Ashton Kemerling


Unusual Productivity Hacks

The internet is lousy with productivity ideas, mostly about how to work harder or longer. I personally believe that good productivity is about maximizing per hour results, not working harder. And the fastest way to improve your productivity is to eliminate some of the things slowing you down. So rather than going over the usual suspects, let’s take a look at eliminating some of the low hanging fruit.

1. Conquer Your Diet.

What you eat is the cornerstone of who you are and what you do. The proteins in your muscle, the fats in your cell walls and your brain, and the amino acids used throughout your body must all come from, or be synthesized from your food. Low quality food products like trans fats have been connected with apathy, depression, and might be related to ADD. In order for your brain and body to perform at peak levels you need to give it high quality food to repair and refuel.

2. Sleep

Sleep is massively underrated. Everyone knows at this point that Americans are typically not getting enough sleep on a nightly basis, but distressingly few people consider it to be an issue. After all, hours spent asleep aren’t hours spent working right? Unfortunately it isn’t that simple. Insufficient or low quality sleep is one of the fastest ways that we know of to destroy per hour productivity. Get sleep or waste your precious waking hours in a mind fog.

3. Know when to stop.

Athletes regularly destroy their bodies by “over training”; exercising to the point of injury or chronic fatigue. The results of over training are often slow growth or even frustrating setbacks despite hundreds of hours at the gym or on the track.

Mental workers regularly do the exact same thing to their mind by working well past the point of mental burnout. There is very little use in working when you are not going to be putting out at least average results, and you risk ruining your morale after hours of low-results work. Instead of ritualistically working even when you are spent gain an intuitive sense for when you will accomplish little and instead go recharge and try again later.

4. You must come out unharmed 1 time or 1000 times.

No productivity regime is worthwhile if you can only maintain it for 2 weeks at the start of each year. To be successful, you must find a pattern that you can maintain years. Whether that is a small amount per day or a cycle between intense work and relaxation, you must find a balance between work and play or you will be plagued by failures to meet your goals.

5. Know thyself.

Everyone wants to be successful, but most people overestimate how much money motivates them. Find ways to motivate yourself with something other than riches, or better yet find something that you love to do. Love of the work will make it easier to get up, or home, every day and work rather than abstract future financial rewards.

The Swordsman and the Software Engineer

One of the largest mistakes you can make as a knowledge worker is to focus 100% of your time on your craft. It’s easy to believe that specializing and focusing will make you better than your peers, but I do not think that is the case. Not only will specializing cause you to plateau earlier than your peers, it will cause you to be less happy and healthy than your diversified peers.

A bit of background at this point would probably be helpful. I’m a software engineer and I’ve coded both professionally and on a hobbyist basis for nearly a decade. After a particularly stressful few months at a previous job, my fiancé forced me to join a local gym to de-stress. The gym focused on various European martial arts and I ended up in a class for the Italian longsword circa 1409.

A few years ago I would have suspected that choosing to surrender 2-8 hours a week to swinging steel around instead of programming on hobbyist projects would slow down my growth. Now I believe that I owe a lot of my growth, professionally and as a human being to this practice. A lot of what I’m going to cover here will probably be old news to anyone who was heavily involved in sports, nor is it particularly unique to fencing. That being said I’m fairly confident that a lot of knowledge workers have lost the involvement with physical activities they might have had, or never were all that “athletic” even in school.

The biggest modern challenge is that humans are not wired for the type of work that we now do. We are a fairly clever species by nature, which is why we have been making art for hundreds of thousands of years. But we are still more or less genetically and mentally hunter gatherers from 100,000+ years ago who largely worked for their survival. Our bodies, genes, and minds are wired to expect a specific ratio of play and physical activity to signal that all is well. Unfortunately we work a lot longer than our ancestors did, and under very different conditions.

This high level of nothing but work, physical or mental, indicates to our bodies that times are tough and that it should release stress hormones to help us survive the coming hard times; these stress hormones tend to have serious detrimental effects on mental performance and long term health. The phrase “all work and no play” may be over-used, but it does have some truth. All work and no play leaves Jack pumped full of cortisol, short on sleep, and low on testosterone.

