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Conscious Coding Practice
The Three Concrete Steps
There's a slide link later. You don't need to write frantically. @codefolio
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Who's This Guy?
I wrote the book "Rebuilding Rails."
Also a lot about Ruby performance for
engineering.appfolio.com.
I've been a pro coder for over 20 years.
But if you have to care about me
to understand this, I did it
wrong.
And I give out chalk-bear stickers! Ask me after the talk.
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You want to get
better at coding.
Faster.
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The Dragon in the Room:
"The Computer Science Stuff"
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Coding is Practical
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Good Practice
is Better
than
Bad Practice
(There's a whole "mindful practice" thing
you can find in books. Practicing well is a
whole field of study.)
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"Fingertip Feel"
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Coding Exercises
are... Okay.
• Somebody experienced has to
write them
• Don't usually exercise your
judgement about what to build
• Hard to learn things you don't
know
• Have to find new ones constantly
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A Better Choice:
The Coding Study
I'll tell you where I stole this technique later. It's really good.
You pick three things: a Tool, a Task and a Purpose.
You do it for yourself (or pairing.)
And it's useful for beginners through twenty-year veterans.
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The Coding Study,
In Simple Steps
1. Choose and write your Tool, Task and Purpose
2. Choose how long to work on it
3. Do the work until done, or until time runs out
4. Look back: what went well or poorly?
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Definitions: Tool, Task,
Purpose
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Tool: Your Language,
Libraries, and So On
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Task: What You Build
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Purpose: Why You're
Building
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Choosing Your Tool is Easy
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Two Ways to Choose Task
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Choose a Task: Easy Way
Pick something simple. Pick something you've
done before, or a simple exercise from online.
Mostly, this method is... fine.
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Choose a Task: Fun Way
Observe the world. Pick something, anything.
Turn it into a system of behaviour.
(Yes, there will be an example.)
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How to Choose Your Purpose
(unless you have one already)
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Method 1: What Superpower
Do You Wish You Had?
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Method 2: What Decision
Scares You?
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M
ethod
3: W
hat's
the
W
eirdest Thing
that
M
ight Possibly
W
ork?
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An Example Coding Study:
The Merry-Go-Round
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Tool: simple Ruby
Task: a tiny simulation of kids on a Merry-Go-Round
Purpose: play with that behaviour (age, strength and pushing)
to understand it better
Timebox: 1 hour (for me, then)
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# First half
kids = [15, 12, 11, 5, 4, 3]
kids = kids.map { |age|
{
age: age,
push: 3 * (age - 3),
weight: 5 * Math.sqrt(age),
cling: 4 * (age - 2),
}
}
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# Second half
speed = 0
loop do
oomph = kids.map { |k| k[:push] }.sum
weight = kids.map { |k| k[:weight] }.sum
speed += oomph.to_f / weight
puts "o: #{oomph}, w: #{weight}, s: #{speed}"
if speed > kids[-1][:cling]
kids.pop
if kids.size == 0
break
end
end
end
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# Second half (expanded a bit)
speed = 0
loop do
oomph = kids.map { |k| k[:push] }.sum
weight = kids.map { |k| k[:weight] }.sum
speed += oomph.to_f / weight
if speed > kids[-1][:cling]
puts "#{kids.size} little monkeys," +
" on the merry-go-round..."
puts "#{kids[-1][:age]} fell off and bumped his head"
kids.pop
if kids.size == 0
puts "No more monkeys on the merry-go-round!"
break
end
end
end
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Different Purpose,
Different Results
(A partial example)
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Tool: simple Ruby
Task: a tiny simulation of kids on a Merry-Go-Round
Purpose: Object-Oriented Design
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class Kid
attr_reader :push, :weight, :cling
def initialize(age)
@age = age
@weight = 5 * Math.sqrt(age)
@push = 3 * (age - 3)
@cling = 4 * (age - 2)
end
end
class MerryGoRound
def initialize(kids)
# ...and so on
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Seven Guidelines
(But no rules!)
Oh? And what if I break them?
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1: Choose First and Write
That is:
Choose your Tool, Task and Purpose first, before you begin
coding.
Write them out, in words.
If broken: feature creep.
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2: Time Limit
Choose a time limit. If you're not done by then, stop.
If broken: long failures where you don't learn
much and long 'successes' where you keep
building but stop learning.
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3: Throw It Away
When you've finished the exercise, don't use it for anything
else. You're not producing a finished product.
If broken: over-engineered prototypes that
teach you less and take longer to produce; you
start building to use, not to learn.
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4: One Idea at Once
Your Purpose is the idea you're studying. You want it to be one
idea big, no more.
If broken: your studies take much longer to
get started; feature creep; hard to finish.
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5: Simple, with Layers
Start your code very simply and build up in layers. Debug
statements help, too. Since you're doing development from
scratch on each study, get the benefits of starting from scratch.
If broken: long startup for each study; dread
of starting; less writing, more debugging.
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6: Work from Life
Look at a real system in the real world. Staring at real
complexity and letting it surprise you is the hidden purpose
here.
If broken: you only refine what you already
know instead of learning something nobody
(yet) knows; you lose your best cheat.
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7: Break Rules
Nothing is set in stone here. Break all these rules when it makes
sense. Or just to see what happens!
(Or un-break!)
This is play, not work. Break every rule that
gets in the way of learning. Or playing!
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The Fun Way (Again)
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Pair Coding Studies
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Pair on defining the task and purpose, not just writing the code
Start "flat-footed," don't bring in a fully-developed idea
Brainstorm together before typing
One person on the keyboard at once
Do something small; then swap roles and continue or restart
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Where I Stole This
Who else has too many tools, and must learn by practice? Artists.
They call this a "life study." They choose their tasks from life --
drawing people, landscapes, fruit, etc. They have many purposes
-- colour studies, composition studies, shading studies...
I explain differently for the coding crowd, but only a little.
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Where Next?
@codefolio
Slides: https://bit.ly/rubyconf2019-gibbs
Ask me in person
for chalk teddy
bear stickers!
You can find more blog posts about this
at https://codefol.io and an in-process
book at software-technique.com.
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Questions?
@codefolio
Slides: https://bit.ly/rubyconf2019-gibbs
Ask me in person
for chalk teddy
bear stickers!