From a5f19ecae1368ce0add6e0037f970270effdc165 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=BCdiger=20Ludwig?= <ruediger.ludwig@posteo.de>
Date: Sat, 29 Jul 2023 17:02:25 +0200
Subject: [PATCH 1/3] Made everything a bit more rustic

---
 src/common/file.rs    | 11 +++--
 src/days/day01/mod.rs | 22 ++++++----
 src/days/day02/mod.rs | 18 ++++----
 src/days/day03/mod.rs | 22 +++++-----
 src/days/day04/mod.rs | 18 ++++----
 src/days/day05/mod.rs | 44 +++++++++++---------
 src/days/day06/mod.rs | 14 +++----
 src/days/day07/mod.rs | 26 +++++++-----
 src/days/day08/mod.rs | 47 +++++++++++----------
 src/days/day09/mod.rs | 21 +++++-----
 src/days/day10/mod.rs | 25 +++++++-----
 src/days/day11/mod.rs | 37 ++++++++++-------
 src/days/day12/mod.rs | 31 ++++++++------
 src/days/day13/mod.rs | 21 +++++-----
 src/days/day14/mod.rs | 95 +++++++++++++++++++++++--------------------
 src/days/day15/mod.rs | 25 ++++++++----
 src/days/day16/mod.rs | 37 +++++++++--------
 src/days/day17/mod.rs | 80 ++++++++++++++++++++++++------------
 src/days/day18/mod.rs | 27 +++++++-----
 src/days/day__/mod.rs | 19 ++++++---
 src/days/template.rs  |  4 +-
 src/main.rs           |  6 +--
 22 files changed, 376 insertions(+), 274 deletions(-)

diff --git a/src/common/file.rs b/src/common/file.rs
index 5712052..3c5b86c 100644
--- a/src/common/file.rs
+++ b/src/common/file.rs
@@ -5,13 +5,16 @@ fn format_path(day_num: usize, file: &str) -> String {
     format!("data/day{day_num:02}/{file}")
 }
 
-pub fn read_lines(day_num: usize, file: &str) -> io::Result<Vec<String>> {
-    Ok(fs::read_to_string(format_path(day_num, file))?
+pub fn read_string(day_num: usize, file: &str) -> io::Result<String> {
+    Ok(fs::read_to_string(format_path(day_num, file))?)
+}
+
+pub fn split_lines<'a>(lines: &'a str) -> impl Iterator<Item = &'a str> + 'a {
+    lines
         .split('\n')
         .with_position()
         .filter_map(|(pos, line)| match pos {
             itertools::Position::Last if line.is_empty() => None,
-            _ => Some(line.to_owned()),
+            _ => Some(line),
         })
-        .collect())
 }
diff --git a/src/days/day01/mod.rs b/src/days/day01/mod.rs
index 0bda729..6419b99 100644
--- a/src/days/day01/mod.rs
+++ b/src/days/day01/mod.rs
@@ -3,6 +3,8 @@ use std::num::ParseIntError;
 
 use thiserror::Error;
 
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 
 pub struct Day;
@@ -13,13 +15,15 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let lines = split_lines(lines);
         let vector = Day::parse(lines)?;
         let max = vector.iter().max().ok_or(CalorieError::Empty)?;
         Ok(ResultType::Integer(*max))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let lines = split_lines(lines);
         let vector = Day::parse(lines)?;
         let sum = vector.iter().sorted_by(|a, b| Ord::cmp(b, a)).take(3).sum();
         Ok(ResultType::Integer(sum))
@@ -27,9 +31,8 @@ impl DayTrait for Day {
 }
 
 impl Day {
-    fn parse(lines: &[String]) -> Result<Vec<i64>, CalorieError> {
+    fn parse<'a>(lines: impl Iterator<Item = &'a str>) -> Result<Vec<i64>, CalorieError> {
         Ok(lines
-            .iter()
             .batching(|it| {
                 let result = it
                     .take_while(|line| !line.is_empty())
@@ -57,13 +60,13 @@ pub enum CalorieError {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(24_000);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -74,7 +77,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(45_000);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
@@ -84,9 +87,10 @@ mod test {
 
     #[test]
     fn test_parse() -> Result<()> {
-        let lines = read_lines(DAY_NUMBER, "example01.txt")?;
+        let lines = read_string(DAY_NUMBER, "example01.txt")?;
+        let lines = split_lines(&lines);
         let expected = vec![6000, 4000, 11000, 24000, 10000];
-        let result = Day::parse(&lines)?;
+        let result = Day::parse(lines)?;
         assert_eq!(result, expected);
 
         Ok(())
diff --git a/src/days/day02/mod.rs b/src/days/day02/mod.rs
index 73fc25e..9f19241 100644
--- a/src/days/day02/mod.rs
+++ b/src/days/day02/mod.rs
@@ -1,5 +1,7 @@
 use std::cmp::Ordering;
 
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use thiserror::Error;
 
@@ -12,9 +14,8 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let sum = lines
-            .iter()
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = split_lines(lines)
             .map(|line| Rps::parse_line(line))
             .collect::<Result<Vec<_>, _>>()?
             .into_iter()
@@ -24,9 +25,8 @@ impl DayTrait for Day {
         Ok(ResultType::Integer(sum))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let sum = lines
-            .iter()
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = split_lines(lines)
             .map(|line| Strategy::parse_line(line))
             .collect::<Result<Vec<_>, _>>()?
             .into_iter()
@@ -155,7 +155,7 @@ impl TryFrom<&str> for Strategy {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -182,7 +182,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(15);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -214,7 +214,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(12);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day03/mod.rs b/src/days/day03/mod.rs
index f263f63..a86653c 100644
--- a/src/days/day03/mod.rs
+++ b/src/days/day03/mod.rs
@@ -1,3 +1,5 @@
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use itertools::Itertools;
 use thiserror::Error;
@@ -11,9 +13,8 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let sum = lines
-            .iter()
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = split_lines(lines)
             .map(|line| find_double(line))
             .map_ok(priority)
             .flatten_ok()
@@ -21,12 +22,11 @@ impl DayTrait for Day {
         Ok(ResultType::Integer(sum))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let sum = lines
-            .iter()
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = split_lines(lines)
             .chunks(3)
             .into_iter()
-            .map(|chunk| find_badge(&chunk.collect::<Vec<_>>()))
+            .map(|chunk| find_badge(&chunk.collect_vec()))
             .map_ok(priority)
             .flatten_ok()
             .fold_ok(0, |a, b| a + b)?;
@@ -71,7 +71,7 @@ fn find_double(content: &str) -> Result<char, RucksackError> {
     Err(RucksackError::NoDoubleFound)?
 }
 