Secondly, most knowledge workers spend their entire time thinking only with their frontal cortex, or the analytical portion of the brain. This is very helpful if your job involves concentrating on difficult problems all day, but it is incredibly easy to let that portion of your brain become the only driving factor on your day to day life. The brain, like your muscles, should have ample opportunity to exercise all of its faculties and have recovery time between each heavy usage. Expecting it to be able to focus deeply on your work day in and day out without giving it time to relax is simply asking for lowered performance and burnout, and only working on one aspect of your mental performance is akin to only doing curls at the gym; the result is an odd shape with very little practical strength.

Thankfully exercise and hobbies help other parts of the brain. This is one of the things I love about fencing: it isn’t very analytical once you actually start using it. There are a ton of cuts and guards to be memorized, but you never have time to think about it when you are actually fencing. All of the drills are designed so that your mind and body learn to move with instinctual grace from one guard to another. There is very little conscious thought that happens mid-move in a match; there simply is not enough time to stop and think. Instead you learn to have an internalized notion of time and measure, and an ability to make new decisions as the fight progresses quickly and correctly.

And while none of this directly relates to software engineering, it has a positive effect on my daily work. The ability to move with a fight and think with my toes and fingertips have given me a greater appreciation to the importance of gut instinct in more situations. And the constant practice of excluding my analytical mind in a fast moving match have improved my ability to enter a flow state more easily. Combine these things with the general good effects of mental down time and exercise, and I think it’s hard to argue that my time would have been better spent working on hobbyist projects.

Confessions of a Language Snob

I am a language snob. In particular I fall head over heels for most functional languages, especially MLs and Lisps. Show me the latest and greatest Javascript framework and I will just wish I had immutable data types and a saner method dispatch system. I try to keep quiet about it at work with varying degrees of success, but it’s frustrating to work around one language’s problems when you know of other solutions.

The difficult reality that few admit is that every language has a weak point. Ruby is slow and the lack of import semantics and proper namespaces makes it difficult to determine what code will run. Python lacks a good lambda and whitespace sensitivity brings new difficulties. Javascript is just pure insanity. Lisp is poorly standardized and tends to have subpar documentation. The list goes on and on. No language is perfect, but it’s very easy to focus on the high points of one language while working through the low points of another.

The real bummer about being a language snob is that there’s really nothing to be done about it. For any given issue there will always be another language that exceeds in that area, but it’s almost always insane and impractical to convert your entire company over to it. So even if you think Go would solve every problem that your Python codebase has, and you know that the downsides wouldn’t be insurmountable, the simple reality is that convincing the organization to throw away their perfectly good Python code on a whim is insane at best. And that’s assuming that converting to your language wouldn’t come with downsides worse than the language you are coming from.

Thankfully, there is an upside to being a language snob. Polyglots have a far more flexible understanding of what a program should do, especially when they’re used to a wide range of paradigms. Someone who has done nothing but C or Java programming might have very little context into why mutable state can be so problematic, but someone who knows Clojure or Haskell will know the tradeoffs of mutable vs. immutable state intimately. Each new paradigm a programmer embraces means that they have more internal views on how a particular problem could be solved, a bit like having an experienced team in your head to discuss the merits of various techniques at lightning speed.

While it may be very frustrating to know of better solutions in other languages, there is a benefit to knowing about them. Being a language snob can help you evaluate your choices more effectively and discover solutions and strategies that might not be immediately obvious if you only knew one language. And between being a bit of a snob and attempting to shoe-horn every problem into a one-size fits all paradigm, I’ll take being a snob.

The Primacy of the Build Tool

No programming language stands alone. Besides the compiler, every programming language includes an ecosystem of libraries, build tools, analyzers, debuggers, and other utilities. Languages often rise and fall depending on the quality of these tools and libraries.

For every language there needs to be one central item upon which every other tool depends. In most languages, this is the compiler or interpreter. Your Rails project is entirely dependent on the version of Ruby provided by the current environment, and similarly Maven depends on the version of javac and java available on the path.

Unfortunately, this makes our code more fragile and dependent on the machine it was first created on. Someone cloning your code from a different machine must take care to ensure that their development environment is close to the original authors, and deployment must ship the correct compilers and interpeters for production to work well. We have created tools to help enforce the requirements of the code, but they are fragile and make upgrading dependencies a pain, as anyone who has had to fight with RVM can attest.

