Add poker

config.json

@@ -914,6 +914,14 @@
         "prerequisites": [],
         "difficulty": 7
       },
+      {
+        "slug": "poker",
+        "name": "Poker",
+        "uuid": "662bce2e-94bb-4b1e-94a0-d69be06ab7e8",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 7
+      },
       {
         "slug": "rectangles",
         "name": "Rectangles",

exercises/practice/poker/.busted

@@ -0,0 +1,5 @@
+return {
+  default = {
+    ROOT = { '.' }
+  }
+}

exercises/practice/poker/.docs/instructions.md

@@ -0,0 +1,7 @@
+# Instructions
+
+Pick the best hand(s) from a list of poker hands.
+
+See [Wikipedia][poker-hands] for an overview of poker hands.
+
+[poker-hands]: https://en.wikipedia.org/wiki/List_of_poker_hands

exercises/practice/poker/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "files": {
+    "solution": [
+      "poker.moon"
+    ],
+    "test": [
+      "poker_spec.moon"
+    ],
+    "example": [
+      ".meta/example.moon"
+    ]
+  },
+  "blurb": "Pick the best hand(s) from a list of poker hands.",
+  "source": "Inspired by the training course from Udacity.",
+  "source_url": "https://www.udacity.com/course/design-of-computer-programs--cs212"
+}

exercises/practice/poker/.meta/example.moon

@@ -0,0 +1,110 @@
+List = require 'pl.List'
+import fold from require 'moon'
+
+class Card
+  new: (cardString) =>
+    @cardString = cardString
+    @suit = cardString\sub -1
+    @rank = switch cardString\sub 0, -2
+      when 'A' then 14
+      when 'K' then 13
+      when 'Q' then 12
+      when 'J' then 11
+      else tonumber(cardString\sub 0, -2)
+
+  __lt: (other) => @rank < other.rank
+  __eq: (other) => @rank == other.rank
+  __gt: (other) => @rank > other.rank
+
+-- ------------------------------------------------------------------
+class PokerHand
+  new: (handString) =>
+    @handString = handString
+    @cards = List [Card cardString for cardString in handString\gmatch '%S+']
+    @category, @value = @initialize!
+
+  initialize: =>
+    @cards\sort (a, b) -> a.rank > b.rank -- sort descending by rank
+
+    ranks = [card.rank for card in *@cards]
+    -- handle the ranks as the digits of a base-14 number, so we can easily compare hands of the same category
+    ranking = (...) -> fold({0, ...}, (acc, rank) -> acc * 14 + rank)
+
+    -- ignore five of a kind
+
+    is_straight, straight_val = @isStraight!
+    is_flush = @isFlush!
+
+    if is_straight and is_flush
+      return 2, ranking straight_val
+
+    -- four of a kind
+    if ranks[1] == ranks[4]
+      return 3, ranking(ranks[1], ranks[5])
+    elseif ranks[2] == ranks[5]
+      return 3, ranking(ranks[2], ranks[1])
+
+    -- full house
+    if ranks[1] == ranks[3] and ranks[4] == ranks[5]
+      return 4, ranking(ranks[1], ranks[4])
+    elseif ranks[1] == ranks[2] and ranks[3] == ranks[5]
+      return 4, ranking(ranks[3], ranks[1])
+
+    if is_flush
+      return 5, ranking(table.unpack ranks)  
+    if is_straight
+      return 6, ranking straight_val
+
+    -- three of a kind
+    if ranks[1] == ranks[3]
+      return 7, ranking(ranks[1], ranks[4], ranks[5])
+    elseif ranks[2] == ranks[4]
+      return 7, ranking(ranks[2], ranks[1], ranks[5])
+    elseif ranks[3] == ranks[5]
+      return 7, ranking(ranks[3], ranks[1], ranks[2])
+
+    -- two pair
+    if ranks[1] == ranks[2] and ranks[3] == ranks[4]
+      return 8, ranking(ranks[1], ranks[3], ranks[5])
+    elseif ranks[1] == ranks[2] and ranks[4] == ranks[5]
+      return 8, ranking(ranks[1], ranks[4], ranks[3])
+    elseif ranks[2] == ranks[3] and ranks[4] == ranks[5]
+      return 8, ranking(ranks[2], ranks[4], ranks[1])
+
+    -- one pair
+    for i = 1, 4
+      if ranks[i] == ranks[i+1]
+        return 9, ranking(ranks[i], table.unpack [ranks[j] for j = 1, 5 when j < i or j > i+1])
+
+    -- high card
+    return 10, ranking(table.unpack ranks)
+
+
+  isFlush: =>
+    suits = [card.suit for card in *@cards when card.suit == @cards[1].suit]
+    #suits == #@cards
+
+  isStraight: =>
+    ranks = List [card.rank for card in *@cards]
+    return true, 5 if ranks == {14, 5, 4, 3, 2}
+    for i = 2, 5
+      return false, 0 if ranks[i] != ranks[i-1] - 1
+    true, ranks[1]
+
+  isRoyalFlush: =>
+    @isStraight() and @isFlush() and @cards[1].rank == 14 
+
+  __lt: (other) =>
+    -- lower category wins; if same category, higher value wins
+    @category < other.category or (@category == other.category and @value > other.value)
+
+  __eq: (other) =>
+    @category == other.category and @value == other.value
+
+-- ------------------------------------------------------------------
+{
+  bestHands: (handsStrings) ->
+    hands = List [PokerHand hand for hand in *handsStrings]
+    hands\sort!
+    [hand.handString for hand in *hands when hand == hands[1]]
+}

