moved flatten to read_lines

Author: sourproton

src/helpers.rs

@@ -2,7 +2,8 @@
 
 use {
     std::fs::File,
-    std::io::{self, BufRead},
+    std::io::{BufRead, BufReader, Lines},
+    std::iter::Flatten,
     std::path::Path,
 };
 
@@ -54,10 +55,12 @@ pub fn solve_day(day: u8) {
     }
 }
 
-/// returns an iterator over each line in the input file
-pub fn read_lines<P>(filename: P) -> std::io::Lines<std::io::BufReader<std::fs::File>>
+/// returns an iterator over each line in the input file, ignoring lines that failed to be read
+pub fn read_lines<P>(filename: P) -> Flatten<Lines<BufReader<File>>>
 where
     P: AsRef<Path>,
 {
-    io::BufReader::new(File::open(filename).expect("not able to open file")).lines()
+    BufReader::new(File::open(filename).expect("not able to open file"))
+        .lines()
+        .flatten()
 }

src/solutions/day01.rs

@@ -6,13 +6,14 @@
 
 use {crate::helpers::read_lines, std::time::SystemTime};
 
+/// solves the part 1 of day 01 and return its result and elapsed time
 pub fn pt1(filename: &str) -> (u32, u32) {
     let time = SystemTime::now();
 
     let mut biggest = 0;
     let mut current = 0;
 
-    read_lines(filename).flatten().for_each(|line| {
+    read_lines(filename).for_each(|line| {
         match line.as_str() {
             // if empty line, compare current block with biggest found until then
             "" => {
@@ -32,6 +33,7 @@ pub fn pt1(filename: &str) -> (u32, u32) {
     (answer, time)
 }
 
+/// solves the part 2 of day 01 and return its result and elapsed time
 pub fn pt2(filename: &str) -> (u32, u32) {
     let time = SystemTime::now();
 
@@ -40,7 +42,7 @@ pub fn pt2(filename: &str) -> (u32, u32) {
     let mut current = 0;
 
     // iterating through each line of the file
-    read_lines(filename).flatten().for_each(|line| {
+    read_lines(filename).for_each(|line| {
         match line.as_str() {
             // if empty line, compare current block with 3 biggest known
             "" => {

src/solutions/day02.rs

@@ -6,11 +6,11 @@
 
 use {crate::helpers::read_lines, std::time::SystemTime};
 
+/// solves the part 1 of day 02 and return its result and elapsed time
 pub fn pt1(filename: &str) -> (u32, u32) {
     let time = SystemTime::now();
 
     let answer = read_lines(filename)
-        .flatten()
         .map(|line| RoundMoves::from_line(line).total_points())
         .sum();
 
@@ -19,11 +19,11 @@ pub fn pt1(filename: &str) -> (u32, u32) {
     (answer, time)
 }
 
+/// solves the part 2 of day 02 and return its result and elapsed time
 pub fn pt2(filename: &str) -> (u32, u32) {
     let time = SystemTime::now();
 
     let answer = read_lines(filename)
-        .flatten()
         .map(|line| RoundOutcome::from_line(line).total_points())
         .sum();
 

src/solutions/day03.rs

@@ -6,11 +6,11 @@
 
 use {crate::helpers::read_lines, std::time::SystemTime};
 
+/// solves the part 1 of day 03 and return its result and elapsed time
 pub fn pt1(filename: &str) -> (u32, u32) {
     let time = SystemTime::now();
 
     let answer = read_lines(filename)
-        .flatten()
         .map(|line| Rucksack::from_line(line).value_of_common())
         .sum();
 
@@ -19,6 +19,7 @@ pub fn pt1(filename: &str) -> (u32, u32) {
     (answer, time)
 }
 
+/// solves the part 2 of day 03 and return its result and elapsed time
 pub fn pt2(filename: &str) -> (u32, u32) {
     let time = SystemTime::now();
 
@@ -32,7 +33,7 @@ pub fn pt2(filename: &str) -> (u32, u32) {
 
     let mut answer = 0;
 
-    for line in read_lines(filename).flatten() {
+    for line in read_lines(filename) {
         match current_index {
             1 => {
                 current_group.first = line;