wreczek

BOARD = [
    [7,8,0,4,0,0,1,2,0],
    [6,0,0,0,7,5,0,0,9],
    [0,0,0,6,0,1,0,7,8],
    [0,0,7,0,4,0,2,6,0],
    [0,0,1,0,5,0,9,3,0],
    [9,0,4,0,6,0,0,0,5],
    [0,7,0,3,0,0,0,1,2],
    [1,2,0,0,0,7,4,0,0],
    [0,4,9,2,0,6,0,0,7]

wreczek

#!/usr/bin/env python
"""Server site implementation of the product, where users can
    save URLs and retrieve them later."""

__author__ = "Wiktor Reczek"


class UrlService:
    """CRUD service without `update`."""

wreczek

{-# LANGUAGE RankNTypes #-}
module ChurchNumerals
    ( church, unchurch, zero, one, two, three, four,
      five, six, seven, eight, nine, ten
    ) where

-- we define natural numbers of Church
type Church a = (a -> a) -> a -> a

-- converting functions

wreczek

module ChurchBooleans
    (true, false, not', and', or', xor', to_boolean) where


-- defining Church values: true and false
true :: t1 -> t -> t1
true= \x y -> x

false :: t -> t1 -> t1
false= \x y -> y

wreczek

module Calculation
    (increment, decrement, add, mul, pow) where


-- arithmetic operations, additionally give us the
-- view of new, undefined numerals
increment :: ((a -> b) -> c -> a) -> (a -> b) -> c -> b
increment = \g f x -> f(g(f)(x))

decrement :: (((r -> b) -> (b -> c) -> c) ->

wreczek

module Pairs
    (first, second,pair) where

--needed for first and second operations, uses true and false
-- from ChurchBooleans
import ChurchBooleans

-- functions that are needed for list operations
first :: ((t1 -> t2 -> t1) -> t) -> t
first = \f -> f(true)

wreczek

module Calculation
    (increment, decrement, add, mul, pow) where


-- arithmetic operations, additionally give us the
-- view of new, undefined numerals
increment :: ((a -> b) -> c -> a) -> (a -> b) -> c -> b
increment = \g f x -> f(g(f)(x))

decrement :: (((r -> b) -> (b -> c) -> c) ->