Sha256: 7d99525680e1ef8948185fc73201270d2390f8591538157d971ff9d813451669
Contents?: true
Size: 1.08 KB
Versions: 46
Compression:
Stored size: 1.08 KB
Contents
use "itertools"
primitive Atbash
fun _transpose(c: U8): U8 =>
if (('a' <= c) and (c <= 'z')) then
('z' - c) + 'a'
else
c
end
fun _transposable(c: U8): Bool =>
(('a' <= c) and (c <= 'z')) or (('0' <= c) and (c <= '9'))
fun _group(groups: Array[String ref], c: U8): Array[String ref]^ =>
let last_idx = groups.size() - 1
let last = try groups(last_idx)? else String end
if last.size() < 5 then
last.push(c)
else
last.push(' ')
groups.push(String(6) .> push(c))
end
groups
fun encode(input: String): String iso^ =>
try
String.join(
Iter[U8](input.lower().values())
.filter(this~_transposable())
.map[U8]({(c: U8): U8 => Atbash._transpose(c) })
.fold[Array[String ref]](this~_group(), [String(6)])?
.values())
else
recover String end
end
fun decode(input: String): String iso^ =>
recover
Iter[U8](input.values())
.filter({(c: U8): Bool => c != ' '})
.map[U8](this~_transpose())
.collect[String ref](String)
end
Version data entries
46 entries across 46 versions & 1 rubygems