The one exception to this I have found is Clojure. Clojure inverts the normal order making the build tool the central item, with the compiler provided by the project definition file.

(defproject foo "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url ""
  :license {:name "All Rights Reserved."}
  :dependencies [[org.clojure/clojure "1.5.1"]
                 [org.clojure/clojure-contrib "1.2.0"]
                 [clj-time "0.6.0"]]
  :profiles {:dev {:dependencies [[midje "1.5.1"]]}})

The beauty of this change is that it makes setup trivial for another developer. All they need is the same build tool, and it will deal with the correct versions of both the compiler and any libraries for the project. Have other projects that depend on different versions of the compiler? The build tool only cares about the dependencies in front of it, and will call the correct version from the correct project.

This also makes upgrading trivial. Want to try Clojure 1.6.0? Change “1.5.1” to “1.6.0” in the above snippet. Want to write a library that supports multiple versions of the compiler? The build tool supports profiles which allow you to swap out compilers trivially because it’s just a dependency.

:profiles {:1.3 {:dependencies [[org.clojure/clojure "1.3.0"]]}
           :1.4 {:dependencies [[org.clojure/clojure "1.4.0-beta1"]]}}

Deployment gets easier as well. If you’re deploying an uberjar, the core libraries you tested against are also shipped to production in the same jar. No need to upgrade your deployment scripts when a new version of Clojure comes out, as everything is included automatically.

There is one catch to this wonderfulness, which is that Clojure depends on the JVM, and the build tool cannot change the JVM around. But Clojure has very simple requirements, Java 1.6 or greater, which makes it simple to deploy anywhere.


One of my hobbies is fencing. Not modern Olympic fencing, but 14th century longsword fencing in the Italian school. In every class the instructor reminds us that we should act “like haughty Italian nobles, tall and relaxed” in the way that we stand, move, and handle the weapon.

The word “Sprezzatura” crops up a lot in these discussions. The simplest translation is literally “disdain”, but a more careful translation would be “studied carelessness”. To act with Sprezzatura means to make learned actions look easy and natural.

It turns out there is a really good reason for a fencer to act this way. A relaxed and calm fencer can move more rapidly and adjust their actions depending on whether they are winning or losing the bind. Their actions happen without any tell, catching their opponent by surprise and allowing them to act within their opponents tempo. In sword fighting the ultimate goal is to strike your opponent without being hit. Thus the shortest and simplest actions are favored, as large embellished actions only increase personal risk.

There is a similar grace in programming. While programming is not usually a competitive or dangerous hobby, there are practical benefits to acting quickly and gracefully. The most effective engineer completes their task with the minimal amount of time and added complexity. Showing off in the code only increases the risk of regressions and makes the code harder to modify later. The ultimate goal is a maintainable application that meets requirements in the minimal amount of time, and an accomplished engineer will take the shortest route to that goal.

Sword fighting is not about strength. It is never effective to swing a sword with all of your strength. Even if this wasn’t unsafe and an obvious tell, it isn’t a good way to cut with an edged weapon. Swords depend on a cutting edge to do damage, and thus a smooth arc that draws the weapon through the target will always cut more effectively than a ham-fisted baseball swing.

Similarly, the accomplished engineer knows that completing a task is not about the number of hours spent, but the quality. The mind is a tool that can be both sharpened and dulled with both work and rest, and programming is a task of the mind. Thus the quality engineer avoids excessive hours, as they are unhealthy and ineffective. Instead the engineer makes their limited productive hours as effective as possible without excessive strain.

It may not be the connection you expected, but humans haven’t changed in a very long time. Even if our circumstances have changed, there is always something to be learned from even the most esoteric sources.

Managing Is a Craft Too

I’m getting a little tired of seeing posts saying that the best managers must be an ex-engineer or a current one. I think coding skill is a very narrow minded way to judge both a human and a professional, and a terrible way to run a business.

Here’s the simple truth, a manager is a craftsperson just like a designer or engineer. The only difference is that their craft is organizing people, not designs or code. In their trade the best tools are flexibility, communication, empathy, and comprehension. My personal opinion is that a good manager is at least as hard to find as a good engineer, if not harder.

