Add Darts exercise (#77)

config.json

@@ -83,6 +83,14 @@
                 "difficulty": 2,
                 "practices": []
             },
+            {
+                "slug": "darts",
+                "name": "Darts",
+                "uuid": "773c9910-ae75-4560-b110-e9d057438aa9",
+                "prerequisites": [],
+                "difficulty": 2,
+                "practices": []
+            },
             {
                 "slug": "bob",
                 "name": "Bob",
@@ -252,4 +260,4 @@
         "used_for/mobile",
         "used_for/web_development"
     ]
-}
+}

exercises/practice/darts/.docs/instructions.md

@@ -0,0 +1,23 @@
+# Instructions
+
+Write a function that returns the earned points in a single toss of a Darts game.
+
+[Darts][darts] is a game where players throw darts at a [target][darts-target].
+
+In our particular instance of the game, the target rewards 4 different amounts of points, depending on where the dart lands:
+
+- If the dart lands outside the target, player earns no points (0 points).
+- If the dart lands in the outer circle of the target, player earns 1 point.
+- If the dart lands in the middle circle of the target, player earns 5 points.
+- If the dart lands in the inner circle of the target, player earns 10 points.
+
+The outer circle has a radius of 10 units (this is equivalent to the total radius for the entire target), the middle circle a radius of 5 units, and the inner circle a radius of 1.
+Of course, they are all centered at the same point — that is, the circles are [concentric][] defined by the coordinates (0, 0).
+
+Write a function that given a point in the target (defined by its [Cartesian coordinates][cartesian-coordinates] `x` and `y`, where `x` and `y` are [real][real-numbers]), returns the correct amount earned by a dart landing at that point.
+
+[darts]: https://en.wikipedia.org/wiki/Darts
+[darts-target]: https://en.wikipedia.org/wiki/Darts#/media/File:Darts_in_a_dartboard.jpg
+[concentric]: https://mathworld.wolfram.com/ConcentricCircles.html
+[cartesian-coordinates]: https://www.mathsisfun.com/data/cartesian-coordinates.html
+[real-numbers]: https://www.mathsisfun.com/numbers/real-numbers.html

exercises/practice/darts/.meta/config.json

@@ -0,0 +1,18 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "files": {
+    "solution": [
+      "darts.8th"
+    ],
+    "test": [
+      "darts-tests.8th"
+    ],
+    "example": [
+      ".meta/example.8th"
+    ]
+  },
+  "blurb": "Write a function that returns the earned points in a single toss of a Darts game.",
+  "source": "Inspired by an exercise created by a professor Della Paolera in Argentina"
+}

exercises/practice/darts/.meta/example.8th

@@ -0,0 +1,14 @@
+\ Courtesy @ron at https://8th-dev.com/forum/index.php/topic,2713.0.html
+
+with: n
+: distance \ x y -- n
+  sqr swap sqr + sqrt ;
+
+: score \ n -- n
+  dup 10 > if drop 0 ;then
+  dup 5  > if drop 1 ;then
+  dup 1  > if drop 5 ;then
+  drop 10 ;
+
+: darts-score \ x y -- n
+  distance score ;

exercises/practice/darts/.meta/tests.toml

@@ -0,0 +1,49 @@
+# 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.
+
+[9033f731-0a3a-4d9c-b1c0-34a1c8362afb]
+description = "Missed target"
+
+[4c9f6ff4-c489-45fd-be8a-1fcb08b4d0ba]
+description = "On the outer circle"
+
+[14378687-ee58-4c9b-a323-b089d5274be8]
+description = "On the middle circle"
+
+[849e2e63-85bd-4fed-bc3b-781ae962e2c9]
+description = "On the inner circle"
+
+[1c5ffd9f-ea66-462f-9f06-a1303de5a226]
+description = "Exactly on center"
+
+[b65abce3-a679-4550-8115-4b74bda06088]
+description = "Near the center"
+
+[66c29c1d-44f5-40cf-9927-e09a1305b399]
+description = "Just within the inner circle"
+
+[d1012f63-c97c-4394-b944-7beb3d0b141a]
+description = "Just outside the inner circle"
+
+[ab2b5666-b0b4-49c3-9b27-205e790ed945]
+description = "Just within the middle circle"
+
+[70f1424e-d690-4860-8caf-9740a52c0161]
+description = "Just outside the middle circle"
+
+[a7dbf8db-419c-4712-8a7f-67602b69b293]
+description = "Just within the outer circle"
+
+[e0f39315-9f9a-4546-96e4-a9475b885aa7]
+description = "Just outside the outer circle"
+
+[045d7d18-d863-4229-818e-b50828c75d19]
+description = "Asymmetric position between the inner and middle circles"