exercises/practice/poker/.meta/spec_generator.moon

@@ -0,0 +1,17 @@
+import indent, string_list from require 'spec_helpers'
+assertions = require 'spec_helpers/assertions'
+
+{
+  module_name: 'Poker',
+
+  test_helpers: assertions.same_elements
+
+  generate_test: (case, level) ->
+    lines = {
+      "hands = #{string_list case.input.hands, level, inline: 1}",
+      "expected = #{string_list case.expected, level, inline: 1}",
+    }
+    assertion = if #case.expected == 1 then 'assert.are.same' else 'assert.has.same_elements'
+    table.insert lines, "#{assertion} expected, Poker.#{case.property} hands"
+    table.concat [indent line, level for line in *lines], '\n'
+}

exercises/practice/poker/.meta/tests.toml

@@ -0,0 +1,131 @@
+# 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.
+
+[161f485e-39c2-4012-84cf-bec0c755b66c]
+description = "single hand always wins"
+
+[370ac23a-a00f-48a9-9965-6f3fb595cf45]
+description = "highest card out of all hands wins"
+
+[d94ad5a7-17df-484b-9932-c64fc26cff52]
+description = "a tie has multiple winners"
+
+[61ed83a9-cfaa-40a5-942a-51f52f0a8725]
+description = "multiple hands with the same high cards, tie compares next highest ranked, down to last card"
+
+[da01becd-f5b0-4342-b7f3-1318191d0580]
+description = "winning high card hand also has the lowest card"
+
+[f7175a89-34ff-44de-b3d7-f6fd97d1fca4]
+description = "one pair beats high card"
+
+[e114fd41-a301-4111-a9e7-5a7f72a76561]
+description = "highest pair wins"
+
+[b3acd3a7-f9fa-4647-85ab-e0a9e07d1365]
+description = "both hands have the same pair, high card wins"
+
+[935bb4dc-a622-4400-97fa-86e7d06b1f76]
+description = "two pairs beats one pair"
+
+[c8aeafe1-6e3d-4711-a6de-5161deca91fd]
+description = "both hands have two pairs, highest ranked pair wins"
+
+[88abe1ba-7ad7-40f3-847e-0a26f8e46a60]
+description = "both hands have two pairs, with the same highest ranked pair, tie goes to low pair"
+
+[15a7a315-0577-47a3-9981-d6cf8e6f387b]
+description = "both hands have two identically ranked pairs, tie goes to remaining card (kicker)"
+
+[f761e21b-2560-4774-a02a-b3e9366a51ce]
+description = "both hands have two pairs that add to the same value, win goes to highest pair"
+
+[fc6277ac-94ac-4078-8d39-9d441bc7a79e]
+description = "two pairs first ranked by largest pair"
+
+[21e9f1e6-2d72-49a1-a930-228e5e0195dc]
+description = "three of a kind beats two pair"
+
+[c2fffd1f-c287-480f-bf2d-9628e63bbcc3]
+description = "both hands have three of a kind, tie goes to highest ranked triplet"
+
+[eb856cc2-481c-4b0d-9835-4d75d07a5d9d]
+description = "with multiple decks, two players can have same three of a kind, ties go to highest remaining cards"
+include = false
+
+[26a4a7d4-34a2-4f18-90b4-4a8dd35d2bb1]
