No more expect, we use Result now

Cargo.lock

@@ -11,10 +11,17 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.51"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b26702f315f53b6071259e15dd9d64528213b44d61de1ec926eca7715d62203"
+
 [[package]]
 name = "aoc2021"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "chrono",
  "clap",
 ]

Cargo.toml

@@ -8,3 +8,4 @@ edition = "2021"
 [dependencies]
 clap = "2.34.0"
 chrono = "0.4.19"
+anyhow = "1.0.51"

src/day.rs

@@ -1,5 +1,7 @@
+use anyhow::Result;
+
 pub trait Day {
-    fn init(content: String) -> Self where Self: Sized;
-    fn part1(&self) -> String;
-    fn part2(&self) -> String;
+    fn init(content: String) -> Result<Self> where Self: Sized;
+    fn part1(&self) -> Result<String>;
+    fn part2(&self) -> Result<String>;
 }

src/day01.rs

@@ -1,21 +1,22 @@
+use anyhow::Result;
 
 pub struct Day01(Vec<i32>);
 
 impl crate::day::Day for Day01 {
-    fn init(f: String) -> Self {
-        let v = f.lines().map(|x| x.parse::<i32>().unwrap()).collect::<Vec<i32>>();
-        Self(v)
+    fn init(f: String) -> Result<Self> {
+        let v = f.lines().map(str::parse).collect::<Result<Vec<_>, _>>()?;
+        Ok(Self(v))
     }
 
-    fn part1(&self) -> String {
+    fn part1(&self) -> Result<String> {
         let (a, _) = self.0.iter().copied().fold((0, -1), increments);
-        format!("{}", a)
+        Ok(format!("{}", a))
     }
 
-    fn part2(&self) -> String {
+    fn part2(&self) -> Result<String> {
         let ws = self.0.windows(3).map(|a| a.iter().fold(0, std::ops::Add::add)).collect::<Vec<i32>>();
         let (a, _) = ws.iter().copied().fold((0, -1), increments);
-        format!("{}", a)
+        Ok(format!("{}", a))
     }
 }
 
@@ -37,32 +38,36 @@ pub mod tests {
     use crate::day::Day;
 
     #[test]
-    pub fn part1_real() {
-        let f = read_to_string("./input/day01").expect("Could not load input");
-        let d = Day01::init(f);
-        assert_eq!("1466", d.part1())
+    pub fn part1_real() -> anyhow::Result<()> {
+        let f = read_to_string("./input/day01")?;
+        let d = Day01::init(f)?;
+        assert_eq!("1466", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    pub fn part2_real() {
-        let f = read_to_string("./input/day01").expect("Could not load input");
-        let d = Day01::init(f);
-        assert_eq!("1491", d.part2())
+    pub fn part2_real() -> anyhow::Result<()> {
+        let f = read_to_string("./input/day01")?;
+        let d = Day01::init(f)?;
+        assert_eq!("1491", d.part2()?);
+        Ok(())
     }
 
     #[test]
-    pub fn part1_test() {
+    pub fn part1_test() -> anyhow::Result<()>{
         let v = vec![199, 200, 208, 210, 200, 207, 240, 269, 260, 263];
         let strs = v.iter().map(i32::to_string).collect::<Vec<String>>().join("\n");
-        let d = Day01::init(strs);
-        assert_eq!("7", d.part1())
+        let d = Day01::init(strs)?;
+        assert_eq!("7", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    pub fn part2_test() {
+    pub fn part2_test() -> anyhow::Result<()>{
         let v = vec![199, 200, 208, 210, 200, 207, 240, 269, 260, 263];
         let strs = v.iter().map(i32::to_string).collect::<Vec<String>>().join("\n");
-        let d = Day01::init(strs);
-        assert_eq!("5", d.part2())
+        let d = Day01::init(strs)?;
+        assert_eq!("5", d.part2()?);
+        Ok(())
     }
 }

src/day02.rs

@@ -1,4 +1,5 @@
 use crate::Day;
+use anyhow::Result;
 
 pub struct Day02(Vec<Instruction>);
 
