Add bottle-song exercise

config.json

@@ -423,6 +423,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "bottle-song",
+        "name": "Bottle Song",
+        "uuid": "92fd7655-0e70-4f6d-9485-dbfbdce89dba",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "circular-buffer",
         "name": "Circular Buffer",

exercises/practice/bottle-song/.docs/instructions.md

@@ -0,0 +1,57 @@
+# Instructions
+
+Recite the lyrics to that popular children's repetitive song: Ten Green Bottles.
+
+Note that not all verses are identical.
+
+```text
+Ten green bottles hanging on the wall,
+Ten green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be nine green bottles hanging on the wall.
+
+Nine green bottles hanging on the wall,
+Nine green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be eight green bottles hanging on the wall.
+
+Eight green bottles hanging on the wall,
+Eight green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be seven green bottles hanging on the wall.
+
+Seven green bottles hanging on the wall,
+Seven green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be six green bottles hanging on the wall.
+
+Six green bottles hanging on the wall,
+Six green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be five green bottles hanging on the wall.
+
+Five green bottles hanging on the wall,
+Five green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be four green bottles hanging on the wall.
+
+Four green bottles hanging on the wall,
+Four green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be three green bottles hanging on the wall.
+
+Three green bottles hanging on the wall,
+Three green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be two green bottles hanging on the wall.
+
+Two green bottles hanging on the wall,
+Two green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be one green bottle hanging on the wall.
+
+One green bottle hanging on the wall,
+One green bottle hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be no green bottles hanging on the wall.
+```

exercises/practice/bottle-song/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "bottle-song.v"
+    ],
+    "test": [
+      "run_test.v"
+    ],
+    "example": [
+      ".meta/example.v"
+    ]
+  },
+  "blurb": "Produce the lyrics to the popular children's repetitive song: Ten Green Bottles.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Ten_Green_Bottles"
+}

exercises/practice/bottle-song/.meta/example.v

@@ -0,0 +1,40 @@
+module main
+
+import strings
+
+const numbers = ['No', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine',
+	'Ten']
+
+fn append_line(mut builder strings.Builder, bottles int, lower bool) {
+	if lower {
+		builder.write_rune(numbers[bottles][0] | 32)
+		builder.write_string(numbers[bottles][1..])
+	} else {
+		builder.write_string(numbers[bottles])
+	}
+	builder.write_string(' green bottle')
+	if bottles != 1 {
+		builder.write_rune(`s`)
+	}
+	builder.write_string(' hanging on the wall')
+}
+
+fn recite(start_bottles int, take_down int) string {
+	mut builder := strings.new_builder(4000)
+	mut bottles := start_bottles
+	for bottles > start_bottles - take_down {
+		append_line(mut &builder, bottles, false)
+		builder.write_string(',\n')
+
+		append_line(mut &builder, bottles, false)
+		builder.write_string(',\n')
+
+		builder.write_string("And if one green bottle should accidentally fall,\nThere'll be ")
+		bottles--
+
+		append_line(mut &builder, bottles, true)
+		builder.write_string('.\n\n')
+	}
+	builder.go_back(2)
+	return builder.str()
+}

exercises/practice/bottle-song/.meta/tests.toml

@@ -0,0 +1,24 @@
+# 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.
+
+[d4ccf8fc-01dc-48c0-a201-4fbeb30f2d03]
+description = "verse -> single verse -> first generic verse"
+
+[0f0aded3-472a-4c64-b842-18d4f1f5f030]
+description = "verse -> single verse -> last generic verse"
+
+[f61f3c97-131f-459e-b40a-7428f3ed99d9]
+description = "verse -> single verse -> verse with 2 bottles"
+
+[05eadba9-5dbd-401e-a7e8-d17cc9baa8e0]
+description = "verse -> single verse -> verse with 1 bottle"
+
+[a4a28170-83d6-4dc1-bd8b-319b6abb6a80]
+description = "lyrics -> multiple verses -> first two verses"
+
+[3185d438-c5ac-4ce6-bcd3-02c9ff1ed8db]
+description = "lyrics -> multiple verses -> last three verses"
+
+[28c1584a-0e51-4b65-9ae2-fbc0bf4bbb28]
+description = "lyrics -> multiple verses -> all verses"

exercises/practice/bottle-song/bottle-song.v

@@ -0,0 +1,4 @@
+module main
+
+fn recite(start_bottles int, take_down int) string {
+}

exercises/practice/bottle-song/run_test.v

@@ -0,0 +1,124 @@
+module main
+
+fn test_verse__single_verse__first_generic_verse() {
+	expected :=
+("Ten green bottles hanging on the wall,
+Ten green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be nine green bottles hanging on the wall.")
+	assert recite(10, 1) == expected
+}
+
+fn test_verse__single_verse__last_generic_verse() {
+	expected :=
+("Three green bottles hanging on the wall,
+Three green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be two green bottles hanging on the wall.")
+	assert recite(3, 1) == expected
+}
+
+fn test_verse__single_verse__verse_with_2_bottles() {
+	expected :=
+("Two green bottles hanging on the wall,
+Two green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be one green bottle hanging on the wall.")
+	assert recite(2, 1) == expected
+}
+
+fn test_verse__single_verse__verse_with_1_bottle() {
+	expected :=
+("One green bottle hanging on the wall,
+One green bottle hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be no green bottles hanging on the wall.")
+	assert recite(1, 1) == expected
+}
+
+fn test_lyrics__multiple_verses__first_two_verses() {
+	expected :=
+("Ten green bottles hanging on the wall,
+Ten green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be nine green bottles hanging on the wall.
+
+Nine green bottles hanging on the wall,
+Nine green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be eight green bottles hanging on the wall.")
+	assert recite(10, 2) == expected
+}
+
+fn test_lyrics__multiple_verses__last_three_verses() {
+	expected :=
+("Three green bottles hanging on the wall,
+Three green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be two green bottles hanging on the wall.
+
+Two green bottles hanging on the wall,
+Two green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be one green bottle hanging on the wall.
+
+One green bottle hanging on the wall,
+One green bottle hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be no green bottles hanging on the wall.")
+	assert recite(3, 3) == expected
+}
+
+fn test_lyrics__multiple_verses__all_verses() {
+	expected :=
+("Ten green bottles hanging on the wall,
+Ten green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be nine green bottles hanging on the wall.
+
+Nine green bottles hanging on the wall,
+Nine green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be eight green bottles hanging on the wall.
+
+Eight green bottles hanging on the wall,
+Eight green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be seven green bottles hanging on the wall.
+
+Seven green bottles hanging on the wall,
+Seven green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be six green bottles hanging on the wall.
+
+Six green bottles hanging on the wall,
+Six green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be five green bottles hanging on the wall.
+
+Five green bottles hanging on the wall,
+Five green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be four green bottles hanging on the wall.
+
+Four green bottles hanging on the wall,
+Four green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be three green bottles hanging on the wall.
+
+Three green bottles hanging on the wall,
+Three green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be two green bottles hanging on the wall.
+
+Two green bottles hanging on the wall,
+Two green bottles hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be one green bottle hanging on the wall.
+
+One green bottle hanging on the wall,
+One green bottle hanging on the wall,
+And if one green bottle should accidentally fall,
+There'll be no green bottles hanging on the wall.")
+	assert recite(10, 10) == expected
+}