Another update from ingydotnet^djgoku

Task/Caesar-cipher/00DESCRIPTION

@@ -9,3 +9,9 @@ This simple "monoalphabetic substitution cipher" provides almost no security, be
 
 Caesar cipher is identical to [[Vigenère cipher]] with a key of length 1. <br>
 Also, [[Rot-13]] is identical to Caesar cipher with key 13.
+
+;See also:
+* [[Rot-13]]
+* [[Substitution Cipher]]
+* [[Vigenère Cipher/Cryptanalysis]]
+<br>

Task/Caesar-cipher/Befunge/caesar-cipher-1.bf

@@ -0,0 +1,3 @@
+65+>>>>10p100p1>:v:+>#*,#g1#0-#0:#!<<
+"`"::_@#!`\*84:<~<$<^+"A"%*2+9<v"{"\`
+**-"A"-::0\`\55*`+#^_\0g+"4"+4^>\`*48

Task/Caesar-cipher/Befunge/caesar-cipher-2.bf

@@ -0,0 +1,3 @@
+65+>>>>10p100p1>:v:+>#*,#g1#0-#0:#!<<
+"`"::_@#!`\*84:<~<$<^+"A"%*2+9<v"{"\`
+**-"A"-::0\`\55*`+#^_\0g-"4"+4^>\`*48

Task/Caesar-cipher/Elena/caesar-cipher.elena

@@ -1,74 +1,71 @@
 #define system.
 #define system'routines.
-#define extensions.
 #define system'math.
-
-// --- Constants ---
+#define extensions.
 
 #symbol Letters    = "abcdefghijklmnopqrstuvwxyz".
 #symbol BigLetters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".
 #symbol TestText   = "Pack my box with five dozen liquor jugs.".
 #symbol Key = 12.
 
-// --- Encrypt / Decript ---
-
-#class Encrypting
+#class Encrypting :: Enumerator
 {
     #field theKey.
-    #field theExtendee.
+    #field theEnumerator.
 
-    #constructor new : aKey &extending:anObject
+    #constructor new &key:aKey &text:aText
     [
         theKey := aKey.
-        theExtendee := anObject.
+        theEnumerator := aText enumerator.
     ]
 
-    #method eval : aChar
+    #method next => theEnumerator.
+
+    #method reset => theEnumerator.
+
+    #method get
     [
-        #var anIndex := Letters indexOf &index:0 &char:aChar.
+        #var aChar := theEnumerator get.
+
+        #var anIndex := Letters indexOf:0:aChar.
 
         (-1 < anIndex)
             ? [
-                theExtendee eval:(Letters @ ((theKey+anIndex) int mod:26))
+                ^ Letters @ ((theKey+anIndex) mod:26).
             ]
             ! [
-                anIndex := BigLetters indexOf &index:0 &char:aChar.
+                anIndex := BigLetters indexOf:0:aChar.
                 (-1 < anIndex)
                     ? [
-                        theExtendee eval:(BigLetters @ ((theKey+anIndex) int mod:26))
+                        ^ BigLetters @ ((theKey+anIndex) mod:26).
                     ]
                     ! [
-                        theExtendee eval:aChar.
+                        ^ aChar.
                     ].
             ].
     ]
-
-    #method => theExtendee.
 }
 
-// --- Functions ---
+#class(extension)encryptOp
+{
+    #method encrypt : aKey
+        = Encrypting new &key:aKey &text:self summarize:(String new).
 
-#symbol encrypt = (:aText:aKey)
-    [ Encrypting new:aKey &extending:(Summing new:(String new)) foreach:aText literal ].
-
-#symbol decrypt = (:aText:aKey)
-    [ Encrypting new:(26 - aKey) &extending:(Summing new:(String new)) foreach:aText literal ].
-
-// --- Program ---
+    #method decrypt :aKey
+        = Encrypting new &key:(26 - aKey) &text:self summarize:(String new).
+}
 
 #symbol program =
 [
-    #var anS := TestText.
+    console writeLine:"Original text :" :TestText.
 
-    consoleEx writeLine:"Original text :" :anS.
+    #var anEncryptedText := TestText encrypt:Key.
 
-    anS := encrypt:anS:Key.
+    console writeLine:"Encrypted text:" :anEncryptedText.
 
-    consoleEx writeLine:"Encrypted text:" :anS.
+    #var aDecryptedText := anEncryptedText decrypt:Key.
 
-    anS := decrypt:anS:Key.
+    console writeLine:"Decrypted text:" :aDecryptedText.
 
-    consoleEx writeLine:"Decrypted text:" :anS.
-
-    consoleEx readChar.
+    console readChar.
 ].

Task/Caesar-cipher/Elixir/caesar-cipher.elixir

@@ -0,0 +1,18 @@
+defmodule Caesar_cipher do
+  defp set_map(map, range, key) do
+    org = Enum.map(range, &List.to_string [&1])
+    {a, b} = Enum.split(org, key)
+    Enum.zip(org, b ++ a) |> Enum.into(map)
+  end
+
+  def encode(text, key) do
+    map = Map.new |> set_map(?a..?z, key) |> set_map(?A..?Z, key)
+    String.codepoints(text) |> Enum.map_join(fn c -> Dict.get(map, c, c) end)
+  end
+end
+
+text = "The five boxing wizards jump quickly"
+key = 3
+IO.puts "Original:  #{text}"
+IO.puts "Encrypted: #{enc = Caesar_cipher.encode(text, key)}"
+IO.puts "Decrypted: #{Caesar_cipher.encode(enc, -key)}"

Task/Caesar-cipher/R/caesar-cipher.r

@@ -0,0 +1,26 @@
+# based on Rot-13 solution: http://rosettacode.org/wiki/Rot-13#R
+ceasar <- function(x, key)
+{
+  # if key is negative, wrap to be positive
+  if (key < 0) {
+    key <- 26 + key
+  }
+
+  old <- paste(letters, LETTERS, collapse="", sep="")
+  new <- paste(substr(old, key * 2 + 1, 52), substr(old, 1, key * 2), sep="")
+  chartr(old, new, x)
+}
+
+# simple examples from description
+print(ceasar("hi",2))
+print(ceasar("hi",20))
+
+# more advanced example
+key <- 3
+plaintext <- "The five boxing wizards jump quickly."
+cyphertext <- ceasar(plaintext, key)
+decrypted <- ceasar(cyphertext, -key)
+
+print(paste("    Plain Text: ", plaintext, sep=""))
+print(paste("   Cypher Text: ", cyphertext, sep=""))
+print(paste("Decrypted Text: ", decrypted, sep=""))