[robot-name] Add new practice exercise

config.json

@@ -575,6 +575,14 @@
         "prerequisites": [],
         "difficulty": 6
       },
+      {
+        "slug": "robot-name",
+        "name": "Robot Name",
+        "uuid": "c768d50f-3c25-44cc-8a83-fe8cc9d7e93f",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 6
+      },
       {
         "slug": "swift-scheduling",
         "name": "Swift Scheduling",

exercises/practice/robot-name/.docs/instructions.md

@@ -0,0 +1,14 @@
+# Instructions
+
+Manage robot factory settings.
+
+When a robot comes off the factory floor, it has no name.
+
+The first time you turn on a robot, a random name is generated in the format of two uppercase letters followed by three digits, such as RX837 or BC811.
+
+Every once in a while we need to reset a robot to its factory settings, which means that its name gets wiped.
+The next time you ask, that robot will respond with a new random name.
+
+The names must be random: they should not follow a predictable sequence.
+Using random names means a risk of collisions.
+Your solution must ensure that every existing robot has a unique name.

exercises/practice/robot-name/.meta/config.json

@@ -0,0 +1,21 @@
+{
+  "authors": [
+    "IsaacG"
+  ],
+  "files": {
+    "solution": [
+      "robot_name.gd"
+    ],
+    "test": [
+      "robot_name_test.gd",
+      "run_tests",
+      "lib/test_runner.gd",
+      "project.godot"
+    ],
+    "example": [
+      ".meta/example.gd"
+    ]
+  },
+  "blurb": "Manage robot factory settings.",
+  "source": "A debugging session with Paul Blackwell at gSchool."
+}

exercises/practice/robot-name/.meta/example.gd

@@ -0,0 +1,26 @@
+const ALPHA = "QWERTYUIOPASDFGHJKLZXCVBNM"
+
+
+class Robot:
+	var name = null
+	var _rng = null
+	static var names = {}
+
+	func _init(rng):
+		_rng = rng
+		reset()
+
+	func gen_name():
+		return (
+			"%s%s%03d"
+			% [
+				ALPHA[_rng.randi_range(0, 25)],
+				ALPHA[_rng.randi_range(0, 25)],
+				_rng.randi_range(0, 999),
+			]
+		)
+
+	func reset():
+		while name == null or name in Robot.names:
+			name = gen_name()
+		Robot.names[name] = true