Dance Computer, Dance

by Ray Grasso

Links

Think of me as a web crawler with taste.

An Index of Ideas

Shawn Blanc:

Your own index is something you put in the back of the book (or the front if you prefer). It’s a list of the book’s themes and topics that most resonate with you, and the pages which have the best quotes and ideas around those topics.

I’ll use an index card to do this for the ebooks I read.

Open Source Project Principles

Ryan Florence:

Rackt is a GitHub organization that was created to ensure critical open source projects in the React community receive long-term support and maintenance.

…

We believe these four principles will provide a strong ecosystem of our open source projects by ensuring projects have active and enthusiastic owners and contributors.

Experiments and Projects

Jesper Louis Andersen:

I’m very fond of Erlang creator Mike Williams point: “If you don’t make experiments before starting a project, then your whole project will be an experiment”

If we instead ask about prototyping, then we need a programming language with certain traits. The team is usually small, so we need an expressive language, and we need to address the core kernel of the system in isolation, first. We don’t need a lot of interfacing to foreign systems and in general we won’t care too much if the system we build is fast. Also, we usually won’t need to operate the prototype in production, since it is simply a proof of concept.

There are more interesting points about language design in part one and two of this broad reaching interview.

Javascript Fatigue

Eric Clemmons:

At work this past quarter, we painstakingly started three new projects at work. I say “painstakingly” because every project required decisions to be made around tooling depending on the scope & needs.

Ultimately, the problem is that by choosing React (and inherently JSX), you’ve unwittingly opted into a confusing nest of build tools, boilerplate, linters, & time-sinks to deal with before you ever get to create anything.

the React ecosystem have, largely, opted for discrete modularization at the cost of terse APIs by offloading their architectural underpinnings to the user and, as a result, worsen the developer experience in aggregate.

Yep, the developer experience in Javascript at the moment is painful. The wide array of choice is crippling and the boilerplates and generators aren’t enough. I hope the following prediction from the article comes true.

2016 will likely involve a serious, focused conjoining of projects, tools, and language features to merge the best and brightest packages/tools/boilerplates into more formalized projects. — Matt Keas in State of the Union.js

Compilers as Assistants

Evan Czaplicki:

One of Elm’s goals is to change our relationship with compilers. Compilers should be assistants, not adversaries. A compiler should not just detect bugs, it should then help you understand why there is a bug. It should not berate you in a robot voice, it should give you specific hints that help you write better code. Ultimately, a compiler should make programming faster and more fun!

I’ve enjoyed stretching my brain a bit whilst learning Elm. These changes will improve the learning process tremendously.

How to Write a Git Commit Message

Chris Beams:

A properly formed git commit subject line should always be able to complete the following sentence:

If applied, this commit will your subject line here

For example:

  • If applied, this commit will refactor subsystem X for readability
  • If applied, this commit will update getting started documentation
  • If applied, this commit will remove deprecated methods
  • If applied, this commit will release version 1.0.0
  • If applied, this commit will merge pull request #123 from user/branch

Remove the stress, pick a deadline

DHH:

The purpose of a self-imposed deadline is to sharpen the edge of your prioritization sword and stake a flag of coordination for the team. It’s not a hill to die on. It’s not a justification for weeks of death marching. It’s a voluntary constraint on scope.

Yes, deadlines are wonderful! They’re the tie-breaker on feature debates. They suck all the excess heat out of the prioritization joust: “Hey, I’d love to get your additional pet feature into the first release, but, you know: THE DEADLINE”.

Haunted by Data

Maciej Cegłowski:

A more recent and less fictitious example is electronic logging devices on trucks. These are intended to limit the hours people drive, but what do you do if you’re caught ten miles from a motel?

The device logs only once a minute, so if you accelerate to 45 mph, and then make sure to slow down under the 10 mph threshold right at the minute mark, you can go as far as you want.

So we have these tired truckers staring at their phones, bunny-hopping down the freeway late at night.

Of course there’s an obvious technical countermeasure. You can start measuring once a second.

Notice what you’re doing, though. Now you’re in an adversarial arms race with another human being that has nothing to do with measurement. It’s become an issue of control, agency and power.

You thought observing the driver’s behavior would get you closer to reality, but instead you’ve put another layer between you and what’s really going on.