To say that a manager of engineers needs to know how code and needs to code daily is like saying that you have to be a doctor to manage a doctor’s office, and that you need to be practicing right now. While a bit of knowledge aids in communication, there are a wide range of tasks that need to be performed that are not coding. And to ignore these tasks would be just as disastrous as not writing the software that the company sells.

We’ve all heard the horror stories of non-engineer managers not knowing or caring what engineers do, or the ex-engineer manager thinking that they’re still on the team when their knowledge is 20 years out of date. Clearly both of these people are being ineffective managers, but not because of whether or not they can code. These people are being bad managers because they are not listening to their staff. Anyone, coder or not, will be a terrible manager without the requisite people skills.

So hire and keep managers that listen and communicate well. Managers that manage expectations of those uphill and divert shit rolling downhill. The best manager is the one that helps their team be the best, whether or not there are any commits with their name on it.

Internationalization Golf

Martin Grüner had a fun article about his experience writing an internationalized app. I thought it would be fun to share my own experiences.

My first job out of college was working on a Common Lisp (CL) web application. The application was only a few years younger than me, and had originally written in CL due to a particularly good HTML/XML library available in CL at the time. Unfortunately in the intervening years the HTML library stopped being state of the art, and the whims of enterprise software engineering had left CL behind for web development, resulting in a serious lack of common programming conveniences.

Right after joining the company, I was informed that the sales person had a potential lead with clients in a Spanish speaking country. The application at this point was English only, but the QA engineer was married to a native Spanish speaker who was willing to help translate the application. All we needed to do was wire the application up for internationalization and localization. I was tasked with picking or creating a library and interspersing it throughout the application. The only criteria was that it both looked good and was capable of displaying different languages to different users depending on their browser’s “accept-language” header. So compiling or packaging up a new application with hard-coded languages was not an option.

I eventually decided that all the existing libraries were insufficient and we needed to make our own. I’m still not sure if that was the right choice or not. CL doesn’t have the strongest library ecosystem around, but I was also a very young engineer and more susceptible to the “Not Invented Here” syndrome than I am now. Although a quick perusal through the current offerings involves libraries whose home pages are 404s, libraries who are nothing but FFI bindings to a GNU C library, and those whose list of defects includes “no documentation”, “undocumented code” and “slow PO parser”.

Compounding the issue was CL’s format function. CL has an exceedingly powerful formatter that is capable of unwrapping loops and interspersing the correct combination of “,” and “and” for a list of strings. This function was used with (reckless) abandon throughout the codebase, something for which I deserve some blame. The lack of dedicated template files compounded the issues; it’s a lot easier to reach for format when you’re producing HTML the handler-function itself.

There was no way I was going to explain the (non-technical) translator how to deal with format directives like this: “~#[NONE~;~a~;~a and ~a~:;~a, ~a~]~#[~; and ~a~:;, ~a, etc~].”, and I didn’t want to dig through 500kloc and unroll all the directives. So any translation system I made would need to support at least a subset of the CL formatting directives while hiding them for the translator’s sanity.

Worse still, CL’s formatter accepts positional arguments only, to my knowledge. Thus there’s no particular way to convince the formatter to modify the order of the parameters if the target language has different language structure than English. So my system would need to deal with that.

The final format I settled on would look something like this. The programmer (me) would change (format nil “~a” var) to (jibberish:format “<~a:variable-name>” “Descriptive sentence for translator” :variable-name var). We could then convince our code to print out a file for a language like this:


Original: <variable-name>
Translation: Translation goes here
Note for translator: Descriptive sentence for translator
Original Argument Order: [variable-name]

And so on. At runtime the language file would be parsed into a in-memory hash map, which would allow us to replace the format-string with the new one, re-order the argument list according to the translator’s needs, and strip the identifiers from the formatting string leaving the raw format directives.

So, how’d I do? Mixed results. The conversion was long and painful, requiring that each format directive and raw string be touched. A huge portion of the “Notes for translator” were either blank due to difficulty and fatigue, or were something along the line “Description, part 1/n” due to multiple calls being joined together in HTML. Changes in formatting calls required that the matching translation entry be hunted down in every translation file for the translation to still work.

