finished ch12

ch12/README.md

@@ -149,3 +149,4 @@ I prefer the `do while`, cause the process according with our logic.
 The `vector` can not ensure no duplicates. Hence, in terms of this programme `set` is a better option.
 
 ## Exercise 12.32 [Header](ex12_32.h)|[Implementation](ex12_32.cpp)
+## Exercise 12.33 [Header](ex12_33.h)|[Implementation](ex12_33.cpp)

ch12/ex12_33.cpp

@@ -0,0 +1,49 @@
+//
+//  ex12_33.cpp
+//  Exercise 12.33
+//
+//  Created by pezy on 1/1/15.
+//  Copyright (c) 2015 pezy. All rights reserved.
+//
+//  Rewrite the TextQuery and QueryResult classes to use a StrBlob
+//  instead of a vector<string> to hold the input file.
+
+#include "ex12_33.h"
+#include <sstream> 
+#include <algorithm>
+
+TextQuery::TextQuery(std::ifstream &ifs) : input(new StrBlob)
+{
+    StrBlob::size_type lineNo{0};
+    for (string line; std::getline(ifs, line); ++lineNo) {
+        input->push_back(line);
+        std::istringstream line_stream(line);
+        for (string text, word; line_stream >> text; word.clear()) {
+            // avoid read a word followed by punctuation(such as: word, )
+            std::remove_copy_if(text.begin(), text.end(), std::back_inserter(word), ispunct);
+            // use reference avoid count of shared_ptr add. 
+            auto &nos = result[word];
+            if (!nos) nos.reset(new std::set<StrBlob::size_type>);
+            nos->insert(lineNo);
+        }
+    }
+}
+
+QueryResult TextQuery::query(const string& str) const 
+{
+    // use static just allocate once.
+    static shared_ptr<std::set<StrBlob::size_type>> nodate(new std::set<StrBlob::size_type>);
+    auto found = result.find(str);
+    if (found == result.end()) return QueryResult(str, nodate, input);
+    else return QueryResult(str, found->second, input);
+}
+
+std::ostream& print(std::ostream &out, const QueryResult& qr)
+{
+    out << qr.word << " occurs " << qr.nos->size() << (qr.nos->size() > 1 ? " times" : " time") << std::endl;
+    for (auto it = qr.begin(); it != qr.end(); ++it) {
+        ConstStrBlobPtr p(*qr.get_file(), *it);
+        out << "\t(line " << *it + 1 << ") " << p.deref() << std::endl;
+    }
+    return out;
+}

ch12/ex12_33.h

@@ -0,0 +1,52 @@
+//
+//  ex12_33.h
+//  Exercise 12.33
+//
+//  Created by pezy on 1/1/15.
+//  Copyright (c) 2015 pezy. All rights reserved.
+//
+//  In Chapter 15 we’ll extend our query system and will need some additional members
+//  in the QueryResult class.
+//  Add members named [begin] and [end] that return iterators into the set of line numbers
+//  returned by a given query, and a member named [get_file] that
+//  returns a shared_ptr to the file in the QueryResult object.
+
+#ifndef CP5_ex12_33_h
+#define CP5_ex12_33_h
+
+#include "ex12_22.h"
+using std::shared_ptr;
+
+#include <iostream>
+#include <fstream>
+#include <map>
+#include <set>
+
+class QueryResult;
+class TextQuery {
+public:
+    TextQuery(std::ifstream &);
+    QueryResult query(const string&) const;
+private:
+    shared_ptr<StrBlob> input;
+    std::map<string, shared_ptr<std::set<StrBlob::size_type>>> result;
+};
+
+class QueryResult {
+public:
+    using ResultIter = std::set<StrBlob::size_type>::iterator;
+    friend std::ostream& print(std::ostream &, const QueryResult&);
+public:
+    QueryResult(const string &s, shared_ptr<std::set<StrBlob::size_type>> set, shared_ptr<StrBlob> v) : word(s), nos(set), input(v) {}
+    ResultIter begin() const { return nos->begin(); }
+    ResultIter end() const { return nos->end(); }
+    shared_ptr<StrBlob> get_file() const { return input; }
+private:
+    string word;
+    shared_ptr<std::set<StrBlob::size_type>> nos;
+    shared_ptr<StrBlob> input;
+};
+
+std::ostream& print(std::ostream &, const QueryResult&);
+
+#endif