Code Golf Talk @ Ruby Sauna

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CodeGolf

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Create something in 1024 characters

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Create something in 140 characters

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Create something

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Constraints stimulate Creativity

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https://www.youtube.com/watch?v=Ugz_oOWOzlM&feature=youtu.be

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(f=proc{|x,y|sleep 1;puts "\033c",x;f[x.gsub(/\/\ \./,'~/\\').gsub(/.o./,y ? '\o/':'|o|'),!y]})['~/\ \'+'~'*12+'o~~']

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116 characters …but what do they mean?

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☺ cat lucas.md # Lucas Dohmen * Consultant @ innoQ GmbH * From Cologne, Germany * Open Source Developer * Podcaster * CoderDojo Cologne Organizer * Code Golfer

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(f=proc{|x,y|sleep 1;puts "\033c",x;f[x.gsub(/\/\ \./,'~/\\').gsub(/.o./,y ? '\o/':'|o|'),!y]})['~/\ \'+'~'*12+'o~~']

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Recursion using a Proc (f=proc{|x,y| sleep 1 system 'clear' puts x f[…] })[…]

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>> f = proc { |a,b| puts a } => # >> f['hello'] hello => nil Calling a Proc

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>> f = proc { |a,b| puts a } => # >> f['hello'] hello => nil Arguments that were not provided are initialised as nil (not the case for a lambda) Calling a Proc

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>> f = proc { |a,b| puts a } => # >> f['hello'] hello => nil Arguments that were not provided are initialised as nil (not the case for a lambda) Calling a Proc

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First time we call it… '~/\\'+'~'*12+'o~~'

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'~/\\'+'~'*12+'o~~' => '~/\~~~~~~~~~~~~o~~' First time we call it…

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On every call from now on we will do two things 1. Move the shark 2. Change the arms

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Moving the shark x.gsub(/\/\\./,'~/\\')

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Moving the shark x.gsub(/\/\\./,'~/\\')

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Moving the shark x.gsub(/\/\\./,'~/\\') /\

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Moving the shark x.gsub(/\/\\./,'~/\\')

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Moving the shark x.gsub(/\/\\./,'~/\\') remove one character from the right

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Moving the shark x.gsub(/\/\\./,'~/\\')

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Moving the shark x.gsub(/\/\\./,'~/\\') add one wave to the left

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~/\~~~~~~~~~~~~~~~ ~~/\~~~~~~~~~~~~~~ ~~~/\~~~~~~~~~~~~~ ~~~~/\~~~~~~~~~~~~ Moving the shark

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Changing the arms .gsub(/.o./,y ? '\o/':'|o|')

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matches all stages ~o~ \o/ |o| of the animation Changing the arms .gsub(/.o./,y ? '\o/':'|o|')

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depending on y we change it to either \o/ or |o| Changing the arms .gsub(/.o./,y ? '\o/':'|o|')

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Changing the arms (f=proc{|x,y| sleep 1 system 'clear' puts x f[…,!y] })[…]

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(f=proc{|x,y|sleep 1;puts "\033c",x;f[x.gsub(/\/\ \./,'~/\\').gsub(/.o./,y ? '\o/':'|o|'),!y]})['~/\ \'+'~'*12+'o~~']

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https://www.youtube.com/watch?v=d68x-RI-yqw&feature=youtu.be

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This app has one main trick: The list is 1- indexed

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If you enter a line it will be stored as 1. a string 2. a ﬁxnum

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If the ﬁxnum is 0 it is a todo item otherwise it is a check-off action

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'Clean the house'.to_i #=> 0 '12'.to_i #=> 12 '0'.to_i #=> 0

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There is no item 0, does not matter 'Clean the house'.to_i #=> 0 '12'.to_i #=> 12 '0'.to_i #=> 0

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todo_list = [] loop do input_as_string = gets input_as_int = input_as_string.to_i system "clear" if input_as_int > 0 todo_list.delete_at(input_as_int - 1) else todo_list << input_as_string end todo_list.each_with_index do |item, index| puts "#{index+1}: #{item}" end end

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Ok, that’s pretty short. Now let’s golf it.