These kinds of arms races are a symptom of data disease. We’ve seen them reach the point of absurdity in the online advertising industry, which unfortunately is also the economic cornerstone of the web. Advertisers have built a huge surveillance apparatus in the dream of perfect knowledge, only to find themselves in a hall of mirrors, where they can’t tell who is real and who is fake.

What Forces Layout/Reflow

Paul Irish:

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout. This is also called reflow or layout thrashing, and is common performance bottleneck.

The Right Way to Ship Software

Jocelyn Goldfein:

Facebook’s struggle pivoting to mobile illustrates the potential for trouble. Facebook’s speedy, individualistic and iterative way of designing and shipping software was deeply embedded in product team culture. If you worked in the web tier, the cost of releasing was pretty close to zero and literally everything else about the way you worked was optimized to take advantage of that assumption. As the company’s focus shifted to native mobile apps, the engineers hired for their mobile expertise insisted on a heretofore unknown process like feature and UI freeze, functional specs and QA.

Computer Science Courses That Don't Exist, but Should

James Hague:

PSYC 4410: Obsessions of the Programmer Mind

Identify and understand tangential topics that software developers frequently fixate on: code formatting, taxonomy, type systems, splitting projects into too many files. Includes detailed study of knee-jerk criticism when exposed to unfamiliar systems.

Music Curation at Spotify

Alex Heath:

During internal testing, his team realized that if you don’t recognize a single artist in a playlist, you might question if it’s actually geared for you. That’s why the playlist is intended to have a mix of mostly new tracks with a few songs you’ve heard before.

“There’s something compelling about this humans versus robots narrative: a lovingly curated playlist versus an algorithm screwing up your sexy time,” says Ogle. “That whole distinction no longer really describes how we work. Discover Weekly is humans all the way down. Every single track that appears in Discover Weekly is because other humans being have said, ‘Hey this is a good song, and here’s why.’”

My Discover Weekly playlist has been hitting the spot and it’s interesting to get an insight into how they are put together.

Although Spotify has had humans making playlists for years, its efforts got a major boost last year with the introduction of Truffle Pig, an internal tool from The Echo Nest that breaks music down into thousands of categories like “wonky,” “chillwave,” “stomp and holler,” or “downtempo.”

What you hear from everyone at Spotify is that humans using data insights are key to curating music on a large scale. Naturally, they’re also using data to evaluate how well playlists are working.

An example of data-centric tools aiding human decision makers.

Fluid Coupling

Asymco:

This implies that the problem with enterprises is not the stupidity of its buyers. They are no less smart than the average person–in fact, they are as smart with their personal choices for computing as anybody. The problem is that enterprises have a capital use and allocation model which is obsolete. This capital decision process assumes that capital goods are expensive, needing depreciation, and therefore should be regulated, governed and carefully chosen. The processes built for capital goods are extended to ephemera like devices, software and networking.

It does not help that these new capital goods are used to manage what became the most important asset of the company: information. We thus have a perfect storm of increasingly inappropriate allocation of resources to resolving firms’ increasingly important processes. The result is loss of productivity, increasingly bizarre regulation and prohibition of the most desirable tools.

Choosing Boring Technology

Dan McKinley:

If you think about innovation as a scarce resource, it starts to make less sense to be on the front lines of innovating on databases. Or on programming paradigms.

The point isn’t really that these things can’t work. Of course they can work. But exciting new technology takes a great deal more attention to work than boring, proven technology does.

Some fantastic points about what your job is when building software and the trade-offs that are constantly in front of you.

We Don't Sell Saddles Here

Stuart Butterfield:

The best — maybe the only?— real, direct measure of “innovation” is change in human behaviour. In fact, it is useful to take this way of thinking as definitional: innovation is the sum of change across the whole system, not a thing which causes a change in how people behave. No small innovation ever caused a large shift in how people spend their time and no large one has ever failed to do so.

This is the best definition for an overused term I’ve heard in a while.

The whole piece is an enthralling call to arms to a group of people building a product.

You Might Not Need Underscore

Ville Immonen:

JavaScript is evolving and new ES2015 and ES2016 editions (previously known as ES6 and ES7, respectively) pack a bunch of new features and Babel makes it very easy to use of them today. These features make some previously essential functions from utility libraries obsolete.