-fn find_badge(elves: &[&String]) -> Result<char, RucksackError> {
+fn find_badge(elves: &[&str]) -> Result<char, RucksackError> {
     if elves.len() < 2 {
         return Err(RucksackError::NeedAtLeastTwo);
     };
@@ -92,7 +92,7 @@ fn find_badge(elves: &[&String]) -> Result<char, RucksackError> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -108,7 +108,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(157);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -119,7 +119,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(70);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day04/mod.rs b/src/days/day04/mod.rs
index 2696dc7..62a84a9 100644
--- a/src/days/day04/mod.rs
+++ b/src/days/day04/mod.rs
@@ -1,3 +1,5 @@
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use itertools::Itertools;
 use std::num::ParseIntError;
@@ -12,18 +14,16 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let sum = lines
-            .iter()
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = split_lines(lines)
             .map(|line| parse(line))
             .filter_ok(fully_contained)
             .fold_ok(0i64, |a, _| a + 1)?;
         Ok(ResultType::Integer(sum))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let sum = lines
-            .iter()
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let sum = split_lines(lines)
             .map(|line| parse(line))
             .filter_ok(overlaps)
             .fold_ok(0i64, |a, _| a + 1)?;
@@ -77,7 +77,7 @@ fn overlaps((first, second): &(Range, Range)) -> bool {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -93,7 +93,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(2);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -104,7 +104,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(4);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day05/mod.rs b/src/days/day05/mod.rs
index 98a292f..57429eb 100644
--- a/src/days/day05/mod.rs
+++ b/src/days/day05/mod.rs
@@ -1,4 +1,7 @@
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
+use itertools::Itertools;
 use std::num::ParseIntError;
 use thiserror::Error;
 
@@ -11,7 +14,7 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         let (mut stacks, commands) = parse(lines)?;
         for command in commands {
             command.with_turn(&mut stacks)?;
@@ -19,7 +22,7 @@ impl DayTrait for Day {
         Ok(ResultType::String(get_word(&stacks)))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         let (mut stacks, commands) = parse(lines)?;
         for command in commands {
             command.without_turn(&mut stacks)?;
@@ -57,11 +60,13 @@ fn parse_crate(line: &str) -> Vec<Option<char>> {
         .collect()
 }
 
-fn parse_all_crates(line_it: &mut dyn Iterator<Item = &String>) -> Result<Vec<String>, CrateError> {
-    let rows: Vec<_> = line_it
+fn parse_all_crates<'a>(
+    line_it: &mut dyn Iterator<Item = &'a str>,
+) -> Result<Vec<String>, CrateError> {
+    let rows = line_it
         .take_while(|line| !line.is_empty())
         .map(|row| parse_crate(row))
-        .collect();
+        .collect_vec();
     let Some(stacks_count) = rows.iter().map(|row| row.len()).max() else {
         return Err(CrateError::NoCargoStacksGiven);
     };
@@ -79,11 +84,11 @@ fn parse_all_crates(line_it: &mut dyn Iterator<Item = &String>) -> Result<Vec<St
     Ok(stacks)
 }
 
-fn parse(line: &[String]) -> Result<(Vec<String>, Vec<Move>), CrateError> {
-    let mut iter = line.iter();
+fn parse<'a>(lines: &'a str) -> Result<(Vec<String>, Vec<Move>), CrateError> {
+    let mut iter = split_lines(lines);
     let stacks = parse_all_crates(&mut iter)?;
     let moves: Vec<_> = iter
-        .map(|command| Move::try_from(command.as_str()))
+        .map(|command| Move::try_from(command))
         .collect::<Result<_, _>>()?;
     Ok((stacks, moves))
 }
@@ -167,7 +172,7 @@ impl TryFrom<&str> for Move {
 mod test {
 
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -191,14 +196,15 @@ mod test {
     #[test]
     fn test_parse_all_crates() -> Result<()> {
         let lines = vec![
-            "    [D]    ".to_owned(),
-            "[N] [C]    ".to_owned(),
-            "[Z] [M] [P]".to_owned(),
-            " 1   2   3 ".to_owned(),
-            "".to_owned(),
-            "move 1 from to 2 1".to_owned(),
-        ];
-        let mut input = lines.iter();
+            "    [D]    ",
+            "[N] [C]    ",
+            "[Z] [M] [P]",
+            " 1   2   3 ",
+            "",
+            "move 1 from to 2 1",
+        ]
+        .join("\n");
+        let mut input = split_lines(&lines);
         let expected = vec!["NZ1".to_owned(), "DCM2".to_owned(), "P3".to_owned()];
         let result = parse_all_crates(&mut input)?;
 
@@ -221,7 +227,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::String("CMZ".to_owned());
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -243,7 +249,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::String("MCD".to_owned());
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day06/mod.rs b/src/days/day06/mod.rs
index 7a04a3f..6a4bc51 100644
--- a/src/days/day06/mod.rs
+++ b/src/days/day06/mod.rs
@@ -10,13 +10,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let count = find_marker(&lines[0], 4)?;
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let count = find_marker(lines.trim_end(), 4)?;
         Ok(ResultType::Integer(count as i64))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let count = find_marker(&lines[0], 14)?;
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let count = find_marker(lines.trim_end(), 14)?;
         Ok(ResultType::Integer(count as i64))
     }
 }
@@ -82,7 +82,7 @@ fn find_marker(word: &str, marker_length: usize) -> Result<usize, MarkerError> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -98,7 +98,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(10);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -109,7 +109,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(29);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day07/mod.rs b/src/days/day07/mod.rs
index 8c4c791..beb77c6 100644
--- a/src/days/day07/mod.rs
+++ b/src/days/day07/mod.rs
@@ -4,6 +4,8 @@ use std::{
     rc::{Rc, Weak},
 };
 
