Haskell web programming update: updated for Yesod 1.2 tl;dr: A simple Yesod tutorial. Yesod is a Haskell web framework. You shouldn’t need to know Haskell. Why Haskell? View topic - Haskell vs Prolog, or "Giving Haskell a choice" I've become more and more familiar with Haskell, and more and more have I begun to realize its true potential. It's truly frightening, really. One of the things I've started to realize is how well it can adapt different programming paradigms without sacrificing its functional purity.Another language I'm quite fond of is Prolog, and I'm actually somewhat sad I haven't spent more time hacking in it.That said, I decided to try a little experiment: writing Prolog in Haskell, staying as true to Prolog as possible, and see if the forced paradigm breaks it. I'll be rather thorough in explaining how things work for the benefit of the Prolog and Haskell illiterates out there, so if you're familiar with both you might want to tl;dr, or just bask in the glory that is Prolog and Haskell combined. At first this might seem somewhat difficult.
babysteps in using Persistent to interact with PostgreSQL as I mentioned I want to try some real-life Haskell and of course this means using some kind of database. I looked around a bit and found the really great Persistent package from Micheal Snoyman. Not only is this wonderfuly documented – no you get an yesod integration and a online-book(chapter) explaining it for free – thank you Micheal! This post will only detail the setup and installation I had to do on top of my PostgresSQL installation and it’s more or less my notes I wrote along the way (I hope you enjoy this experiment).
Wadler: Monads Philip Wadler The arrow calculus Sam Lindley, Philip Wadler, and Jeremy Yalloop, Journal of Functional Programming 20(1):51&em;69, 2010. We introduce the arrow calculus, a metalanguage for manipulating Hughesâ€™s arrows with close relations both to Moggiâ€™s metalanguage for monads and to Patersonâ€™s arrow notation. Arrows are classically defined by extending lambda calculus with three constructs satisfying nine (somewhat idiosyncratic) laws; in contrast, the arrow calculus adds four constructs satisfying five laws (which fit two well-known patterns). Composing Reactive Animations Conal Elliott Microsoft Research Graphics Group Copyright 1998 We have all seen a lot of wonderful looking computer graphics, and many of us have spent time playing video games or watching our kids (or their kids) play them.
Pointfree Pointfree Style It is very common for functional programmers to write functions as a composition of other functions, never mentioning the actual arguments they will be applied to. For example, compare: with: These functions perform the same operation, however, the former is more compact, and is considered cleaner. A Little Lens Starter Tutorial lens is a package which provides the type synonym Lens which is one of a few implementations of the concept of lenses, or functional references. lens also provides a number of generalizations of lenses including Prisms, Traversals, Isos, and Folds. Lenses and their cousins are a way of declaring how to focus deeply into a complex structure. They form a combinator library with sensible, general behavior for things like composition, failure, multiplicity, transformation, and representation. Lenses let you apply some of the power of libraries like hxt to all data types in all programs that you write.
Typeclassopedia By Brent Yorgey, email@example.com Originally published 12 March 2009 in issue 13 of the Monad.Reader. Ported to the Haskell wiki in November 2011 by Geheimdienst. This is now the official version of the Typeclassopedia and supersedes the version published in the Monad.Reader. Please help update and extend it by editing it yourself or by leaving comments, suggestions, and questions on the talk page. The standard Haskell libraries feature a number of type classes with algebraic or category-theoretic underpinnings.
Haskell Haskell is a functional programming language. If you've programmed before and would like to see a little bit of how Haskell works and is different from other programming languages, see the overview. Haskell is unique in two ways. First, it is a pure functional programming language. If you have a function and you call it twice in two different places with the same arguments then it will return exactly the same value both times. Haskell Communities and Activities Report - HaskellWiki The Haskell Communities and Activities Report was initiated at the 2001 Haskell workshop, as a status report of the Haskell community as a whole, to be updated twice a year. The purpose is twofold: to establish what communities, people, and projects are out there, working with or on Haskell, and what their areas of interest are; to feed back summary information about ongoing activities in the diverse Haskell sub-communities and amongst Haskell users (commercial or otherwise) to the Haskell Community as a whole. To this end, there is a half-yearly informal survey of the main Haskell mailing list, inviting everyone to volunteer brief summary reports of their own community, project, company, research group, or whatever.
Haskell Haskell is a functional programming language. If you have some programming experience, see the overview to see a bit of how Haskell works and is different from other languages. Haskell is distinct in a few ways: Haskell is a pure functional programming language.