diff --git a/aoc2023/Aoc.newt b/aoc2023/Aoc.newt
index 65fc575..d36c1fa 100644
--- a/aoc2023/Aoc.newt
+++ b/aoc2023/Aoc.newt
@@ -17,3 +17,21 @@ isDigit '7' = True
 isDigit '8' = True
 isDigit '9' = True
 isDigit _ = False
+
+indexOf? : ∀ a. {{Eq a}} → a → List a → Maybe Nat
+indexOf? {a} z xs = go Z z xs
+  where
+    go : Nat → a → List a → Maybe Nat
+    go ix z Nil = Nothing
+    go ix z (x :: xs) =
+      if z == x then Just ix else go (S ix) z xs
+
+-- if_then_else shorthand
+-- Lean version uses a decidable instead of Bool
+ite : ∀ a. Bool → a → a → a
+ite c t e = if c then t else e
+
+-- probably not super efficient, but it works
+qsort : ∀ a. (a → a → Bool) → List a → List a
+qsort lt Nil = Nil
+qsort lt (x :: xs) = qsort lt (filter (λ y => not $ lt x y) xs) ++ x :: qsort lt (filter (lt x) xs)
diff --git a/aoc2023/Day5.newt b/aoc2023/Day5.newt
index 3df60a7..e69e99f 100644
--- a/aoc2023/Day5.newt
+++ b/aoc2023/Day5.newt
@@ -2,10 +2,11 @@ module Day5
 
 import Prelude
 import Node
+import Aoc
 
 -- AoC lib?
-nums : String → List Int
-nums s = map stringToInt $ filter (_/=_ "") $ split (trim s) " "
+-- nums : String → List Int
+-- nums s = map stringToInt $ filter (_/=_ "") $ split (trim s) " "
 
 data MapEntry : U where
   -- dest / src / len
@@ -78,10 +79,6 @@ apply' (r1, r2) x = case x of
     else
       (r1 + d - s, r2) :: Nil
 
--- probably not super efficient, but it works
-qsort : ∀ a. (a → a → Bool) → List a → List a
-qsort lt Nil = Nil
-qsort lt (x :: xs) = qsort lt (filter (λ y => not $ lt x y) xs) ++ x :: qsort lt (filter (lt x) xs)
 
 apply : List Range → List MapEntry → List Range
 apply ranges entries =
diff --git a/aoc2023/Prelude.newt b/aoc2023/Prelude.newt
index 631c202..b9bbcb8 100644
--- a/aoc2023/Prelude.newt
+++ b/aoc2023/Prelude.newt
@@ -164,6 +164,13 @@ class Applicative (f : U → U) where
 class Traversable (t : U → U) where
   traverse : {f : U → U} → {{appf : Applicative f}} → {a : U} → {b : U} → (a → f b) → t a → f (t b)
 
+instance Traversable List where
+  traverse f nil = return Nil
+  traverse f (x :: xs) = return _::_ <*> f a <*> traverse f xs
+
+for : {t : U → U} {f : U → U} → {{Traversable t}} {{appf : Applicative f}} → {a : U} → {b : U} → t a → (a → f b) → f (t b)
+for stuff fun = traverse fun stuff
+
 instance Applicative Maybe where
   return a = Just a
   Nothing <*> _ = Nothing
@@ -308,6 +315,7 @@ instance Monad IO where
     MkIORes a w => mab a w
   pure a = \ w => MkIORes a w
 
+
 bindList : ∀ a b. List a → (a → List b) → List b
 
 instance ∀ a. Concat (List a) where
@@ -386,11 +394,11 @@ pfunc pack : List Char → String := `(cs) => {
 
