Blindly follow all clippy's decrees

src/day01.rs

@@ -8,7 +8,7 @@ pub fn process_part_1(input: &str) -> u32 {
         })
         .max()
         .unwrap();
-    return result;
+    result
 }
 
 pub fn process_part_2(input: &str) -> u32 {

src/day02.rs

@@ -37,7 +37,7 @@ pub fn process_part_1(input: &str) -> u32 {
         .lines()
         .map(|line| {
             let moves = line
-                .split(" ")
+                .split(' ')
                 .map(|s| s.parse::<Move>().unwrap())
                 .collect::<Vec<_>>();
             match moves[1].partial_cmp(&moves[0]) {
@@ -49,14 +49,14 @@ pub fn process_part_1(input: &str) -> u32 {
         })
         .sum();
 
-    return result;
+    result
 }
 
 pub fn process_part_2(input: &str) -> u32 {
     let result = input
         .lines()
         .map(|line| {
-            let moves = line.split(" ").collect::<Vec<_>>();
+            let moves = line.split(' ').collect::<Vec<_>>();
             let opponent_move: Move = moves[0].parse().unwrap();
             match moves[1] {
                 "X" => {
@@ -85,7 +85,7 @@ pub fn process_part_2(input: &str) -> u32 {
         })
         .sum();
 
-    return result;
+    result
 }
 
 #[cfg(test)]

src/day03.rs

@@ -35,7 +35,7 @@ pub fn process_part_2(input: &str) -> u32 {
             }
         })
         .sum();
-    return result;
+    result
 }
 
 #[cfg(test)]

src/day04.rs

@@ -1,6 +1,9 @@
-use nom::IResult;
 use std::ops::RangeInclusive;
 
+use nom::IResult;
+
+type RangePair = (RangeInclusive<u32>, RangeInclusive<u32>);
+
 pub fn process_part_1(input: &str) -> usize {
     let (_, assignments) = section_assignments(input).unwrap();
     assignments
@@ -21,9 +24,7 @@ fn range_contains(haystack: &RangeInclusive<u32>, needle: &RangeInclusive<u32>)
     haystack.contains(needle.start()) && haystack.contains(needle.end())
 }
 
-fn section_assignments(
+fn section_assignments(input: &str) -> IResult<&str, Vec<RangePair>> {
-    input: &str,
-) -> IResult<&str, Vec<(RangeInclusive<u32>, RangeInclusive<u32>)>> {
     use nom::character::complete::newline;
     use nom::multi::separated_list1;
 
@@ -31,7 +32,7 @@ fn section_assignments(
     Ok((input, ranges))
 }
 
-fn line(input: &str) -> IResult<&str, (RangeInclusive<u32>, RangeInclusive<u32>)> {
+fn line(input: &str) -> IResult<&str, RangePair> {
     use nom::bytes::complete::tag;
 
     let (input, start) = sections(input)?;

src/day05.rs

@@ -50,7 +50,8 @@ struct Move {
     to: u32,
 }
 
-fn parse_crates(input: &str) -> IResult<&str, (Vec<Vec<&str>>, Vec<u32>, Vec<Move>)> {
+type CrateStacks<'a> = Vec<Vec<&'a str>>;
+fn parse_crates(input: &str) -> IResult<&str, (CrateStacks, Vec<u32>, Vec<Move>)> {
     let (input, crates_transposed) = parse_crate_stacks(input)?;
     let (input, _) = newline(input)?;
     let (input, crate_numbers) = separated_list1(tag(" "), parse_crate_name)(input)?;
@@ -62,13 +63,13 @@ fn parse_crates(input: &str) -> IResult<&str, (Vec<Vec<&str>>, Vec<u32>, Vec<Mov
     // ] => [ [D, A], [E, B], [C]
     // (its transposed for pop() and push() magic :))
     // it also unwraps all `None`'s from the lists
-    let crates: Vec<Vec<&str>> = (0..crates_transposed[0].len())
+    let crates: CrateStacks = (0..crates_transposed[0].len())
         .map(|i| {
             crates_transposed
                 .iter()
                 .map(|items| items[i])
                 .rev()
-                .filter_map(|item| item)
+                .flatten()
                 .collect()
         })
         .collect();

src/day07.rs

@@ -26,7 +26,7 @@ pub fn process_part_2(input: &str) -> u32 {
     directories
         .values()
         .filter(|&size| *size >= wanted_space)
-        .map(|&size| size)
+        .copied()
         .min()
         .unwrap_or(0)
 }

src/day08.rs

@@ -52,7 +52,7 @@ pub fn process_part_2(input: &str) -> usize {
 fn parse_trees(input: &str) -> Vec<Vec<u8>> {
     input
         .trim()
-        .split("\n")
+        .split('\n')
         .map(|i| i.chars().map(|c| c.to_digit(10).unwrap() as u8).collect())
         .collect()
 }

src/day09.rs

@@ -11,13 +11,13 @@ use nom::IResult;
 pub fn process_part_1(input: &str) -> usize {
     let (_, moves) = parse(input).unwrap();
     let visited = simulate_rope(moves, 2);
-    return visited.len();
+    visited.len()
 }
 
 pub fn process_part_2(input: &str) -> usize {
     let (_, moves) = parse(input).unwrap();
     let visited = simulate_rope(moves, 10);
-    return visited.len();
+    visited.len()
 }
 
 fn simulate_rope(moves: Vec<(Direction, usize)>, rope_size: usize) -> BTreeSet<(i32, i32)> {