Counting flowers (#2249)

Another challenge scenario to showcase the use of `print`/`read`.

data/scenarios/Challenges/00-ORDER.txt

@@ -21,6 +21,7 @@ friend.yaml
 pack-tetrominoes.yaml
 dimsum.yaml
 telephone.yaml
+flower-count.yaml
 Mazes
 Ranching
 Sokoban

data/scenarios/Challenges/_flower-count/judge.sw

@@ -0,0 +1,35 @@
+def win =
+  try {
+    firestarter <- robotNamed "firestarter";
+    halt firestarter
+  } {};
+  try {
+    fire <- robotNamed "fire";
+    halt fire; wait 1;
+    reprogram fire { selfdestruct };
+  } {};
+  create "gold"
+end
+
+def judgeCount : Int -> Cmd Unit = \actual.
+  watch down;
+  wait 1024;
+  s <- scan down;
+  case s
+    (\_. return ())
+    (\p.
+      try {
+        let c = (read p : Int) in
+        if (c == actual) { win } {}
+      } {}
+    )
+end
+
+def forever = \c. c; forever c end
+
+def judge =
+  numFlowers <- resonate "flower" ((-59,-19),(60,20));
+  forever (judgeCount numFlowers);
+end;
+
+judge

data/scenarios/Challenges/_flower-count/solution.sw

@@ -0,0 +1,114 @@
+def doN : Int -> Cmd a -> Cmd Unit = \n. \c.
+  if (n == 0) {} {c; doN (n-1) c}
+end
+
+def abs : Int -> Int = \n.
+  if (n < 0) {-n} {n}
+end
+
+// Go to the given absolute coordinates.  End facing east.
+def goto : Int * Int -> Cmd Unit = \dest.
+  cur <- whereami;
+  let x = fst cur in
+  let y = snd cur in
+  let dx = fst dest - x in
+  let dy = snd dest - y in
+  if (dx < 0) {turn west} {turn east};
+  doN (abs dx) move;
+  if (dy < 0) {turn south} {turn north};
+  doN (abs dy) move;
+  turn east;
+end
+
+def liftA2 : (a -> b -> c) -> Cmd a -> Cmd b -> Cmd c = \f. \ca. \cb.
+  a <- ca;
+  b <- cb;
+  return (f a b)
+end
+
+def add : Cmd Int -> Cmd Int -> Cmd Int = liftA2 (\x. \y. x + y) end
+
+def countCell : Cmd Int =
+  s <- scan down;
+  return $ case s
+    (\_. 0)
+    (\t. if (t == "flower") {1} {0})
+end
+
+tydef List a = rec l. Unit + (a * l) end
+
+def sum : List Int -> Int = \l.
+  case l
+    (\_. 0)
+    (\cons. fst cons + sum (snd cons))
+end
+
+def for : Int -> (Int -> Cmd a) -> Cmd (List a) = \n. \k.
+  if (n == 0) {return (inl ())} {a <- k n; b <- for (n-1) k; return (inr (a,b))}
+end
+
+def countRow : Int -> Cmd Int = \w.
+  ns <- for (w-1) (\_. n <- countCell; move; return n);
+  last <- countCell;
+  return (sum ns + last)
+end
+
+def isEven : Int -> Bool = \n. (n / 2) * 2 == n end
+
+def around : Dir -> Cmd Unit = \d. turn d; move; turn d end
+
+// countFlowers (w,h) (x,y) counts the number of flowers
+// in the w by h rectangle with lower-left corner at (x,y)
+def countFlowers : Int * Int -> Int * Int -> Cmd Int = \size. \ll.
+  goto ll;
+  let w = fst size in
+  let h = snd size in
+  cnts <- for (h-1) (\i.
+    cnt <- countRow w;
+    if (isEven i) { around right } { around left };
+    return cnt
+  );
+  last <- countRow w;
+  return (sum cnts + last)
+end
+
+def acquire : Cmd Text =
+  thing <- atomic (b <- isempty; if b {return ""} {grab});
+  if (thing == "") {acquire} {return thing}
+end
+
+def countAndReport : Int * Int -> Int * Int -> Cmd Unit = \size. \ll.
+  cnt <- countFlowers size ll;
+  goto (0,0);
+  paper <- acquire;
+  let soFar = (read paper : Int) in
+  erase paper;
+  newPaper <- print "paper" (format (soFar + cnt));
+  place newPaper;
+end
+
+def until : Cmd Bool -> Cmd a -> Cmd Unit = \test. \body.
+  b <- test; if b {} {body; until test body}
+end
+
+def acquireFlower : Cmd Unit =
+  until (ishere "flower") move; grab; return ()
+end
+
+def go =
+  for 4 (\r.
+    for 3 (\c.
+      build {countAndReport (40,10) (-59 + 40*(c-1), -19 + 10*(r-1))}
+    )
+  );
+  print "paper" "0";
+  turn left; move; place "paper: 0";
+  wait 1024;
+  acquireFlower;
+  turn back;
+  goto (20,0);
+  res <- meet;
+  case res (\_. return ()) (\truelove. give truelove "flower")
+end;
+
+go;

