Cleaner

2024/rust/src/day1.rs

@@ -1,10 +1,9 @@
 mod prelude;
 pub use crate::prelude::*;
 
-fn main() -> EmptyResult {
-    let mut note: HistorianNote = day_input(1).parse()?;
+fn main() {
+    let mut note: HistorianNote = day_input(1).parse().unwrap();
     show_answers(note.smallests_distances(), note.similarity_score());
-    Ok(())
 }
 
 struct HistorianNote {
@@ -12,16 +11,15 @@ struct HistorianNote {
     right: Vec<i64>,
 }
 
-impl std::str::FromStr for HistorianNote {
-    type Err = std::num::ParseIntError;
-
+impl FromStr for HistorianNote {
+    type Err = ParseIntError;
     fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let mut line_tokens = s.lines().map(|l| l.split_once("   "));
         let mut left = Vec::<i64>::new();
         let mut right = Vec::<i64>::new();
-        for l in s.lines() {
-            let mut tokens = l.split("   ");
-            left.push(tokens.next().unwrap_or("").parse()?);
-            right.push(tokens.next().unwrap_or("").parse()?);
+        while let Some((l, r)) = line_tokens.next().flatten() {
+            left.push(l.parse()?);
+            right.push(r.parse()?);
         }
         Ok(Self { left, right })
     }
@@ -31,7 +29,7 @@ impl HistorianNote {
     fn smallests_distances(&mut self) -> i64 {
         self.left.sort();
         self.right.sort();
-        std::iter::zip(&self.left, &self.right).fold(0, |sum, (l, r)| sum + (l - r).abs())
+        zip(&self.left, &self.right).fold(0, |sum, (l, r)| sum + (l - r).abs())
     }
 
     fn similarity_score(&self) -> i64 {
@@ -50,10 +48,9 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test() -> EmptyResult {
-        let mut note: HistorianNote = "3   4\n4   3\n2   5\n1   3\n3   9\n3   3".parse()?;
+    fn test() {
+        let mut note: HistorianNote = "3   4\n4   3\n2   5\n1   3\n3   9\n3   3".parse().unwrap();
         assert_eq!(note.smallests_distances(), 11);
         assert_eq!(note.similarity_score(), 31);
-        Ok(())
     }
 }

2024/rust/src/prelude.rs

@@ -1,9 +1,12 @@
-pub use std::collections::HashMap;
-pub use std::fs::File;
-pub use std::io::Read;
-
 use std::path::{Path, PathBuf};
-use std::{env, io};
+pub use std::{
+    collections::HashMap,
+    fs::File,
+    io::Read,
+    iter::zip,
+    num::{ParseFloatError, ParseIntError},
+    str::FromStr,
+};
 
 pub type AnyResult<T> = std::result::Result<T, Box<dyn std::error::Error>>;
 pub type EmptyResult = AnyResult<()>;
@@ -11,15 +14,15 @@ pub type EmptyResult = AnyResult<()>;
 #[derive(Debug)]
 enum InputFileError {
     #[allow(dead_code)]
-    EnvVar(env::VarError),
+    EnvVar(std::env::VarError),
 
     #[allow(dead_code)]
-    Io(io::Error),
+    Io(std::io::Error),
 }
 
 /// Ensures that the input file exists
 fn ensure_input_file(day: u8) -> Result<PathBuf, InputFileError> {
-    let path = Path::new(&env::var("HOME").map_err(InputFileError::EnvVar)?)
+    let path = Path::new(&std::env::var("HOME").map_err(InputFileError::EnvVar)?)
         .join(format!("./.cache/aoc2024/{0}.input", day));
     if !path.exists() {
         eprintln!("Running input downloaded script with day arg {}...", day);