文本查询程序

重写TextQuery和QueryResult类，用StrBlob代替vector<string>保存输入文件：

我为StrBlobPtr重载了一个deref成员函数：

string& StrBlobPtr::deref(int num) const{std::shared_ptr<vector<string>> p = check(curr + num, "dereference past end!");return (*p)[curr + num];}

头文件：

#ifndef HEAD_H#define HEAD_H#include <iostream>#include <vector>#include <map>#include <string>#include <fstream>#include <sstream>#include <set>#include <initializer_list>#include <memory>using std::cout;using std::cin;using std::endl;using std::ends;using std::string;using std::vector;using std::map;using std::set;#endif

StrBlob类：

#ifndef STRBLOB_H#define STRBLOB_H#include "Head.h"#include "Head.h"#include "StrBlobPtr.h"class Strblob{friend class StrBlobPtr;/*friend StrBlobPtr::StrBlobPtr(Strblob &a, size_t i);friend std::shared_ptr<vector<string>> StrBlobPtr::check(size_t, const string&) const;*/public:typedef vector<string>::size_type size_type;Strblob();Strblob(std::initializer_list<string> li);size_type size() const { return data->size(); }bool empty() const { return data->empty(); }void push_back(string val) { data->push_back(val); }void pop_back();const string& back() const;string& back();const string& front() const;string& front();StrBlobPtr begin();StrBlobPtr end();private:std::shared_ptr<vector<string>> data;void check(const size_type&, const string&) const;};#endif

#include "Strblob.h"#include "StrBlobPtr.h"Strblob::Strblob() : data(std::make_shared<vector<string>>()) {}Strblob::Strblob(std::initializer_list<string> il) :data(std::make_shared<vector<string>>(il)) {}void Strblob::pop_back(){check(0, "Strblob is empty!");data->pop_back();}string& Strblob::front(){check(0, "Strblob is empty!");return data->front();}const string& Strblob::front() const{check(0, "Strblob is empty!");return data->front();}string& Strblob::back(){check(0, "Strblob is empty!");return data->back();}const string& Strblob::back() const{check(0, "Strblob is empty!");return data->back();}void Strblob::check(const size_type &i, const string &msg) const{if (i < data->size())throw std::out_of_range(msg);}StrBlobPtr Strblob::begin(){return StrBlobPtr(*this);}StrBlobPtr Strblob::end(){auto ret = StrBlobPtr(*this, data->size());return ret;}

StrBlobPtr类：

#ifndef StrBlobPtr_h#define StrBlobPtr_h#include "Head.h"class Strblob;class StrBlobPtr{public:StrBlobPtr();StrBlobPtr(Strblob &a, size_t i = 0);StrBlobPtr(const Strblob &a, size_t sz = 0);string& deref() const;string& deref(int) const;StrBlobPtr& incr();private:std::shared_ptr<vector<string>> check(size_t, const string&) const;std::shared_ptr<vector<string>> check2(size_t, const string&) const;std::weak_ptr<vector<string>> wptr;//保存一个weak_ptr。std::weak_ptr<vector<string>> wptrr;std::size_t curr;//当前位置};#endif

#include "Strblob.h"#include "StrBlobPtr.h"StrBlobPtr::StrBlobPtr() : curr(0) {}StrBlobPtr::StrBlobPtr(Strblob &a, size_t i) :wptr(a.data), curr(i) {}StrBlobPtr::StrBlobPtr(const Strblob &a, size_t sz) : wptrr(a.data), curr(sz) {}std::shared_ptr<vector<string>> StrBlobPtr::check(size_t sz, const string &msg) const{auto p = wptr.lock();if (!p){p = check2(sz, msg);if (p) return p;throw std::runtime_error(msg);}else if (sz >= p->size())throw std::out_of_range(msg);return p;}string& StrBlobPtr::deref() const{std::shared_ptr<vector<string>> p = check(curr, "dereference past end!");return (*p)[curr];}string& StrBlobPtr::deref(int num) const{std::shared_ptr<vector<string>> p = check(curr + num, "dereference past end!");return (*p)[curr + num];}StrBlobPtr& StrBlobPtr::incr(){auto p = check(curr, "increment past end of StrBlobPtr!");++curr;return *this;}std::shared_ptr<vector<string>> StrBlobPtr::check2(size_t sz, const string &msg) const{auto p = wptrr.lock();if (!p)throw std::runtime_error(msg);else if (sz >= p->size())throw std::out_of_range(msg);return p;}

