Robot simulator (#178)

* Add robot-simulator

* use fold

* create

config.json

@@ -304,6 +304,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "robot-simulator",
+        "name": "Robot Simulator",
+        "uuid": "5faa4ded-1358-4310-84b6-ad3a8d4f03ea",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "pythagorean-triplet",
         "name": "Pythagorean Triplet",

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": [
+      "src/RobotSimulator.idr"
+    ],
+    "test": [
+      "test/src/Main.idr"
+    ],
+    "example": [
+      "example/RobotSimulator.idr"
+    ]
+  },
+  "blurb": "Write a robot simulator.",
+  "source": "Inspired by an interview question at a famous company."
+}

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/example/RobotSimulator.idr

@@ -0,0 +1,42 @@
+module RobotSimulator
+
+import Data.Vect
+
+public export
+data Direction = North | East | South | West
+
+public export
+data Instruction = R | L | A
+
+public export
+record Robot where
+  constructor MkRobot
+  direction : Direction
+  coordinates : Vect 2 Integer
+
+public export
+create : Direction -> Integer -> Integer -> Robot
+create direction x y = MkRobot direction [x, y]
+
+public export
+move : Robot -> List Instruction -> Robot
+move = foldl movement
+  where movement : Robot -> Instruction -> Robot
+        movement (MkRobot direction coordinates) R = MkRobot (right direction) coordinates
+          where right : Direction -> Direction
+                right North = East
+                right East = South
+                right South = West
+                right West = North
+        movement (MkRobot direction coordinates) L = MkRobot (left direction) coordinates
+          where left : Direction -> Direction
+                left North = West
+                left East = North
+                left South = East
+                left West = South
+        movement (MkRobot direction coordinates) A = MkRobot direction (advance direction coordinates)
+          where advance : Direction -> Vect 2 Integer -> Vect 2 Integer
+                advance North [x, y] = [x, y + 1]
+                advance East [x, y] = [x + 1, y]
+                advance South [x, y] = [x, y - 1]
+                advance West [x, y] = [x - 1, y]

exercises/practice/robot-simulator/pack.toml

@@ -0,0 +1,10 @@
+[custom.all.robot-simulator]
+type = "local"
+path = "."
+ipkg = "robot-simulator.ipkg"
+test = "test/test.ipkg"
+
+[custom.all.robot-simulator-test]
+type = "local"
+path = "test"
+ipkg = "test.ipkg"

exercises/practice/robot-simulator/robot-simulator.ipkg

@@ -0,0 +1,3 @@
+package robot-simulator
+modules = RobotSimulator
+sourcedir = "src"

exercises/practice/robot-simulator/src/RobotSimulator.idr

@@ -0,0 +1,23 @@
+module RobotSimulator
+
+import Data.Vect
+
+public export
+data Direction = North | East | South | West
+
+public export
+data Instruction = R | L | A
+
+public export
+record Robot where
+  constructor MkRobot
+  direction : Direction
+  coordinates : Vect 2 Integer
+
+public export
+create : Direction -> Integer -> Integer -> Robot
+create direction x y = ?create_rhs
+
+public export
+move : Robot -> List Instruction -> Robot
+move robot instructions = ?move_rhs

