Add atbash-cipher exercise

config.json

@@ -385,6 +385,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 8
+      },
+      {
+        "slug": "atbash-cipher",
+        "name": "Atbash Cipher",
+        "uuid": "3da8ba25-b6a2-431f-a4a7-e7fc33318fdb",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
       }
     ]
   },

exercises/practice/atbash-cipher/.docs/instructions.md

@@ -0,0 +1,27 @@
+# Instructions
+
+Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.
+
+The Atbash cipher is a simple substitution cipher that relies on transposing all the letters in the alphabet such that the resulting alphabet is backwards.
+The first letter is replaced with the last letter, the second with the second-last, and so on.
+
+An Atbash cipher for the Latin alphabet would be as follows:
+
+```text
+Plain:  abcdefghijklmnopqrstuvwxyz
+Cipher: zyxwvutsrqponmlkjihgfedcba
+```
+
+It is a very weak cipher because it only has one possible key, and it is a simple mono-alphabetic substitution cipher.
+However, this may not have been an issue in the cipher's time.
+
+Ciphertext is written out in groups of fixed length, the traditional group size being 5 letters, leaving numbers unchanged, and punctuation is excluded.
+This is to make it harder to guess things based on word boundaries.
+All text will be encoded as lowercase letters.
+
+## Examples
+
+- Encoding `test` gives `gvhg`
+- Encoding `x123 yes` gives `c123b vh`
+- Decoding `gvhg` gives `test`
+- Decoding `gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt` gives `thequickbrownfoxjumpsoverthelazydog`

exercises/practice/atbash-cipher/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "eNascimento178"
+  ],
+  "files": {
+    "solution": [
+      "atbash-cipher.ijs"
+    ],
+    "test": [
+      "test.ijs"
+    ],
+    "example": [
+      ".meta/example.ijs"
+    ]
+  },
+  "blurb": "Create an implementation of the atbash cipher, an ancient encryption system created in the Middle East.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Atbash"
+}

exercises/practice/atbash-cipher/.meta/example.ijs

@@ -0,0 +1,7 @@
+require 'strings'
+
+numbers=: a. {~ 48 + i. 10
+alphabet=: numbers ,~ |. a. {~ 97 + i. 26
+
+encode=: (' ' joinstring _5 <\ alphabet {~ [: (75&+^:(0&>)@(_97 + a.&i.))"0 ('[^0-9a-z]';'')&rxrplc@tolower)
+decode=: (a. {~ [: (_75&+^:(122&<)@(97 + alphabet&i.))"0 -.&' ')

exercises/practice/atbash-cipher/.meta/tests.toml

@@ -0,0 +1,52 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[2f47ebe1-eab9-4d6b-b3c6-627562a31c77]
+description = "encode -> encode yes"
+
+[b4ffe781-ea81-4b74-b268-cc58ba21c739]
+description = "encode -> encode no"
+
+[10e48927-24ab-4c4d-9d3f-3067724ace00]
+description = "encode -> encode OMG"
+
+[d59b8bc3-509a-4a9a-834c-6f501b98750b]
+description = "encode -> encode spaces"
+
+[31d44b11-81b7-4a94-8b43-4af6a2449429]
+description = "encode -> encode mindblowingly"
+
+[d503361a-1433-48c0-aae0-d41b5baa33ff]
+description = "encode -> encode numbers"
+
+[79c8a2d5-0772-42d4-b41b-531d0b5da926]
+description = "encode -> encode deep thought"
+
+[9ca13d23-d32a-4967-a1fd-6100b8742bab]
+description = "encode -> encode all the letters"
+
+[bb50e087-7fdf-48e7-9223-284fe7e69851]
+description = "decode -> decode exercism"
+
+[ac021097-cd5d-4717-8907-b0814b9e292c]
+description = "decode -> decode a sentence"
+
+[18729de3-de74-49b8-b68c-025eaf77f851]
+description = "decode -> decode numbers"
+
+[0f30325f-f53b-415d-ad3e-a7a4f63de034]
+description = "decode -> decode all the letters"
+
+[39640287-30c6-4c8c-9bac-9d613d1a5674]
+description = "decode -> decode with too many spaces"
+
+[b34edf13-34c0-49b5-aa21-0768928000d5]
+description = "decode -> decode with no spaces"

exercises/practice/atbash-cipher/atbash-cipher.ijs

@@ -0,0 +1,4 @@
+require 'general/unittest'
+
+encode=: 'You need to implement this verb.'13!:8 (55)
+decode=: 'You need to implement this verb.'13!:8 (55)

