cleanup many clippy pedantic warnings

Signed-off-by: Stephen Waits <swaits@amazon.com>

src/day04.rs

@@ -45,29 +45,23 @@ impl Passport {
 
     // byr (Birth Year) - four digits; at least 1920 and at most 2002.
     fn is_byr_valid(&self) -> bool {
-        if let Some(s) = &self.byr {
+        self.byr.as_ref().map_or(false, |s| {
             utils::parse_usize_in_range(&s, 1920, 2002).is_some()
-        } else {
-            false
-        }
+        })
     }
 
     // iyr (Issue Year) - four digits; at least 2010 and at most 2020.
     fn is_iyr_valid(&self) -> bool {
-        if let Some(s) = &self.iyr {
+        self.iyr.as_ref().map_or(false, |s| {
             utils::parse_usize_in_range(&s, 2010, 2020).is_some()
-        } else {
-            false
-        }
+        })
     }
 
     // eyr (Expiration Year) - four digits; at least 2020 and at most 2030.
     fn is_eyr_valid(&self) -> bool {
-        if let Some(s) = &self.eyr {
+        self.eyr.as_ref().map_or(false, |s| {
             utils::parse_usize_in_range(&s, 2020, 2030).is_some()
-        } else {
-            false
-        }
+        })
     }
 
     // hgt (Height) - a number followed by either cm or in:
@@ -98,11 +92,7 @@ impl Passport {
                 Regex::new(r"^#[0-9a-f]{6}$").expect("regex compilation failure");
         }
 
-        if let Some(s) = &self.hcl {
-            HCL_RE.is_match(s)
-        } else {
-            false
-        }
+        self.hcl.as_ref().map_or(false, |s| HCL_RE.is_match(s))
     }
 
     // ecl (Eye Color) - exactly one of: amb blu brn gry grn hzl oth.
@@ -112,11 +102,7 @@ impl Passport {
                 Regex::new(r"^(amb|blu|brn|gry|grn|hzl|oth)$").expect("regex compilation failure");
         }
 
-        if let Some(s) = &self.ecl {
-            ECL_RE.is_match(s)
-        } else {
-            false
-        }
+        self.ecl.as_ref().map_or(false, |s| ECL_RE.is_match(s))
     }
 
     // pid (Passport ID) - a nine-digit number, including leading zeroes.
@@ -126,14 +112,11 @@ impl Passport {
                 Regex::new(r"^[0-9]{9}$").expect("regex compilation failure");
         }
 
-        if let Some(s) = &self.pid {
-            PID_RE.is_match(s)
-        } else {
-            false
-        }
+        self.pid.as_ref().map_or(false, |s| PID_RE.is_match(s))
     }
 
     // cid (Country ID) - ignored, missing or not.
+    #[allow(clippy::unused_self)]
     fn is_cid_valid(&self) -> bool {
         true
     }
@@ -149,7 +132,7 @@ impl FromStr for Passport {
                     .expect("regex compilation failure");
         }
 
-        let mut ret: Self = Default::default();
+        let mut ret: Self = Passport::default();
         s.split_whitespace().for_each(|s| {
             PASSPORT_RE.captures_iter(&s).for_each(|cap| match &cap[1] {
                 "byr" => ret.byr = Some(cap[2].to_string()),

src/day06.rs

@@ -8,7 +8,14 @@ use std::{
 };
 
 fn count_uniq_alpha_chars(s: &str) -> usize {
-    HashSet::<usize>::from_iter(s.chars().filter(|c| c.is_alphabetic()).map(|c| c as usize)).len()
+    HashSet::<usize>::from_iter(s.chars().filter_map(|c| {
+        if c.is_alphabetic() {
+            Some(c as usize)
+        } else {
+            None
+        }
+    }))
+    .len()
 }
 
