One Pomodoro A Day - A Core Wars Kata

This is the project page for an experiment in doing a very long kata (30-40 hours), working an average of only 25 minutes per day. See below for a better description of what I am doing, and why I am doing it.

Structure of this repository

The master branch of this repository contains only the tools I used to do the kata. If you wish to do the same kata (or a different kata using the same tools), you can easily fork this project and branch off from master.

Each pomodoro session (approximately 25 minutes of work) is checked into it's own branch. The first session is branch first, the second is second, etc. The most recent branch is always merged into the gh-pages branch, so if you simply want to look at the most recent code, that's the place to look.

I have recorded every pomodoro session using a tool called Asciinema. You can view these sessions by going to the project page. The speed of replay can be adjusted by using the '<' and '>' keys. I have found that by increasing the speed, you can comfortably watch a 25 minute pomodoro in as little as 5 minutes.

What is One Pomodoro A Day?

One Pomodoro A Day is an attempt to do a very long kata in manageable chunks. If you are not familiar with the concept of a kata, it is a term taken from Japanese martial arts and refers to a form that one executes in order to practice. The term was coined by Dave Thomas here.

One of the downsides of doing a kata as practice is that it is necessarily limited. Usually it is a task that last 30 minutes or so. Trying to explore larger problems of requirements gathering and program design is much more difficult because ordinarily people don't have time to devote themselves to a large project for an extended period of time. Enter the pomodoro technique.

The pomodoro technique is a time management method for splitting up your task into small chunks of time (usually 25 minutes), separated by short breaks. The chunks of time are called pomodoros. My approach in this experiment is to try to do a very long kata (approximately 30-40 hours), doing an average of one pomodoro a day. I use Asciinema to record each pomodoro session so that I can review it later.

What is Core Wars?

Core Wars is a game devised by computer scientist A. K. Dewdney in 1984. It was first described in an article in Scientific American and became relatively popular in the late 1980s and early 1990s with computer programmers. From the original article:

Two computer programs in their native habitat -- the memory chips of a digital computer -- stalk each other from address to address. Sometimes they go scouting for the enemy; sometimes they lay down a barrage of numeric bombs; sometimes they copy themselves out of danger or stop to repair damage. This is the game I call Core War. It is unlike almost all other computer games in that people do not play at all! The contending programs are written by people, of course, but once a battle is under way the creator of a program can do nothing but watch helplessly as the product of hours spent in design and implementation either lives or dies on the screen. The outcome depends entirely on which program is hit first in a vulnerable area.

Core Wars is quite nostalgic for me as, after reading the original article, I rushed to write my own implementation of the game. I remember starting on a Friday evening and working every waking hour so that I could have it functional by Sunday night. It was a crude implementation with numerous bugs, but it was very fun to play.

I have often thought, "How long would it take me to write Core Wars now". It's been almost 30 years since I first implemented it and I hope I have improved a considerable amount. The old me probably edges the new me in raw mental horse power, but I should have a trick or two up my sleeve now.

Using the tools for your own kata

The tools checked into the master branch can be used to do your own kata (even to implement Core Wars yourself and compare your kata to mine!).

Scripts

There are 3 scripts in the scripts directory:

geometry
record
start-tmux

geometry will tell you the geometry of your terminal application. Asciinema works well using a geometry of 80x25 and I recommend using that. All of my recordings are done at that size. It takes some practice to get used to working with such a small screen, but it's good for building memory skills about the structure of your code.

record will start a tmux session, a thyme pomodoro timer, and start and asciinema recording. record takes one argument: the name of the asciinema file to record. I usually invoke it like:

record sessions/5.ascii

This will create 2 files: the 5.ascii file that has the asciinema recording, and also a 5.ascii.json file that contains a transformed version that can be used on the webpage. Unfortunately, the program that transforms the file currently only works on Linux. This is a limitation of asciinema which I hope will be fixed some time.

In order for the record script to work, you have to install asciinema and place it in your executable path. I have built and included the conversion script that creates the converted version (that can be displayed by the asciinema web plugin) in the third-party/asciinema-convert directory. This was built from the asciinema source package. Unfortunately, asciinema is not really packaged up to be used easily, so I had to resort to this approach.

The record script also uses the thyme pomodoro timer. You need to install it using Ruby's bundler gem. Once you have installed bundler with gem install bundler you simply need to do bundle install to get set up. However, the pomodoro timer will still not show up in your tmux session unless you add it to your .tmux.conf. I use the following:

# thyme integration
set-option -g status-left '#(cat ~/.thyme-tmux) |#S| '
set-option -g status-interval 30
set-option -g status-left-length 20

The final script is start-tmux. This is called by the record script to start up tmux. This opens up some default windows and makes a couple of specific key bindings that I use for the kata. You can modify it to suit your needs.