But technical challenges are usually not a big deal, after all that’s a fairly large portion of what engineers do. Probably the worst problem with my system was how it worked for non-technical folk. The first attempt at giving this file to a translator resulted in her helpfully translating all the variable names into spanish, changing “It is <today>” to “que es <hoy>”, which resulted in some rather exciting errors. I think my own design sabotaged me in this particular instance, as it required way too much careful explanation to be usable. It was my first encounter with the major difference between using a program whose internals you are familiar and explaining its use to someone else who has never seen anything similar.

I think if I had to do it again, I would’ve probably spent more time and modified the way the program generated strings instead. I suspect that my custom library avoiding refactoring everything was a case of false economy, as the time saved up front would have been lost in the time required to train translators and maintain overly fragile translation files. I also learned that if you plan on selling an application in another language market, you need to think about that before you start writing code. Internationalization limits some of the choices you can make with your software and design, and it’s a lot easier to use that restricted set up front than it is to unwind them after the fact.

As a final irony, while attempting to write this post in Octopress (which uses Jekyll), it crashed several times because the SASS files in Octopress use unicode, which Octopress appears to hate out of the box. You have to change a few environment variables to convince it that Unicode is ok.

Thoughts on RubyMine

As part of my new job at Pivotal Labs I’ve been pair programming almost every day. The obvious challenge with pair programming, especially in a popular language like ruby, is in choosing what tools to work with. Vim, Emacs, RubyMine, TextMate, the choices are various and divisive.

To make peace among the engineers, it makes sense to dictate one set of tools to make peace among all your employees, and to make provisioning the machines easier. Pivotal has decided to standardize on RubyMine with a dark color scheme and a few custom configurations.

The Good

RubyMine, being set up for ruby in particular, works very well with navigating, indenting, and colorizing ruby code. With the exception of setting a variable as the result of an if expression, I have never seen RubyMine indent code incorrectly or get confused on coloration.

It also does a decent job of navigating to ruby classes and functions, something that is quite hard since ruby lacks explicit import semantics. It definitely makes hunting down odd test harness functions down a breeze, and has saved me in the past. It also is good at identifying the view that cooresponds to a controller method, but due to the way that tracker is laid out, I haven’t had a chance to use this feature often.

And as the cherry on top RubyMine includes a “Textmate like” quick find feature. In large code bases this will save you about a minute trying to find a particular file, so ling as you have an idea of what it’s called!

The Bad

If you only have unique controllers and models, you will absolutely love the ability to jump to a class definition. Since we use a lot of similarly named controllers inside namespaces to control API versions, it often gets confused about what version I want. The quick find feature sometimes ignores the path if you provide it, which makes copying files from stacktraces occasionally unreliable.

Javascript and less support is mediocre. No real complaints, but nothing to set it apart from other environments in my opinion. Maybe my colleagues who work on the front end would have a more nuanced opinion.

Also sometimes with large files the coloring or error checking can lag behind. This usually kicks in at files longer than 3000 lines, which is not unusual for test files. For the most part this is just an annoyance which doesn’t affect editing in any serious way.

It has git integration, which lags behind the offerings from Emacs, Vim, and Eclipse in my opinion. I end up using the command line instead of the built in tools.

The Ugly

RubyMine is incredibly dim witted when it comes to parenthesis and quotes. If you wish to put an escaped quote at the end of a string, RubyMine will let you escape your ending quote, then insert a matching pair right afterwords when you try and fix the mistake! To add insult to injury, you must move the cursor before fixing the issue lest RubyMine delete both of the extra quotes. Very frustrating.

RubyMine is also one of the most memory consuming programs I use. At least once a week it will grind my machine to a halt due to memory usage, which is impressive on a machine with 16G in memory.


Out of the box, RubyMine works very well. I think it is a good compromise for large teams. But if you have time to learn some more complicated tools, I believe you would be way better off learning a more customizable editor like Emacs or Vim. It might take some effort, but these editors can do just as much as their commercial cousins and will continue to do well no matter what language you decide to use in the future.

Org Mode

Recently I’ve taken interest in making myself more productive, and at least so far it’s going well. I personally attribute part of my current productivity to a new “shut up and get back to work” mentality, and partly to a new (to me) organization system.