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use thiserror::Error;
 
@@ -16,7 +18,8 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let lines = split_lines(lines);
         let root = Directory::parse(lines)?;
         let result = root
             .iter()
@@ -32,9 +35,10 @@ impl DayTrait for Day {
         Ok(ResultType::Integer(result))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         const AVAIL: i64 = 70_000_000;
         const REQUIRED: i64 = 30_000_000;
+        let lines = split_lines(lines);
         let root = Directory::parse(lines)?;
         let to_free = REQUIRED - (AVAIL - root.size());
         let result = root
@@ -167,7 +171,7 @@ impl Directory {
         sub_node.map(|node| Directory::create(node.clone()))
     }
 
-    pub fn parse(lines: &[String]) -> Result<Directory, DirectoryError> {
+    pub fn parse<'a>(lines: impl Iterator<Item = &'a str>) -> Result<Directory, DirectoryError> {
         let root = Directory::root();
         let mut current = root.clone();
         for line in lines {
@@ -269,7 +273,7 @@ impl Iterator for DirectoryIterator {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -298,8 +302,9 @@ mod test {
     #[test]
     fn test_total_size() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let dir = Directory::parse(&lines)?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let lines = split_lines(&lines);
+        let dir = Directory::parse(lines)?;
         assert_eq!(dir.size(), 48381165);
 
         Ok(())
@@ -308,9 +313,10 @@ mod test {
     #[test]
     fn test_iterator() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let lines = split_lines(&lines);
         let expected = vec!["/", "a", "e", "d"];
-        let dir = Directory::parse(&lines)?;
+        let dir = Directory::parse(lines)?;
         let result: Vec<_> = dir.iter().map(|dir| dir.name()).collect();
         assert_eq!(result, expected);
 
@@ -320,7 +326,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(95437);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -331,7 +337,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(24933642);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day08/mod.rs b/src/days/day08/mod.rs
index 77b5fcc..aa671ea 100644
--- a/src/days/day08/mod.rs
+++ b/src/days/day08/mod.rs
@@ -1,3 +1,5 @@
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use itertools::{iproduct, FoldWhile, Itertools};
 use thiserror::Error;
@@ -11,14 +13,14 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let forest = Forest::parse(lines)?;
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let forest = Forest::try_from(lines)?;
         let result = forest.count_visible();
         Ok(ResultType::Integer(result))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let forest = Forest::parse(lines)?;
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let forest = Forest::try_from(lines)?;
         let result = forest.best_score();
         Ok(ResultType::Integer(result))
     }
@@ -67,18 +69,6 @@ impl Forest {
         })
     }
 
-    pub fn parse(lines: &[String]) -> Result<Forest, ForestError> {
-        lines
-            .iter()
-            .map(|line| {
-                line.chars()
-                    .map(|height| height.to_digit(10).ok_or(ForestError::NoLegalDigit(height)))
-                    .collect::<Result<Vec<_>, _>>()
-            })
-            .collect::<Result<Vec<_>, _>>()
-            .and_then(Forest::create)
-    }
-
     pub fn count_visible(&self) -> i64 {
         let mut vis_count = 2 * (self.width + self.height - 2) as i64;
         let mut visible = vec![vec![false; self.width - 2]; self.height - 2];
@@ -191,17 +181,32 @@ impl Forest {
     }
 }
 
+impl TryFrom<&str> for Forest {
+    type Error = ForestError;
+
+    fn try_from(lines: &str) -> Result<Self, Self::Error> {
+        split_lines(lines)
+            .map(|line| {
+                line.chars()
+                    .map(|height| height.to_digit(10).ok_or(ForestError::NoLegalDigit(height)))
+                    .collect::<Result<Vec<_>, _>>()
+            })
+            .collect::<Result<Vec<_>, _>>()
+            .and_then(Forest::create)
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_parse() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let forest = Forest::parse(&lines)?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let forest = Forest::try_from(lines.as_str())?;
         assert_eq!(forest.width, 5);
         assert_eq!(forest.height, 5);
 
@@ -211,7 +216,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(21);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -222,7 +227,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(8);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day09/mod.rs b/src/days/day09/mod.rs
index 533acf4..7f11710 100644
--- a/src/days/day09/mod.rs
+++ b/src/days/day09/mod.rs
@@ -1,5 +1,6 @@
 use super::template::{DayTrait, ResultType};
-use crate::common::{direction::Direction, pos::Pos};
+use crate::common::{direction::Direction, file::split_lines, pos::Pos};
+use itertools::Itertools;
 use std::{collections::HashSet, num::ParseIntError};
 use thiserror::Error;
 
@@ -12,14 +13,14 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         let commands = parse_commands(lines)?;
         let mut rope = Rope::create(2);
         let result = rope.run(&commands);
         Ok(ResultType::Integer(result))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         let commands = parse_commands(lines)?;
         let mut rope = Rope::create(10);
         let result = rope.run(&commands);
@@ -39,12 +40,12 @@ enum RopeError {
     StepParseError(#[from] ParseIntError),
 }
 
-fn parse_commands(lines: &[String]) -> Result<Vec<(Direction, usize)>, RopeError> {
-    lines.iter().map(parse_line).collect::<Result<_, _>>()
+fn parse_commands(lines: &str) -> Result<Vec<(Direction, usize)>, RopeError> {
+    split_lines(lines).map(parse_line).try_collect()
 }
 
