module SubstitutionCipher { const key = %c"]kYV}(!7P$n5_0i R:?jOWtF/=-pe'AD&@r6%ZXs\"v*N[#wSl9zq2^+g;LoB`aGh{3.HIu4fbK)mU8|dMET><,Qc\\C1yxJ" func encode(String s) { var r = "" s.each {|c| r += key[c.ord - 32] } return r } func decode(String s) { var r = "" s.each {|c| r += (key.first_index { _ == c } + 32 -> chr) } return r } } with ("The quick brown fox jumps over the lazy dog, who barks VERY loudly!") { |s| var enc = SubstitutionCipher::encode(s) var dec = SubstitutionCipher::decode(enc) say("Original: ", s, "\n -> Encoded: ", enc, "\n -> Decoded: ", dec) }