From 67b5d50f26e464ca0696af48ac2427d93df0f170 Mon Sep 17 00:00:00 2001
From: Karl Ostmo <kostmo@gmail.com>
Date: Tue, 2 Jan 2024 10:27:20 -0800
Subject: [PATCH] caterpillar

---
 data/scenarios/Fun/00-ORDER.txt             |   3 +-
 data/scenarios/Fun/_caterpillar/solution.sw | 129 ++++++++++++++++++++
 data/scenarios/Fun/caterpillar.yaml         |  66 ++++++++++
 3 files changed, 197 insertions(+), 1 deletion(-)
 create mode 100644 data/scenarios/Fun/_caterpillar/solution.sw
 create mode 100644 data/scenarios/Fun/caterpillar.yaml

diff --git a/data/scenarios/Fun/00-ORDER.txt b/data/scenarios/Fun/00-ORDER.txt
index 162469def..b688f7170 100644
--- a/data/scenarios/Fun/00-ORDER.txt
+++ b/data/scenarios/Fun/00-ORDER.txt
@@ -1,3 +1,4 @@
 GoL.yaml
 logo-burst.yaml
-horton.yaml
\ No newline at end of file
+horton.yaml
+caterpillar.yaml
\ No newline at end of file
diff --git a/data/scenarios/Fun/_caterpillar/solution.sw b/data/scenarios/Fun/_caterpillar/solution.sw
new file mode 100644
index 000000000..ff9d20645
--- /dev/null
+++ b/data/scenarios/Fun/_caterpillar/solution.sw
@@ -0,0 +1,129 @@
+def bindE = \f. \x. case x inL f end
+def fmapE = \f. \x. case x inL (\y. inR $ f y) end
+
+def nil : (a -> b -> b) ->
+           b ->
+           b = \_. \x. x end
+
+def cons : a ->
+           ((a -> b -> b) -> b -> b) ->
+           (a -> b -> b) ->
+           b ->
+           b = \x. \xs. \f. \b. f x $ xs f b end
+
+// Accumulator functions
+
+def offsetCoords : (int * int) -> (int * int) -> (int * int) = \coord. \offset.
+  (fst coord + fst offset, snd coord + snd offset)
+  end
+
+def getLength : ((a -> int -> int) -> int -> int) -> int = \list.
+  list (\_. \y. 1 + y) 0
+  end
+
+def lastAccumulatorFunc : a -> (unit + a) -> (unit + a) = \x. \b.
+  case b (\_. inR x) inR
+  end
+
+def getLast : ((a -> (unit + a) -> (unit + a)) -> (unit + a) -> (unit + a)) -> (unit + a) = \list.
+  list lastAccumulatorFunc $ inL ()
+  end
+
+def initAccumulatorFunc : a ->
+           unit + ((a -> b -> b) -> b -> b) ->
+           unit + ((a -> b -> b) -> b -> b) = \x. \b.
+  case b (\_. inR nil) (\y. inR $ cons x y)
+  end
+
+def getInit = \list.
+  list initAccumulatorFunc $ inL ()
+  end
+
+// "pop" from the tail;
+// returns the last element of the list and the truncated list.
+def shift = \list.
+  list (\x. \b. case b (\_. inR (x, nil)) (\y. inR (fst y, cons x $ snd y))) $ inL ()
+  end
+
+
+def getPassthrough = \list.
+  list cons nil
+  end
+
+
+
+// Scenario-specific functions
+
+def doAtLoc = \currLoc. \targetLoc. \func.
+  teleport self targetLoc;
+  func;
+  teleport self currLoc;
+  end;
+
+def makeList = \i. \currentList.
+  if (i > 0) {
+    move;
+    myLoc <- whereami;
+    place "tail";
+    
+    newList <- makeList (i - 1) $ cons myLoc currentList;
+    return newList;
+  } {
+    return currentList;
+  };
+  end
+
+def go2 = \myList.
+
+
+  wait 10;
+  move;
+
+  newLoc <- whereami;
+
+  let maybeLastElem = getLast myList in
+  case maybeLastElem return (\lastElem.
+    log $ "Going to teleport to: " ++ format lastElem;
+    doAtLoc newLoc lastElem grab;
+  );
+
+
+  // let listInit = getPassthrough myList in
+  // log $ "List length: " ++ format (getLength listInit);
+
+  // let shifted = shift myList in
+
+  // FIXME: Uncommenting the following line causes a type error!
+  // let oldRattleLoc = fst shifted in
+  // let shiftedList = snd shifted in
+  // doAtLoc newLoc oldRattleLoc grab;
+
+  go2 $ cons newLoc myList;
+  end;
+
+
+def go =
+  myList <- makeList 5 $ nil;
+
+  let w = myList offsetCoords (0, 0) in
+  let x = getLength myList in
+  let y = getLast myList in
+  let z = bindE getLast $ getInit myList in
+
+  let shifted = shift myList in
+
+  log "======";
+  log $ format w;
+  log $ format x;
+  log $ format y;
+  log $ format z;
+
+  log "-------";
+  log $ format $ fmapE fst shifted;
+  log $ format $ fmapE fst $ bindE shift $ fmapE snd shifted;
+  log $ format $ fmapE fst $ bindE shift $ fmapE snd $ bindE shift $ fmapE snd shifted;
+
+  go2 myList;
+  end;
+
+go;
\ No newline at end of file
diff --git a/data/scenarios/Fun/caterpillar.yaml b/data/scenarios/Fun/caterpillar.yaml
new file mode 100644
index 000000000..3e0334eeb
--- /dev/null
+++ b/data/scenarios/Fun/caterpillar.yaml
@@ -0,0 +1,66 @@
+version: 1
+name: Caterpillar
+author: Karl Ostmo
+seed: 1
+description: |
+  Crawl along
+creative: true
+objectives:
+  - goal:
+      - |
+        Eat 30 apples
+    condition: |
+      return false
+robots:
+  - name: base
+    dir: north
+    devices:
+      - ADT calculator
+      - branch predictor
+      - clock
+      - comparator
+      - compass
+      - dictionary
+      - GPS receiver
+      - grabber
+      - hourglass
+      - hearing aid
+      - lambda
+      - logger
+      - net
+      - scanner
+      - strange loop
+      - string
+      - treads
+    inventory:
+      - [5, tail]
+solution: |
+  run "scenarios/Fun/_caterpillar/solution.sw"
+entities:
+  - name: tail
+    display:
+      char: '@'
+      attr: green
+    description:
+      - |
+        Segment of snake's tail
+    properties: [known]
+known: [water, boulder, flower]
+world:
+  dsl: |
+    {grass}
+  upperleft: [-4, 4]
+  palette:
+    'B': [grass, erase, base]
+    '.': [grass, erase]
+    's': [stone, erase]
+  map: |
+    ..sssss..
+    .sssssss.
+    sssssssss
+    sssssssss
+    ssssBssss
+    sssssssss
+    sssssssss
+    .sssssss.
+    ..sssss..
\ No newline at end of file