Add dnd-character exercise (#705)

config.json

@@ -276,6 +276,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "dnd-character",
+        "name": "D&D Character",
+        "uuid": "f018dfdd-001f-4ec7-a46c-9dcea229c4c4",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "etl",
         "name": "ETL",

exercises/practice/dnd-character/.docs/instructions.md

@@ -0,0 +1,32 @@
+# Instructions
+
+For a game of [Dungeons & Dragons][dnd], each player starts by generating a character they can play with.
+This character has, among other things, six abilities; strength, dexterity, constitution, intelligence, wisdom and charisma.
+These six abilities have scores that are determined randomly.
+You do this by rolling four 6-sided dice and recording the sum of the largest three dice.
+You do this six times, once for each ability.
+
+Your character's initial hitpoints are 10 + your character's constitution modifier.
+You find your character's constitution modifier by subtracting 10 from your character's constitution, divide by 2 and round down.
+
+Write a random character generator that follows the above rules.
+
+For example, the six throws of four dice may look like:
+
+- 5, 3, 1, 6: You discard the 1 and sum 5 + 3 + 6 = 14, which you assign to strength.
+- 3, 2, 5, 3: You discard the 2 and sum 3 + 5 + 3 = 11, which you assign to dexterity.
+- 1, 1, 1, 1: You discard the 1 and sum 1 + 1 + 1 = 3, which you assign to constitution.
+- 2, 1, 6, 6: You discard the 1 and sum 2 + 6 + 6 = 14, which you assign to intelligence.
+- 3, 5, 3, 4: You discard the 3 and sum 5 + 3 + 4 = 12, which you assign to wisdom.
+- 6, 6, 6, 6: You discard the 6 and sum 6 + 6 + 6 = 18, which you assign to charisma.
+
+Because constitution is 3, the constitution modifier is -4 and the hitpoints are 6.
+
+~~~~exercism/note
+Most programming languages feature (pseudo-)random generators, but few programming languages are designed to roll dice.
+One such language is [Troll][troll].
+
+[troll]: https://di.ku.dk/Ansatte/?pure=da%2Fpublications%2Ftroll-a-language-for-specifying-dicerolls(84a45ff0-068b-11df-825d-000ea68e967b)%2Fexport.html
+~~~~
+
+[dnd]: https://en.wikipedia.org/wiki/Dungeons_%26_Dragons

exercises/practice/dnd-character/.docs/introduction.md

@@ -0,0 +1,10 @@
+# Introduction
+
+After weeks of anticipation, you and your friends get together for your very first game of [Dungeons & Dragons][dnd] (D&D).
+Since this is the first session of the game, each player has to generate a character to play with.
+The character's abilities are determined by rolling 6-sided dice, but where _are_ the dice?
+With a shock, you realize that your friends are waiting for _you_ to produce the dice; after all it was your idea to play D&D!
+Panicking, you realize you forgot to bring the dice, which would mean no D&D game.
+As you have some basic coding skills, you quickly come up with a solution: you'll write a program to simulate dice rolls.
+
+[dnd]: https://en.wikipedia.org/wiki/Dungeons_%26_Dragons

exercises/practice/dnd-character/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "files": {
+    "solution": [
+      "lib/DndCharacter.pm"
+    ],
+    "test": [
+      "t/dnd-character.t"
+    ],
+    "example": [
+      ".meta/solutions/lib/DndCharacter.pm"
+    ]
+  },
+  "blurb": "Randomly generate Dungeons & Dragons characters.",
+  "source": "Simon Shine, Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/616#issuecomment-437358945"
+}

