Sha256: 0e7219e56b696e92d2c5ced918ca4595e0cb1090bf451ebbc2ca17291a37585a
Contents?: true
Size: 1.33 KB
Versions: 68
Compression:
Stored size: 1.33 KB
Contents
open Base
let substitute = function
| 'a' .. 'z' as c ->
let offset = (Char.to_int c) - (Char.to_int 'a') in
let code = (Char.to_int 'z') - offset in
Char.of_int_exn code
| other -> other
let is_encodable = function
| 'a' .. 'z' | '0' .. '9' -> true
| _ -> false
let explode s =
let rec expl i l =
if i < 0 then
l
else
expl (i - 1) (s.[i] :: l)
in
expl ((String.length s) - 1) []
let implode l =
let character_at i = List.nth_exn l i in
String.init (List.length l) ~f:character_at
let rec group n l =
if (List.length l) <= n then
[l]
else
(List.take l n) :: (group n (List.drop l n))
let encode ?block_size:(block_size = 5) text =
let lowercase_text = String.lowercase text in
let characters = explode lowercase_text in
let filtered_characters = List.filter ~f:is_encodable characters in
let groups = group block_size filtered_characters in
let preprocessed_texts = List.map ~f:implode groups in
let texts = List.map ~f:(String.map ~f:substitute) preprocessed_texts in
String.concat ~sep:" " texts
let decode text =
let lowercase_text = String.lowercase text in
let characters = explode lowercase_text in
let filtered_characters = List.filter ~f:is_encodable characters in
let preprocessed_text = implode filtered_characters in
String.map ~f:substitute preprocessed_text
Version data entries
68 entries across 68 versions & 1 rubygems