-fn parse_line(line: &String) -> Result<(Direction, usize), RopeError> {
-    match line.split_whitespace().collect::<Vec<_>>()[..] {
+fn parse_line(line: &str) -> Result<(Direction, usize), RopeError> {
+    match line.split_whitespace().collect_vec()[..] {
         [direction, steps] => {
             let direction = match direction {
                 "U" => Direction::North,
@@ -125,13 +126,13 @@ impl Rope {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(13);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -142,7 +143,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example02.txt")?;
+        let lines = read_string(day.get_day_number(), "example02.txt")?;
         let expected = ResultType::Integer(36);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day10/mod.rs b/src/days/day10/mod.rs
index 13bfdcf..255231b 100644
--- a/src/days/day10/mod.rs
+++ b/src/days/day10/mod.rs
@@ -1,3 +1,5 @@
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use std::{num::ParseIntError, slice::Iter};
 use thiserror::Error;
@@ -11,18 +13,16 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let instructions = lines
-            .iter()
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let instructions = split_lines(lines)
             .map(|line| Instruction::parse(line))
             .collect::<Result<Vec<_>, _>>()?;
         let result = CpuCycles::signal_strength(&instructions, &[20, 60, 100, 140, 180, 220]);
         Ok(ResultType::Integer(result as i64))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let instructions = lines
-            .iter()
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let instructions = split_lines(lines)
             .map(|line| Instruction::parse(line))
             .collect::<Result<Vec<_>, _>>()?;
         let result = CpuCycles::draw(&instructions);
@@ -128,8 +128,9 @@ impl<'a> Iterator for CpuCycles<'a> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
+    use itertools::Itertools;
 
     #[test]
     fn test_simple() -> Result<()> {
@@ -144,7 +145,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(13140);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -155,8 +156,12 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let expected = ResultType::Lines(read_lines(day.get_day_number(), "expected01.txt")?);
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let expected_lines = read_string(day.get_day_number(), "expected01.txt")?;
+        let expected_lines = split_lines(&expected_lines)
+            .map(|s| s.to_owned())
+            .collect_vec();
+        let expected = ResultType::Lines(expected_lines);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
 
diff --git a/src/days/day11/mod.rs b/src/days/day11/mod.rs
index 2e8b3c7..058cb57 100644
--- a/src/days/day11/mod.rs
+++ b/src/days/day11/mod.rs
@@ -1,3 +1,5 @@
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use once_cell::sync::Lazy;
 use regex::Regex;
@@ -13,13 +15,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let troop = Troop::parse(lines)?;
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let troop = Troop::try_from(lines)?;
         Ok(ResultType::Integer(troop.play(20)))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let troop = Troop::parse(lines)?;
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let troop = Troop::try_from(lines)?;
         Ok(ResultType::Integer(troop.play_again(10_000)))
     }
 }
@@ -90,7 +92,7 @@ impl Monkey {
     }
 
     pub fn parse_one(
-        iterator: &mut dyn Iterator<Item = &String>,
+        iterator: &mut dyn Iterator<Item = &str>,
     ) -> Result<Option<Monkey>, MonkeyError> {
         if let Some(line) = iterator.next() {
             let number: usize = Monkey::parse_line(&MONKEY, line)?.parse()?;
@@ -142,16 +144,20 @@ struct Troop {
     monkeys: Vec<Monkey>,
 }
 
-impl Troop {
-    pub fn parse(lines: &[String]) -> Result<Troop, MonkeyError> {
-        let mut iter = lines.iter();
+impl TryFrom<&str> for Troop {
+    type Error = MonkeyError;
+
+    fn try_from(value: &str) -> Result<Self, Self::Error> {
+        let mut iter = split_lines(value);
         let mut monkeys = Vec::new();
         while let Some(monkey) = Monkey::parse_one(&mut iter)? {
             monkeys.push(monkey);
         }
         Ok(Troop { monkeys })
     }
+}
 
+impl Troop {
     fn do_play<F>(&self, rounds: usize, alter: F) -> i64
     where
         F: Fn(i64) -> i64,
@@ -191,13 +197,14 @@ impl Troop {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_parse() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let mut lines = split_lines(&lines);
         let expected = Monkey {
             number: 0,
             items: vec![79, 98],
@@ -206,7 +213,7 @@ mod test {
             good_monkey: 2,
             bad_monkey: 3,
         };
-        let result = Monkey::parse_one(&mut lines.iter())?.unwrap();
+        let result = Monkey::parse_one(&mut lines)?.unwrap();
         assert_eq!(result, expected);
 
         Ok(())
@@ -215,9 +222,9 @@ mod test {
     #[test]
     fn test_parse_all() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = 4;
-        let result = Troop::parse(&lines)?;
+        let result = Troop::try_from(lines.as_str())?;
         assert_eq!(result.monkeys.len(), expected);
 
         Ok(())
@@ -226,7 +233,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(10605);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -237,7 +244,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(2713310158);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day12/mod.rs b/src/days/day12/mod.rs
index c3f6ab1..1c099d0 100644
--- a/src/days/day12/mod.rs
+++ b/src/days/day12/mod.rs
@@ -1,6 +1,6 @@
 use std::collections::{BinaryHeap, HashSet};
 
-use crate::common::pos::Pos;
+use crate::common::{file::split_lines, pos::Pos};
 
 use super::template::{DayTrait, ResultType};
 use thiserror::Error;
@@ -14,13 +14,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let valley = Valley::parse(lines)?;
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let valley = Valley::try_from(lines)?;
         Ok(ResultType::Integer(valley.walk()? as i64))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let valley = Valley::parse(lines)?;
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let valley = Valley::try_from(lines)?;
         Ok(ResultType::Integer(valley.walk_short()? as i64))
     }
 }
@@ -158,13 +158,16 @@ struct Valley {
     width: usize,
 }
 
-impl Valley {
-    pub fn parse(lines: &[String]) -> Result<Valley, ValleyError> {
+impl TryFrom<&str> for Valley {
+    type Error = ValleyError;
+
+    fn try_from(lines: &str) -> Result<Self, Self::Error> {
+        let lines = split_lines(lines);
         let mut map = Vec::new();
         let mut start = None;
         let mut exit = None;
         let mut valley_width = None;
-        for (y, row) in lines.iter().enumerate() {
+        for (y, row) in lines.enumerate() {
             let mut height_row = Vec::new();
             for (x, height_char) in row.chars().enumerate() {
                 match height_char {
@@ -205,7 +208,9 @@ impl Valley {
             width,
         })
     }
+}
 