Designing Data-Driven Interfaces

Truth Labs:

“Dashboard”, “Big Data”, “Data visualization”, “Analytics” — there’s been an explosion of people and companies looking to do interesting things with their data. I’ve been lucky to work on dozens of data-heavy interfaces throughout my career and I wanted to share some thoughts on how to arrive at a distinct and meaningful product.

I’ve been doing a lot of data-driven interface work over the last few years and the advice in this article is spot on.

Moving Past the Scaling Myth

Michael Feathers:

It’s funny. I can’t count the number of times I’ve seen organizations with large monolithic software applications move toward SOA. It’s easy to think that we’ve learned a lesson in the industry and that services are just the new “best practice.” Surely we would’ve started with them if we were just starting development now. Actually, I think the truth is a bit more jarring. Different architectures work at different scales. Maybe we need to recognize that and understand when to leap from one to another.

The process space has similar issues. If we cargo-cult anything from the small team space into the large organization space, we’re falling prey to a blind spot. We’re missing an opportunity to re-think things and figure out what works best for small teams, interacting teams, and large-scale development. They may be quite different things.

I agree that the rules are different for different organisation sizes. I like Michael’s comparison of moving across organisation sizes to state transitions in physics.

Running Lisp in Production

Vsevolod Dyomkin:

At Grammarly, the foundation of our business, our core grammar engine, is written in Common Lisp. It currently processes more than a thousand sentences per second, is horizontally scalable, and has reliably served in production for almost 3 years.

Fighting spam with Haskell

Simon Marlow:

Haskell isn’t a common choice for large production systems like Sigma, and in this post, we’ll explain some of the thinking that led to that decision. We also wanted to share the experiences and lessons we learned along the way. We made several improvements to GHC (the Haskell compiler) and fed them back upstream, and we were able to achieve better performance from Haskell compared with the previous implementation.

Terminology for OSX Dictionary

Agile Tortoise:

Terminology for iOS is based on WordNet, a great semantic lexical reference. We do not offer a full Mac app for Terminology, but have prepared a dictionary using this same great data for use in the built-in OS X Dictionary app.

Alternate history

Brian Marick:

So, interesting: an enormous amount of effort is spent on apps that convert map/vector-structured data into map/vector-structured data.

However, because of the mindshare dominance of object-oriented programming that came because of Java - “Smalltalk for the masses” - it’s hard for most people to think of an approach other than a pipeline of structured data -> objects -> structured data. The tools and frameworks and languages push you toward that. So: a programming model tailored to objects with serious lifetimes has been used for data that lasts only for one HTTP request.

Anatomy of a Rails Service Object

Dave Copeland:

We’ve given up on “fat models, skinny controllers” as a design style for our Rails apps—in fact we abandoned it before we started. Instead, we factor our code into special-purpose classes, commonly called service objects. We’ve thrashed on exactly how these classes should be written, so this post is going to outline what I think is the most successful way to create a service object.

Some good advice for building service objects in Rails.

Haskell at Front Row

Michael Snoyman:

As of today Front Row uses Haskell for anything that needs to run on a server machine that is more complex than a 20 line ruby script. This includes most web services, cron-driven mailers, command-line support tools, applications for processing and validating content created by our teachers and more. We’ve been using Haskell actively in production since 2014.

An experience report on using Haskell in production.

Explaining List Folds

Tony Morris:

In this talk, I will explain to you how list folds work using an explanation that is very easy to understand, but most importantly, without sacrificing accuracy.

I particularly like the constructor replacement analogy for foldr.

I Prefer This Over That

Elisabeth Hendrickson:

I prefer:

  • Recovery over Perfection
  • Predictability over Commitment
  • Safety Nets over Change Control
  • Collaboration over Handoffs

Ultimately all these statements are about creating responsive systems.

When we design processes that attempt to corral reality into a neat little box, we set ourselves up for failure. Such systems are brittle. We may feel in control, but it’s an illusion. The real world is not constrained by our imagined boundaries. There are surprises just around the corner.

A Parable

Dijkstra:

I have told this story to different audiences. Programmers as a rule are delighted by it and managers, invariably, get more and more annoyed as the story progresses; true mathematicians, however, fail to see the point.

Why Lisp?