The problem I’ve had is that every single organization app is broken in some way. The only truly flexible system uses paper and pen, and I don’t really want to deal with that.

The solution appears to be org-files. Think of them as a close cousin to Markdown, but for organization instead of HTML. The systems that use org-files support basically any kind of work flow imaginable because the storage mechanism is just text, so in the worst case scenario you can always just edit the file manually.

Org-files are originally from the Emacs plugin org-mode, but there are now org-file readers for Vim, iPhone, and Android.

Example File.

#+LAST_MOBILE_CHANGE: 2013-10-01 19:59:54

* Butler                                                           :projects:
Butler is an Emacs plugin for Jenkins/Hudson use. Currently it supports:
+ Viewing jobs.
+ Encrypted authentication info.
+ Triggering non-parameterized jobs.
** Wish List.
*** Paramtererized jobs
Possible to get the parameter information along with the job status in one query.
*** DONE Better formatting.
DEADLINE: <2013-11-02 Sat>
CLOCK: [2013-05-06 Mon 20:21]--[2013-05-06 Mon 20:40] =>  0:19
:ID:       6A634BFA-F18E-4C92-A48D-DC3254A67CAE
Tabular mode?
*** DONE COMPLETED Job Progress
*** TODO Improved HTTP
:ID:       F720BD2F-4966-455B-8F14-5530393340CD
**** DONE Avoid roundtrip to encrypted auth file
**** TODO Silence message output
:ID:       DE9913E9-AC68-42D3-B7D2-613BB775A16B
**** TODO Auto refresh
:ID:       01EC3DB8-ABCA-4063-8999-AA68D8D05528
**** TODO Console output
:ID:       112F3FD6-7D23-485F-8B5E-43F0B0BA839E

Okay Ashton, What the Hell is That?

Let’s break this down bit by bit. Any line starting with #+ is used to tell the org-mode reader something. In this case it lets us know the last time we synced this to our mobile device, and the possible TODO states that an item can be in. It’s not unusual to see formatting directives at the top of the file to control color, indentation, and similar settings. A lot of settings can either be set globally, or on a per-file basis.

Next we have the individual headings. Each heading starts with a number of asterisks. The number of asterisks indicates the level. So ** Wish List. is a child of * Butler. Most editors allow you to fold headings to show or hide their children, for convenience.

Each heading can optionally have a TODO state, which is displayed in front of the heading title.. The default is one of blank, TODO, IN-PROGRESS, and DONE. A simple keystroke in most editors cycles from one state to the next. It’s also possible to support multiple paths that a project can flow through. I personally use the default along with REFERENCE and ABANDONED, which allows for me to easily filter for abandoned projects, along with notes that aren’t actionable yet.

Org-mode supports 3 different kinds of time tracking and scheduling. Each heading can have up to one deadline entry, one scheduled entry, and multiple clock entries. Deadlines are for when an item should be finished, and scheduled is for when a project should be started. Clocks are for recording the amount of time used for an item. You can see an example of both the deadline and clock under the “Better formatting.” header. Org-mode also supports a very flexible type of repeat scheduling.

With any good organization system you’ll need the ability to tag and filter items. Org provides two ways to do this, properties and tags. Tags are generally shared across multiple entries, with values like “work” and “home”. They are displayed on the far right of the tagged line, such as “:projects:” on the Butler line above. You can tag a line with as many tags as you want.

Unlike tags, properties are composed of keys and values, many of which are unique to a specific entry. If you use any kind of syncing system, each item will get an ID property used to enforce uniqueness. A lot of systems will also respect the LOCATION property if you sync to a system that understands this, such as iCal.

And finally you can have notes and text underneath each entry. Most org-mode readers understand free text, unordered lists (- or +), numbered lists, and check boxes (- [ ] and - [X]). Many of these can be easily manipulated with simple keyboard macros, such as the check boxes.

As you can see, org-mode basically provides a super set of all the organizational features available. It’s up to you how you wish to nest these, mark them due, and prioritize. That’s why I love it, I’m not locked into one particular layout that may or may not fit me, instead I can slowly evolve it as my systems mature. Expect more posts in the future about Emacs specific configuration settings to make org-mode easier to use.

The Best of Lisp™

Edit: Dan Benjamin himself informed me that I missed the sarcasm boat here. I’m leaving the relevant bits, and cutting out the now irrelevant criticism.