+impl Valley {
     fn get_height(&self, pos: Pos<usize>) -> char {
         self.map[pos.y()][pos.x()]
     }
@@ -255,14 +260,14 @@ impl Valley {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_parse() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let valley = Valley::parse(&lines)?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let valley = Valley::try_from(lines.as_str())?;
         assert_eq!(valley.width, 8);
         assert_eq!(valley.start, Pos::new(0, 0));
         assert_eq!(valley.exit, Pos::new(5, 2));
@@ -273,7 +278,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(31);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -284,7 +289,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(29);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day13/mod.rs b/src/days/day13/mod.rs
index 0e33a74..f6b146a 100644
--- a/src/days/day13/mod.rs
+++ b/src/days/day13/mod.rs
@@ -1,5 +1,7 @@
 use std::cmp::Ordering;
 
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use itertools::Itertools;
 use thiserror::Error;
@@ -13,7 +15,7 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         let packets = Packets::parse_all(lines)?;
         let result: i64 = packets
             .iter()
@@ -30,7 +32,7 @@ impl DayTrait for Day {
         Ok(ResultType::Integer(result))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         let small = Packets::parse("[[2]]")?;
         let large = Packets::parse("[[6]]")?;
         let mut pos_small = 1;
@@ -144,9 +146,8 @@ impl Packets {
         Err(PacketError::PrematureEndOfInput)
     }
 
-    pub fn parse_all(lines: &[String]) -> Result<Vec<Packets>, PacketError> {
-        lines
-            .iter()
+    pub fn parse_all(lines: &str) -> Result<Vec<Packets>, PacketError> {
+        split_lines(lines)
             .filter(|line| !line.is_empty())
             .map(|line| Packets::parse(line))
             .collect::<Result<Vec<_>, _>>()
@@ -156,7 +157,7 @@ impl Packets {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
@@ -174,7 +175,7 @@ mod test {
     #[test]
     fn test_parse_all() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let result = Packets::parse_all(&lines)?;
         assert_eq!(result.len(), 16);
         Ok(())
@@ -183,7 +184,7 @@ mod test {
     #[test]
     fn test_compare_all() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = vec![true, true, false, true, false, true, false, false];
         let result = Packets::parse_all(&lines)?;
         let compare = result
@@ -199,7 +200,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(13);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -210,7 +211,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(140);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day14/mod.rs b/src/days/day14/mod.rs
index e8ace33..56a1e02 100644
--- a/src/days/day14/mod.rs
+++ b/src/days/day14/mod.rs
@@ -2,7 +2,7 @@ use itertools::Itertools;
 use std::{collections::HashSet, num::ParseIntError};
 use thiserror::Error;
 
-use crate::common::pos::Pos;
+use crate::common::{file::split_lines, pos::Pos};
 
 use super::template::{DayTrait, ResultType};
 
@@ -15,13 +15,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let cave = Cave::parse(lines)?;
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let cave = Cave::try_from(lines)?;
         Ok(ResultType::Integer(cave.drop_bottomless() as i64))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let cave = Cave::parse(lines)?;
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let cave = Cave::try_from(lines)?;
         Ok(ResultType::Integer(cave.drop_floor()))
     }
 }
@@ -51,6 +51,46 @@ struct Cave {
     height: i32,
 }
 
+impl TryFrom<&str> for Cave {
+    type Error = CaveError;
+
+    fn try_from(lines: &str) -> Result<Self, Self::Error> {
+        let lines = split_lines(lines);
+        let mut cave: HashSet<Pos<i32>> = HashSet::new();
+        for line in lines {
+            cave.extend(Cave::parse_one(line)?.iter());
+        }
+        if cave.is_empty() {
+            Err(CaveError::EmptyCave)
+        } else {
+            let mut max_x = i32::MIN;
+            let mut min_x = i32::MAX;
+            let mut max_y = i32::MIN;
+            for block in &cave {
+                if block.x() < min_x {
+                    min_x = block.x();
+                }
+                if block.x() > max_x {
+                    max_x = block.x();
+                }
+                if block.y() > max_y {
+                    max_y = block.y()
+                }
+            }
+            let mut map = vec![vec![false; (max_x - min_x + 1) as usize]; (max_y + 1) as usize];
+            for block in cave {
+                map[block.y() as usize][(block.x() - min_x) as usize] = true;
+            }
+            Ok(Cave {
+                map,
+                min_x,
+                max_x,
+                height: max_y + 1,
+            })
+        }
+    }
+}
+
 impl Cave {
     fn get(&self, map: &[Vec<bool>], pos: Pos<i32>) -> bool {
         if pos.y() >= self.height || pos.x() < self.min_x || pos.x() > self.max_x {
@@ -118,41 +158,6 @@ impl Cave {
         Ok(blocks)
     }
 
-    pub fn parse(lines: &[String]) -> Result<Cave, CaveError> {
-        let mut cave: HashSet<Pos<i32>> = HashSet::new();
-        for line in lines {
-            cave.extend(Cave::parse_one(line)?.iter());
-        }
-        if cave.is_empty() {
-            Err(CaveError::EmptyCave)
-        } else {
-            let mut max_x = i32::MIN;
-            let mut min_x = i32::MAX;
-            let mut max_y = i32::MIN;
-            for block in &cave {
-                if block.x() < min_x {
-                    min_x = block.x();
-                }
-                if block.x() > max_x {
-                    max_x = block.x();
-                }
-                if block.y() > max_y {
-                    max_y = block.y()
-                }
-            }
-            let mut map = vec![vec![false; (max_x - min_x + 1) as usize]; (max_y + 1) as usize];
-            for block in cave {
-                map[block.y() as usize][(block.x() - min_x) as usize] = true;
-            }
-            Ok(Cave {
-                map,
-                min_x,
-                max_x,
-                height: max_y + 1,
-            })
-        }
-    }
-
     pub fn drop_bottomless(&self) -> u32 {
         let mut drops = 0;
         let mut filled_map = self.map.to_vec();
@@ -243,7 +248,7 @@ impl Cave {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::{common::file::read_lines, hashset};
+    use crate::{common::file::read_string, hashset};
     use anyhow::Result;
 
