Functional Programming in C++

Overview

This repository contains my attempt to explore basic functional programming in C++. It builds on the availability of λ's and variadic templates (among other things).

One self-imposed limitation was to avoid weirdsyntax or to overload operators away from their semantics.

The goal is to provide some examples of the us of functional techniques in C++ using existing language features and libraries.

This does not cover template meta-programming in case you were wondering.

Why

It's a great way to explore functional programming and C++, neither of which are well served by this approach.

I primarily use it as a test bench and don't intend to turn this into some sort of library.

###Build

1. Use the latest version of gcc.I've build this with gcc 4.8 on mac osx 10.8.4.
2. Clone the repo.
3. Run make in the src directory.
4. run ../bin/main or ../bin/main all
5. ../bin/main is a very primitive 'repl' which allows you to run the test functions.

What

./src

The main file in the source directory contains a 'repl' and a set of registered test functions.

The .cpp files contain simple example code for the functional concepts in the header. So bracket.cpp contains example code for bracket.hpp and bracket_helper.hpp

./docs

This directory contains .tex files. These document provide more background for the code. pp-fp-1.tex discusses basic functional programming available in C++. pp-fp-2.tex discusses more advanced concepts.

pp-fp-1.tex was submitted to pragpub for publication.

Related Work

I've been able to track down two articles which discuss functional programming in C++.

1. Work by Yannis and McNamara circa early 2000 http://people.cs.umass.edu/~yannis/fc++/
2. Work by David Sankel circa 2010. http://zao.se/~zao/boostcon/10/2010_presentations/thu/funccpp.pdf

Yannis and McNamara develop a library using C++ as it existed circa 2000. Interesting, but you need to stay within their framework.

Sankel uses boost to implement advanced functional programming concepts in C++.

Functional Programming

Basics

Immutability

Higher Order Functions

Combine functions to construct other functions

Currying

Turn any function into a unary higher order function

Map

Apply a function to a list of values

Reduce

Apply a function to a list of values and accumulate the result.

Advanced

Functors

Generalizes maps for data "containers" other than lists.

Applicative Functors

Enables pure functions to be used in a "container"

Bracket Notation

Monads

Helpful Hints

Books

C++

1. The C++ Programming Language; 4th ed.
2. The C++ Standard Library; 2nd ed.

Functional Programming

Articles