day 1 part 1

gleam.toml

···
 
 [dependencies]
 gleam_stdlib = ">= 0.44.0 and < 2.0.0"
+simplifile = ">= 2.3.1 and < 3.0.0"
+gleam_regexp = ">= 1.1.1 and < 2.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.0.0 and < 2.0.0"

manifest.toml

···
+# This file was generated by Gleam
+# You typically do not need to edit this file
+
+packages = [
+  { name = "filepath", version = "1.1.2", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "filepath", source = "hex", outer_checksum = "B06A9AF0BF10E51401D64B98E4B627F1D2E48C154967DA7AF4D0914780A6D40A" },
+  { name = "gleam_regexp", version = "1.1.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_regexp", source = "hex", outer_checksum = "9C215C6CA84A5B35BB934A9B61A9A306EC743153BE2B0425A0D032E477B062A9" },
+  { name = "gleam_stdlib", version = "0.67.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "6368313DB35963DC02F677A513BB0D95D58A34ED0A9436C8116820BF94BE3511" },
+  { name = "gleeunit", version = "1.9.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "DA9553CE58B67924B3C631F96FE3370C49EB6D6DC6B384EC4862CC4AAA718F3C" },
+  { name = "simplifile", version = "2.3.1", build_tools = ["gleam"], requirements = ["filepath", "gleam_stdlib"], otp_app = "simplifile", source = "hex", outer_checksum = "957E0E5B75927659F1D2A1B7B75D7B9BA96FAA8D0C53EA71C4AD9CD0C6B848F6" },
+]
+
+[requirements]
+gleam_regexp = { version = ">= 1.1.1 and < 2.0.0" }
+gleam_stdlib = { version = ">= 0.44.0 and < 2.0.0" }
+gleeunit = { version = ">= 1.0.0 and < 2.0.0" }
+simplifile = { version = ">= 2.3.1 and < 3.0.0" }

src/advent_2025.gleam

···
+import day1
 import gleam/io
 
-pub fn main() -> Nil {
-  io.println("Hello from advent_2025!")
+pub fn main() {
+  day1.day1main()
 }

src/day1.gleam

···
+import gleam/int
+import gleam/list
+import gleam/string
+import herbie
+import simplifile
+
+pub fn day1main() {
+  let assert Ok(file) = simplifile.read("./data/day1test")
+  let file =
+    file
+    |> string.trim_end()
+    |> string.split("\n")
+
+  let moves = list.map(file, signed)
+  list.fold(moves, #(50, 0), make_move)
+  |> echo
+}
+
+fn crosses_zero(starting: Int, move: Int) -> Int {
+  todo
+}
+
+fn make_move(acc: #(Int, Int), move: Int) -> #(Int, Int) {
+  let position = { acc.0 + move + 100 } % 100
+  let zeroes = case position {
+    0 -> acc.1 + 1
+    _ -> acc.1
+  }
+  #(position, zeroes)
+}
+
+fn signed(input: String) -> Int {
+  let graphemes = string.to_graphemes(input)
+  let assert [sign, ..nums] = graphemes
+  let nums = nums |> string.concat() |> herbie.quickint()
+  case sign {
+    "L" -> nums * -1
+    _ -> nums
+  }
+}

src/herbie.gleam

···
 import gleam/dict
 import gleam/int
 import gleam/list
+import gleam/result
 import gleam/string
 import simplifile
 
 pub type Coord =
   #(Int, Int)
+
+pub fn quickint(input: String) -> Int {
+  let assert Ok(return) = int.parse(input)
+  return
+}
+
+pub fn quickfirst(input: List(a)) -> a {
+  let assert Ok(return) = list.first(input)
+  return
+}
+
+pub fn quicklast(input: List(a)) -> a {
+  let assert Ok(return) = list.last(input)
+  return
+}
 
 pub fn path_to_string(path: String) -> String {
   let assert Ok(return) = simplifile.read(from: path)