exercises/practice/dnd-character/.meta/solutions/lib/DndCharacter.pm

@@ -0,0 +1,44 @@
+use strict;
+use warnings;
+use experimental qw<signatures postderef postderef_qq>;
+use Feature::Compat::Class;
+
+class DndCharacter;
+
+use POSIX qw<floor>;
+
+sub modifier ( $class, $score ) {
+    return floor( ( $score - 10 ) / 2 );
+}
+
+sub ability {
+    my $d6  = sub { 1 + int( rand(6) ) };
+    my $min = 6;
+    my $sum = 0;
+    for $_ ( 1 .. 4 ) {
+        my $die = $d6->();
+        $sum += $die;
+        $min = $die if $min > $die;
+    }
+    return $sum - $min;
+}
+
+field $strength :reader;
+field $dexterity :reader;
+field $constitution :reader;
+field $intelligence :reader;
+field $wisdom :reader;
+field $charisma :reader;
+field $hitpoints :reader;
+
+ADJUST {
+    $strength     = __CLASS__->ability;
+    $dexterity    = __CLASS__->ability;
+    $constitution = __CLASS__->ability;
+    $intelligence = __CLASS__->ability;
+    $wisdom       = __CLASS__->ability;
+    $charisma     = __CLASS__->ability;
+    $hitpoints    = __CLASS__->modifier($constitution) + 10;
+}
+
+1;

exercises/practice/dnd-character/.meta/solutions/t/dnd-character.t

@@ -0,0 +1 @@
+../../../t/dnd-character.t

exercises/practice/dnd-character/.meta/template-data.yaml

@@ -0,0 +1,109 @@
+class: true
+properties:
+  modifier:
+    test: |-
+      use Data::Dmp;
+      sprintf(<<~'END', $case->{input}{score}, $case->{expected}, dmp($case->{description}));
+      is( 
+          DndCharacter->modifier(%d),
+          %d,
+          %s
+      );
+      END
+
+  ability:
+    test: |-
+      use Data::Dmp;
+      sprintf(<<~'END', dmp($case->{description}));
+      ok(
+          lives {
+              for my $i (1..100) {
+                  my $score = DndCharacter->ability();
+                  die if $score < 3 || $score > 18;
+              }
+          },
+          %s
+      );
+      END
+
+  character:
+    test: |-
+      use Data::Dmp;
+      if ($case->{description} eq 'random character is valid') {
+          sprintf(<<~'END', dmp($case->{description}));
+      ok(
+          lives {
+              for my $i (1..100) {
+                  my $character = DndCharacter->new();
+                  die if $character->strength < 3 || $character->strength > 18;
+                  die if $character->dexterity < 3 || $character->dexterity > 18;
+                  die if $character->constitution < 3 || $character->constitution > 18;
+                  die if $character->intelligence < 3 || $character->intelligence > 18;
+                  die if $character->wisdom < 3 || $character->wisdom > 18;
+                  die if $character->charisma < 3 || $character->charisma > 18;
+                  die if $character->hitpoints != 10 + DndCharacter->modifier($character->constitution);
+              }
+          },
+          %s
+      );
+      END
+      }
+      elsif ($case->{description} eq 'each ability is only calculated once') {
+          sprintf(<<~'END', dmp($case->{description}));
+      ok(
+          lives {
+              for my $i (1..100) {
+                  my $character = DndCharacter->new();
+                  die if $character->strength != $character->strength;
+                  die if $character->dexterity != $character->dexterity;
+                  die if $character->constitution != $character->constitution;
+                  die if $character->intelligence != $character->intelligence;
+                  die if $character->wisdom != $character->wisdom;
+                  die if $character->charisma != $character->charisma;
+              }
+          },
+          %s
+      );
+      END
+      }
+
+stub: |-
+  # implement the DndCharacter class
+
+example: |-
+  use POSIX qw<floor>;
+
+  sub modifier ($class, $score) {
+      return floor(($score - 10) / 2);
+  }
+
+  sub ability {
+      my $d6 = sub { 1 + int(rand(6)) };
+      my $min = 6;
+      my $sum = 0;
+      for $_ (1..4) {
+          my $die = $d6->();
+          $sum += $die;
+          $min = $die if $min > $die;
+      }
+      return $sum - $min;
+  }
+
+
+  field $strength :reader;
+  field $dexterity :reader;
+  field $constitution :reader;
+  field $intelligence :reader;
+  field $wisdom :reader;
+  field $charisma :reader;
+  field $hitpoints :reader;
+
+  ADJUST {
+      $strength = __CLASS__->ability;
+      $dexterity = __CLASS__->ability;
+      $constitution = __CLASS__->ability;
+      $intelligence = __CLASS__->ability;
+      $wisdom = __CLASS__->ability;
+      $charisma = __CLASS__->ability;
+      $hitpoints = __CLASS__->modifier($constitution) + 10;
+  }

