A few folks suggested I try lazy enumerables to make my extremely chained style practical. I was curious about the actual costs of my style, so it’s time for lies and microbenchmarks! Turns out naively chaining a bunch of maps together isn’t very costly, so go with that to start.

Lazy came in much slower than consolidating the logic in one loop or chaining them without lazy. I thought, I must not have used lazy properly. Turns out, I’m probably showing that laziness isn’t well suited to iterating over collections without an early termination clause (e.g. a take, first, or find) and that for small collections (like an 87-line /etc/passwd), the cost of the lazy plumbing can noticeably outweigh the work done inside the loops. Thanks to Rein Heinrich for talking me to the bottom line!

One idea per line

Lately, I’m doing a weird thing when writing Ruby code. I’m trying to only put one idea or action per line. I’m not sure about it yet.

Here’s what a method to fetch item-y things might look like:

def fetch_items(options={})
  limit = options.fetch(:limit)
  timestamp = options.fetch(:timestamp)
  paged_helper = PagedHelper
  client = OurHttpClient

  responses = paged_helper.
    new(limit, timestamp).
    fetch_pages { |params| client.get(params) }

  responses.
    map { |r| JSON.parse(r) }.
    map { |h| ItemCollection.new(h) }.
    map { |ic| ic.items }.
    flatten
end

For the sake of comparison, here’s how I may have written that method a couple years ago:

def fetch_items(options={})
  helper = PagedHelper.new(limit, timestamp)
  responses = helper.fetch_pages { |params| OurHttpClient.get(params) }
  
  responses.map { |r| ItemCollection.new(JSON.parse(r)).items }.flatten
end

I like that the pace of reading the first example is even. You don’t arrive upon some monster line of code that does a multiple things. You don’t have to unpack what’s happening in a situation where you’re calling f(g(h(some_args))). It makes moving lines of code around much simpler because each one is only dependent on what comes before, and not what happens inside. It’s a little easier to write a three-part method, which I really like.

But still, I hesitate. My methods end up about 50% longer. Breaking up the Enumerable transformations into multiple loops instead of one loop doing a bunch of work is probably pretty slow. I have to come up with a lot of names (which is, I think a net good), some of which end up a little redundant.

I’ll let you know how it goes. It may not even survive code review, who knows!

Programming is easier when you know how to stop solving 100 problems with 1 fancy thing and solve 100 problems with 20 plain things.

Ember is probably leading the JavaScript framework pack by supporting releases with security patches for slight more than a year. By comparison, there’s a cottage industry of garages restoring and updating old Porsche sports cars then selling them for ridiculous prices. The USAF (the same one, curiously, that is spending $1.5 trillion on a useless jet, somehow) is going to use their largest strategic bomber, the B-52, for one hundred years.

I’m always thinking about Greg Borenstein’s words when it comes to technology churn:

The constant churn of web technologies hobbles the creation of timeless learning materials and continuity of knowledge across generations.

We should try harder on this.

Code that resists

Kellan Elliott-McCrea, on the way towards an understanding of technical debt, catalogs the ways we end up with code that resists our efforts to change it:

Therefore the second common meaning of “technical debt” is the features of the codebase we encounter in our work that make it resist change. Examples of features that can make a codebase resist change include: poor modularization, poor documentation or poor test coverage. Just as easily though an abundance of modularization (and complexity) or an abundance documentation, and tests encoding the now the incorrect old behavior can apply a strong downward pressure on change.

A little discussed and poorly understood design goal for code is disposability. Given change, what design patterns can we follow that allow us to quickly expunge incorrect behavior from our codebase? Interestingly it is a much more tractable metric for measuring as opposed to more popular criteria like “elegance”. (a post for another day)

Put that in your thinker. Does something like Strategy or Adapter let you throw out whole classes when they prove unnecessary? Or is that so only when you luck out and chose the exact right axes of disposability? Does a microservice really let you discard codebases wholesale? Can maps and functions free you from intertwingled state and behavior or does it move the resistance somewhere else?

Grumpy, opinionated answers: possibly! Even more possibly! Meh. Very meh.

Three part method

I find methods/functions decomposed into three parts really satisfying. Consider a typical xUnit test:

def test_grants_new_role
  # setup
  user = make_user
  new_role = make_new_role
  
  # behavior under test
  user.add_role(new_role)
  
  # assert results
  assert_equal [new_role], user.roles
end

Lately I’ve been structuring Rails controller similarly:

def create
  # Extract inputs/parameters from HTTP request
  person_params = params.require(:person).permit(:name, :age)

  # Invoke behavior encapsulated in a Plain(ish) Ruby object somewhere
  user = UserService.create_user(person_params)
  
  # Check the result and make some HTTP output
  if user.persisted?
    redirect_to user_path(user.id)
  else
    @user = user
    render :new
  end
end

Clojure even has the let form which encourages this style:

; annotated from clj-http
; https://github.com/dakrone/clj-http/blob/master/src/clj_http/util.clj
(defn gzip
  "Returns a gzip'd version of the given byte array."
  [b]
  (when b
    ; set the table
    (let [baos (ByteArrayOutputStream.)
          gos  (GZIPOutputStream. baos)]
     
      ; do the work and clean up
      (IOUtils/copy (ByteArrayInputStream. b) gos)
      (.close gos)

      ; produce a result
      (.toByteArray baos))))

I don’t think there’s anything inherently wrong if a method or function isn’t organized this way. But when I read code structured this way, it feels less like a bunch of random logic and more like a cohesive unit that someone put time into thinking through how someone might try to understand it later. The Rule of Three rules everything around us.

Of all the pop culture beefs going on at the time of this writing (Meek vs. Drake, BoB vs. Neil deGrasse Tyson, Trump vs. Everyone), my favorite is now Tim O’Reilly vs. Paul Graham on income inequality.

When a startup doesn’t have an underlying business model that will eventually produce real revenues and profits, and the only way for its founders to get rich is to sell to another company or to investors, you have to ask yourself whether that startup is really just a financial instrument, not that dissimilar to the CDOs of the 2008 financial crisis — a way of extracting value from the economy without actually creating it.

This has always bugged me in particular. So few startups have an idea beyond “get smart people together, maybe make something, hope that selling the team ends up profitable”. We need a much better word for “speculative technology-focused company funded by speculation”.

Threaded discussions: nope nope nope

Pet peeve #73: threaded discussions. You may have seen it in a Usenet reader or perhaps even your email. It may seem like a great way to manage a long conversation with multiple ideas and lines of discussion. OK, that’s fine, I think you’re wrong and looking at this a little too technically but it’s not forcing that perspective on anyone else so fine.

I get peeved when its suggested that conversational tools like Twitter or Slack should implement threaded messages. Nope. You have now failed my secret test, please disembark from the pragmatic train.

If a conversation requires threading, that conversation has already gone way off the rails.

Two people talking about one thing and another two people talking about another thing in the same conversation is the definition of talking past each other. Why should our software enable that?

If an email or chat ends up covering two important topics, e.g. whether to use solid or liquid fuel on a rocket and what color to paint the rocket, it was poorly written in the first place. A reasonable person can easily jump in and say “let’s talk about the fuel now and we can figure out the color later”.

Bottom line: I think people can and should handle breaking off side discussions on their own instead of trying to push weird hierarchy on participants.