Data commit

Task/Vigen-re-cipher/Julia/vigen-re-cipher.julia

@@ -0,0 +1,16 @@
+→(a::Char, b::Char, ± = +) = 'A'+((a-'A')±(b-'A')+26)%26
+←(a::Char, b::Char) = →(a,b,-)
+
+cleanup(str) = filter(a-> a in 'A':'Z', collect(uppercase.(str)))
+match_length(word, len) = repeat(word,len)[1:len]
+
+function →(message::String, codeword::String, ↔ = →)
+    plaintext = cleanup(message)
+    key = match_length(cleanup(codeword),length(plaintext))
+    return String(plaintext .↔ key)
+end
+←(message::String, codeword::String) = →(message,codeword,←)
+
+cyphertext = "I want spearmint gum" → "Gimme!"
+println(cyphertext)
+println(cyphertext ← "Gimme!")