@@ -9,12 +10,12 @@ enum Instruction {
 }
 
 impl Day for Day02 {
-    fn init(content: String) -> Self {
-        let lines = content.lines().map(str_to_instr).collect::<Vec<Instruction>>();
-        Day02(lines)
+    fn init(content: String) -> Result<Self> {
+        let lines = content.lines().map(str_to_instr).collect::<Result<Vec<Instruction>>>()?;
+        Ok(Self(lines))
     }
 
-    fn part1(&self) -> String {
+    fn part1(&self) -> Result<String> {
         let mut depth = 0;
         let mut fw = 0;
         for i in &self.0 {
@@ -24,10 +25,10 @@ impl Day for Day02 {
                 Instruction::Up(n) => depth -= n,
             }
         }
-        format!("{}", depth * fw)
+        Ok(format!("{}", depth * fw))
     }
 
-    fn part2(&self) -> String {
+    fn part2(&self) -> Result<String> {
         let mut depth = 0;
         let mut fw = 0;
         let mut aim = 0;
@@ -41,19 +42,19 @@ impl Day for Day02 {
                 Instruction::Up(n) => aim -= n,
             }
         }
-        format!("{}", depth * fw)
+        Ok(format!("{}", depth * fw))
     }
 }
 
-fn str_to_instr(s: &str) -> Instruction {
+fn str_to_instr(s: &str) -> Result<Instruction> {
     let v = s.split(' ').collect::<Vec<&str>>();
     let name = v[0];
-    let height = v[1].parse().expect("This should be an int :p");
+    let height = v[1].parse()?;
     match name {
-        "forward" => Instruction::Forward(height),
-        "up" => Instruction::Up(height),
-        "down" => Instruction::Down(height),
-        _ => panic!("How did this happen???")
+        "forward" => Ok(Instruction::Forward(height)),
+        "up" => Ok(Instruction::Up(height)),
+        "down" => Ok(Instruction::Down(height)),
+        _ => Err(anyhow::Error::msg("This is not a valid direction!"))
     }
 }
 
@@ -62,6 +63,7 @@ mod tests {
     use std::fs::read_to_string;
     use crate::day02::Day02;
     use crate::day::Day;
+    use super::Result;
 
     const D: &str = r"forward 5
 down 5
@@ -71,28 +73,28 @@ down 8
 forward 2";
 
     #[test]
-    fn part1_test() {
-        let d2 = Day02::init(String::from(D));
-        assert_eq!("150", d2.part1())
+    fn part1_test() -> Result<()> {
+        let d2 = Day02::init(String::from(D))?;
+        Ok(assert_eq!("150", d2.part1()?))
     }
 
     #[test]
-    fn part2_test() {
-        let d2 = Day02::init(String::from(D));
-        assert_eq!("900", d2.part2())
+    fn part2_test() -> Result<()> {
+        let d2 = Day02::init(String::from(D))?;
+        Ok(assert_eq!("900", d2.part2()?))
     }
 
     #[test]
-    pub fn part1_real() {
-        let f = read_to_string("./input/day02").expect("Could not load input");
-        let d = Day02::init(f);
-        assert_eq!("1524750", d.part1())
+    pub fn part1_real() -> Result<()> {
+        let f = read_to_string("./input/day02")?;
+        let d = Day02::init(f)?;
+        Ok(assert_eq!("1524750", d.part1()?))
     }
 
     #[test]
-    pub fn part2_real() {
-        let f = read_to_string("./input/day02").expect("Could not load input");
-        let d = Day02::init(f);
-        assert_eq!("1592426537", d.part2())
+    pub fn part2_real()-> Result<()>  {
+        let f = read_to_string("./input/day02")?;
+        let d = Day02::init(f)?;
+        Ok(assert_eq!("1592426537", d.part2()?))
     }
 }

src/day03.rs

@@ -1,19 +1,20 @@
 use crate::Day;
+use anyhow::Result;
 
 pub struct Day03(Vec<Vec<bool>>);
 
 impl Day for Day03 {
-    fn init(content: String) -> Self {
+    fn init(content: String) -> Result<Self> {
         let v = content.lines().map(split_lines).collect();
-        Self(v)
+        Ok(Self(v))
     }
 