 fn count_common_answers(s: &str) -> usize {

src/day08.rs

@@ -91,16 +91,16 @@ impl Console {
 
         // execute instruction at pc
         self.hits[self.pc] += 1;
-        match self.program[self.pc] {
+        match self.program.get(self.pc).unwrap() {
             Instruction::Acc(n) => {
                 self.accumulator += n;
                 self.pc += 1;
             }
             Instruction::Jmp(n) => {
-                if n < 0 {
+                if *n < 0 {
                     self.pc -= n.abs() as usize;
                 } else {
-                    self.pc += n as usize;
+                    self.pc += *n as usize;
                 }
             }
             Instruction::Nop(_) => {
@@ -127,13 +127,12 @@ impl Console {
             .hits
             .iter()
             .enumerate()
-            .filter(|(_, hits)| **hits > 0) // filter only instructions we hit
-            .map(|(i, _)| i) // map just the index
-            .filter(|i| match self.program[*i as usize] {
+            .filter_map(|(i, hits)| if *hits > 0 { Some(i) } else { None })
+            .filter(|i| match self.program.get(*i as usize).unwrap() {
                 // filter instructions we can modify
                 Instruction::Jmp(_) => true,
-                Instruction::Nop(n) => n != 0,
-                _ => false,
+                Instruction::Nop(n) => *n != 0,
+                Instruction::Acc(_) => false,
             })
             .collect();
 

src/day10.rs

@@ -13,12 +13,12 @@ pub fn count_diff1_diff3(diffs: &[i64]) -> usize {
 // follows the pattern 0, 1, 1, 2, 4, where the total paths for a runlength N
 // is sum of the paths in N-3, N-2, and N-1.
 fn paths_by_runlength(runlength: usize) -> usize {
-    let mut p: Vec<usize> = vec![0, 1, 1]; // vec of most recent 4 in sequence
-    const L: usize = 3; // length of p Vec
-    for i in L..runlength + 1 {
-        p[i % L] = p[(i - 3) % L] + p[(i - 2) % L] + p[(i - 1) % L];
+    let mut p: Vec<usize> = vec![0, 1, 1];
+    let p_len = p.len();
+    for i in p.len()..=runlength {
+        p[i % p_len] = p[(i - 3) % p_len] + p[(i - 2) % p_len] + p[(i - 1) % p_len];
     }
-    p[runlength % L]
+    p[runlength % p_len]
 }
 
 fn count_paths(diffs: &[i64]) -> usize {

src/day11.rs

@@ -12,7 +12,7 @@ enum Location {
 
 // compute the 8 immediately adjacent coordinates which contian chairs
 fn adjacent_coords(
-    map: &[Vec<Location>],
+    seat_map: &[Vec<Location>],
     pos: (usize, usize),
     max: (usize, usize),
 ) -> Vec<(usize, usize)> {
@@ -27,9 +27,9 @@ fn adjacent_coords(
     let max_row = max.0.min(pos.0 + 1);
     let max_col = max.1.min(pos.1 + 1);
 
-    (min_row..max_row + 1)
-        .flat_map(|i| (min_col..max_col + 1).map(move |j| (i, j)))
-        .filter(|p| *p != pos && map[p.0][p.1] != Location::Floor)
+    (min_row..=max_row)
+        .flat_map(|i| (min_col..=max_col).map(move |j| (i, j)))
+        .filter(|p| *p != pos && seat_map[p.0][p.1] != Location::Floor)
         .collect()
 }
 
@@ -49,7 +49,7 @@ fn compute_basic_adjacency(map: &[Vec<Location>]) -> Vec<Vec<Vec<(usize, usize)>
 fn search_direction_for_chair(
     map: &[Vec<Location>],
     start: (usize, usize),
-    step: &(i32, i32),
+    step: (i32, i32),
 ) -> Option<(usize, usize)> {
     let mut i = start.0 as i32 + step.0;
     let mut j = start.1 as i32 + step.1;
@@ -80,7 +80,7 @@ fn compute_advanced_adjacency(map: &[Vec<Location>]) -> Vec<Vec<Vec<(usize, usiz
                     dirs.iter()
                         .filter_map(move |d| {
                             let dir = *d;
-                            search_direction_for_chair(map, (i, j), &dir)
+                            search_direction_for_chair(map, (i, j), dir)
                         })
                         .collect()
                 })
@@ -99,7 +99,7 @@ fn seating_round(
 