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input_as_string=gets;input_as_int=input_as_string.to_i input_as_int=(input_as_string=gets).to_i

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input_as_string=gets;input_as_int=input_as_string.to_i input_as_int=(input_as_string=gets).to_i -14

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Use ternary if/else instead of if/else

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todo_list.each_with_index do |item, index| puts "#{index+1}: #{item}" end

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Way too long… todo_list.each_with_index do |item, index| puts "#{index+1}: #{item}" end

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todo_list.each_with_index{|item, index| puts "#{index+1}: #{item}"}

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todo_list.each_with_index{|item, index| puts "#{index+1}: #{item}"} index=0;todo_list.each{|item|puts "#{index+=1}: #{item}"}

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todo_list.each_with_index{|item, index| puts "#{index+1}: #{item}"} index=0;todo_list.each{|item|puts "#{index+=1}: #{item}"} index=0;todo_list.map{|item|puts "#{index+=1}: #{item}"}

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todo_list.each_with_index{|item, index| puts "#{index+1}: #{item}"} index=0;todo_list.each{|item|puts "#{index+=1}: #{item}"} index=0;todo_list.map{|item|puts "#{index+=1}: #{item}"} -11

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todo_list = [] loop do input_as_int=(input_as_string=gets).to_i system "clear" input_as_int>0?todo_list.delete_at(input_as_int-1):todo_list<

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Replace names & save whitespace 103 characters t=[] loop{i,j=(s=gets).to_i,0 system "clear" i>0?t.delete_at(i-1):t<

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bonus round

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delete_at is way too long t=[] loop{i,j=(s=gets).to_i,0 system "clear" i>0?t.delete_at(i-1):t<

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t.delete_at(i-1) t=t-[t[i-1]] t-=[t[i-1]]

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t.delete_at(i-1) t=t-[t[i-1]] t-=[t[i-1]] -5

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t=[] loop{i,j=(s=gets).to_i,0 system "clear" i>0?t-=[t[i-1]]:t<

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t=[] loop{i,j=(s=gets).to_i,0 system "clear" i>0?t-=[t[i-1]]:t<

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system "clear" puts "\033c"

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system "clear" puts "\033c" -2

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t=[] loop{i,j=(s=gets).to_i,0 puts "\033c" i>0?t-=[t[i-1]]:t<

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t=[] loop{i,j=(s=gets).to_i,0 puts "\033c" i>0?t-=[t[i-1]]:t<

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DRY

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DRY

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t=[] loop{i,j=(s=gets).to_i,0 puts "\033c" i>0?t-=[t[i-1]]:t<

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t=[] loop{i,j=(s=gets).to_i,0 i>0?t-=[t[i-1]]:t<

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puts "\033c";t.map{|g|puts "#{j+=1}: #{g}"} puts "\033c",t.map{|g|"#{j+=1}: #{g}"}

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puts "\033c";t.map{|g|puts "#{j+=1}: #{g}"} puts "\033c",t.map{|g|"#{j+=1}: #{g}"} -5

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t=[] loop{i,j=(s=gets).to_i,0 i>0?t-=[t[i-1]]:t<

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t=[] loop{i,j=gets.to_i,0 i>0?t-=[t[i-1]]:t<<$_ puts "\033c",t.map{|g|"#{j+=1}: #{g}"}}

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t=[] loop{i,j=gets.to_i,0 i>0?t-=[t[i-1]]:t<<$_ puts "\033c",t.map{|g|"#{j+=1}: #{g}"}} -3

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88 characters t=[] loop{i,j=gets.to_i,0 i>0?t-=[t[i-1]]:t<<$_ puts "\033c",t.map{|g|"#{j+=1}: #{g}"}}

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88 characters? Now we have space again.

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88 characters? Now we have space again. A persistent todo app in 129 characters.

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loop{t=IO.readlines(?a)rescue[] j=0 puts "\033c",t.map{|g|"#{j+=1}: #{g}"} i=gets.to_i i>0?t-=[t[i-1]]:t<<$_ IO.write ?a,t.join}

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loop{t=IO.readlines(?a)rescue[] j=0 puts "\033c",t.map{|g|"#{j+=1}: #{g}"} i=gets.to_i i>0?t-=[t[i-1]]:t<<$_ IO.write ?a,t.join} +41