-    fn part1(&self) -> String {
-        format!("{}", self.gamma() * self.epsilon())
+    fn part1(&self) -> Result<String> {
+        Ok(format!("{}", self.gamma() * self.epsilon()))
     }
 
-    fn part2(&self) -> String {
-        format!("{}", self.ox() * self.co2())
+    fn part2(&self) -> Result<String> {
+        Ok(format!("{}", self.ox() * self.co2()))
     }
 }
 
@@ -127,6 +128,7 @@ mod tests {
 
     use crate::Day03;
     use crate::day::Day;
+    use anyhow::Result;
 
     const INPUT: &str = r"00100
 11110
@@ -142,32 +144,36 @@ mod tests {
 01010";
 
     #[test]
-    fn part1_test() {
-        let t = Day03::init(String::from(INPUT));
-        let p1 = t.part1();
-        assert_eq!("198", p1)
+    fn part1_test() -> Result<()>{
+        let t = Day03::init(String::from(INPUT))?;
+        let p1 = t.part1()?;
+        assert_eq!("198", p1);
+        Ok(())
     }
 
     #[test]
-    fn part2_test() {
-        let t = Day03::init(String::from(INPUT));
-        let p2 = t.part2();
-        assert_eq!("230", p2)
+    fn part2_test() -> Result<()>{
+        let t = Day03::init(String::from(INPUT))?;
+        let p2 = t.part2()?;
+        assert_eq!("230", p2);
+        Ok(())
     }
 
     #[test]
-    fn part1_real() {
-        let f = read_to_string("./input/day03").expect("Could not load input");
-        let t = Day03::init(f);
-        let p1 = t.part1();
-        assert_eq!("4118544", p1)
+    fn part1_real() -> Result<()>{
+        let f = read_to_string("./input/day03")?;
+        let t = Day03::init(f)?;
+        let p1 = t.part1()?;
+        assert_eq!("4118544", p1);
+        Ok(())
     }
 
     #[test]
-    fn part2_real() {
-        let f = read_to_string("./input/day03").expect("Could not load input");
-        let t = Day03::init(f);
-        let p2 = t.part2();
-        assert_eq!("3832770", p2)
+    fn part2_real() -> Result<()>{
+        let f = read_to_string("./input/day03")?;
+        let t = Day03::init(f)?;
+        let p2 = t.part2()?;
+        assert_eq!("3832770", p2);
+        Ok(())
     }
 }

src/day04.rs

@@ -1,4 +1,5 @@
 use crate::Day;
+use anyhow::Result;
 
 #[derive(Clone)]
 pub struct Day04 {
@@ -10,11 +11,11 @@ pub struct Day04 {
 struct Board(Vec<Vec<Option<u32>>>);
 
 impl Day for Day04 {
-    fn init(content: String) -> Self where Self: Sized {
+    fn init(content: String) -> Result<Self> {
         let l = content.lines().collect::<Vec<&str>>();
         let (a, b) = l.split_at(2);
         let first = a[0];
-        let nums = first.split(',').map(|x| x.parse::<u32>().expect("wat?")).collect();
+        let nums = first.split(',').map(str::parse).collect::<Result<Vec<_>, _>>()?;
 
         let split = b.split(|x| x.is_empty());
 
@@ -25,13 +26,13 @@ impl Day for Day04 {
                 ).map(Option::Some).collect()).collect()
         ).map(Board).collect();
 
-        Day04 {
+        Ok(Self {
             numbers: nums,
             boards,
-        }
+        })
     }
 
-    fn part1(&self) -> String {
+    fn part1(&self) -> Result<String> {
         let z = self.clone();
         let mut boards = z.boards;
         for number in z.numbers {
@@ -39,15 +40,15 @@ impl Day for Day04 {
                 let res = board.mark(number);
                 if res {
                     let s = board.unmarked_sum();
-                    return format!("{}", s * number);
+                    return Ok(format!("{}", s * number));
                 }
             }
         }
 
-        panic!("no board can win?")
+        Err(anyhow::Error::msg("could not find a working sum..."))
     }
 