     for row in 0..map.len() {
         for col in 0..map[row].len() {
-            match map[row][col] {
+            match map[row].get(col).unwrap() {
                 Location::Floor => (),
                 Location::Unoccupied => {
                     if !adj[row][col]

src/day12.rs

@@ -17,11 +17,10 @@ fn navigate(data: &str) -> usize {
             "E" => pos_e += dist,
             "W" => pos_e -= dist,
             "F" => match heading {
-                0 => pos_n += dist,
+                0 | 360 => pos_n += dist,
                 90 => pos_e += dist,
                 180 => pos_n -= dist,
                 270 => pos_e -= dist,
-                360 => pos_n += dist,
                 _ => panic!("non cardinal heading!"),
             },
             "L" => heading = (heading + 360 - dist) % 360,

src/day13.rs

@@ -37,6 +37,7 @@ fn mins_to_next_departure(dep_time: usize, bus: &BusRoute) -> usize {
 // the Chinese Remainder Theorem.
 //
 // code from https://rosettacode.org/wiki/Chinese_remainder_theorem#Rust
+#[allow(clippy::many_single_char_names)]
 fn egcd(a: i64, b: i64) -> (i64, i64, i64) {
     if a == 0 {
         (b, 0, 1)

src/day14.rs

@@ -42,7 +42,7 @@ fn parse_write(s: &str) -> Instruction {
 fn parse(input: &str) -> Vec<Instruction> {
     input
         .lines()
-        .map(|l| l.trim())
+        .map(str::trim)
         .map(|l| match &l[0..4] {
             "mask" => parse_mask(l),
             "mem[" => parse_write(l),
@@ -74,7 +74,6 @@ fn simulate1(program: &[Instruction]) -> u64 {
     memory.values().sum()
 }
 
-#[inline(always)]
 fn set_bit(n: u64, bit: usize, value: bool) -> u64 {
     if value {
         n | (1 << bit)

src/day15.rs

@@ -33,7 +33,7 @@ pub fn run() -> Result<(i64, i64)> {
     let answers = utils::read_i64s("data/output-15.txt")?;
 
     let p1 = play_speaking_game(&data, 2020);
-    let p2 = play_speaking_game(&data, 30000000);
+    let p2 = play_speaking_game(&data, 30_000_000);
 
     assert_eq!(p1, answers[0]);
     assert_eq!(p2, answers[1]);

src/day16.rs

@@ -41,7 +41,7 @@ fn parse_fields(input: &str) -> Result<Vec<Field>> {
 }
 
 fn parse_tickets(input: &str) -> Result<(Vec<i64>, Vec<Vec<i64>>)> {
-    let mut lines = input.lines().map(|l| l.trim()).filter(|l| l.contains(','));
+    let mut lines = input.lines().map(str::trim).filter(|l| l.contains(','));
 
     let my_ticket: Vec<i64> = lines
         .next()
@@ -98,8 +98,8 @@ fn find_field_locations(fields: &[Field], my_ticket: &[i64], tickets: &[Vec<i64>
     let mut matches: HashMap<&str, usize> = HashMap::new();
     for _ in 0..my_ticket.len() {
         // find a matching field
-        for col_id in 0..viable_fields.len() {
-            let possible_fields = viable_fields[col_id]
+        for (col_id, fields_for_column) in viable_fields.iter().enumerate() {
+            let possible_fields = fields_for_column
                 .iter()
                 .filter(|(k, _)| !matches.contains_key(*k))
                 .filter(|(_, v)| **v == valid_tickets.len())

src/utils.rs

@@ -23,11 +23,6 @@ pub fn parse_usize_in_range(s: &str, min: usize, max: usize) -> Option<usize> {
     }
 }
 
-#[allow(dead_code)]
-pub fn times(n: usize) -> impl Iterator<Item = usize> {
-    (0..n).into_iter()
-}
-
 // Lexicographic combinations.
 //
 // This algorithm generates all t-combinations of n numbers {0, 1, ..., n-1},