exercises/practice/darts/darts-tests.8th

@@ -0,0 +1,15 @@
+"Missed target" 0 ( -9 9 darts-score ) test_eq
+"On the outer circle" 1 ( 0 10 darts-score ) test_eq
+"On the middle circle" 5 ( -5 0 darts-score ) test_eq
+"On the inner circle" 10 ( 0 -1 darts-score ) test_eq
+"Exactly on center" 10 ( 0 0 darts-score ) test_eq
+"Near the center" 10 ( -0.1 -0.1 darts-score ) test_eq
+"Just within the inner circle" 10 ( 0.7 0.7 darts-score ) test_eq
+"Just outside the inner circle" 5 ( 0.8 -0.8 darts-score ) test_eq
+"Just within the middle circle" 5 ( -3.5 3.5 darts-score ) test_eq
+"Just outside the middle circle" 1 ( -3.6 -3.6 darts-score ) test_eq
+"Just within the outer circle" 1 ( -7.0 7.0 darts-score ) test_eq
+"Just outside the outer circle" 0 ( 7.1 -7.1 darts-score ) test_eq
+"Asymmetric position between the inner and middle circles" 5 ( 0.5 -4 darts-score ) test_eq
+
+bye

exercises/practice/darts/darts.8th

@@ -0,0 +1,3 @@
+: darts-score \ n n -- n
+
+;

exercises/practice/darts/test-words.8th

@@ -0,0 +1,53 @@
+needs console/loaded
+
+: isword?  \ x -- x f
+   dup  >kind  ns:w   n:= 
+;
+
+: test_eq \ s x w -- | s w x --
+   isword? !if swap then
+   a:new swap 0 swap a:! 0 a:@ nip w:exec
+   n:= if
+    con:green con:onBlack . space " ... OK" . con:white con:onBlack cr
+   else
+    con:red con:onBlack . space " ... FAIL" . con:white con:onBlack cr
+   then 
+;
+
+: test_eqs \ s x w -- | s w x -- 
+   isword? !if swap then
+   a:new swap 0 swap a:! 0 a:@ nip w:exec
+   s:= if
+    con:green con:onBlack . space " ... OK" . con:white con:onBlack cr
+   else
+    con:red con:onBlack . space " ... FAIL" . con:white con:onBlack cr
+   then 
+;
+
+: test_true \ s w --
+   a:new swap 0 swap a:! 0 a:@ nip w:exec
+   if
+    con:green con:onBlack . space " ... OK" . con:white con:onBlack cr
+   else
+    con:red con:onBlack . space " ... FAIL" . con:white con:onBlack cr
+   then 
+;
+
+: test_false \ s w --
+   a:new swap 0 swap a:! 0 a:@ nip w:exec
+   !if
+    con:green con:onBlack . space " ... OK" . con:white con:onBlack cr
+   else
+    con:red con:onBlack . space " ... FAIL" . con:white con:onBlack cr
+   then 
+;
+
+: test_null \ s w --
+   a:new swap 0 swap a:! 0 a:@ nip w:exec
+   null? if
+    drop con:green con:onBlack . space " ... OK" . con:white con:onBlack cr
+   else
+    drop con:red con:onBlack . space " ... FAIL" . con:white con:onBlack cr
+   then 
+;
+

exercises/practice/darts/test.8th

@@ -0,0 +1,3 @@
+"test-words.8th" dup . cr f:include
+"darts.8th" dup . cr f:include
+"darts-tests.8th" dup . cr f:include