-    fn part2(&self) -> String {
+    fn part2(&self) -> Result<String> {
         let z = self.clone();
         let mut boards = z.boards;
         for number in z.numbers {
@@ -56,13 +57,13 @@ impl Day for Day04 {
                 let res = board.mark(number);
                 if res && len == 1 {
                     let s = board.unmarked_sum();
-                    return format!("{}", s * number);
+                    return Ok(format!("{}", s * number));
                 }
             }
             boards = boards.iter().filter(|x| !x.complete()).cloned().collect();
         }
 
-        panic!("no board can win?")
+        Err(anyhow::Error::msg("could not find a working sum..."))
     }
 }
 
@@ -130,6 +131,7 @@ mod tests {
     use crate::Day04;
     use crate::day04::Board;
     use crate::day::Day;
+    use anyhow::Result;
 
     const INPUT: &str = r"7,4,9,5,11,17,23,2,0,14,21,24,10,16,13,6,15,25,12,22,18,20,8,19,3,26,1
 
@@ -190,33 +192,37 @@ mod tests {
     }
 
     #[test]
-    fn part1_test() {
-        let t = Day04::init(INPUT.to_string());
-        let p1 = t.part1();
-        assert_eq!("4512", p1)
+    fn part1_test() -> Result<()> {
+        let t = Day04::init(INPUT.to_string())?;
+        let p1 = t.part1()?;
+        assert_eq!("4512", p1);
+        Ok(())
     }
 
     #[test]
-    fn part2_test() {
-        let t = Day04::init(INPUT.to_string());
-        let p2 = t.part2();
-        assert_eq!("1924", p2)
+    fn part2_test() -> Result<()> {
+        let t = Day04::init(INPUT.to_string())?;
+        let p2 = t.part2()?;
+        assert_eq!("1924", p2);
+        Ok(())
     }
 
 
     #[test]
-    fn part1_real() {
-        let f = read_to_string("./input/day04").expect("Could not load input");
-        let t = Day04::init(f);
-        let p1 = t.part1();
-        assert_eq!("8136", p1)
+    fn part1_real() -> Result<()> {
+        let f = read_to_string("./input/day04")?;
+        let t = Day04::init(f)?;
+        let p1 = t.part1()?;
+        assert_eq!("8136", p1);
+        Ok(())
     }
 
     #[test]
-    fn part2_real() {
-        let f = read_to_string("./input/day04").expect("Could not load input");
-        let t = Day04::init(f);
-        let p2 = t.part2();
-        assert_eq!("12738", p2)
+    fn part2_real() -> Result<()> {
+        let f = read_to_string("./input/day04")?;
+        let t = Day04::init(f)?;
+        let p2 = t.part2()?;
+        assert_eq!("12738", p2);
+        Ok(())
     }
 }

src/day05.rs

@@ -1,10 +1,9 @@
 use std::cmp::Ordering;
 use std::collections::HashMap;
 use crate::Day;
+use anyhow::Result;
 
-pub struct Day05 {
-    vents: Vec<Path>,
-}
+pub struct Day05(Vec<Path>);
 
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Debug)]
 struct Path {
@@ -20,20 +19,18 @@ struct Coordinate {
 }
 
 impl Day for Day05 {
-    fn init(content: String) -> Self {
-        let paths = content.lines().map(str_to_vent).collect::<Vec<Path>>();
-        Self {
-            vents: paths,
-        }
+    fn init(content: String) -> Result<Self> {
+        let paths = content.lines().map(str_to_vent).collect::<Result<Vec<Path>, _>>()?;
+        Ok(Self(paths))
     }
 
-    fn part1(&self) -> String {
-        let new_vents = self.vents.iter().filter(|p| p.is_straight()).cloned().collect::<Vec<Path>>();
-        format!("{}", covered_twice(&new_vents))
+    fn part1(&self) -> Result<String> {
+        let new_vents = self.0.iter().filter(|p| p.is_straight()).cloned().collect::<Vec<Path>>();
+        Ok(format!("{}", covered_twice(&new_vents)))
     }
 
-    fn part2(&self) -> String {
-        format!("{}", covered_twice(&self.vents))
+    fn part2(&self) -> Result<String> {
+        Ok(format!("{}", covered_twice(&self.0)))
     }
 }
 