     #[test]
@@ -259,8 +264,8 @@ mod test {
     #[test]
     fn test_parse_all() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let result = Cave::parse(&lines)?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let result = Cave::try_from(lines.as_str())?;
         assert_eq!(result.min_x, 494);
         assert_eq!(result.max_x, 503);
         assert_eq!(result.height, 10);
@@ -271,7 +276,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(24);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -282,7 +287,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(93);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day15/mod.rs b/src/days/day15/mod.rs
index 28e4ee4..8292730 100644
--- a/src/days/day15/mod.rs
+++ b/src/days/day15/mod.rs
@@ -1,5 +1,5 @@
 use super::template::{DayTrait, ResultType};
-use crate::common::pos::Pos;
+use crate::common::{file::split_lines, pos::Pos};
 use itertools::Itertools;
 use once_cell::sync::Lazy;
 use regex::Regex;
@@ -15,14 +15,22 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let lines = split_lines(lines).collect_vec();
+        if lines.len() < 2 {
+            Err(SensorError::ToFewLines)?;
+        }
         let row = lines[0].parse()?;
         let (sensors, beacons) = Day::parse_all(&lines[1..])?;
         let result = Day::count_coverage_at(&sensors, &beacons, row);
         Ok(ResultType::Integer(result))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let lines = split_lines(lines).collect_vec();
+        if lines.len() < 2 {
+            Err(SensorError::ToFewLines)?;
+        }
         let (sensors, _) = Day::parse_all(&lines[1..])?;
         let mid_lines = Day::dividing_lines(&sensors);
         let points = mid_lines
@@ -43,7 +51,7 @@ impl DayTrait for Day {
 }
 
 impl Day {
-    fn parse_all(lines: &[String]) -> Result<(HashSet<Sensor>, HashSet<Pos<i64>>), SensorError> {
+    fn parse_all(lines: &[&str]) -> Result<(HashSet<Sensor>, HashSet<Pos<i64>>), SensorError> {
         let mut sensors = HashSet::new();
         let mut beacons = HashSet::new();
         for line in lines {
@@ -91,6 +99,9 @@ enum SensorError {
 
     #[error("Did not find exactly one point for the sensor: {0}")]
     NotExactlyOneResult(usize),
+
+    #[error("Too few lines in input.txt")]
+    ToFewLines,
 }
 
 #[derive(Debug)]
@@ -256,7 +267,7 @@ impl Sensor {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
     #[test]
     fn test_parse() -> Result<()> {
@@ -295,7 +306,7 @@ mod test {
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(26);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -306,7 +317,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(56000011);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day16/mod.rs b/src/days/day16/mod.rs
index 1e7cfb1..67dd832 100644
--- a/src/days/day16/mod.rs
+++ b/src/days/day16/mod.rs
@@ -5,6 +5,8 @@ use std::iter::Sum;
 use std::ops::{Add, Deref, Mul, Sub};
 use std::{collections::BinaryHeap, num::ParseIntError};
 
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 use const_format::concatcp;
 use itertools::Itertools;
@@ -21,13 +23,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         let system = ValveSystem::build(lines, "AA")?;
         let result = system.maximum_flow(system.single_actor(Time(30)))?;
         Ok(ResultType::Integer(*result))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         let system = ValveSystem::build(lines, "AA")?;
         let result = system.maximum_flow(system.double_actor(Time(26)))?;
         Ok(ResultType::Integer(*result))
@@ -264,10 +266,9 @@ struct ValveSystem {
 }
 
 impl ValveSystem {
-    fn build(lines: &[String], start: &str) -> Result<ValveSystem, ValveError> {
-        let mut raw = lines
-            .iter()
-            .map(|line| RawValve::try_from(line.as_str()))
+    fn build(lines: &str, start: &str) -> Result<ValveSystem, ValveError> {
+        let mut raw = split_lines(lines)
+            .map(|line| RawValve::try_from(line))
             .collect::<Result<Vec<_>, _>>()?;
         raw.sort_unstable_by_key(|valve| valve.id);
 
@@ -912,13 +913,13 @@ impl Hash for HashableState {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(1651);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -949,7 +950,7 @@ mod test {
     #[test]
     fn parse_system() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
 
         assert_eq!(10, system.len());
@@ -966,7 +967,7 @@ mod test {
     #[test]
     fn single_state_init() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = system.single_actor(Time(5));
 
@@ -980,7 +981,7 @@ mod test {
     #[test]
     fn next_single_actor_states() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = system.single_actor(Time(5));
         let state = ValveState::init(&system, actor);
@@ -1002,7 +1003,7 @@ mod test {
     #[test]
     fn next_single_states() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = system.single_actor(Time(6));
         let state = ValveState::init(&system, actor);
@@ -1023,7 +1024,7 @@ mod test {
     #[test]
     fn double_state_init() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = system.double_actor(Time(5));
         let state = ValveState::init(&system, actor);
@@ -1037,7 +1038,7 @@ mod test {
     #[test]
     fn next_double_actor_states() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = system.double_actor(Time(5));
         let state = ValveState::init(&system, actor);
@@ -1068,7 +1069,7 @@ mod test {
     #[test]
     fn next_double_states() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = system.double_actor(Time(5));
         let state = ValveState::init(&system, actor);
@@ -1090,7 +1091,7 @@ mod test {
     #[test]
     fn special_double_stats() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = DoubleActor(DoubleWork::Simultaneous(Index(1), Index(7), Time(19)));
         let state = ValveState {
@@ -1132,7 +1133,7 @@ mod test {
     #[test]
     fn double_long_run() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let system = ValveSystem::build(&lines, "AA")?;
         let actor = DoubleActor(DoubleWork::Sequential(Index(3), Time(5), Index(7), Time(2)));
         let state = ValveState {
@@ -1158,7 +1159,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(1707);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day17/mod.rs b/src/days/day17/mod.rs
index 07f954a..b64a7d6 100644
--- a/src/days/day17/mod.rs
+++ b/src/days/day17/mod.rs
@@ -1,6 +1,6 @@
 use std::{cell::Cell, marker::PhantomData, ops::Index};
 