Ron Garret:

The Lisp model is that programming is a more general kind of interaction with a machine. The act of describing what you want the machine to do is interleaved with the machine actually doing what you have described, observing the results, and then changing the description of what you want the machine to do based on those observations. There is no bright line where a program is finished and becomes an artifact unto itself.

Rails in Production

RDX:

Having deployed a variety of Ruby apps (Rails and non-Rails) over the course of many years, here are some lessons I’ve learned to keep things afloat.

Ownership in Rust

Yehuda Katz:

  • In Rust, as in garbage collected languages, you never explicitly free memory
  • In Rust, unlike in garbage collected languages, you never explicitly close or release resources like files, sockets and locks
  • Rust achieves both of these features without runtime costs (garbage collection or reference counting), and without sacrificing safety.

This post contains a nice summary of Rust’s ownership model.

The ROI of a solved problem

Dorian Taylor:

If 90% of every­thing is crap, the obvious strategy should be to produce as much crap as you can afford, because the other 10% will be spectacular.

Monoids without tears

Scott Wlaschin:

But now we have something much more abstract, a set of generalized requirements that can apply to all sorts of things:

  • You start with a bunch of things, and some way of combining them two at a time.
  • Rule 1 (Closure): The result of combining two things is always another one of the things.
  • Rule 2 (Associativity): When combining more than two things, which pairwise combination you do first doesn’t matter.
  • Rule 3 (Identity element): There is a special thing called “zero” such that when you combine any thing with “zero” you get the original thing back.

With these rules in place, we can come back to the definition of a monoid. A “monoid” is just a system that obeys all three rules. Simple!

…

To sum up, a monoid is basically a way to describe an aggregation pattern – we have a list of things, we have some way of combining them, and we get a single aggregated object back at the end.

The first of three posts that give a simple definition of what monoids are and the benefits they provide.

Kent Beck's Design Rules

Martin Fowler:

Kent Beck came up with his four rules of simple design while he was developing ExtremeProgramming in the late 1990’s. I express them like this.

  • Passes the tests
  • Reveals intention
  • No duplication
  • Fewest elements

Core Location Changes in iOS 8

Nevan King:

In iOS 8, this code doesn’t just fail, it fails silently. You will get no error or warning, you won’t ever get a location update and you won’t understand why. Your app will never even ask for permission to use location.

I just got bitten by this while updating an app. This post goes through what is needed to fix it.

60 FPS on the mobile web

Michael Johnston:

You cannot build a 60fps scrolling list view with DOM.

The Flipboard team have gone to great lengths to get the performance they want from the browser.

Everything is rendered to canvas elements. They’ve created their own representation of elements which they pool aggressively to avoid GC hits.

This is another place where React’s virtual DOM comes into its own. Flipboard use React to render to canvas elements. They’ve wrapped this up into react-canvas.

This is an extreme approach but the app feels slick because of it.

The pain of mixing synchronous and asynchronous code in-language

Bob Nystrom:

When they create 4089 libraries for doing asynchronous programming, they’re trying to cope at the library level with a problem that the language foisted onto them.

Each of those function expressions closes over all of its surrounding context. That moves parameters like iceCream and caramel off the callstack and onto the heap. When the outer function returns and the callstack is trashed, it’s cool. That data is still floating around the heap.

The problem is you have to manually reify every damn one of these steps. There’s actually a name for this transformation: continuation-passing style. It was invented by language hackers in the 70s as an intermediate representation to use in the guts of their compilers. It’s a really bizarro way to represent code that happens to make some compiler optimizations easier to do.

No one ever for a second thought that a programmer would write actual code like that. And then Node came along and all of the sudden here we are pretending to be compiler back-ends. Where did we go wrong?

Red and Green callbacks:

It’s actually worse, every Javascript programmer who has a concurrent problem to solve must invent their own concurrency model. The problem is that they don’t know that this is what they are doing. Every time a Javascript programmer writes a line of code that says “on this do that” they are actually inventing a new concurrency model, and they haven’t a clue how the code will interleave when it executes.

What’s even more difficult to understand is errors. Errors in multi-threaded callback code with shared memory is something that would give me an extremely large headache.

The in-language mixing of synchronous and asynchronous calls makes code hard to reason about. The language-side simplicity of Ruby or Java’s concurrency model is something I have taken for granted.