@@ -115,12 +112,12 @@ impl Direction {
     }
 }
 
-fn str_to_vent(st: &str) -> Path {
+fn str_to_vent(st: &str) -> Result<Path> {
     let mut v = st.split(" -> ");
-    let a = v.next().unwrap();
-    let b = v.next().unwrap();
-    let start = a.split(',').map(|x| x.parse().unwrap()).collect::<Vec<i64>>();
-    let end = b.split(',').map(|x| x.parse().unwrap()).collect::<Vec<i64>>();
+    let a = v.next().ok_or_else(|| anyhow::Error::msg("could not get next..."))?;
+    let b = v.next().ok_or_else(|| anyhow::Error::msg("could not get next..."))?;
+    let start = a.split(',').map(str::parse).collect::<Result<Vec<i64>,_>>()?;
+    let end = b.split(',').map(str::parse).collect::<Result<Vec<i64>,_>>()?;
     let start = Coordinate::from_vec(&start);
     let end = Coordinate::from_vec(&end);
 
@@ -135,11 +132,11 @@ fn str_to_vent(st: &str) -> Path {
     }
     covers.push(end.clone());
 
-    Path {
+    Ok(Path {
         start,
         end,
         covers,
-    }
+    })
 }
 
 #[cfg(test)]
@@ -147,6 +144,7 @@ mod tests {
     use crate::Day05;
     use crate::day05::{Coordinate, Direction};
     use crate::day::Day;
+    use anyhow::Result;
 
     const INPUT: &str = r"0,9 -> 5,9
 8,0 -> 0,8
@@ -172,26 +170,30 @@ mod tests {
     }
 
     #[test]
-    fn part1_test() {
-        let d = Day05::init(INPUT.to_string());
-        assert_eq!("5", d.part1());
+    fn part1_test() -> Result<()> {
+        let d = Day05::init(INPUT.to_string())?;
+        assert_eq!("5", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    fn part2_test() {
-        let d = Day05::init(INPUT.to_string());
-        assert_eq!("12", d.part2());
+    fn part2_test() -> Result<()> {
+        let d = Day05::init(INPUT.to_string())?;
+        assert_eq!("12", d.part2()?);
+        Ok(())
     }
 
     #[test]
-    fn part1_real() {
-        let d = Day05::init(crate::load_input("05"));
-        assert_eq!("6564", d.part1());
+    fn part1_real() -> Result<()> {
+        let d = Day05::init(crate::load_input("05")?)?;
+        assert_eq!("6564", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    fn part2_real() {
-        let d = Day05::init(crate::load_input("05"));
-        assert_eq!("19172", d.part2());
+    fn part2_real() -> Result<()> {
+        let d = Day05::init(crate::load_input("05")?)?;
+        assert_eq!("19172", d.part2()?);
+        Ok(())
     }
 }

src/day06.rs

@@ -1,23 +1,24 @@
 use crate::Day;
+use anyhow::Result;
 
 pub struct Day06([u64; 9]);
 
 impl Day for Day06 {
-    fn init(content: String) -> Self {
-        let c = content.split(',').map(|x| x.parse().expect("This is not an int!")).collect::<Vec<usize>>();
+    fn init(content: String) -> anyhow::Result<Self> {
+        let c = content.split(',').map(str::parse).collect::<Result<Vec<usize>, _>>()?;
         let mut w: [u64; 9] = [0, 0, 0, 0, 0, 0, 0, 0, 0];
         for z in c {
             w[z as usize] += 1;
         }
-        Self(w)
+        Ok(Self(w))
     }
 
-    fn part1(&self) -> String {
-        format!("{}", self.do_magic(80))
+    fn part1(&self) -> Result<String> {
+        Ok(format!("{}", self.do_magic(80)))
     }
 
-    fn part2(&self) -> String {
-        format!("{}", self.do_magic(256))
+    fn part2(&self) -> Result<String> {
+        Ok(format!("{}", self.do_magic(256)))
     }
 }
 
@@ -35,30 +36,42 @@ impl Day06 {
 mod tests {
     use crate::day06::Day06;
     use crate::day::Day;
+    use anyhow::Result;
 
     const INPUT: &str = r"3,4,3,1,2";
 