 pfunc debugStr uses (natToInt listToArray) : ∀ a. a → String := `(_, obj) => {
   const go = (obj) => {
-    if (obj?.tag === '_::_') {
+    if (obj?.tag === '_::_' || obj?.tag === 'Nil') {
       let stuff = listToArray(undefined,obj)
       return '['+(stuff.map(go).join(', '))+']'
     }
-    if (obj?.tag === 'S') {
+    if (obj?.tag === 'S' || obj?.tag === 'Z') {
       return ''+natToInt(obj)
     } else if (obj?.tag) {
       let rval = '('+obj.tag
@@ -564,3 +572,29 @@ instance Add Double where x + y = addDouble x y
 instance Sub Double where x - y = subDouble x y
 instance Mul Double where x * y = mulDouble x y
 instance Div Double where x / y = divDouble x y
+
+ptype IOArray : U → U
+pfunc newArray uses (MkIORes) : ∀ a. Int → a → IO (IOArray a) :=
+  `(_, n, v) => (w) => MkIORes(undefined,Array(n).fill(v),w)`
+pfunc arrayGet : ∀ a. IOArray a → Int → IO a := `(_, arr, ix) => w => MkIORes(undefined, arr[ix], w)`
+pfunc arraySet uses (MkUnit) : ∀ a. IOArray a → Int → a → IO Unit := `(_, arr, ix, v) => w => {
+  arr[ix] = v
+  return MkIORes(undefined, MkUnit, w)
+}`
+
+class Cast a b where
+  cast : a → b
+
+instance Cast Nat Int where
+  cast = natToInt
+
+instance Cast Int Double where
+  cast = intToDouble
+
+instance Applicative IO where
+  return a = \ w => MkIORes a w
+  f <*> a = \ w =>
+    let (MkIORes f w) = trace "fw" $ f w in
+    let (MkIORes a w) = trace "aw" $ a w in
+    MkIORes (f a) w
+
diff --git a/aoc2024/Day1.newt b/aoc2024/Day1.newt
new file mode 100644
index 0000000..fc4a364
--- /dev/null
+++ b/aoc2024/Day1.newt
@@ -0,0 +1,60 @@
+module Day1
+
+import Prelude
+import Node
+import Aoc
+
+pairUp : List Int -> List (Int × Int)
+pairUp (a :: b :: rest) = (a,b) :: pairUp rest
+pairUp (a :: rest) = trace "fail" Nil
+pairUp Nil = Nil
+
+dist : (Int × Int) → Int
+dist (a,b) = if a < b then b - a else a - b
+
+part1 : String -> Int
+part1 text =
+  let pairs = pairUp $ join $ map nums $ split text "\n"
+      left  = qsort _<_ $ map fst pairs
+      right = qsort _<_ $ map snd pairs
+      dists = map dist $ zip left right
+  in foldl _+_ 0 dists
+
+
+lookup : ∀ a b. {{Eq a}} → a → List (a × b) → Maybe b
+lookup key Nil = Nothing
+lookup key ((k,v) :: rest) = if k == key then Just v else lookup key rest
+
+
+coalesce : List Int → Int -> List (Int × Int)
+coalesce (a :: b :: rest) cnt =
+  if a == b then coalesce (b :: rest) (cnt + 1) else (a,cnt) :: coalesce (b :: rest) 1
+coalesce (a :: Nil) cnt = (a,cnt) :: Nil
+coalesce Nil cnt = Nil
+
+cross : List (Int × Int) → List (Int × Int) → Int → Int
+cross xs ys acc =
+  let ((a,cnt) :: xs') = xs | Nil => acc in
+  let ((b,cnt') :: ys') = ys | Nil => acc in
+  if a == b then cross xs' ys' (acc + a * cnt * cnt')
+  else if a < b then cross xs' ys acc
+  else cross xs ys' acc
+
+part2 : String → Int
+part2 text =
+  let pairs = pairUp $ join $ map nums $ split text "\n"
+      left  = coalesce (qsort _<_ $ map fst pairs) 1
+      right = coalesce (qsort _<_ $ map snd pairs) 1
+  in cross left right 0
+
+run : String -> IO Unit
+run fn = do
+  putStrLn fn
+  text <- readFile fn
+  putStrLn $ "part1 " ++ show (part1 text)
+  putStrLn $ "part2 " ++ show (part2 text)
+
+main : IO Unit
+main = do
+  run "aoc2024/day1/eg.txt"
+  run "aoc2024/day1/input.txt"
diff --git a/aoc2024/day1/eg.txt b/aoc2024/day1/eg.txt
new file mode 100644
index 0000000..dfca0b1
--- /dev/null
+++ b/aoc2024/day1/eg.txt
@@ -0,0 +1,6 @@
+3   4
+4   3
+2   5
+1   3
+3   9
+3   3
\ No newline at end of file
diff --git a/src/Lib/Compile.idr b/src/Lib/Compile.idr
index 518d0f3..2b57220 100644
--- a/src/Lib/Compile.idr
+++ b/src/Lib/Compile.idr
@@ -202,7 +202,7 @@ keywords : List String
 keywords = [
   "var", "true", "false", "let", "case", "switch", "if", "then", "else", "String",
   "function", "void", "undefined", "null", "await", "async", "return", "const",
-  "Number", "default"
+  "Number", "default", "for", "while", "Function"
 ]
 
 ||| escape identifiers for js