exercises/practice/dnd-character/.meta/tests.toml

@@ -0,0 +1,72 @@
+# 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.
+
+[1e9ae1dc-35bd-43ba-aa08-e4b94c20fa37]
+description = "ability modifier -> ability modifier for score 3 is -4"
+
+[cc9bb24e-56b8-4e9e-989d-a0d1a29ebb9c]
+description = "ability modifier -> ability modifier for score 4 is -3"
+
+[5b519fcd-6946-41ee-91fe-34b4f9808326]
+description = "ability modifier -> ability modifier for score 5 is -3"
+
+[dc2913bd-6d7a-402e-b1e2-6d568b1cbe21]
+description = "ability modifier -> ability modifier for score 6 is -2"
+
+[099440f5-0d66-4b1a-8a10-8f3a03cc499f]
+description = "ability modifier -> ability modifier for score 7 is -2"
+
+[cfda6e5c-3489-42f0-b22b-4acb47084df0]
+description = "ability modifier -> ability modifier for score 8 is -1"
+
+[c70f0507-fa7e-4228-8463-858bfbba1754]
+description = "ability modifier -> ability modifier for score 9 is -1"
+
+[6f4e6c88-1cd9-46a0-92b8-db4a99b372f7]
+description = "ability modifier -> ability modifier for score 10 is 0"
+
+[e00d9e5c-63c8-413f-879d-cd9be9697097]
+description = "ability modifier -> ability modifier for score 11 is 0"
+
+[eea06f3c-8de0-45e7-9d9d-b8cab4179715]
+description = "ability modifier -> ability modifier for score 12 is +1"
+
+[9c51f6be-db72-4af7-92ac-b293a02c0dcd]
+description = "ability modifier -> ability modifier for score 13 is +1"
+
+[94053a5d-53b6-4efc-b669-a8b5098f7762]
+description = "ability modifier -> ability modifier for score 14 is +2"
+
+[8c33e7ca-3f9f-4820-8ab3-65f2c9e2f0e2]
+description = "ability modifier -> ability modifier for score 15 is +2"
+
+[c3ec871e-1791-44d0-b3cc-77e5fb4cd33d]
+description = "ability modifier -> ability modifier for score 16 is +3"
+
+[3d053cee-2888-4616-b9fd-602a3b1efff4]
+description = "ability modifier -> ability modifier for score 17 is +3"
+
+[bafd997a-e852-4e56-9f65-14b60261faee]
+description = "ability modifier -> ability modifier for score 18 is +4"
+
+[4f28f19c-2e47-4453-a46a-c0d365259c14]
+description = "random ability is within range"
+
+[385d7e72-864f-4e88-8279-81a7d75b04ad]
+description = "random character is valid"
+
+[2ca77b9b-c099-46c3-a02c-0d0f68ffa0fe]
+description = "each ability is only calculated once"
+include = false
+
+[dca2b2ec-f729-4551-84b9-078876bb4808]
+description = "each ability is only calculated once"
+reimplements = "2ca77b9b-c099-46c3-a02c-0d0f68ffa0fe"

exercises/practice/dnd-character/lib/DndCharacter.pm

@@ -0,0 +1,8 @@
+use v5.40;
+use experimental qw<class>;
+
+class DndCharacter;
+
+# implement the DndCharacter class
+
+1;