     #[test]
-    fn part1_test() {
-        let d = Day06::init(INPUT.to_string());
-        assert_eq!("5934", d.part1());
+    fn part1_test() -> Result<()> {
+        let d = Day06::init(INPUT.to_string())?;
+        assert_eq!("5934", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    fn part2_test() {
-        let d = Day06::init(INPUT.to_string());
-        assert_eq!("26984457539", d.part2());
+    fn part2_test() -> Result<()> {
+        let d = Day06::init(INPUT.to_string())?;
+        assert_eq!("26984457539", d.part2()?);
+        Ok(())
     }
 
     #[test]
-    fn part1_real() {
-        let d = Day06::init(crate::load_input("06"));
-        assert_eq!("362740", d.part1());
+    fn part1_real() -> Result<()> {
+        let d = Day06::init(crate::load_input("06")?)?;
+        assert_eq!("362740", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    fn part2_real() {
-        let d = Day06::init(crate::load_input("06"));
-        assert_eq!("1644874076764", d.part2());
+    fn part2_real() -> Result<()> {
+        let d = Day06::init(crate::load_input("06")?)?;
+        assert_eq!("1644874076764", d.part2()?);
+        Ok(())
+    }
+
+    #[test]
+    fn youri_test() -> Result<()> {
+        let d = Day06::init(String::from("3,4,3,1,2"))?;
+        assert_eq!(17614907331943978900, d.do_magic(489));
+        Ok(())
     }
 }

src/day07.rs

@@ -1,30 +1,31 @@
 use std::collections::HashMap;
 use crate::Day;
+use anyhow::Result;
 
 pub struct Day07(HashMap<i32, i32>);
 
 impl Day for Day07 {
-    fn init(content: String) -> Self {
+    fn init(content: String) -> Result<Self> {
         let mut hm = HashMap::new();
-        for n in &content.split(',').map(|x| x.parse().expect("This is not a number?")).collect::<Vec<_>>() {
+        for n in &content.split(',').map(str::parse).collect::<Result<Vec<_>, std::num::ParseIntError>>()? {
             let entry = hm.entry(*n).or_insert(0);
             *entry += 1;
         }
-        Self(hm)
+        Ok(Self(hm))
     }
 
-    fn part1(&self) -> String {
+    fn part1(&self) -> Result<String> {
         let m = self.0.keys().copied().map(
             |x| self.0.iter().map(
                 |(n, count)| (x - *n).abs() * (*count)
             ).sum::<i32>()
-        ).min().expect("there is no min?");
+        ).min().ok_or_else(|| anyhow::Error::msg("Could not find min"))?;
 
-        format!("{}", m)
+        Ok(format!("{}", m))
     }
 
-    fn part2(&self) -> String {
-        let max = *self.0.keys().max().expect("This should have a value...");
+    fn part2(&self) -> Result<String> {
+        let max = *self.0.keys().max().ok_or_else(|| anyhow::Error::msg("Could not find max"))?;
         let m = (0..=max).map(
             |x| self.0.iter().map(
                 |(n, count)| {
@@ -32,8 +33,8 @@ impl Day for Day07 {
                     (n * (n + 1) / 2) * (*count)
                 }
             ).sum::<i32>()
-        ).min().expect("there is no min?");
-        format!("{}", m)
+        ).min().ok_or_else(|| anyhow::Error::msg("Could not find min"))?;
+        Ok(format!("{}", m))
     }
 }
 
@@ -41,30 +42,35 @@ impl Day for Day07 {
 mod tests {
     use crate::day07::Day07;
     use crate::day::Day;
+    use anyhow::Result;
 
     const INPUT: &str = "16,1,2,0,4,2,7,1,2,14";
 
     #[test]
-    fn part1_test() {
-        let d = Day07::init(INPUT.to_string());
-        assert_eq!("37", d.part1())
+    fn part1_test() -> Result<()> {
+        let d = Day07::init(INPUT.to_string())?;
+        assert_eq!("37", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    fn part2_test() {
-        let d = Day07::init(INPUT.to_string());
-        assert_eq!("168", d.part2())
+    fn part2_test() -> Result<()> {
+        let d = Day07::init(INPUT.to_string())?;
+        assert_eq!("168", d.part2()?);
+        Ok(())
     }
 
