Add robot-simulator exercise

config.json

@@ -106,6 +106,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 2
+      },
+      {
+        "slug": "robot-simulator",
+        "name": "Robot Simulator",
+        "uuid": "31a8cb4a-c211-4daa-a14b-7347fed015a6",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
       }
     ]
   },

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

@@ -0,0 +1,25 @@
+# Instructions
+
+Write a robot simulator.
+
+A robot factory's test facility needs a program to verify robot movements.
+
+The robots have three possible movements:
+
+- turn right
+- turn left
+- advance
+
+Robots are placed on a hypothetical infinite grid, facing a particular direction (north, east, south, or west) at a set of {x,y} coordinates,
+e.g., {3,8}, with coordinates increasing to the north and east.
+
+The robot then receives a number of instructions, at which point the testing facility verifies the robot's new position, and in which direction it is pointing.
+
+- The letter-string "RAALAL" means:
+  - Turn right
+  - Advance twice
+  - Turn left
+  - Advance once
+  - Turn left yet again
+- Say a robot starts at {7, 3} facing north.
+  Then running this stream of instructions should leave it at {9, 4} facing west.

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

@@ -0,0 +1,18 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "robot_simulator.gd"
+    ],
+    "test": [
+      "robot_simulator_test.gd"
+    ],
+    "example": [
+      ".meta/example.gd"
+    ]
+  },
+  "blurb": "Write a robot simulator.",
+  "source": "Inspired by an interview question at a famous company."
+}

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

@@ -0,0 +1,27 @@
+var current_position: Vector2i
+var current_direction: String
+var allowed_directions = ['north', 'east', 'south', 'west']
+
+func _init(position: Vector2i = Vector2i(0, 0), direction: String = 'north'):
+	current_position = position
+	current_direction = direction
+
+
+func move(instructions: String):
+	for instruction in instructions:
+		match [instruction, current_direction]:
+			['L', _]:
+				var index = allowed_directions.find(current_direction) - 1
+				current_direction = allowed_directions[index]
+			['R', _]:
+				var index = allowed_directions.find(current_direction)
+				index = (index + 1) % 4
+				current_direction = allowed_directions[index]
+			['A', 'north']:
+				current_position += Vector2i(0, 1)
+			['A', 'south']:
+				current_position += Vector2i(0, -1)
+			['A', 'east']:
+				current_position += Vector2i(1, 0)
+			['A', 'west']:
+				current_position += Vector2i(-1, 0)

exercises/practice/robot-simulator/.meta/tests.toml

@@ -0,0 +1,64 @@
+# 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.
+
+[c557c16d-26c1-4e06-827c-f6602cd0785c]
+description = "Create robot -> at origin facing north"
+
+[bf0dffce-f11c-4cdb-8a5e-2c89d8a5a67d]
+description = "Create robot -> at negative position facing south"
+
+[8cbd0086-6392-4680-b9b9-73cf491e67e5]
+description = "Rotating clockwise -> changes north to east"
+
+[8abc87fc-eab2-4276-93b7-9c009e866ba1]
+description = "Rotating clockwise -> changes east to south"
+
+[3cfe1b85-bbf2-4bae-b54d-d73e7e93617a]
+description = "Rotating clockwise -> changes south to west"
+
+[5ea9fb99-3f2c-47bd-86f7-46b7d8c3c716]
+description = "Rotating clockwise -> changes west to north"
+
+[fa0c40f5-6ba3-443d-a4b3-58cbd6cb8d63]
+description = "Rotating counter-clockwise -> changes north to west"
+
+[da33d734-831f-445c-9907-d66d7d2a92e2]
+description = "Rotating counter-clockwise -> changes west to south"
+
+[bd1ca4b9-4548-45f4-b32e-900fc7c19389]
+description = "Rotating counter-clockwise -> changes south to east"
+
+[2de27b67-a25c-4b59-9883-bc03b1b55bba]
+description = "Rotating counter-clockwise -> changes east to north"
+
+[f0dc2388-cddc-4f83-9bed-bcf46b8fc7b8]
+description = "Moving forward one -> facing north increments Y"
+
+[2786cf80-5bbf-44b0-9503-a89a9c5789da]
+description = "Moving forward one -> facing south decrements Y"
+
+[84bf3c8c-241f-434d-883d-69817dbd6a48]
+description = "Moving forward one -> facing east increments X"
+
+[bb69c4a7-3bbf-4f64-b415-666fa72d7b04]
+description = "Moving forward one -> facing west decrements X"
+
+[e34ac672-4ed4-4be3-a0b8-d9af259cbaa1]
+description = "Follow series of instructions -> moving east and north from README"
+
+[f30e4955-4b47-4aa3-8b39-ae98cfbd515b]
+description = "Follow series of instructions -> moving west and north"
+
+[3e466bf6-20ab-4d79-8b51-264165182fca]
+description = "Follow series of instructions -> moving west and south"
+
+[41f0bb96-c617-4e6b-acff-a4b279d44514]
+description = "Follow series of instructions -> moving east and north"