-use crate::common::file::read_lines;
+use crate::common::file::{read_string, split_lines};
 
 use super::template::{DayTrait, ResultType};
 use itertools::Itertools;
@@ -16,16 +16,28 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let pushes = Dispenser::new(lines[0].chars().map(|c| Push::parse(c)).try_collect()?);
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let pushes = Dispenser::new(
+            lines
+                .trim_end()
+                .chars()
+                .map(|c| Push::parse(c))
+                .try_collect()?,
+        )?;
 
         let result = Day::run(pushes, 2022)?;
 
         Ok(ResultType::Integer(result as i64))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let pushes = Dispenser::new(lines[0].chars().map(|c| Push::parse(c)).try_collect()?);
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let pushes = Dispenser::new(
+            lines
+                .trim_end()
+                .chars()
+                .map(|c| Push::parse(c))
+                .try_collect()?,
+        )?;
 
         let result = Day::run(pushes, 1000000000000)?;
 
@@ -35,8 +47,8 @@ impl DayTrait for Day {
 
 impl Day {
     fn run(push_cycle: Dispenser<Push>, max_cycles: i64) -> Result<i64, RockError> {
-        let raw = read_lines(DAY_NUMBER, "blocks.txt")?;
-        let rock_cycle = Dispenser::new(Rock::parse(&raw)?);
+        let raw = read_string(DAY_NUMBER, "blocks.txt")?;
+        let rock_cycle = Dispenser::new(Rock::parse(&raw)?)?;
         let mut cycle = 0;
         let mut stack = Stack::new();
 
@@ -114,6 +126,9 @@ enum RockError {
 
     #[error("Unknown direction: {0}")]
     UnknownDirection(char),
+
+    #[error("A Dispenser must never be empty")]
+    EmptyDispenserNotAllowed,
 }
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
@@ -158,9 +173,8 @@ impl Rock {
         })
     }
 
-    pub fn parse(lines: &[String]) -> Result<Vec<Rock>, RockError> {
-        lines
-            .iter()
+    pub fn parse(lines: &str) -> Result<Vec<Rock>, RockError> {
+        split_lines(lines)
             .batching(|it| {
                 let blocks = it
                     .skip_while(|line| line.is_empty())
@@ -330,11 +344,15 @@ where
 }
 
 impl<'a, T> Dispenser<'a, T> {
-    pub fn new(data: Vec<T>) -> Self {
-        Dispenser {
-            data,
-            current: Cell::new(0),
-            _marker: PhantomData,
+    pub fn new(data: Vec<T>) -> Result<Self, RockError> {
+        if data.is_empty() {
+            Err(RockError::EmptyDispenserNotAllowed)
+        } else {
+            Ok(Dispenser {
+                data,
+                current: Cell::new(0),
+                _marker: PhantomData,
+            })
         }
     }
 
@@ -351,13 +369,13 @@ impl<'a, T> Dispenser<'a, T> {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(3068);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -368,7 +386,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(1514285714288);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
@@ -379,7 +397,7 @@ mod test {
     #[test]
     fn read_blocks() -> Result<()> {
         let day = Day {};
-        let raw = read_lines(day.get_day_number(), "blocks.txt")?;
+        let raw = read_string(day.get_day_number(), "blocks.txt")?;
         let rocks = Rock::parse(&raw)?;
         let expected = Rock::new(vec![vec![true]; 4])?;
         assert_eq!(rocks[3], expected);
@@ -396,10 +414,16 @@ mod test {
     #[test]
     fn drop_one() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let pushes = Dispenser::new(lines[0].chars().map(|c| Push::parse(c)).try_collect()?);
-        let raw = read_lines(day.get_day_number(), "blocks.txt")?;
-        let rocks = Dispenser::new(Rock::parse(&raw)?);
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let pushes = Dispenser::new(
+            lines
+                .trim_end()
+                .chars()
+                .map(|c| Push::parse(c))
+                .try_collect()?,
+        )?;
+        let raw = read_string(day.get_day_number(), "blocks.txt")?;
+        let rocks = Dispenser::new(Rock::parse(&raw)?)?;
 
         let mut stack = Stack::new();
         stack.one_rock(rocks.next(), &pushes);
@@ -412,8 +436,14 @@ mod test {
     #[test]
     fn drop_some() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
-        let pushes = Dispenser::new(lines[0].chars().map(|c| Push::parse(c)).try_collect()?);
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let pushes = Dispenser::new(
+            lines
+                .trim_end()
+                .chars()
+                .map(|c| Push::parse(c))
+                .try_collect()?,
+        )?;
 
         let result = Day::run(pushes, 10)?;
 
diff --git a/src/days/day18/mod.rs b/src/days/day18/mod.rs
index 1885f3d..d5d339b 100644
--- a/src/days/day18/mod.rs
+++ b/src/days/day18/mod.rs
@@ -2,6 +2,8 @@ use itertools::Itertools;
 use std::{collections::HashSet, num::ParseIntError};
 use thiserror::Error;
 
+use crate::common::file::split_lines;
+
 use super::template::{DayTrait, ResultType};
 
 const DAY_NUMBER: usize = 18;
@@ -13,13 +15,13 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let blob = Blob::parse(lines)?;
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let blob = Blob::try_from(lines)?;
         Ok(ResultType::Integer(blob.count_sides()))
     }
 
-    fn part2(&self, lines: &[String]) -> anyhow::Result<ResultType> {
-        let blob = Blob::parse(lines)?;
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let blob = Blob::try_from(lines)?;
         Ok(ResultType::Integer(blob.count_outside()))
     }
 }
@@ -131,15 +133,18 @@ struct Blob {
     droplets: HashSet<Droplet>,
 }
 
