Add split-second-stopwatch exercise (#272)

Author: keiravillekode

config.json

@@ -760,6 +760,14 @@
         "prerequisites": [],
         "difficulty": 5
       },
+      {
+        "slug": "split-second-stopwatch",
+        "name": "Split-Second Stopwatch",
+        "uuid": "1dfe7caf-9391-444c-94ef-7e22c84a2256",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
+      },
       {
         "slug": "state-of-tic-tac-toe",
         "name": "State of Tic-Tac-Toe",

exercises/practice/split-second-stopwatch/.docs/instructions.md

@@ -0,0 +1,22 @@
+# Instructions
+
+Your task is to build a stopwatch to keep precise track of lap times.
+
+The stopwatch uses four commands (start, stop, lap, and reset) to keep track of:
+
+1. The current lap's tracked time
+2. Previously recorded lap times
+
+What commands can be used depends on which state the stopwatch is in:
+
+1. Ready: initial state
+2. Running: tracking time
+3. Stopped: not tracking time
+
+| Command | Begin state | End state | Effect                                                   |
+| ------- | ----------- | --------- | -------------------------------------------------------- |
+| Start   | Ready       | Running   | Start tracking time                                      |
+| Start   | Stopped     | Running   | Resume tracking time                                     |
+| Stop    | Running     | Stopped   | Stop tracking time                                       |
+| Lap     | Running     | Running   | Add current lap to previous laps, then reset current lap |
+| Reset   | Stopped     | Ready     | Reset current lap and clear previous laps                |

exercises/practice/split-second-stopwatch/.docs/introduction.md

@@ -0,0 +1,6 @@
+# Introduction
+
+You've always run for the thrill of it — no schedules, no timers, just the sound of your feet on the pavement.
+But now that you've joined a competitive running crew, things are getting serious.
+Training sessions are timed to the second, and every split second counts.
+To keep pace, you've picked up the _Split-Second Stopwatch_ — a sleek, high-tech gadget that's about to become your new best friend.

exercises/practice/split-second-stopwatch/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "split-second-stopwatch.v"
+    ],
+    "test": [
+      "run_test.v"
+    ],
+    "example": [
+      ".meta/example.v"
+    ]
+  },
+  "blurb": "Keep track of time through a digital stopwatch.",
+  "source": "Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/2547"
+}

exercises/practice/split-second-stopwatch/.meta/example.v

@@ -0,0 +1,99 @@
+module main
+
+import strconv
+
+enum State {
+	ready
+	running
+	stopped
+}
+
+struct Stopwatch {
+mut:
+	current_state State
+
+	current  int
+	previous []int
+}
+
+fn Stopwatch.new() Stopwatch {
+	return Stopwatch{
+		current_state: .ready
+	}
+}
+
+fn (stopwatch Stopwatch) state() State {
+	return stopwatch.current_state
+}
+
+fn (stopwatch Stopwatch) current_lap() string {
+	return serialize(stopwatch.current)
+}
+
+fn (stopwatch Stopwatch) previous_laps() []string {
+	return stopwatch.previous.map(serialize)
+}
+
+fn (stopwatch Stopwatch) total() string {
+	mut total := stopwatch.current
+	for entry in stopwatch.previous {
+		total += entry
+	}
+	return serialize(total)
+}
+
+fn (mut stopwatch Stopwatch) start() ! {
+	if stopwatch.current_state != .running {
+		stopwatch.current_state = .running
+	} else {
+		return error('cannot start an already running stopwatch')
+	}
+}
+
+fn (mut stopwatch Stopwatch) stop() ! {
+	if stopwatch.current_state == .running {
+		stopwatch.current_state = .stopped
+	} else {
+		return error('cannot stop a stopwatch that is not running')
+	}
+}
+
+fn (mut stopwatch Stopwatch) reset() ! {
+	if stopwatch.current_state == .stopped {
+		stopwatch.current_state = .ready
+		stopwatch.current = 0
+		stopwatch.previous.clear()
+	} else {
+		return error('cannot reset a stopwatch that is not stopped')
+	}
+}
+
+fn (mut stopwatch Stopwatch) advance_time(by string) {
+	if stopwatch.current_state == .running {
+		stopwatch.current += deserialize(by)
+	}
+}
+
+fn (mut stopwatch Stopwatch) lap() ! {
+	if stopwatch.current_state == .running {
+		stopwatch.previous << stopwatch.current
+		stopwatch.current = 0
+	} else {
+		return error('cannot lap a stopwatch that is not running')
+	}
+}
+
+fn serialize(time int) string {
+	hours := time / 3600
+	minutes := time % 3600 / 60
+	seconds := time % 60
+	return '${hours:02}:${minutes:02}:${seconds:02}'
+}
+
+fn deserialize(time string) int {
+	parts := time.split(':')
+	hours := strconv.atoi(parts[0]) or { 0 }
+	minutes := strconv.atoi(parts[1]) or { 0 }
+	seconds := strconv.atoi(parts[2]) or { 0 }
+	return 3600 * hours + 60 * minutes + seconds
+}