exercises/practice/robot-simulator/robot_simulator.gd

@@ -0,0 +1,6 @@
+func _init(position, direction):
+	pass
+
+
+func move(instructions):
+	pass

exercises/practice/robot-simulator/robot_simulator_test.gd

@@ -0,0 +1,126 @@
+func same_field_values(robot_a, robot_b):
+	return robot_a.position == robot_b.position && robot_a.direction == robot_b.direction
+
+
+func test_create_robot_at_origin_facing_north(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'north')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'north')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_create_robot_at_negative_position_facing_south(solution_script):
+	var robot_a = solution_script.new(Vector2i(-1, -1), 'south')
+	var robot_b = solution_script.new(Vector2i(-1, -1), 'south')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_clockwise_changes_north_to_east(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'north')
+	robot_a.move('R')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'east')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_clockwise_changes_east_to_south(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'east')
+	robot_a.move('R')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'south')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_clockwise_changes_south_to_west(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'south')
+	robot_a.move('R')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'west')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_clockwise_changes_west_to_north(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'west')
+	robot_a.move('R')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'north')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_counterclockwise_changes_north_to_west(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'north')
+	robot_a.move('L')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'west')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_counterclockwise_changes_west_to_south(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'west')
+	robot_a.move('L')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'south')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_counterclockwise_changes_south_to_east(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'south')
+	robot_a.move('L')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'east')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_rotating_counterclockwise_changes_east_to_north(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'east')
+	robot_a.move('L')
+	var robot_b = solution_script.new(Vector2i(0, 0), 'north')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_forward_one_facing_north_increments_y(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'north')
+	robot_a.move('A')
+	var robot_b = solution_script.new(Vector2i(0, 1), 'north')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_forward_one_facing_south_decrements_y(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'south')
+	robot_a.move('A')
+	var robot_b = solution_script.new(Vector2i(0, -1), 'south')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_forward_one_facing_east_increments_x(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'east')
+	robot_a.move('A')
+	var robot_b = solution_script.new(Vector2i(1, 0), 'east')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_forward_one_facing_west_decrements_x(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'west')
+	robot_a.move('A')
+	var robot_b = solution_script.new(Vector2i(-1, 0), 'west')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_east_and_north_from_readme(solution_script):
+	var robot_a = solution_script.new(Vector2i(7, 3), 'north')
+	robot_a.move('RAALAL')
+	var robot_b = solution_script.new(Vector2i(9, 4), 'west')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_west_and_north(solution_script):
+	var robot_a = solution_script.new(Vector2i(0, 0), 'north')
+	robot_a.move('LAAARALA')
+	var robot_b = solution_script.new(Vector2i(-4, 1), 'west')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_west_and_south(solution_script):
+	var robot_a = solution_script.new(Vector2i(2, -7), 'east')
+	robot_a.move('RRAAAAALA')
+	var robot_b = solution_script.new(Vector2i(-3, 8), 'south')
+	return [true, same_field_values(robot_a, robot_b)]
+
+
+func test_moving_west_and_south(solution_script):
+	var robot_a = solution_script.new(Vector2i(8, 4), 'south')
+	robot_a.move('LAAARRRALLLL')
+	var robot_b = solution_script.new(Vector2i(11, 5), 'north')
+	return [true, same_field_values(robot_a, robot_b)]