exercises/practice/robot-simulator/test/src/Main.idr

@@ -0,0 +1,61 @@
+module Main
+
+import System
+import Tester
+import Tester.Runner
+
+import RobotSimulator
+import Data.Vect
+
+public export
+implementation Eq Direction where
+  (==) North North = True
+  (==) East East = True
+  (==) South South = True
+  (==) West West = True
+  (==) _ _ = False
+
+public export
+implementation Show Direction where
+  show North = "North"
+  show East = "East"
+  show South = "South"
+  show West = "West"
+
+public export
+implementation Eq Robot where
+  (==) (MkRobot d1 c1) (MkRobot d2 c2) = (d1 == d2) && (c1 == c2)
+
+public export
+implementation Show Robot where
+  show (MkRobot direction coordinates) = "MkRobot " ++ (show direction) ++ " " ++ (show coordinates)
+
+tests : List Test
+tests =
+  [ test "at origin facing north"            (assertEq (create North 0 0) (MkRobot North [0, 0]))
+  , test "at negative position facing south" (assertEq (create South (-1) (-1)) (MkRobot South [-1, -1]))
+  , test "changes north to east"             (assertEq (move (MkRobot North [0, 0]) [R]) (MkRobot East [0, 0]))
+  , test "changes east to south"             (assertEq (move (MkRobot East [0, 0]) [R]) (MkRobot South [0, 0]))
+  , test "changes south to west"             (assertEq (move (MkRobot South [0, 0]) [R]) (MkRobot West [0, 0]))
+  , test "changes west to north"             (assertEq (move (MkRobot West [0, 0]) [R]) (MkRobot North [0, 0]))
+  , test "changes north to west"             (assertEq (move (MkRobot North [0, 0]) [L]) (MkRobot West [0, 0]))
+  , test "changes west to south"             (assertEq (move (MkRobot West [0, 0]) [L]) (MkRobot South [0, 0]))
+  , test "changes south to east"             (assertEq (move (MkRobot South [0, 0]) [L]) (MkRobot East [0, 0]))
+  , test "changes east to north"             (assertEq (move (MkRobot East [0, 0]) [L]) (MkRobot North [0, 0]))
+  , test "facing north increments Y"         (assertEq (move (MkRobot North [0, 0]) [A]) (MkRobot North [0, 1]))
+  , test "facing south decrements Y"         (assertEq (move (MkRobot South [0, 0]) [A]) (MkRobot South [0, -1]))
+  , test "facing east increments X"          (assertEq (move (MkRobot East [0, 0]) [A]) (MkRobot East [1, 0]))
+  , test "facing west decrements X"          (assertEq (move (MkRobot West [0, 0]) [A]) (MkRobot West [-1, 0]))
+  , test "moving east and north from README" (assertEq (move (MkRobot North [7, 3]) [R, A, A, L, A, L]) (MkRobot West [9, 4]))
+  , test "moving west and north"             (assertEq (move (MkRobot North [0, 0]) [L, A, A, A, R, A, L, A]) (MkRobot West [-4, 1]))
+  , test "moving west and south"             (assertEq (move (MkRobot East [2, -7]) [R, R, A, A, A, A, A, L, A]) (MkRobot South [-3, -8]))
+  , test "moving east and north"             (assertEq (move (MkRobot South [8, 4]) [L, A, A, A, R, R, R, A, L, L, L, L]) (MkRobot North [11, 5]))
+  ]
+
+export
+main : IO ()
+main = do
+  success <- runTests tests
+  if success
+     then putStrLn "All tests passed"
+     else exitFailure

exercises/practice/robot-simulator/test/test.ipkg

@@ -0,0 +1,6 @@
+package robot-simulator-test
+depends = robot-simulator
+  , tester
+main = Main
+executable = "robot-simulator-test"
+sourcedir = "src"

generators/exercises/robot_simulator.py

@@ -0,0 +1,53 @@
+
+HEADER = """import Data.Vect
+
+public export
+implementation Eq Direction where
+  (==) North North = True
+  (==) East East = True
+  (==) South South = True
+  (==) West West = True
+  (==) _ _ = False
+
+public export
+implementation Show Direction where
+  show North = "North"
+  show East = "East"
+  show South = "South"
+  show West = "West"
+
+public export
+implementation Eq Robot where
+  (==) (MkRobot d1 c1) (MkRobot d2 c2) = (d1 == d2) && (c1 == c2)
+
+public export
+implementation Show Robot where
+  show (MkRobot direction coordinates) = "MkRobot " ++ (show direction) ++ " " ++ (show coordinates)
+"""
+
+def header():
+    return HEADER
+
+def generate_test(case):
+    def to_robot(data):
+      direction = data["direction"].title()
+      x = data["position"]["x"]
+      y = data["position"]["y"]
+      return f'(MkRobot {direction} [{x}, {y}])'
+
+    property = case["property"]
+    expected = to_robot(case["expected"])
+    if property == 'create':
+      direction = case["input"]["direction"].title()
+      x = case["input"]["position"]["x"]
+      if x < 0:
+        x = f'({x})'
+      y = case["input"]["position"]["y"]
+      if y < 0:
+        y = f'({y})'
+      return f'assertEq (create {direction} {x} {y}) {expected}'
+
+    robot = to_robot(case["input"])
+    instructions = case["input"]["instructions"]
+    instructions = str(list(instructions)).replace("'", "")
+    return f'assertEq ({property} {robot} {instructions}) {expected}'