data/scenarios/Challenges/flower-count.yaml

@@ -0,0 +1,178 @@
+version: 1
+name: Flower Count
+author: Brent Yorgey
+description: |
+  Count the flowers quickly... or else!
+creative: false
+objectives:
+  - id: count_flowers
+    teaser: Count the flowers!
+    goal:
+      - |
+        Your evil nemesis, the sadistic arithmomaniac supervillain Count Nemesis, is
+        at it again!  They have wired up some explosives to your
+        `True Love`{=robot} and lit the fuse, but promised to stop it... IF you can
+        count all the flowers in time!
+      - |
+        Specifically, Count Nemesis demands that you count the
+        total number of flowers in the 120x40 field bounded by walls,
+        `print` the number on a piece of `paper`{=entity}, and place
+        the paper at the origin, `(0,0)`.  If the number is correct,
+        the countdown stops and your True Love is saved.  If the
+        number is incorrect... nothing happens, but the fuse continues
+        to burn!
+      - |
+        And watch out, Count Nemesis won't abide anyone picking his flowers.
+    condition: |
+      judge <- robotNamed "judge";
+      as judge { has "gold" }
+  - id: pick_flower
+    hidden: true
+    optional: true
+    teaser: You just don't listen, do you
+    goal:
+      - |
+        I told you not to pick any flowers!  Now your True Love is
+        dead... because of YOU!
+      - |
+        Perhaps you would like to go back in time and try again.
+    condition: |
+      f <- as base { has "flower" };
+      judge <- robotNamed "judge";
+      g <- as judge { has "gold" };
+      return (not g && f)
+  - id: out_of_time
+    hidden: true
+    optional: true
+    teaser: Not fast enough
+    goal:
+      - |
+        You were not fast enough, and now your True Love is
+        dead... because of YOU!
+      - |
+        Perhaps you would like to go back in time and try again.
+    condition: |
+      truelove <- robotNamed "truelove";
+      as truelove { b <- ishere "fuse"; return (not b) }
+  - id: joinpoint
+    hidden: true
+    teaser: Follow instructions!
+    prerequisite:
+      logic:
+        and:
+          - count_flowers
+          - not: pick_flower
+          - not: out_of_time
+    condition: |
+      return true
+  - id: win
+    teaser: Give a flower
+    prerequisite: joinpoint
+    goal:
+      - |
+        Congratulations!  You foiled the plan of evil Dr. Nemesis and
+        saved your True Love!  The only thing left is to give your
+        True Love a `flower`{=entity}!
+    condition: |
+      truelove <- robotNamed "truelove";
+      as truelove { has "flower" }
+solution: |
+  run "scenarios/Challenges/_flower-count/solution.sw"
+robots:
+  - name: base
+    dir: north
+    devices:
+      - solar panel
+      - treads
+      - antenna
+      - comparator
+      - ADT calculator
+      - workbench
+      - grabber
+      - dictionary
+      - lambda
+      - logger
+      - welder
+      - scanner
+      - strange loop
+      - typewriter
+      - 3D printer
+      - branch predictor
+      - clock
+      - GPS receiver
+      - compass
+      - counter
+    inventory:
+      - [12, solar panel]
+      - [12, dictionary]
+      - [12, lambda]
+      - [12, treads]
+      - [12, branch predictor]
+      - [12, comparator]
+      - [12, hyperloop]
+      - [12, compass]
+      - [12, scanner]
+      - [12, logger]
+      - [12, GPS receiver]
+      - [12, string]
+      - [12, typewriter]
+      - [12, rubber band]
+      - [12, grabber]
+      - [12, parsley]
+      - [1, paper]
+  - name: igniter
+    system: true
+    dir: east
+    devices:
+      - logger
+    program: 'ignite down'
+  - name: judge
+    system: true
+    dir: east
+    devices:
+      - logger
+    program: |
+      run "scenarios/Challenges/_flower-count/judge.sw"
+  - name: truelove
+    system: true
+    display:
+      invisible: false
+      attr: red
+      char: '♥'
+    description: Your One True Love.
+attrs:
+  - name: fuse
+    fg: '#cccccc'
+    bg: '#002f00'
+entities:
+  - name: fuse
+    display:
+      attr: fuse
+      char: '-'
+    description:
+      - Slow-burning fuse
+    properties: [combustible, known, boundary]
+    combustion:
+      ignition: 20
+      duration: [64, 64]
+      delay: 63
+      product: ash
+known: [flower, wall, ash]
+world:
+  dsl: |
+    overlay
+    [ if (hash % 7 <= 2) then {grass, flower} else {grass}
+    , mask ((x == 61 || x == (-60)) && y <= 21 && y >= -20) {wall, stone}
+    , mask ((y == 21 || y == (-20)) && x <= 61 && x >= -60) {wall, stone}
+    ]
+  upperleft: [0, 0]
+  offset: false
+  palette:
+    'B': [grass, null, base]
+    'J': [grass, erase, judge]
+    '.': [grass]
+    '-': [grass, fuse]
+    'L': [grass, fuse, truelove]
+    'I': [grass, fuse, igniter]
+  map: |
+    JB..I---------------L

test/integration/Main.hs

@@ -250,6 +250,7 @@ testScenarioSolutions rs ui key =
         , testSolution (Sec 10) "Challenges/dimsum"
         , testSolution (Sec 15) "Challenges/gallery"
         , testSolution (Sec 10) "Challenges/telephone"
+        , testSolution (Sec 10) "Challenges/flower-count"
         , testGroup
             "Mazes"
             [ testSolution Default "Challenges/Mazes/easy_cave_maze"