Being mindful of other developers

Coding with love

Alex Peattie

CTO @ Peg

@alexpeattie

slides.com/alexpeattie/love

• Cryptic (Junior)
• Clever (Mid-level)
• "Computer friendly" (Senior)

Cryptic

Junior

dd = Time.now + (wl == [] ? 1814400 : 1209600)
Loan.new(dd)

if wl == []
  dd = Time.now + 1814400
else
  dd = Time.now + 1209600
end

Loan.new(dd)

if waiting_list == []
  due_date = Time.now + 1814400
else
  due_date = Time.now + 1209600
end

Loan.new(due_date)

if waiting_list.empty?
  due_date = Time.now + 1814400
else
  due_date = Time.now + 1209600
end

Loan.new(due_date)

if waiting_list.empty?
  # due date 3 weeks from now
  due_date = Time.now + 1814400
else
  # due date 2 weeks from now
  due_date = Time.now + 1209600
end

Loan.new(due_date)

week = (7 * 24 * 60 * 60)

if waiting_list.empty?
  due_date = Time.now + (3 * week)
else
  due_date = Time.now + (2 * week)
end

Loan.new(due_date)

if waiting_list.empty?
  due_date = weeks_from_now(3)
else
  due_date = weeks_from_now(2)
end

Loan.new(due_date)

if waiting_list.empty?
  due_date = weeks_from_now(3)
else
  due_date = weeks_from_now(2)
end

Loan.new(due_date)

dd = Time.now + (wl == [] ? 1814400 : 1209600)
Loan.new(dd)

Clever

Mid-level

class Yogi
  def cat_pose
    imitate Cat.new
  end

  def cow_pose
    imitate Cow.new
  end

  def cobra_pose
    imitate Cobra.new
  end
end

denise = Yogi.new
denise.cat_pose

class Yogi
  %w(cat cow cobra).each do |animal|
    define_method("#{animal}_pose") do
      imitate Object.const_get(animal.capitalize).new
    end
  end
end

denise = Yogi.new
denise.cat_pose

• Confusing
• Hard to search
• Tightly coupled

class Yogi
  def cat_pose
    imitate Cat.new
  end

  def cow_pose
    imitate Cow.new
  end

  def cobra_pose
    imitate Cobra.new
  end
end

denise = Yogi.new
denise.cat_pose

"Computer friendly"

Senior

def is_something?(string)
  1.upto(string.length) do |n|
    return false if string[n - 1] != string[-n]
  end
  true
end

A

def is_something?(string)
  string == string.reverse
end

B

def is_something?(string)
  string == string.reverse
end

def is_something?(string)
  1.upto(string.length) do |n|
    return false if string[n - 1] != string[-n]
  end
  true
end

The quick brown fox jumps over the lazy dog

The quick brown fox jumps over the lazy dog

god yzal eht revo spmuj xof nworb kciuq ehT

B is 30% slower

but....

But for 1 million runs with a 20,000 word string..

the difference is 2s

AWS clusters start from $0.013/hr

Conclusion

• Coding isn't a solitary pursuit
• Be mindful of being...
• Cryptic
• Clever
• Computer friendly
• Love your fellow developers!

alex@peg.co

@alexpeattie

slides.com/alexpeattie/love