What is functional programming? Jonathan Müller — @foonathan Back to Basics: Functional Programming in C++ CppCon 2024-09-19 1Imperative Programming Definition Specify instructions that manipulate state state in order to achieve a goal. Jonathan Müller — @foonathan Back to Basics: Functional Programming in C++ CppCon 2024-09-19 2Imperative Programming Definition Specify instructions that manipulate manipulate state in order to achieve a goal. C and C++ Jonathan Müller — @foonathan Back to Basics: Functional Programming in C++ CppCon 2024-09-19 2Imperative Programming Definition Specify instructions that

Overview of ROS 2 ● ROS 2 Conventional Approach ● Introduction to Functional Programming Principles ● Refactoring using Functional Programming Principles ● ConclusionIntroductionAbout Me ● Robotics object-oriented paradigm that can lead to trouble writing code that achieves the goal ● Adopting functional programming techniques into our code has made it easier to test, maintain, and extend code!Overview join(); }Introduction to Functional Programming Principles● A programming paradigm characterized by the use of mathematical functions and the avoidance of side effects What is Functional Programming?● A programming

std::for_each( 21 first, 22 23 last, 24 25 26 27 } 28 }; 29 92.6#include <functional> // std::greater #include // std::priority_queue #include

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 1.5. Functional Endpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Netty) that are well-established in the async, non-blocking space. The other part of the answer is functional programming. Much as the addition of annotations in Java 5 created opportunities (such as annotated controllers or unit tests), the addition of lambda expressions in Java 8 created opportunities for functional APIs in Java. This is a boon for non-blocking applications and continuation-style APIs (as popularized

amount of work the team estimates it can deliver in a sprint Development teams, aided by cross-functional representatives, analyze each user story and use measures known as story points to estimate the decisions to be made at that level. Development can be effectively managed by a small cross-functional government team. Team Size Many government stakeholders will be involved in the software the acquisition support team, which consists of the program staff, contractor, and supporting functional areas. A good example can be found in the Air Force Integrated Strategic Planning and Analysis

of New Lean Constructs . . . . . . . . . . . . . . . . . . . . . 49 iii II Functional–Logic Programming 51 4 Functional Programming 53 4.1 Inductive Types . . . . . . . . . . . . . . . . . . . . . familiarize yourselves with some areas in which proof assistants are success- fully applied, such as functional programming, the semantics of imperative programming languages, and mathematics; develop some on simple type theory, such as HOL4 or Isabelle/HOL. We assume that you are familiar with typed functional programming, as em- bodied in the languages Haskell, OCaml, and Standard ML. If you do not see

philosophy” sounds a lot like functional programming.What is functional programming about? • It’s about chaining functions to make programs: 𝐻 𝐺 𝐹(𝐷𝑎𝑡𝑎!"#$%) 11What is functional programming about? programs: 𝐻 𝐺 𝐹(𝐷𝑎𝑡𝑎!"#$%) • If you squeeze them together then we could have: 12What is functional programming about? • It’s about chaining functions to make programs: 𝐻 𝐺 𝐹(𝐷𝑎𝑡𝑎!"#$%) something: 𝐷𝑎𝑡𝑎&$%#$% = 𝐹(𝐷𝑎𝑡𝑎!"#$%) 13Data oriented design = Functional programmingOn the ”equality”… • DoD and functional programming may have strong differences • … But they also have strong

template operator()()); return r; } };"FUNCTIONAL PROGRAMMING" "FUNCTIONAL PROGRAMMING" Functional programming in C++? Polarising? Functional programming in C++? Polarising? Higher order functions "visiting", [... it's] really about really about approximating the functional style within an OOP language." approximating the functional style within an OOP language."VISITOR PATTERN VISITOR PATTERN In world. but adding behaviour (methods) require touching the world. In a functional language, it's the other way around: In a functional language, it's the other way around: functions are easy functions are