Add proverb (#807)

config.json

@@ -541,6 +541,14 @@
         "prerequisites": [],
         "difficulty": 2
       },
+      {
+        "slug": "proverb",
+        "name": "Proverb",
+        "uuid": "8df744a9-6788-40b6-83c7-d39e705f17cf",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "trinary",
         "name": "Trinary",

exercises/practice/proverb/.docs/instructions.md

@@ -0,0 +1,19 @@
+# Instructions
+
+For want of a horseshoe nail, a kingdom was lost, or so the saying goes.
+
+Given a list of inputs, generate the relevant proverb.
+For example, given the list `["nail", "shoe", "horse", "rider", "message", "battle", "kingdom"]`, you will output the full text of this proverbial rhyme:
+
+```text
+For want of a nail the shoe was lost.
+For want of a shoe the horse was lost.
+For want of a horse the rider was lost.
+For want of a rider the message was lost.
+For want of a message the battle was lost.
+For want of a battle the kingdom was lost.
+And all for the want of a nail.
+```
+
+Note that the list of inputs may vary; your solution should be able to handle lists of arbitrary length and content.
+No line of the output text should be a static, unchanging string; all should vary according to the input given.

exercises/practice/proverb/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "proverb.jl"
+    ],
+    "test": [
+      "runtests.jl"
+    ],
+    "example": [
+      ".meta/example.jl"
+    ]
+  },
+  "blurb": "For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/For_Want_of_a_Nail"
+}

exercises/practice/proverb/.meta/example.jl

@@ -0,0 +1,11 @@
+function recite(pieces)
+    if length(pieces) == 0
+        return ""
+    end
+    proverb = ""
+    for i in 1:length(pieces)-1
+        proverb *= "For want of a $(pieces[i]) the $(pieces[i+1]) was lost.\n"
+    end
+    proverb *= "And all for the want of a $(pieces[1])."
+    proverb
+end

exercises/practice/proverb/.meta/tests.toml

@@ -0,0 +1,28 @@
+# 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.
+
+[e974b73e-7851-484f-8d6d-92e07fe742fc]
+description = "zero pieces"
+
+[2fcd5f5e-8b82-4e74-b51d-df28a5e0faa4]
+description = "one piece"
+
+[d9d0a8a1-d933-46e2-aa94-eecf679f4b0e]
+description = "two pieces"
+
+[c95ef757-5e94-4f0d-a6cb-d2083f5e5a83]
+description = "three pieces"
+
+[433fb91c-35a2-4d41-aeab-4de1e82b2126]
+description = "full proverb"
+
+[c1eefa5a-e8d9-41c7-91d4-99fab6d6b9f7]
+description = "four pieces modernized"

exercises/practice/proverb/proverb.jl

@@ -0,0 +1,3 @@
+function recite(pieces)
+
+end

exercises/practice/proverb/runtests.jl

@@ -0,0 +1,56 @@
+using Test
+include("proverb.jl")
+
+@testset verbose = true "tests" begin
+    @testset "zero pieces" begin
+        pieces = []
+        expected = ""
+        @test recite(pieces) == expected
+    end
+
+    @testset "one piece" begin
+        pieces = ["nail"]
+        expected = "And all for the want of a nail."
+        @test recite(pieces) == expected
+    end
+
+    @testset "two pieces" begin
+        pieces = ["nail", "shoe"]
+        expected = """
+            For want of a nail the shoe was lost.
+            And all for the want of a nail."""
+        @test recite(pieces) == expected
+    end
+
+    @testset "three pieces" begin
+        pieces = ["nail", "shoe", "horse"]
+        expected = """
+            For want of a nail the shoe was lost.
+            For want of a shoe the horse was lost.
+            And all for the want of a nail."""
+        @test recite(pieces) == expected
+    end
+
+    @testset "full proverb" begin
+        pieces = ["nail", "shoe", "horse", "rider", "message", "battle", "kingdom"]
+        expected = """
+            For want of a nail the shoe was lost.
+            For want of a shoe the horse was lost.
+            For want of a horse the rider was lost.
+            For want of a rider the message was lost.
+            For want of a message the battle was lost.
+            For want of a battle the kingdom was lost.
+            And all for the want of a nail."""
+        @test recite(pieces) == expected
+    end
+
+    @testset "four pieces modernized" begin
+        pieces = ["pin", "gun", "soldier", "battle"]
+        expected = """
+            For want of a pin the gun was lost.
+            For want of a gun the soldier was lost.
+            For want of a soldier the battle was lost.
+            And all for the want of a pin."""
+        @test recite(pieces) == expected
+    end
+end