT CLASS......................
struct Document {
list<Line> line; //doucument is a list of lines
Document() { line.push_back(Line { }); }
Text_iterator begin() // first character of first line
{
return Text_iterator(line.begin(), (*line.begin()).begin());
}
Text_iterator end() // one beyond the last character of the last line
{
auto last = line.end();
--last; // we know that the document is not empty
return Text_iterator(last, (*last).end());
}
};
istream& operator>>(istream& is, Document& d) {
for (char ch; is.get(ch);) {
d.line.back().push_back(ch); // add the character
if (ch == '\n')
d.line.push_back(Line { }); // add another line
}
if (d.line.back().size()) d.line.push_back(Line { }); // add final empty line
return is;
}
//....................HELPER FUNCTIONS......................
void erase_line(Document& d, int n) {
if (n < 0 || d.line.size() - 1 <= n) return;
auto p = d.line.begin();
advance(p, n);
d.line.erase(p);
}
void print(Document& d) {
for (auto p : d) cout << p;
// int the book sample code is different: "cout<<*p"` but the book code gives error of illegal transition. This would also need a comment
}
/*
bool match(Text_iterator first, Text_iterator last, const string& s) {
for (int i = 0; i < s.size(); ++i) {
if (*first == s[i]);
if (*first != s[i])return false;
}
return true;
}
Text_iterator find_txt(Text_iterator first, Text_iterator last, const string& s) {
if (s.size() == 0) return last; // can’t find an empty string
char first_char = s[0];
while (true) {
auto p = find(first, last, first_char);
if (p == last || match(p, last, s)) return p;
first = ++p; // look at the next character
}
}
*/
int main() {
string filename1 = "myDoc.txt";
ifstream stream { filename1 };
Document text1;
stream >> text1;
print(text1);
char ch; cin >> ch;
}
我得到的錯誤如下:
Error 6 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 371 1 text processing proov
Error 11 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 372 1 text processing proov
Error 16 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 373 1 text processing proov
Error 21 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 375 1 text processing proov
Error 26 error C4430: missing type specifier - int assumed. Note: C++ does not support default-int c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 376 1 text processing proov
Error 13 error C2868: 'std::iterator_traits<_InIt>::value_type' : illegal syntax for using-declaration; expected qualified-name c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 372 1 text processing proov
Error 28 error C2868: 'std::iterator_traits<_InIt>::reference' : illegal syntax for using-declaration; expected qualified-name c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 376 1 text processing proov
Error 23 error C2868: 'std::iterator_traits<_InIt>::pointer' : illegal syntax for using-declaration; expected qualified-name c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 375 1 text processing proov
Error 8 error C2868: 'std::iterator_traits<_InIt>::iterator_category' : illegal syntax for using-declaration; expected qualified-name c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 371 1 text processing proov
Error 18 error C2868: 'std::iterator_traits<_InIt>::difference_type' : illegal syntax for using-declaration; expected qualified-name c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 373 1 text processing proov
Error 29 error C2665: 'std::_Debug_range2' : none of the 2 overloads could convert all the argument types c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 584 1 text processing proov
Error 12 error C2602: 'std::iterator_traits<_InIt>::value_type' is not a member of a base class of 'std::iterator_traits<_InIt>' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 372 1 text processing proov
Error 27 error C2602: 'std::iterator_traits<_InIt>::reference' is not a member of a base class of 'std::iterator_traits<_InIt>' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 376 1 text processing proov
Error 22 error C2602: 'std::iterator_traits<_InIt>::pointer' is not a member of a base class of 'std::iterator_traits<_InIt>' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 375 1 text processing proov
Error 7 error C2602: 'std::iterator_traits<_InIt>::iterator_category' is not a member of a base class of 'std::iterator_traits<_InIt>' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 371 1 text processing proov
Error 17 error C2602: 'std::iterator_traits<_InIt>::difference_type' is not a member of a base class of 'std::iterator_traits<_InIt>' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 373 1 text processing proov
Error 10 error C2146: syntax error : missing ';' before identifier 'value_type' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 372 1 text processing proov
Error 25 error C2146: syntax error : missing ';' before identifier 'reference' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 376 1 text processing proov
Error 20 error C2146: syntax error : missing ';' before identifier 'pointer' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 375 1 text processing proov
Error 5 error C2146: syntax error : missing ';' before identifier 'iterator_category' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 371 1 text processing proov
Error 15 error C2146: syntax error : missing ';' before identifier 'difference_type' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 373 1 text processing proov
Error 9 error C2039: 'value_type' : is not a member of 'Text_iterator' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 372 1 text processing proov
Error 24 error C2039: 'reference' : is not a member of 'Text_iterator' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 376 1 text processing proov
Error 19 error C2039: 'pointer' : is not a member of 'Text_iterator' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 375 1 text processing proov
Error 4 error C2039: 'iterator_category' : is not a member of 'Text_iterator' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 371 1 text processing proov
Error 14 error C2039: 'difference_type' : is not a member of 'Text_iterator' c:\program files (x86)\microsoft visual studio 12.0\vc\include\xutility 373 1 text processing proov
謝謝你現在的作品,我可以繼續寫功能。據我所知,問題是在Text_iterator類的聲明語法中,而不是該類不符合要求。我複製了這本書的內容,並假定他們未經修改就開始工作,並假定我在其他地方犯了一個錯誤。仍然存在一個問題。如果我使用print()函數的書中的代碼,我會得到非法的間接錯誤。如果刪除解引用操作符,代碼將起作用。那裏有什麼問題。 – fredric