TextQuery类：

#ifndef TEXTQUERY_H#define TEXTQUERY_H#include "Head.h"#include "Strblob.h"class QueryResult;class TextQuery{public:TextQuery() = default;TextQuery(const std::initializer_list<std::string> &il) :ifile(il) {}TextQuery(std::ifstream &);QueryResult query(const std::string &) const;private:Strblob ifile;std::map<std::string, std::shared_ptr<set<size_t>>> iresult;};#endif

#include "TextQuery.h"#include "QueryResult.h"TextQuery::TextQuery(std::ifstream &is){//以文本流的形式构造vectorstd::string s;while (getline(is, s)){ifile.push_back(s);//没有为ifile分配内存int n = ifile.size() - 1;std::istringstream iss;iss.str(s);string word;while (iss >> word){auto &p = iresult[word];if (!p)iresult[word].reset(new set<size_t>);iresult[word]->insert(n);iresult[word]->insert(n);}}}QueryResult TextQuery::query(const std::string &ele) const{std::shared_ptr<set<size_t>> p(new set<size_t>);auto iter = iresult.find(ele);if (iter == iresult.end())return QueryResult(ele, ifile, p);elsereturn QueryResult(ele, ifile, iter->second);}

StrBlobPtr类：

#include "TextQuery.h"#include "QueryResult.h"TextQuery::TextQuery(std::ifstream &is){//以文本流的形式构造vectorstd::string s;while (getline(is, s)){ifile.push_back(s);//没有为ifile分配内存int n = ifile.size() - 1;std::istringstream iss;iss.str(s);string word;while (iss >> word){auto &p = iresult[word];if (!p)iresult[word].reset(new set<size_t>);iresult[word]->insert(n);iresult[word]->insert(n);}}}QueryResult TextQuery::query(const std::string &ele) const{std::shared_ptr<set<size_t>> p(new set<size_t>);auto iter = iresult.find(ele);if (iter == iresult.end())return QueryResult(ele, ifile, p);elsereturn QueryResult(ele, ifile, iter->second);}

#include "Strblob.h"#include "StrBlobPtr.h"StrBlobPtr::StrBlobPtr() : curr(0) {}StrBlobPtr::StrBlobPtr(Strblob &a, size_t i) :wptr(a.data), curr(i) {}StrBlobPtr::StrBlobPtr(const Strblob &a, size_t sz) : wptrr(a.data), curr(sz) {}std::shared_ptr<vector<string>> StrBlobPtr::check(size_t sz, const string &msg) const{auto p = wptr.lock();if (!p){p = check2(sz, msg);if (p) return p;throw std::runtime_error(msg);}else if (sz >= p->size())throw std::out_of_range(msg);return p;}string& StrBlobPtr::deref() const{std::shared_ptr<vector<string>> p = check(curr, "dereference past end!");return (*p)[curr];}string& StrBlobPtr::deref(int num) const{std::shared_ptr<vector<string>> p = check(curr + num, "dereference past end!");return (*p)[curr + num];}StrBlobPtr& StrBlobPtr::incr(){auto p = check(curr, "increment past end of StrBlobPtr!");++curr;return *this;}std::shared_ptr<vector<string>> StrBlobPtr::check2(size_t sz, const string &msg) const{auto p = wptrr.lock();if (!p)throw std::runtime_error(msg);else if (sz >= p->size())throw std::out_of_range(msg);return p;}

runQueries函数

#include "Head.h"#include "TextQuery.h"#include "QueryResult.h"void runQueries(std::ifstream &inifile){TextQuery tq(inifile);while (true){cout << "enter word to look for,or q to quit: " << endl;std::string s;if (!(cin >> s) || s == "q")break;print(cout, tq.query(s)) << endl;}}

主函数：

#include "Head.h"void runQueries(std::ifstream &inifile);int main(){std::ifstream is("f://gao.txt");runQueries(is);return 0;}