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Game of Life in 140 chars of Ruby

Game of Life

An implementation of Conway's Game of Life in 140 characters of Ruby.

Author

Created by Simon Ernst (@sier).

Thanks to @aemkei for feedback and inspiration!

life=->g,s{(0..s*s-1).map{|i|->n{n==3||(g[i]&&n==2)||nil}[[g[i-s-1],g[i-s],g[i-s+1],g[i-1],g[i+1],g[i+s-1],g[i+s],g[i+s+1]].compact.count]}}
# The code with some animation logic for demonstration.
#
life=->g,s{(0..s*s-1).map{|i|->n{n==3||(g[i]&&n==2)||nil}[[g[i-s-1],g[i-s],g[i-s+1],g[i-1],g[i+1],g[i+s-1],g[i+s],g[i+s+1]].compact.count]}}
size = 20
grid = (1..size*size).map { rand(0..1)==1 ? 1 : nil }
while true do
system 'clear'
grid = life[grid, size]
(0..size-1).each do |y|
(0..size-1).each do |x|
print "#{(grid[x+(y*size)] ? 'O' : '.')}"
end
puts
end
sleep 0.1
end
# Expanded version for better readability.
#
life = lambda do |grid, size|
(0..size*size-1).map do |i|
lambda do |neighbours|
neighbours == 3 || ( grid[i] && neighbours == 2 )|| nil
end.call (
[
grid[i-size-1], grid[i-size], grid[i-size+1],
grid[i-1], grid[i+1],
grid[i+size-1], grid[i+size], grid[i+size+1]
].compact.count
)
end
end
# Small rewrite of the original code to support independent x and y values.
# Doesn't fit in 140 chars anymore, though.
#
life = lambda do |grid, x, y|
(0..x*y-1).map do |i|
lambda do |neighbours|
neighbours == 3 || ( grid[i] && neighbours == 2 )|| nil
end.call (
[
grid[i-x-1], grid[i-x], grid[i-x+1],
grid[i-1], grid[i+1],
grid[i+x-1], grid[i+x], grid[i+x+1]
].compact.count
)
end
end
x = 80
y = 20
grid = (1..x*y).map { rand(0..1)==1 ? 1 : nil }
while true do
system 'clear'
grid = life[grid, x, y]
(0..y-1).each do |yi|
(0..x-1).each do |xi|
print "#{(grid[xi+(yi*x)] ? 'O' : '.')}"
end
puts
end
sleep 0.1
end
@maettig
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maettig commented Feb 9, 2012

Just for the sake of completeness, here is Conway's Game of Life in 140byt.es JavaScript.

@Neurogami
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Interesting, but the expanded version gives an error:

`rand': can't convert Range into Integer (TypeError)

@DNNX
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DNNX commented Feb 11, 2012

rand(a..b) does not work by default in 1.8. you should use 1.9 or replace rand(range) call with Random.new.rand(range)

@netmute
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Author

netmute commented Feb 11, 2012

@Neurogami Directly passing ranges to rand only works in Ruby 1.9.3.
Try Random.new.rand instead.

@jablan
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jablan commented Feb 11, 2012

@Neurogami
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Ah, thanks. I had tried it 1.9.2

@pjlsergeant
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I put together a cute little Perl version: https://gist.github.com/1803656

@Roman2K
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Roman2K commented Feb 11, 2012

Reminds me of an experiment I made years ago, world:

$ git clone https://github.com/Roman2K/_world world
$ cd world
$ ruby lib/world.rb

@xem
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xem commented Sep 13, 2013

My attempt, in JavaScript: 130 bytes
http://xem.github.io/miniGameOfLife

@coreyward
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Here's an even shorter version:

require 'open-uri'
eval open('http://bit.ly/16brOlw').read

👅

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