<Query_base>(new AndQuery(lhs, rhs));
}
class OrQuery : public BinaryQuery{
friend Query operator|(const Query&, const Query&);
OrQuery(const Query& l, const Query& r)
: BinaryQuery(l, r, "|"){
std::cout << "OrQuery" << std::endl;
}
QueryResult eva l(const TextQuery&) const;
};
inline Query operator|(const Query& lhs, const Query& rhs){
return std::shared_ptr<Query_base>(new OrQuery(lhs, rhs));
}
#endif
Query.cpp
#include "Query.h"
#include <algorithm>
/*
std::ostream& operator<<(std::ostream& os, const Query& q){
//Query::rep通过它的Query_base指针对rep()进行虚调用
return os << q.rep();
}
*/
Query::Query(const std::string& s) : q(new WordQuery(s)){
std::cout << "Query pub" << std::endl;
}
QueryResult NotQuery::eva l(const TextQuery& text)const{
//通过Query运算对象对eva l进行虚调用
auto result = query.eva l(text);
//开始时结果set为空
auto ret_lines = std::make_shared<std::set<line_no>>();
auto beg = result.begin();
auto end = result.end();
//对于输入文件的每一行，如果该行不在result当中，则将其添加到ret_lines
auto sz = result.get_file()->size();
for(size_t n = 0; n != sz; ++n){
//如果还没有处理完result的所以行
//检查当前行是否存在
if(beg == end || *beg != n){
ret_lines->insert(n);
}
else if(beg != end){
++beg;//继续获取reslut的下一行
}
}
return QueryResult(rep(), ret_lines, result.get_file());
}
QueryResult AndQuery::eva l(const TextQuery& text)const{
//通过Query成员lhs,rhs进行虚调用
//调用eva l返回每个对象的QueryResult
auto right = rhs.eva l(text);
auto left = lhs.eva l(text);
//保存left和right交集的set
auto ret_lines =
std::make_shared<std::set<line_no>>();
//将两个范围的交集写入一个目的迭代其中。
std::set_intersection(left.begin(), left.end(),
right.begin(), right.end(),
inserter(*ret_lines, ret_lines->begin()));
return QueryResult(rep(), ret_lines, left.get_file());
}
QueryResult OrQuery::eva l(const TextQuery& text)const{
//通过Query成员lhs,rhs进行虚调用
//调用eva l返回每个对象的QueryResult
auto right = rhs.eva l(text);
auto left = lhs.eva l(text);
//将左侧运算对象的行号拷贝到结果set中
auto ret_lines =
std::make_shared<std::set<line_no>>(left.begin(), left.end());
//插入右侧运算对象所得的行号
ret_lines->insert(right.begin(), right.end());
//返回一个新的QueryResult，它表示lhs和rhs的并集
return QueryResult(rep(), ret_lines, right.get_file());
}
QueryResult.h
#ifndef __QUERYRESULT_H__
#define __QUERYRESULT_H__
#include <iostream>
#include <set>
#include <vector>
#include <string>
#include <memory>
class QueryResult{
friend std::ostream& print(std::ostream&, const QueryResult&);
public:
using line_no = std::vector<std::string>::size_type;
using Iter = std::set<line_no>::iterator;
QueryResult(std::string s, std::shared_ptr<std::set<line_no>> p,
std::shared_ptr<std::vector<std::string>> f):
sought(s), lines(p), file(f){}
Iter begin() const {return lines->begin();}
Iter end() const {return lines->end();}
std::shared_ptr<std::vector<std::string>> get_file() const{
return file;
}
private:
std::string sought;//查询的单词
std::shared_ptr<std::set<line_no>> lines;//出现的行号
std::shared_ptr<std::vector<s