     #[test]
-    fn part1_real() {
-        let d = Day07::init(crate::load_input("07"));
-        assert_eq!("357353", d.part1())
+    fn part1_real() -> Result<()> {
+        let d = Day07::init(crate::load_input("07")?)?;
+        assert_eq!("357353", d.part1()?);
+        Ok(())
     }
 
     #[test]
-    fn part2_real() {
-        let d = Day07::init(crate::load_input("07"));
-        assert_eq!("104822130", d.part2())
+    fn part2_real() -> Result<()> {
+        let d = Day07::init(crate::load_input("07")?)?;
+        assert_eq!("104822130", d.part2()?);
+        Ok(())
     }
 }

src/main.rs

@@ -9,6 +9,7 @@ use crate::day05::Day05;
 use crate::day06::Day06;
 use crate::day07::Day07;
 use crate::day::Day;
+use anyhow::Result;
 
 mod day;
 mod day01;
@@ -19,22 +20,23 @@ mod day05;
 mod day06;
 mod day07;
 
-fn load_input(day: &str) -> String {
-    read_to_string(format!("./input/day{}", day)).expect("Could not load input")
+fn load_input(day: &str) -> Result<String> {
+    read_to_string(format!("./input/day{}", day)).map_err(|x| x.into())
 }
 
-fn run_day(days: &[Box<dyn Day>], day: usize) {
+fn run_day(days: &[Box<dyn Day>], day: usize) -> Result<()> {
     if let Some(d) = days.get(day - 1) {
         let day_code = d;
         println!("Running day {}!", day);
-        println!("\tPart 1: {}", d.part1());
-        println!("\tPart 2: {}", day_code.part2());
+        println!("\tPart 1: {}", d.part1()?);
+        println!("\tPart 2: {}", day_code.part2()?);
     } else {
         eprintln!("Day {} is not available!", day);
     }
+    Ok(())
 }
 
-fn main() {
+fn main() -> anyhow::Result<()> {
     let matches = App::new("AOC Time!")
         .version("1.0")
         .author("J00LZ")
@@ -52,31 +54,32 @@ fn main() {
             .multiple(true))
         .get_matches();
 
-    let days: Vec<Box<dyn Day>> = vec![Box::new(Day01::init(load_input("01"))),
-                                       Box::new(Day02::init(load_input("02"))),
-                                       Box::new(Day03::init(load_input("03"))),
-                                       Box::new(Day04::init(load_input("04"))),
-                                       Box::new(Day05::init(load_input("05"))),
-                                       Box::new(Day06::init(load_input("06"))),
-                                       Box::new(Day07::init(load_input("07")))];
+    let days: Vec<Box<dyn Day>> = vec![Box::new(Day01::init(load_input("01")?)?),
+                                       Box::new(Day02::init(load_input("02")?)?),
+                                       Box::new(Day03::init(load_input("03")?)?),
+                                       Box::new(Day04::init(load_input("04")?)?),
+                                       Box::new(Day05::init(load_input("05")?)?),
+                                       Box::new(Day06::init(load_input("06")?)?),
+                                       Box::new(Day07::init(load_input("07")?)?)];
 
     let _verbosity = matches.occurrences_of("v");
     if matches.is_present("all") {
         let l = days.len();
         println!("running {} days!", l);
         for v in 1..=l {
-            run_day(&days, v);
+            run_day(&days, v)?;
         }
     } else if let Some(d) = matches.values_of("DAY") {
-        let d = d.map(|x| x.parse::<usize>().expect("Did not provide an int!"));
+        let d = d.map(str::parse);
         for v in d {
-            run_day(&days, v);
+            run_day(&days, v?)?;
         }
     } else {
         let v = chrono::Local::now();
         if v.month() != 12 {
             println!("This was really only meant to be used in december...");
         }
-        run_day(&days, v.day() as usize);
+        run_day(&days, v.day() as usize)?;
     }
+    Ok(())
 }