F# News. The F# Journal. Monad (functional programming) Formally, a monad consists of a type constructor M and two operations, bind and return (where return is often also called unit). The operations must fulfill several properties to allow the correct composition of monadic functions (i.e. functions that use values from the monad as their arguments or return value). The return operation takes a value from a plain type and puts it into a monadic container using the constructor, creating a monadic value.
The bind operation performs the reverse process, extracting the original value from the container and passing it to the associated next function in the pipeline, possibly with additional checks and transformations. Because a monad can insert additional operations around a program's domain logic, monads can be considered a sort of aspect-oriented programming.[7] The domain logic can be defined by the application programmer in the pipeline, while required aside bookkeeping operations can be handled by a pre-defined monad built in advance. Brian Beckman: The Zen of Stateless State - The State Monad - Part 2 | Going Deep.
Concurrency is a problem that faces all developers as we move to the age of ManyCore processor architectures. Managing state is an important aspect of programming generally and for parallel programming especially. The great Brian Beckman demonstrates three ways of labeling a binary tree with unique integer node numbers: (1) by hand, (2) non-monadically, but functionally, by threading an updating counter state variable through function arguments, and (3) monadically, by using a partially generalized state-monad implementation to handle the threading via composition. Of course during this lesson from one of the masters of mathematical programming, we wind through various conversational contexts, but always stay true to the default topic in a stateful monadic way (watch/listen to this piece to understand what this actually means This is another great conversation with astrophysicist and programming master Brian Beckman.
See part 1 here. Exercise 4 (HARD): go from binary tree to n-ary tree. Brian Beckman: The Zen of Stateless State - The State Monad - Part 1 | Going Deep. Concurrency is a problem that faces all developers as we move to the age of ManyCore processor architectures. Managing state is an important aspect of programming generally and for parallel programming especially. The great Brian Beckman demonstrates three ways of labeling a binary tree with unique integer node numbers: (1) by hand, (2) non-monadically, but functionally, by threading an updating counter state variable through function arguments, and (3) monadically, by using a partially generalized state-monad implementation to handle the threading via composition.
Of course during this lesson from one of the masters of mathematical programming, we wind through various conversational contexts, but always stay true to the default topic in a stateful monadic way (watch/listen to this piece to understand what this actually means This is another great conversation with astrophysicist and programming master Brian Beckman. Exercise 4 (HARD): go from binary tree to n-ary tree. Brian Beckman: Don't fear the Monad | Going Deep. Functional programming is increasing in popularity these days given the inherent problems with shared mutable state that is rife in the imperative world. As we march on to a world of multi and many-core chipsets, software engineering must evolve to better equip software engineers with the tools to exploit the vast power of multiple core processors as it won't come for free as it did in the recent past which was predictably based on Moore's law.
Of course, learning new ways to think about programming semantics and code patterns are not always straight forward. For example, most imperative programmers (which include most of us who build software for a living...) are somewhat perplexed by the notion of functions as first class data structures that can be combined to create powerful and composable systems. Dr. This video interview is the result of Brian's idea that he can in fact remove the fear of monads from anybody who pays attention to his explanation. Tune in. Enjoy. F#: Custom Monad (Workflow) Development | Steve Horsfield. It is my experience that learning how to develop monads is hard. I could follow the theory, and I thought I could even read example code, but when I attempted to actually write my own then I found it hard to marry the implementation and the theory. If that is you experience, then I hope this post will help a little. Introduction In a simple sense, monadic development is a way to make functional composition easy, and it does, but only once the supporting code is in place.
If you do not have the supporting code then you have to be able to understand the theory and then apply it to your own software development. For the theory, I recommend the following talks by Microsoft’s Brian Beckman: You should also have the F# specification accessible, particularly section 6.4.10: Computation Expressions. Starting out One thing that I have learnt is that it is worth thinking carefully about what you want to achieve before attempting to understand and create your monad. Execution mode in detail delay. F# Programming. Contents[edit] Preface - About this book and its authors.Introduction - Introducing the F# Programming Language. F# Basics[edit] This section is suitable for complete beginners to F# and Functional Programming in general. Getting Set Up - Installing F# on Windows, Linux and Mac.Basic Concepts - A lightweight crash course in functional programming concepts.
Working With Functions[edit] F# is a functional programming language. Declaring Values and Functions - This article will show you how to declare simple functions, how to use type inference, and how to read F#'s 'arrow' notation.Pattern Matching Basics - Pattern matching is used for control flow. Immutable Data Structures[edit] "Data structure" is a fancy word which refers to anything that helps programmers group and represent related values in useful, logical units. Imperative Programming[edit] Mutable Data - By default, variables in F# are immutable. Object Oriented Programming[edit] F# is a CLI/.NET programming language. F# Advanced[edit] Functional. Monads. Functional Programming. Excellent Overview of Functional Programming. 14 Feb 2008 I just ran into an article on DZone that totally threw me off my chair in terms of content. It’s titled (ambitiously enough) “Functional Programming For the Rest of Us“.
Basically the article attempts to explain many of the common FP techniques in terms that imperative programmers can understand. More importantly, it motivates these explanations with a long and rambling set of real-world reasons. It’s extremely long, extremely involved and well worth the read. It’s worth noting that the author claims to be presenting his explanations in Java, but is in fact devising an extension of Java to represent FP constructs more concisely. The really interesting bit is how the author motivates FP through a combination of real-world examples and lengthy reasoning.
So grab yourself a cup of coffee and a box of donuts (it’ll take you about that long to finish the article), and slog your way through.