You are here not because you are so great, but because your employer believes you can help them to advance the company’s being. ​ Companies don’t want extra risks. Choosing Haskell is a very big risk itself, and it’s a crime to increase it by doing things wrongly. ​ smart code limits your employer’s field of potential workers. This is certainly a risk, too, and this is how you affect the company even if you are not aware about those risks.

adding equalizers and coequalizers to a cartesian closed category amounts to enriching the corresponding type system with refinement types and quotient types respectively.

Programming languages lie at the intersection between the binary, deterministic, silicon world of computers and the inexact, chaotic, organic world of human consciousness and communication. To me, functional programming is the practice of applying mathematical formalisms to real-world programming problems.

but `parseNonEmpty` gives the caller access to the information it learned, while `validateNonEmpty` just throws it away. Consider: what is a parser? Really, a parser is just a function that consumes less-structured input and produces more-structured output.

In some sense, that’s all programming really is, modeling a domain in a way that can be leveraged by a digital computer. ​ and without being willing to invest the time and money into education, smart, diligent people will still fail to grasp the concepts, and they will likely be wholly uninterested in them. ​ programming, like any other field, is not always about what comes easiest: sometimes it’s important to sit down and study for a while to grok a particularly complicated concept, and other times, it’s simply important to learn by trying, failing, and asking questions.

Haskell is a purely functional programming language: by default, Haskell functions do not cause side effects such as system I/O, nondeterminism, or exception handling. As such, Haskell programs are generally expressed in terms of monad transformers, which provide the facility to compose different side effects into a single interface powerful enough to express the programmer's needs. The monad transformer library, mtl, is mature and powerful, but complicates and in some cases constrains the construction and generalization of user-specified monads. A class of libraries known as 'effect systems' have emerged in an attempt to solve the problems associated with monad transformers. Effect systems provide a compositional approach to program construction, generally using a single monadic type specialzed with a programmer-provided list of capabilities. Effect systems are more powerful and flexible than monad transformers, but their adoption in industry has been minimal, due both to their incompatiblity with mtl and their historically poor performance. The new fused-effects library changes the status quo: it provides an extensible and flexible vocabulary for program construction, yielding a more expressive interface than mtl without sacrificing any performance characteristics. I'll describe the history of effect systems, outline the tradeoffs associated with programming with effects, and demonstrate the use of fused-effects in practice. Patrick Thomson GitHub, Inc. @importantshock Patrick is a senior engineer on GitHub's Semantic Code team, building systems to understand and analyze the corpus of code on GitHub. He enjoys peaceful countryside walks and loud rap shows.

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If we want a name to fully describe the concept it points to, then it must be a very simple concept indeed. ​ But we still have to explain what a Mappable is. “What’s a Mappable? Well, it’s something you can map over!” is a terrible explanation! It’s literally just the grammatic expansion of the word. All it does is move the question one bit further ​ Functor is hard to learn. It is not hard to learn because it is named Functor. If you renamed it to anything else, you’d have just as hard of a time, and you’d be cutting off your student from all of the resources and information currently using the word “functor” to refer to that concept.

Selective Applicative Functors: Declare Your Effects Statically, Select Which to Execute Dynamically - GitHub - snowleopard/selective: Selective Applicative Functors: Declare Your Effects Staticall...

Guessing Swift takes a similar approach in [SE-0185](https://github.com/apple/swift-evolution/blob/098152eafbfbd7faa74d81e1443231bd7caabc45/proposals/0185-synthesize-equatable-hashable.md).

A paradigm is sneaking in when you aren’t paying attention. Pay attention. There’s a chance here to influence development practice for decades ​ We really can have languages that give the benefits of tomorrow without losing all the working components of today. I think Swift can be one of those languages. ​ Much of that, I believe, is education.

The Haskell Pyramid This is the Haskell Pyramid The triangle shape represents the knowledge you may learn about Haskell: wide at the bottom, and acute at the top. The pyramid is tall, heavy, and intimidating.

Die HSR Hochschule für Technik Rapperswil begrüsste zusammen mit Google und Digital Asset rund 300 Informatikerinnen und Informatiker aus der ganzen Welt zum 6. Haskell Hackathon. Die jährlich stattfindende Konferenz knackte zum ersten Mal die 300er-Teilnehmergrenze. Sie richtet sich sowohl an ausgewiesene Experten der Programmiersprache Haskell wie auch an interessierte Anfänger. Studierende der HSR, der ETH und weiterer Hochschulen hatten somit die Möglichkeit, vom 9. – 11. Juni 2017 unmittelbar in die Community einzutauchen. Mehr Informationen unter www.hsr.ch/medien

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Andrej Bauer raises a question whether Hask is a real category. I think it’s a legitimate question to ask, especially by a mathematician or programming languages researcher. But I want to look closer at how a (probably negative) answer to this question would affect Haskell and its community.

While no level of type safety is sufficient to ensure all programs' correctness, the fact that the Semantic Code team spends the majority of its time working on features rather than debugging production crashes is truly remarkable—and this can largely be attributed to our choice of language. ​ but in Haskell: its brevity, power, and focus on correctness lets researchers focus on the nature of the problem rather than the onerous task of fitting advanced research into conventional languages. Writing in Haskell allows us to build on top of the work of others rather than getting stuck in a cycle of reading, porting, and bug-fixing. ​ a reputation for being difficult to learn. Some of that is well deserved, but half of it has more to do with how many of us first learned imperative programming and the switch to a functional paradigm takes some patience.

When working with a monad, you work in its Kleisli category which is another example of a CCC. The above discussion relating function evaluation to function composition, would then relate Kleisli evaluation (=) to Kleisli composition (=). Woah, is `bind` just monadic function evaluation?

A case of dis-functional programming.

Jersey City-based artist/engineer Jenn Schiffer makes art with code, teaches code with art, and open-source tools for playing with both. Her hilariously deadpan writing satirizes tech culture and programming tutorials, roping in clueless mansplainers for literally years after publication. Follow Jenn on Twitter: https://twitter.com/jennschiffer And on Medium: https://medium.com/@jennschiffer Her official site: http://jennmoney.biz/ Recorded in September 2016 at XOXO, an experimental festival celebrating independently produced art and technology in Portland, Oregon. For more, visit http://xoxofest.com. Introductory music: "Flaws Run Deep" by Jim Guthrie. Video production by brytCAST. Video thumbnail by Searle Video. Captions by White Coat Captioning.