Save the cow

bin/generate-spec

@@ -85,11 +85,12 @@ if not path.exists(exercise_directory)
 if not path.exists("#{exercise_directory}/.meta/spec_generator.moon")
   die "#{exercise_name} does not have a spec_generator module.\n"
 
-canonical_data_url = "https://raw.githubusercontent.com/exercism/problem-specifications/main/exercises/#{exercise_name}/canonical-data.json"
 canonical_data_path = "canonical-data/#{exercise_name}.json"
 
-assert os.execute('mkdir -p "$(dirname "' .. canonical_data_path .. '")"')
-assert os.execute('curl "' .. canonical_data_url .. '" -s -o "' .. canonical_data_path .. '"')
+if not path.exists canonical_data_path
+  canonical_data_url = "https://raw.githubusercontent.com/exercism/problem-specifications/main/exercises/#{exercise_name}/canonical-data.json"
+  assert os.execute('mkdir -p "$(dirname "' .. canonical_data_path .. '")"')
+  assert os.execute('curl "' .. canonical_data_url .. '" -s -o "' .. canonical_data_path .. '"')
 
 -- "json.null" ref: https://dkolf.de/dkjson-lua/documentation
 canonical_data = json.decode file.read(canonical_data_path, false), 1, json.null

config.json

@@ -578,6 +578,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "save-the-cow",
+        "name": "Save the Cow",
+        "uuid": "7b85dc03-54e5-45ea-ac02-a9da503c89e9",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "series",
         "name": "Series",

exercises/practice/save-the-cow/.busted

@@ -0,0 +1,5 @@
+return {
+  default = {
+    ROOT = { '.' }
+  }
+}

exercises/practice/save-the-cow/.docs/instructions.md

@@ -0,0 +1,7 @@
+# Instructions
+
+Implement the logic for a word-guessing game.
+
+A player tries to solve a secret word by guessing individual letters.
+They win if they reveal all the letters in the secret word.
+They lose if they make ten incorrect guesses before revealing the word.

exercises/practice/save-the-cow/.docs/introduction.md

@@ -0,0 +1,4 @@
+# Introduction
+
+Bessie the cow has wandered onto an alien spaceship.
+Guess the secret door code to bring her home before the ship blasts off.

exercises/practice/save-the-cow/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "glennj"
+  ],
+  "files": {
+    "solution": [
+      "save_the_cow.moon"
+    ],
+    "test": [
+      "save_the_cow_spec.moon"
+    ],
+    "example": [
+      ".meta/example.moon"
+    ]
+  },
+  "blurb": "Implement a word-guessing game."
+}

exercises/practice/save-the-cow/.meta/example.moon

@@ -0,0 +1,35 @@
+class SaveTheCow
+  new: (@word) =>
+    @guessed = {}
+    @errsAvailable = 9
+    @state = 'Ongoing'
+
+  guess: (letters) =>
+    for guess in *letters
+      if @state == 'Win'  then error 'cannot guess after the game is won'
+      if @state == 'Lose' then error 'cannot guess after the game is lost'
+
+      if @guessed[guess]
+        @errsAvailable -= 1
+      else
+        found = not not @word\find guess
+        @guessed[guess] = found
+        if not found
+          @errsAvailable -= 1
+
+      @state = 'Lose' if @errsAvailable < 0
+      @state = 'Win'  if not @mask!\find '_'
+
+    @currentState!
+
+  currentState: =>
+    {
+      state: @state,
+      maskedWord: @mask!,
+      remainingFailures: math.max 0, @errsAvailable
+    }
+
+  mask: =>
+    @word\gsub '%a', (c) -> @guessed[c] and c or '_'
+
+

exercises/practice/save-the-cow/.meta/spec_generator.moon

@@ -0,0 +1,21 @@
+import indent, quote, table_dump, word_list from require 'spec_helpers'
+
+{
+  module_name: 'SaveTheCow',
+
+  generate_test: (case, level) ->
+    lines = if case.expected.error
+      {
+        "game = SaveTheCow #{quote case.input.word}",
+        "f = -> game\\guess #{word_list case.input.guesses}",
+        "assert.has.error f, #{quote case.expected.error}"
+      }
+    else
+      {
+        "game = SaveTheCow #{quote case.input.word}",
+        "result = game\\guess #{word_list case.input.guesses}",
+        "expected = #{table_dump case.expected, level}",
+        "assert.are.same expected, result"
+      }
+    table.concat [indent line, level for line in *lines], '\n'
+}