exercises/practice/atbash-cipher/test.ijs

@@ -0,0 +1,149 @@
+load 'atbash-cipher.ijs'
+
+
+before_all=: monad define
+  (]Description =: (3 : 'descriptions=: i.0')`(3 : 'descriptions=: descriptions , < y'))@.0 ''
+  (]Order       =: (3 : 'order=: i.0')`(3 : 'order=: order , < y'))@.0 ''
+  (]Task        =: (3 : 'tasks=: i.0')`(3 : 'tasks=: tasks , < y'))@.0 '' 
+)
+
+
+atbash_cipher_test_01_ignore=: 0
+test_atbash_cipher_test_01  =: monad define
+  Description@.1 ('encode yes')
+  Order@.1 (1)
+
+  NB. phrase=. 'yes'
+  NB. expected=. 'bvh'
+  assert 'bvh' -: encode 'yes'
+)
+
+atbash_cipher_test_02_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_02  =: monad define
+  Description@.1 ('encode no')
+  Order@.1 (2)
+
+  NB. phrase=. 'no'
+  NB. expected=. 'ml'
+  assert 'ml' -: encode 'no'
+)
+
+atbash_cipher_test_03_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_03  =: monad define
+  Description@.1 ('encode OMG')
+  Order@.1 (3)
+
+  NB. phrase=. 'OMG'
+  NB. expected=. 'lnt'
+  assert 'lnt' -: encode 'OMG'
+)
+
+atbash_cipher_test_04_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_04  =: monad define
+  Description@.1 ('encode spaces')
+  Order@.1 (4)
+
+  NB. phrase=. 'O M G'
+  NB. expected=. 'lnt'
+  assert 'lnt' -: encode 'O M G'
+)
+
+atbash_cipher_test_05_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_05  =: monad define
+  Description@.1 ('encode mindblowingly')
+  Order@.1 (5)
+
+  NB. phrase=. 'mindblowingly'
+  NB. expected=. 'nrmwy oldrm tob'
+  assert 'nrmwy oldrm tob' -: encode 'mindblowingly'
+)
+
+atbash_cipher_test_06_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_06  =: monad define
+  Description@.1 ('encode numbers')
+  Order@.1 (6)
+
+  NB. phrase=. 'Testing,1 2 3, testing.'
+  NB. expected=. 'gvhgr mt123 gvhgr mt'
+  assert 'gvhgr mt123 gvhgr mt' -: encode 'Testing,1 2 3, testing.'
+)
+
+atbash_cipher_test_07_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_07  =: monad define
+  Description@.1 ('encode deep thought')
+  Order@.1 (7)
+
+  NB. phrase=. 'Truth is fiction.'
+  NB. expected=. 'gifgs rhurx grlm'
+  assert 'gifgs rhurx grlm' -: encode 'Truth is fiction.'
+)
+
+atbash_cipher_test_08_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_08  =: monad define
+  Description@.1 ('encode all the letters')
+  Order@.1 (8)
+
+  NB. phrase=. 'The quick brown fox jumps over the lazy dog.'
+  NB. expected=. 'gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt'
+  assert 'gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt' -: encode 'The quick brown fox jumps over the lazy dog.'
+)
+
+atbash_cipher_test_09_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_09  =: monad define
+  Description@.1 ('decode exercism')
+  Order@.1 (9)
+
+  NB. phrase=. 'vcvix rhn'
+  NB. expected=. 'exercism'
+  assert 'exercism' -: decode 'vcvix rhn'
+)
+
+atbash_cipher_test_10_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_10  =: monad define
+  Description@.1 ('decode a sentence')
+  Order@.1 (10)
+
+  NB. phrase=. 'zmlyh gzxov rhlug vmzhg vkkrm thglm v'
+  NB. expected=. 'anobstacleisoftenasteppingstone'
+  assert 'anobstacleisoftenasteppingstone' -: decode 'zmlyh gzxov rhlug vmzhg vkkrm thglm v'
+)
+
+atbash_cipher_test_11_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_11  =: monad define
+  Description@.1 ('decode numbers')
+  Order@.1 (11)
+
+  NB. phrase=. 'gvhgr mt123 gvhgr mt'
+  NB. expected=. 'testing123testing'
+  assert 'testing123testing' -: decode 'gvhgr mt123 gvhgr mt'
+)
+
+atbash_cipher_test_12_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_12  =: monad define
+  Description@.1 ('decode all the letters')
+  Order@.1 (12)
+
+  NB. phrase=. 'gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt'
+  NB. expected=. 'thequickbrownfoxjumpsoverthelazydog'
+  assert 'thequickbrownfoxjumpsoverthelazydog' -: decode 'gsvjf rxpyi ldmul cqfnk hlevi gsvoz abwlt'
+)
+
+atbash_cipher_test_13_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_13  =: monad define
+  Description@.1 ('decode with too many spaces')
+  Order@.1 (13)
+
+  NB. phrase=. 'vc vix    r hn'
+  NB. expected=. 'exercism'
+  assert 'exercism' -: decode 'vc vix    r hn'
+)
+
+atbash_cipher_test_14_ignore=: 1 NB. Change this value to 0 to run this test
+test_atbash_cipher_test_14  =: monad define
+  Description@.1 ('decode with no spaces')
+  Order@.1 (14)
+
+  NB. phrase=. 'zmlyhgzxovrhlugvmzhgvkkrmthglmv'
+  NB. expected=. 'anobstacleisoftenasteppingstone'
+  assert 'anobstacleisoftenasteppingstone' -: decode 'zmlyhgzxovrhlugvmzhgvkkrmthglmv'
+)