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CppCon'15 and Silicon Valley Code Camp Presentations

In last couple of months I did a couple of presentations about my recent projects in C++. Session videos, slides, and code for all the presentations are now available online. Both projects have functional programming at their heart. I've found exploring functional programming in modern C++ quite a fun ride. Without further ado, here's the content

CppCon'15: Reactive Stream Processing in Industrial IoT using DDS and RxCpp

Topic: 50 billion devices will be connected to the Internet by 2020. Many of them will belong to national critical infrastructure (smart power grids, smart roads, smart hospitals, smart cities) – forming the Industrial Internet of Things (IIoT). These devices will generate data streams that will need to be correlated, merged, filtered, and analyzed in real-time at the edge. This talk will explore an elegant solution to this problem that is productive, composable, concurrency-friendly, and scales well. We utilize OMG’s Data Distribution Service for Real-Time Systems (DDS) standard for connectivity, and Reactive Extensions (Rx) for functional-style composable asynchronous data processing in modern C++.

Rx is a generalization of futures and can be thought of as the async equivalent of C++ ranges. It helps create asynchronous data processing pipelines by chaining reusable higher-order functions (map, filter, flatmap, zip etc.) that rely on a common abstraction called an Observable (a continuation monad). RxCpp makes wonderful use of functional programming features in modern C++ including generic lambdas, type inference, variadic templates, and more. Rx is one of the best libraries that truly highlights the power of functional design principles applied in a (primarily) object-oriented programming languages.

DDS and Rx work great together because they are both reactive, use the publish-subscribe paradigm, and facilitate loose coupling between components. This presentation will discuss Rx4DDS, which is a research library that integrates Rx with RTI Connext DDS. Rx4DDS enables a clean, distributed, asynchronous dataflow architecture for stream processing and is available in C#, C++, and JavaScript.


More reading

  • Data-Centric Stream Processing in the Fog is an RTI blog post with detailed description of one of the demonstrations and code I showed at CppCon'15. If you know what I mean by "The finalization actions are baked into each data pipeline at the time of creation" you can skip right ahead.

  • Rx4DDS home page includes all the demonstrations and code I showed at CppCon. The description is somewhat sparse and assumes that you have seen the earlier resources listed here.

Silicon Valley Code Camp: Composable Generators and Property-based Testing in C++14  

Topic: C++14 has an enviable collection of functional programming features such as generic lambdas, type inference, variadic templates, function types with co-/contra-variance and so on. With mature compiler support, designing and implementing performant functional-style libraries has become very pleasant in modern C++. Tools and techniques (e.g., property-based testing) enjoyed by the programmers in only elite functional languages (Haskell, Scala) now appear to be within C++'s reach.

This presentation will discuss two classic techniques from the functional domain -- composable data generators and property-based testing -- implemented in C++14 for testing a generic serialization and deserialization library (RefleX). We will look at techniques of constructing complex generators using a random number generator and a tolerable dose of monoids, functors, and of course, monads. We won't stop there though! We will look at automatic type generators using C++ TMP. Equipped with data and type generators, we'll take property-based testing to a whole new level where lazy programmers don't have to do anything to test their programs beyond just compilation and running the test over and over.

Code on github: generators


Bonus Content: Channel9 Interview at CppCon'15

Here's my really short interview recorded at CppCon'15 by Channel9. Yes, it's about functional programming! Skip ahead to 45m36s into the video to checkout my segment. Alternatively, click here.


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