I’m slowly working my way through the Back to Work podcast. I’m way behind, so please excuse that this post references an episode over 2 years old at this point.

Episode 11 was about “future proofing your passion”, among other things. In it, Merlin mentions that one thing you can do as a low risk investment in a programming career is to maintain current on new languages. He mentions Scala, Erlang, and Lisp as a few. With an uncharacteristic lack of self-awareness unusual amount of sarcasm, Dan expresses pretty much disdain and lack of interest in anything other than Ruby, even going as far as saying “Ruby took the best of Lisp”.

While Dan may have been joking, it is probably worth examining the relationship between Ruby and Lisp. As someone who has worked in Ruby and Lisp professionally, I feel uniquely qualified to talk about their relative strengths. While there are a ton of cases where Ruby clearly learned and copied from Lisp, there is also a laundry list of areas where Ruby failed to learn from Lisp’s successes and failures.


Being a functional language, functions are pretty important to Common Lisp. Ruby thankfully took some of the highlights from CL during its development, like a heavy emphasis on using map & filter over iterative loops, but it missed some important things.

CL only has one kind of function, the function. There are some nice syntax features for the way you define them, and a few extra features for how they’re called, but they’re all just functions. Some might be anonymous, while others might be bound to a symbol. Sometimes you call them by name, or with funcall or apply if you need to pass them around. Sometimes they’re a multimethod from CLOS which dispatches depending on the class of the argument, but at the end of the day they’re all just functions which behave the same. Ruby picked up on the idea of using different syntax for some functions (think Blocks), but for some reason included Procs and Lambdas as well. Most Rubyists I’ve met express confusion over what the exact differences are, and always say “Just use one kind and one kind only”.

Common Lisp also has much better syntax for parameters. In particular it provides for required and optional positional parameters, enumerated keyword parameters, and extra parameters to be collected into a list. Ruby learned well by also allowing default parameters to be evaluated at call time, but it ended up with a way worse syntax. Particularly bad is the way Ruby handles extra keyword arguments, simply dumping them into a lisp, optionally merging it on top of your default arguments hash if needed. CL provides a way for default values to be defined for keyword arguments in the method header, which is far cleaner than the Ruby way.


Ruby often gets compared to Common Lisp in its ability to produce Domain Specific Languages, or DSLs. Both blocks and Ruby’s special dispatch mechanisms are used and abused by programs such as Chef to create an easy interface between high level concepts and low level details.

And Ruby is pretty good at DSLs, I would estimate that it can hit a good 60-80% of the DSL cases fairly easily. But especially once you step outside the bounds of configuration DSLs like Chef, Common Lisp truly shines. In Ruby you can’t really add new syntax or special characters, and you can’t easily force it to recompile a given section of code to behave in a specific way.

But you can do that in Lisp. Lisp’s macros are so powerful, many languages are first prototyped as a large section of Lisp macros. Clojure was originally implemented in a few hundred lines of Lisp macros. This involved adding new meanings to symbols that don’t exist in CL, like { and }. But with Lisp’s reader and regular macros, this is perfectly reasonable.


One of the biggest weaknesses of Common Lisp was its weak standard. The standard did not specify a lot of common behavior, such as threading. The result was a proliferation of both libraries that were implementation specific, and libraries designed to bridge the gap, like Bordeaux Threads. At this point every library and application is so set in its ways, the chances of the standard being unified and fixed is almost none.

Yet somehow Ruby ended up with no spec at all, only a reference implementation. It’s so bad that the Rubinius people proudly proclaim that they created 20,000 specifications to as closely as possible match MRI, the reference implementation. While this is a laudable effort, I think the general opinion is that only the reference implementation is to be trusted, so most libraries assume that you’re not using Rubinius, MacRuby, or anything else. This is sad, because it means that the Ruby community is very unlikely to use anything other than MRI, no matter how good a competing runtime might be.

The Takeaway

I love Ruby. It’s a good language. But if you want truly mind opening programming moments, Lisp is the only way to go. No other language can give you the sense of “I can do anything” quite like it. I highly recommend every Rubyist at least try Common Lisp for a bit, to at least understand where their language of choice came from.