{"id":22,"date":"2007-07-26T23:18:11","date_gmt":"2007-07-27T06:18:11","guid":{"rendered":"http:\/\/www.elbeno.com\/haskell_soe_blog\/?p=22"},"modified":"2008-01-07T22:05:05","modified_gmt":"2008-01-08T06:05:05","slug":"exercise-58","status":"publish","type":"post","link":"https:\/\/www.elbeno.com\/haskell_soe_blog\/?p=22","title":{"rendered":"Exercise 5.8"},"content":{"rendered":"<pre lang=\"haskell\">encrypt :: [Char] -> [Char]\r\nencrypt cs = map encChar cs\r\n    where encChar c = toEnum((fromEnum c + 1) `mod` 256)\r\n\r\ndecrypt :: [Char] -> [Char]\r\ndecrypt cs = map decChar cs\r\n    where decChar c = toEnum((fromEnum c + 256 - 1) `mod` 256)<\/pre>\n<p>The addition of 256 ensures a proper wraparound on decryption. This exercise seemed a bit silly to me: why not have one function to do both, and allow an arbitrary key?<\/p>\n<pre lang=\"haskell\">caesar :: [Char] -> Int -> [Char]\r\ncaesar cs k = map caesarChar cs\r\n    where caesarChar c = toEnum((fromEnum c + 256 + k) `mod` 256)<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>encrypt :: [Char] -> [Char] encrypt cs = map encChar cs where encChar c = toEnum((fromEnum c + 1) `mod` 256) decrypt :: [Char] -> [Char] decrypt cs = map decChar cs where decChar c = toEnum((fromEnum c + 256 &#8211; 1) `mod` 256) The addition of 256 ensures a proper wraparound on decryption. This [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/22"}],"collection":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=22"}],"version-history":[{"count":0,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=\/wp\/v2\/posts\/22\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=22"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=22"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.elbeno.com\/haskell_soe_blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=22"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}