+description = "with multiple decks, two players can have same three of a kind, ties go to highest remaining cards"
+reimplements = "eb856cc2-481c-4b0d-9835-4d75d07a5d9d"
+
+[a858c5d9-2f28-48e7-9980-b7fa04060a60]
+description = "a straight beats three of a kind"
+
+[73c9c756-e63e-4b01-a88d-0d4491a7a0e3]
+description = "aces can end a straight (10 J Q K A)"
+
+[76856b0d-35cd-49ce-a492-fe5db53abc02]
+description = "aces can start a straight (A 2 3 4 5)"
+
+[e214b7df-dcba-45d3-a2e5-342d8c46c286]
+description = "aces cannot be in the middle of a straight (Q K A 2 3)"
+
+[6980c612-bbff-4914-b17a-b044e4e69ea1]
+description = "both hands with a straight, tie goes to highest ranked card"
+
+[5135675c-c2fc-4e21-9ba3-af77a32e9ba4]
+description = "even though an ace is usually high, a 5-high straight is the lowest-scoring straight"
+
+[c601b5e6-e1df-4ade-b444-b60ce13b2571]
+description = "flush beats a straight"
+
+[4d90261d-251c-49bd-a468-896bf10133de]
+description = "both hands have a flush, tie goes to high card, down to the last one if necessary"
+include = false
+
+[e04137c5-c19a-4dfc-97a1-9dfe9baaa2ff]
+description = "both hands have a flush, tie goes to high card, down to the last one if necessary"
+reimplements = "4d90261d-251c-49bd-a468-896bf10133de"
+
+[3a19361d-8974-455c-82e5-f7152f5dba7c]
+description = "full house beats a flush"
+
+[eb73d0e6-b66c-4f0f-b8ba-bf96bc0a67f0]
+description = "both hands have a full house, tie goes to highest-ranked triplet"
+
+[34b51168-1e43-4c0d-9b32-e356159b4d5d]
+description = "with multiple decks, both hands have a full house with the same triplet, tie goes to the pair"
+
+[d61e9e99-883b-4f99-b021-18f0ae50c5f4]
+description = "four of a kind beats a full house"
+
+[2e1c8c63-e0cb-4214-a01b-91954490d2fe]
+description = "both hands have four of a kind, tie goes to high quad"
+
+[892ca75d-5474-495d-9f64-a6ce2dcdb7e1]
+description = "with multiple decks, both hands with identical four of a kind, tie determined by kicker"
+
+[923bd910-dc7b-4f7d-a330-8b42ec10a3ac]
+description = "straight flush beats four of a kind"
+
+[d9629e22-c943-460b-a951-2134d1b43346]
+description = "aces can end a straight flush (10 J Q K A)"
+
+[05d5ede9-64a5-4678-b8ae-cf4c595dc824]
+description = "aces can start a straight flush (A 2 3 4 5)"
+
+[ad655466-6d04-49e8-a50c-0043c3ac18ff]
+description = "aces cannot be in the middle of a straight flush (Q K A 2 3)"
+
+[d0927f70-5aec-43db-aed8-1cbd1b6ee9ad]
+description = "both hands have a straight flush, tie goes to highest-ranked card"
+
+[be620e09-0397-497b-ac37-d1d7a4464cfc]
+description = "even though an ace is usually high, a 5-high straight flush is the lowest-scoring straight flush"

exercises/practice/poker/poker.moon

@@ -0,0 +1,4 @@
+{
+  bestHands: (handsStrings) ->
+    error 'Implement me!'
+}