/RxCpp

Reactive Extensions for C++

Primary LanguageC++Apache License 2.0Apache-2.0

The Reactive Extensions for Native (RxCpp) is a library for composing asynchronous and event-based programs using observable sequences and LINQ-style query operators in C++.

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Linux & OSX Linux & Osx Status
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Documentation rxcpp doxygen documentation
reactivex intro rx marble diagrams

#Example Add Rx/v2/src to the include paths

lines from bytes

#include "rxcpp/rx.hpp"
using namespace rxcpp;
using namespace rxcpp::sources;
using namespace rxcpp::operators;
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);

    // for testing purposes, produce byte stream that from lines of text
    auto bytes = range(1, 10) |
        flat_map([&](int i){
            auto body = from((uint8_t)('A' + i)) |
                repeat(dist(gen)) |
                as_dynamic();
            auto delim = from((uint8_t)'\r');
            return from(body, delim) | concat();
        }) |
        window(17) |
        flat_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);
                    }) |
                as_dynamic();
        }) |
        tap([](vector<uint8_t>& v){
            // print input packet of bytes
            copy(v.begin(), v.end(), ostream_iterator<long>(cout, " "));
            cout << endl;
        });

    //
    // recover lines of text from byte stream
    //

    // create strings split on \r
    auto strings = bytes |
        concat_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));
        }) |
        filter([](string& s){
            return !s.empty();
        });

    // group strings by line
    int group = 0;
    auto linewindows = strings |
        group_by(
            [=](string& s) mutable {
                return s.back() == '\r' ? group++ : group;
            });

    // reduce the strings for a line into one string
    auto lines = linewindows |
        flat_map([](grouped_observable<int, string> w){
            return w | sum();
        });

    // print result
    lines |
        subscribe<string>(println(cout));

    return 0;
}

#Reactive Extensions

The ReactiveX Observable model allows you to treat streams of asynchronous events with the same sort of simple, composable operations that you use for collections of data items like arrays. It frees you from tangled webs of callbacks, and thereby makes your code more readable and less prone to bugs.

Credit ReactiveX.io

###Other language implementations

###Resources

#Cloning RxCpp

RxCpp uses a git submodule (in ext/catch) for the excellent Catch library. The easiest way to ensure that the submodules are included in the clone is to add --recursive in the clone command.

git clone --recursive https://github.com/Reactive-Extensions/RxCpp.git
cd RxCpp

#Building RxCpp

  • RxCpp is regularly tested on OSX and Windows.
  • RxCpp is regularly built with Clang, Gcc and VC
  • RxCpp depends on the latest compiler releases.

RxCpp uses CMake to create build files for several platforms and IDE's

###ide builds

####XCode

mkdir projects/build
cd projects/build
cmake -G"Xcode" ../CMake -B.

####Visual Studio 2013

mkdir projects\build
cd projects\build
cmake -G"Visual Studio 14" ..\CMake -B.
msbuild rxcpp.sln

###makefile builds

####OSX

mkdir projects/build
cd projects/build
cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ../CMake
make

####Linux --- Clang

mkdir projects/build
cd projects/build
cmake -G"Unix Makefiles" -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ../CMake
make

####Linux --- GCC

mkdir projects/build
cd projects/build
cmake -G"Unix Makefiles" -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ../CMake
make

####Windows

mkdir projects\build
cd projects\build
cmake -G"NMake Makefiles" -DCMAKE_BUILD_TYPE=RelWithDebInfo -B. ..\CMake
nmake

The build only produces test and example binaries.

#Running tests

  • You can use the CMake test runner ctest
  • You can run the test binaries directly rxcppv2_test_*
  • Tests can be selected by name or tag Example of by-tag

rxcppv2_test_subscription [perf]

#Documentation

RxCpp uses Doxygen to generate project documentation.

When Doxygen+Graphviz is installed, CMake creates a special build task named doc. It creates actual documentation and puts it to projects/doxygen/html/ folder, which can be published to the gh-pages branch. Each merged pull request will build the docs and publish them.

Developers Material

#Contributing Code

Before submitting a feature or substantial code contribution please discuss it with the team and ensure it follows the product roadmap. Note that all code submissions will be rigorously reviewed and tested by the Rx Team, and only those that meet an extremely high bar for both quality and design/roadmap appropriateness will be merged into the source.

You will be prompted to submit a Contributor License Agreement form after submitting your pull request. This needs to only be done once for any Microsoft OSS project. Fill in the Contributor License Agreement (CLA).