Add robot-simulator exercise (exercism#270)

Author: keiravillekode

bin/reorder-exercises

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+required_tool() {
+    command -v "${1}" >/dev/null 2>&1 ||
+        die "${1} is required but not installed. Please install it and make sure it's in your PATH."
+}
+
+required_tool jq
+
+jq '.exercises.practice |= sort_by(.difficulty, (.name|ascii_upcase))' config.json > tmp && mv tmp config.json
+bin/fetch-configlet && bin/configlet fmt --update --yes

config.json

@@ -600,6 +600,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "robot-simulator",
+        "name": "Robot Simulator",
+        "uuid": "513f8b55-a335-474c-b9bf-4aca8b20c720",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "rotational-cipher",
         "name": "Rotational Cipher",

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": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "robot-simulator.v"
+    ],
+    "test": [
+      "run_test.v"
+    ],
+    "example": [
+      ".meta/example.v"
+    ]
+  },
+  "blurb": "Write a robot simulator.",
+  "source": "Inspired by an interview question at a famous company."
+}

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

@@ -0,0 +1,79 @@
+module main
+
+struct Position {
+	x int
+	y int
+}
+
+enum Direction {
+	north
+	east
+	south
+	west
+}
+
+struct Robot {
+mut:
+	position  Position
+	direction Direction
+}
+
+fn Robot.new(x int, y int, direction Direction) Robot {
+	return Robot{Position{x, y}, direction}
+}
+
+fn (mut robot Robot) move(instructions string) {
+	for instruction in instructions {
+		match instruction {
+			`R` {
+				match robot.direction {
+					.north {
+						robot.direction = .east
+					}
+					.east {
+						robot.direction = .south
+					}
+					.south {
+						robot.direction = .west
+					}
+					.west {
+						robot.direction = .north
+					}
+				}
+			}
+			`L` {
+				match robot.direction {
+					.north {
+						robot.direction = .west
+					}
+					.east {
+						robot.direction = .north
+					}
+					.south {
+						robot.direction = .east
+					}
+					.west {
+						robot.direction = .south
+					}
+				}
+			}
+			`A` {
+				match robot.direction {
+					.north {
+						robot.position = Position{robot.position.x, robot.position.y + 1}
+					}
+					.east {
+						robot.position = Position{robot.position.x + 1, robot.position.y}
+					}
+					.south {
+						robot.position = Position{robot.position.x, robot.position.y - 1}
+					}
+					.west {
+						robot.position = Position{robot.position.x - 1, robot.position.y}
+					}
+				}
+			}
+			else {}
+		}
+	}
+}

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

@@ -0,0 +1,57 @@
+# 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.
+
+[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.v

@@ -0,0 +1,25 @@
+module main
+
+struct Position {
+	x int
+	y int
+}
+
+enum Direction {
+	north
+	east
+	south
+	west
+}
+
+struct Robot {
+	// Please define the `Robot` struct
+}
+
+fn Robot.new(x int, y int, direction Direction) Robot {
+	// Please implement the `Robot.new` function
+}
+
+fn (mut robot Robot) move(instructions string) {
+	// Please implement the `move` function
+}

exercises/practice/robot-simulator/run_test.v

@@ -0,0 +1,143 @@
+module main
+
+fn test_create_robot__at_origin_facing_north() {
+	robot := Robot.new(0, 0, .north)
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .north
+}
+
+fn test_create_robot__at_negative_position_facing_south() {
+	robot := Robot.new(-1, -1, .south)
+	assert robot.position.x == -1
+	assert robot.position.y == -1
+	assert robot.direction == .south
+}
+
+fn test_rotating_clockwise__changes_north_to_east() {
+	mut robot := Robot.new(0, 0, .north)
+	robot.move('R')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .east
+}
+
+fn test_rotating_clockwise__changes_east_to_south() {
+	mut robot := Robot.new(0, 0, .east)
+	robot.move('R')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .south
+}
+
+fn test_rotating_clockwise__changes_south_to_west() {
+	mut robot := Robot.new(0, 0, .south)
+	robot.move('R')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .west
+}
+
+fn test_rotating_clockwise__changes_west_to_north() {
+	mut robot := Robot.new(0, 0, .west)
+	robot.move('R')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .north
+}
+
+fn test_rotating_counter_clockwise__changes_north_to_west() {
+	mut robot := Robot.new(0, 0, .north)
+	robot.move('L')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .west
+}
+
+fn test_rotating_counter_clockwise__changes_west_to_south() {
+	mut robot := Robot.new(0, 0, .west)
+	robot.move('L')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .south
+}
+
+fn test_rotating_counter_clockwise__changes_south_to_east() {
+	mut robot := Robot.new(0, 0, .south)
+	robot.move('L')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .east
+}
+
+fn test_rotating_counter_clockwise__changes_east_to_north() {
+	mut robot := Robot.new(0, 0, .east)
+	robot.move('L')
+	assert robot.position.x == 0
+	assert robot.position.y == 0
+	assert robot.direction == .north
+}
+
+fn test_moving_forward_one__facing_north_increments_y() {
+	mut robot := Robot.new(0, 0, .north)
+	robot.move('A')
+	assert robot.position.x == 0
+	assert robot.position.y == 1
+	assert robot.direction == .north
+}
+
+fn test_moving_forward_one__facing_south_decrements_y() {
+	mut robot := Robot.new(0, 0, .south)
+	robot.move('A')
+	assert robot.position.x == 0
+	assert robot.position.y == -1
+	assert robot.direction == .south
+}
+
+fn test_moving_forward_one__facing_east_increments_x() {
+	mut robot := Robot.new(0, 0, .east)
+	robot.move('A')
+	assert robot.position.x == 1
+	assert robot.position.y == 0
+	assert robot.direction == .east
+}
+
+fn test_moving_forward_one__facing_west_decrements_x() {
+	mut robot := Robot.new(0, 0, .west)
+	robot.move('A')
+	assert robot.position.x == -1
+	assert robot.position.y == 0
+	assert robot.direction == .west
+}
+
+fn test_follow_series_of_instructions__moving_east_and_north_from_readme() {
+	mut robot := Robot.new(7, 3, .north)
+	robot.move('RAALAL')
+	assert robot.position.x == 9
+	assert robot.position.y == 4
+	assert robot.direction == .west
+}
+
+fn test_follow_series_of_instructions__moving_west_and_north() {
+	mut robot := Robot.new(0, 0, .north)
+	robot.move('LAAARALA')
+	assert robot.position.x == -4
+	assert robot.position.y == 1
+	assert robot.direction == .west
+}
+
+fn test_follow_series_of_instructions__moving_west_and_south() {
+	mut robot := Robot.new(2, -7, .east)
+	robot.move('RRAAAAALA')
+	assert robot.position.x == -3
+	assert robot.position.y == -8
+	assert robot.direction == .south
+}
+
+fn test_follow_series_of_instructions__moving_east_and_north() {
+	mut robot := Robot.new(8, 4, .south)
+	robot.move('LAAARRRALLLL')
+	assert robot.position.x == 11
+	assert robot.position.y == 5
+	assert robot.direction == .north
+}