Data commit

Task/Playfair-cipher/Sidef/playfair-cipher.sidef

@@ -0,0 +1,59 @@
+func playfair(key, from = 'J', to = (from == 'J' ? 'I' : '')) {
+
+    func canon(str) {
+        str.gsub(/[^[:alpha:]]/, '').uc.gsub(from, to)
+    }
+
+    var m = canon(key + ('A'..'Z' -> join)).chars.uniq.slices(5)
+
+    var :ENC = gather {
+        m.each { |r|
+            for i,j in (^r ~X ^r) {
+                i == j && next
+                take(Pair("#{r[i]}#{r[j]}", "#{r[(i+1)%5]}#{r[(j+1)%5]}"))
+            }
+        }
+
+        ^5 -> each { |k|
+            var c = m.map {|a| a[k] }
+            for i,j in (^c ~X ^c) {
+                i == j && next
+                take(Pair("#{c[i]}#{c[j]}", "#{c[(i+1)%5]}#{c[(j+1)%5]}"))
+            }
+        }
+
+        cartesian([^5, ^5, ^5, ^5], {|i1,j1,i2,j2|
+            i1 == i2 && next
+            j1 == j2 && next
+            take(Pair("#{m[i1][j1]}#{m[i2][j2]}", "#{m[i1][j2]}#{m[i2][j1]}"))
+        })
+    }.map { (.key, .value) }...
+
+    var DEC = ENC.flip
+
+    func enc(red) {
+        gather {
+            var str = canon(red)
+            while (var m = (str =~ /(.)(?(?=\1)|(.?))/g)) {
+                take("#{m[0]}#{m[1] == '' ? 'X' : m[1]}")
+            }
+        }.map { ENC{_} }.join(' ')
+    }
+
+    func dec(black) {
+        canon(black).split(2).map { DEC{_} }.join(' ')
+    }
+
+    return(enc, dec)
+}
+
+var (encode, decode) = playfair('Playfair example')
+
+var orig = "Hide the gold in...the TREESTUMP!!!"
+say " orig:\t#{orig}"
+
+var black = encode(orig)
+say "black:\t#{black}"
+
+var red = decode(black)
+say "  red:\t#{red}"