exercises/practice/split-second-stopwatch/.meta/tests.toml

@@ -0,0 +1,90 @@
+# 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.
+
+[ddb238ea-99d4-4eaa-a81d-3c917a525a23]
+description = "new stopwatch starts in ready state"
+
+[b19635d4-08ad-4ac3-b87f-aca10e844071]
+description = "new stopwatch's current lap has no elapsed time"
+
+[492eb532-268d-43ea-8a19-2a032067d335]
+description = "new stopwatch's total has no elapsed time"
+
+[8a892c1e-9ef7-4690-894e-e155a1fe4484]
+description = "new stopwatch does not have previous laps"
+
+[5b2705b6-a584-4042-ba3a-4ab8d0ab0281]
+description = "start from ready state changes state to running"
+
+[748235ce-1109-440b-9898-0a431ea179b6]
+description = "start does not change previous laps"
+
+[491487b1-593d-423e-a075-aa78d449ff1f]
+description = "start initiates time tracking for current lap"
+
+[a0a7ba2c-8db6-412c-b1b6-cb890e9b72ed]
+description = "start initiates time tracking for total"
+
+[7f558a17-ef6d-4a5b-803a-f313af7c41d3]
+description = "start cannot be called from running state"
+
+[32466eef-b2be-4d60-a927-e24fce52dab9]
+description = "stop from running state changes state to stopped"
+
+[621eac4c-8f43-4d99-919c-4cad776d93df]
+description = "stop pauses time tracking for current lap"
+
+[465bcc82-7643-41f2-97ff-5e817cef8db4]
+description = "stop pauses time tracking for total"
+
+[b1ba7454-d627-41ee-a078-891b2ed266fc]
+description = "stop cannot be called from ready state"
+
+[5c041078-0898-44dc-9d5b-8ebb5352626c]
+description = "stop cannot be called from stopped state"
+
+[3f32171d-8fbf-46b6-bc2b-0810e1ec53b7]
+description = "start from stopped state changes state to running"
+
+[626997cb-78d5-4fe8-b501-29fdef804799]
+description = "start from stopped state resumes time tracking for current lap"
+
+[58487c53-ab26-471c-a171-807ef6363319]
+description = "start from stopped state resumes time tracking for total"
+
+[091966e3-ed25-4397-908b-8bb0330118f8]
+description = "lap adds current lap to previous laps"
+
+[1aa4c5ee-a7d5-4d59-9679-419deef3c88f]
+description = "lap resets current lap and resumes time tracking"
+
+[4b46b92e-1b3f-46f6-97d2-0082caf56e80]
+description = "lap continues time tracking for total"
+
+[ea75d36e-63eb-4f34-97ce-8c70e620bdba]
+description = "lap cannot be called from ready state"
+
+[63731154-a23a-412d-a13f-c562f208eb1e]
+description = "lap cannot be called from stopped state"
+
+[e585ee15-3b3f-4785-976b-dd96e7cc978b]
+description = "stop does not change previous laps"
+
+[fc3645e2-86cf-4d11-97c6-489f031103f6]
+description = "reset from stopped state changes state to ready"
+
+[20fbfbf7-68ad-4310-975a-f5f132886c4e]
+description = "reset resets current lap"
+
+[00a8f7bb-dd5c-43e5-8705-3ef124007662]
+description = "reset clears previous laps"
+
+[76cea936-6214-4e95-b6d1-4d4edcf90499]
+description = "reset cannot be called from ready state"
+
+[ba4d8e69-f200-4721-b59e-90d8cf615153]
+description = "reset cannot be called from running state"
+
+[0b01751a-cb57-493f-bb86-409de6e84306]
+description = "supports very long laps"