1.7 KiB
Remarks
Just run it with no argument:
ruby entry.rb
Or run it with one non-ascii half-width character argument:
ruby entry.rb ⬮
ruby entry.rb 𓆡
I confirmed the following implementations/platforms:
- ruby 3.0.0p0 (2020-12-25 revision
95aff21468) [x86_64-darwin19] - ruby 3.1.0p0 (2021-12-25 revision
fb4df44d16) [x86_64-darwin20]
Description
This program is an aquatic quine.
Some characters in the code are overwritten with " ", but this program can restore the missing parts.
Every frame of this animation is an executable ruby program that let fishes start swimming again from their current position.
Internals
Error Correction
Error correction is performed for each block of length 135.
It consists of 89 kinds of characters([*('!'..'W'), '[', *(']'..'}')]) and satisfies the following constraint.
matrix(size: 45x135) * block_vector(size: 135) % 89 == zero_vector(size: 45)
To restore the missing characters in the block, we need to solve a linear equation problem in modulo 89. This can be achieved by using bundled gem 'matrix' and overwriting some methods.
require 'matrix'
matrix = Matrix[[3, 1, 4], [1, 5, 9], [2, 6, 5]]
class Integer
def quo(x) = self * x.pow(87, 89) % 89 # Fermat's little theorem. 89 is a prime number.
def abs() = [self % 89, 89 - self % 89].min # To avoid division by multiple of 89.
end
answer = matrix.lup.solve([1, 2, 3]) #=> Vector[24, 42, 83]
(matrix * answer).map { _1 % 89 } #=> Vector[1, 2, 3]
Resuming Animation
The entire animation of this fish tank is a loop of 960 frames. This program uses position of the floating bubbles to detect current frame number from the executed source code.