exercises/practice/save-the-cow/.meta/tests.toml

@@ -0,0 +1,40 @@
+# 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.
+
+[71d340f9-fc29-4826-872e-ad7d0b83dd98]
+description = "Initially 9 failures are allowed and no letters are guessed"
+
+[76759c24-8f1a-4fc8-9ffd-d6a1ff0cf03b]
+description = "After 10 failures the game is over"
+
+[d6f2e202-7857-46fb-b709-43a7f3f3b2de]
+description = "Losing with several correct guesses"
+
+[71bc0cda-2032-4637-80c8-fc8771124c08]
+description = "Feeding a correct letter removes underscores"
+
+[5b568a1c-867d-418f-97a8-7b6f8a7ca0a2]
+description = "Feeding a correct letter twice counts as a failure"
+
+[3d40f15b-0271-4c5d-b1a4-3e1f66ff221f]
+description = "Guessing a repeated letter reveals all instances"
+
+[11a86435-e401-4250-a26e-3b0d8c4049ad]
+description = "Getting all the letters right makes for a win"
+
+[b3d81876-84ee-45bb-b531-baa1b05b4709]
+description = "Winning on the last guess is still a win"
+
+[cf204398-5e9f-402f-8bff-42cb7cbbbda9]
+description = "Guessing after a lose is error"
+
+[c2ec5b3d-4923-4a0e-a485-6aa6e78c7ece]
+description = "Guessing after a win is error"

exercises/practice/save-the-cow/save_the_cow.moon

@@ -0,0 +1,6 @@
+class SaveTheCow
+  new: (word) =>
+    error 'Implement the constructor'
+
+  guess: (letters) =>
+    error 'Implement the guess method'

exercises/practice/save-the-cow/save_the_cow_spec.moon

@@ -0,0 +1,92 @@
+SaveTheCow = require 'save_the_cow'
+
+describe 'save-the-cow:', ->
+  it 'Initially 9 failures are allowed and no letters are guessed', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {}
+    expected = {
+      remainingFailures: 9
+      state: 'Ongoing'
+      maskedWord: '____'
+    }
+    assert.are.same expected, result
+
+  pending 'After 10 failures the game is over', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'}
+    expected = {
+      remainingFailures: 0
+      state: 'Lose'
+      maskedWord: '____'
+    }
+    assert.are.same expected, result
+
+  pending 'Losing with several correct guesses', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'t', 'o', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'}
+    expected = {
+      remainingFailures: 0
+      state: 'Lose'
+      maskedWord: '_oot'
+    }
+    assert.are.same expected, result
+
+  pending 'Feeding a correct letter removes underscores', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'t'}
+    expected = {
+      remainingFailures: 9
+      state: 'Ongoing'
+      maskedWord: '___t'
+    }
+    assert.are.same expected, result
+
+  pending 'Feeding a correct letter twice counts as a failure', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'t', 't'}
+    expected = {
+      remainingFailures: 8
+      state: 'Ongoing'
+      maskedWord: '___t'
+    }
+    assert.are.same expected, result
+
+  pending 'Guessing a repeated letter reveals all instances', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'t', 't', 'o'}
+    expected = {
+      remainingFailures: 8
+      state: 'Ongoing'
+      maskedWord: '_oot'
+    }
+    assert.are.same expected, result
+
+  pending 'Getting all the letters right makes for a win', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'t', 't', 'o', 'l'}
+    expected = {
+      remainingFailures: 8
+      state: 'Win'
+      maskedWord: 'loot'
+    }
+    assert.are.same expected, result
+
+  pending 'Winning on the last guess is still a win', ->
+    game = SaveTheCow 'loot'
+    result = game\guess {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 't', 'o', 'l'}
+    expected = {
+      remainingFailures: 0
+      state: 'Win'
+      maskedWord: 'loot'
+    }
+    assert.are.same expected, result
+
+  pending 'Guessing after a lose is error', ->
+    game = SaveTheCow 'loot'
+    f = -> game\guess {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k'}
+    assert.has.error f, 'cannot guess after the game is lost'
+
+  pending 'Guessing after a win is error', ->
+    game = SaveTheCow 'loot'
+    f = -> game\guess {'t', 'o', 'l', 'l'}
+    assert.has.error f, 'cannot guess after the game is won'