cryptol/docs/ProgrammingCryptol/enigma/Simple.cry

/*
 * Copyright (c) 2013-2016 Galois, Inc.
 * Distributed under the terms of the BSD3 license (see LICENSE file)
 */

type Char = [8]
type Permutation = String 26

invSubst : (Permutation, Char) -> Char
invSubst (key, c) = candidates ! 0
  where candidates = [0] # [ if c == k then a else p
                           | k <- key
                           | a <- ['A' .. 'Z']
                           | p <- candidates
                           ]

myrev : {n,a} (fin n) => [n+1][a] -> [n+1][a]
myrev xs = [ xs!i | i <- [ 0 .. n] ]

sumAll xs = ys ! 0
    where ys = [0] # [x+y | x <- xs | y <- ys]

/*
simpleRec : {n,a} (fin n) => [n]a -> a
simpleRec xs = ret
    where
        (_,ret) = iters ! 0
        iters = [ (1,xs@0) ] #
                    [ (i,x) | x <- xs
                            | (i, _) <- iters ]

joinRotors : {n} (fin n) => [n]() -> [n]()
joinRotors rotors = rotors'
  where
    ncrs = [(True, ())]
               # [ (notch, r)
                 | r <- rotors
                 | (notch, _) <- ncrs
                 ]
    rotors' = tail [ r | (_, r) <- ncrs ]

*/