Add Eliud's eggs exercise (#836)

config.json

@@ -535,6 +535,14 @@
         "difficulty": 4,
         "status": "beta"
       },
+      {
+        "slug": "eliuds-eggs",
+        "name": "Eliud's Eggs",
+        "uuid": "683068c2-97df-430d-a713-b4fca940c12d",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "gigasecond",
         "name": "Gigasecond",

exercises/practice/eliuds-eggs/.docs/instructions.md

@@ -0,0 +1,8 @@
+# Instructions
+
+Your task is to count the number of 1 bits in the binary representation of a number.
+
+## Restrictions
+
+Keep your hands off that bit-count functionality provided by your standard library!
+Solve this one yourself using other basic tools instead.

exercises/practice/eliuds-eggs/.docs/introduction.md

@@ -0,0 +1,47 @@
+# Introduction
+
+Your friend Eliud inherited a farm from her grandma Tigist.
+Her granny was an inventor and had a tendency to build things in an overly complicated manner.
+The chicken coop has a digital display showing an encoded number representing the positions of all eggs that could be picked up.
+
+Eliud is asking you to write a program that shows the actual number of eggs in the coop.
+
+The position information encoding is calculated as follows:
+
+1. Scan the potential egg-laying spots and mark down a `1` for an existing egg or a `0` for an empty spot.
+2. Convert the number from binary to decimal.
+3. Show the result on the display.
+
+Example 1:
+
+```text
+Chicken Coop:
+ _ _ _ _ _ _ _
+|E| |E|E| | |E|
+
+Resulting Binary:
+ 1 0 1 1 0 0 1
+
+Decimal number on the display:
+89
+
+Actual eggs in the coop:
+4
+```
+
+Example 2:
+
+```text
+Chicken Coop:
+ _ _ _ _ _ _ _ _
+| | | |E| | | | |
+
+Resulting Binary:
+ 0 0 0 1 0 0 0 0
+
+Decimal number on the display:
+16
+
+Actual eggs in the coop:
+1
+```

exercises/practice/eliuds-eggs/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "kahgoh"
+  ],
+  "files": {
+    "solution": [
+      "eliuds-eggs.lisp"
+    ],
+    "test": [
+      "eliuds-eggs-test.lisp"
+    ],
+    "example": [
+      ".meta/example.lisp"
+    ]
+  },
+  "blurb": "Help Eliud count the number of eggs in her chicken coop by counting the number of 1 bits in a binary representation.",
+  "source": "Christian Willner, Eric Willigers",
+  "source_url": "https://forum.exercism.org/t/new-exercise-suggestion-pop-count/7632/5"
+}

exercises/practice/eliuds-eggs/.meta/example.lisp

@@ -0,0 +1,14 @@
+(defpackage :eliuds-eggs
+  (:use :cl)
+  (:export :egg-count))
+
+(in-package :eliuds-eggs)
+
+(defun do-egg-count (number &optional (acc 0))
+  (if (= number 0)
+    acc
+    (multiple-value-bind (quot rem) (floor number 2)
+      (do-egg-count quot (+ acc rem)))))
+
+(defun egg-count (number)
+  (do-egg-count number))

exercises/practice/eliuds-eggs/.meta/tests.toml

@@ -0,0 +1,15 @@
+# This is an auto-generated file. Regular comments will be removed when this
+# file is regenerated. Regenerating will not touch any manually added keys,
+# so comments can be added in a "comment" key.
+
+[559e789d-07d1-4422-9004-3b699f83bca3]
+description = "0 eggs"
+
+[97223282-f71e-490c-92f0-b3ec9e275aba]
+description = "1 egg"
+
+[1f8fd18f-26e9-4144-9a0e-57cdfc4f4ff5]
+description = "4 eggs"
+
+[0c18be92-a498-4ef2-bcbb-28ac4b06cb81]
+description = "13 eggs"

exercises/practice/eliuds-eggs/eliuds-eggs-test.lisp

@@ -0,0 +1,36 @@
+;; Ensures that eliuds-eggs.lisp and the testing library are always loaded
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (load "eliuds-eggs")
+  (quicklisp-client:quickload :fiveam))
+
+;; Defines the testing package with symbols from eliuds-eggs and FiveAM in scope
+;; The `run-tests` function is exported for use by both the user and test-runner
+(defpackage :eliuds-eggs-test
+  (:use :cl :fiveam)
+  (:export :run-tests))
+
+;; Enter the testing package
+(in-package :eliuds-eggs-test)
+
+;; Define and enter a new FiveAM test-suite
+(def-suite* eliuds-eggs-suite)
+
+(test 0-eggs
+    (let ((number 0))
+      (is (= 0 (eliuds-eggs:egg-count number)))))
+
+(test 1-egg
+    (let ((number 16))
+      (is (= 1 (eliuds-eggs:egg-count number)))))
+
+(test 4-eggs
+    (let ((number 89))
+      (is (= 4 (eliuds-eggs:egg-count number)))))
+
+(test 13-eggs
+    (let ((number 2000000000))
+      (is (= 13 (eliuds-eggs:egg-count number)))))
+
+(defun run-tests (&optional (test-or-suite 'eliuds-eggs-suite))
+  "Provides human readable results of test run. Default to entire suite."
+  (run! test-or-suite))

exercises/practice/eliuds-eggs/eliuds-eggs.lisp

@@ -0,0 +1,7 @@
+(defpackage :eliuds-eggs
+  (:use :cl)
+  (:export :egg-count))
+
+(in-package :eliuds-eggs)
+
+(defun egg-count (number))