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#include "rxcpp/rx.hpp"
using namespace rxcpp;
using namespace rxcpp::sources;
using namespace rxcpp::util;
#include <regex>
#include <random>
using namespace std;
int main()
{
random_device rd; // non-deterministic generator
mt19937 gen(rd());
uniform_int_distribution<> dist(4, 18);
// produce byte stream that contains lines of text
auto bytes = range(1, 10).
map([&](int i){
return from((uint8_t)('A' + i)).
repeat(dist(gen)).
concat(from((uint8_t)'\r'));
}).
merge().
window(17).
map([](observable<uint8_t> w){
return w.
reduce(
vector<uint8_t>(),
[](vector<uint8_t>& v, uint8_t b){
v.push_back(b);
return move(v);
},
[](vector<uint8_t>& v){return move(v);}).
as_dynamic();
}).
merge().
filter([](vector<uint8_t>& v){
copy(v.begin(), v.end(), ostream_iterator<long>(cout, " "));
cout << endl;
return true;
});
// create strings split on \r
auto strings = bytes.
map([](vector<uint8_t> v){
string s(v.begin(), v.end());
regex delim(R"/(\r)/");
sregex_token_iterator cursor(s.begin(), s.end(), delim, {-1, 0});
sregex_token_iterator end;
vector<string> splits(cursor, end);
return iterate(move(splits));
}).
concat();
// group strings by line
int group = 0;
auto linewindows = strings.
group_by(
[=](string& s) mutable {
return s.back() == '\r' ? group++ : group;
},
[](string& s) { return move(s);});
// reduce the strings for a line into one string
auto lines = linewindows.
map([](grouped_observable<int, string> w){
return w.sum();
}).
merge();
// print result
lines.
subscribe(println(cout));
return 0;
}
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