-impl Blob {
-    fn parse(lines: &[String]) -> Result<Self, DropletError> {
-        let droplets = lines
-            .iter()
+impl TryFrom<&str> for Blob {
+    type Error = DropletError;
+
+    fn try_from(lines: &str) -> Result<Self, Self::Error> {
+        let droplets = split_lines(lines)
             .map(|line| Droplet::parse(line))
             .try_collect()?;
         Ok(Blob { droplets })
     }
+}
 
+impl Blob {
     fn extent(&self) -> Option<Ranges> {
         if self.droplets.is_empty() {
             return None;
@@ -198,13 +203,13 @@ impl Blob {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(64);
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -215,7 +220,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Integer(58);
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/day__/mod.rs b/src/days/day__/mod.rs
index e67b4e2..fe2759b 100644
--- a/src/days/day__/mod.rs
+++ b/src/days/day__/mod.rs
@@ -1,6 +1,7 @@
 use super::template::{DayTrait, ResultType};
+use thiserror::Error;
 
-const DAY_NUMBER: usize = 0;
+const DAY_NUMBER: usize = todo!();
 
 pub struct Day;
 
@@ -9,25 +10,31 @@ impl DayTrait for Day {
         DAY_NUMBER
     }
 
-    fn part1(&self, _lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
         Ok(ResultType::Nothing)
     }
 
-    fn part2(&self, _lines: &[String]) -> anyhow::Result<ResultType> {
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
         Ok(ResultType::Nothing)
     }
 }
 
+#[derive(Debug, Error)]
+enum DayError {
+    #[error("Dummy")]
+    Dummy,
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::common::file::read_lines;
+    use crate::common::file::read_string;
     use anyhow::Result;
 
     #[test]
     fn test_part1() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Nothing;
         let result = day.part1(&lines)?;
         assert_eq!(result, expected);
@@ -38,7 +45,7 @@ mod test {
     #[test]
     fn test_part2() -> Result<()> {
         let day = Day {};
-        let lines = read_lines(day.get_day_number(), "example01.txt")?;
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = ResultType::Nothing;
         let result = day.part2(&lines)?;
         assert_eq!(result, expected);
diff --git a/src/days/template.rs b/src/days/template.rs
index 73a779d..fe84e9a 100644
--- a/src/days/template.rs
+++ b/src/days/template.rs
@@ -11,6 +11,6 @@ pub enum ResultType {
 
 pub trait DayTrait {
     fn get_day_number(&self) -> usize;
-    fn part1(&self, lines: &[String]) -> Result<ResultType>;
-    fn part2(&self, lines: &[String]) -> Result<ResultType>;
+    fn part1(&self, lines: &str) -> Result<ResultType>;
+    fn part2(&self, lines: &str) -> Result<ResultType>;
 }
diff --git a/src/main.rs b/src/main.rs
index 7e90532..07a8ec7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,7 +3,7 @@ mod days;
 mod macros;
 
 use anyhow::Result;
-use common::file::read_lines;
+use common::file::read_string;
 use days::{day_provider, DayTrait, ResultType};
 use std::{
     env,
@@ -47,7 +47,7 @@ fn output(day: usize, part: usize, result: ResultType, time: Duration) {
     }
 }
 
-fn run_part(day: &dyn DayTrait, is_part1: bool, lines: &[String]) -> Result<Duration> {
+fn run_part(day: &dyn DayTrait, is_part1: bool, lines: &str) -> Result<Duration> {
     let now = Instant::now();
     let result = if is_part1 {
         day.part1(lines)?
@@ -70,7 +70,7 @@ fn run_part(day: &dyn DayTrait, is_part1: bool, lines: &[String]) -> Result<Dura
 }
 
 fn run(day: &dyn DayTrait, part1: bool, part2: bool) -> Result<Duration> {
-    let lines = read_lines(day.get_day_number(), "input.txt")?;
+    let lines = read_string(day.get_day_number(), "input.txt")?;
     let elapsed1 = if part1 {
         run_part(day, true, &lines)?
     } else {

From b00835c25e24e12cf8bee89a2ed7f1d3d8c8f001 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=BCdiger=20Ludwig?= <ruediger.ludwig@posteo.de>
Date: Sun, 30 Jul 2023 16:42:17 +0200
Subject: [PATCH 2/3] switch to nom

---
 Cargo.toml            |   4 +-
 src/common/mod.rs     |   1 +
 src/common/parser.rs  |  70 +++++++++++++++++
 src/days/day08/mod.rs |  14 ++--
 src/days/day11/mod.rs | 173 +++++++++++++++++++++++-------------------
 src/days/day15/mod.rs | 107 ++++++++++++++------------
 src/days/day16/mod.rs | 100 +++++++++++++-----------
 7 files changed, 288 insertions(+), 181 deletions(-)
 create mode 100644 src/common/parser.rs

diff --git a/Cargo.toml b/Cargo.toml
index cbeeee5..cf6e37d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,9 +6,7 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0"
-const_format = "0.2.31"
 itertools = "0.11"
 num-traits = "0.2"
-once_cell = "1.18.0"
-regex = "1.7"
 thiserror = "1.0"
+nom = "7"
diff --git a/src/common/mod.rs b/src/common/mod.rs
index 3c42571..3a2379d 100644
--- a/src/common/mod.rs
+++ b/src/common/mod.rs
@@ -3,5 +3,6 @@ pub mod direction;
 pub mod file;
 pub mod helper;
 pub mod math;
+pub mod parser;
 pub mod pos;
 pub mod turn;
diff --git a/src/common/parser.rs b/src/common/parser.rs
new file mode 100644
index 0000000..fa6b022
--- /dev/null
+++ b/src/common/parser.rs
@@ -0,0 +1,70 @@
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::{line_ending, space0, space1},
+    combinator::{eof, opt, value},
+    error::ParseError,
+    multi::many0,
+    sequence::{delimited, preceded, terminated, tuple},
+    Err, IResult, Parser,
+};
+
+pub fn extract_result<I, F, O, E: ParseError<I>>(
+    mut parser: F,
+) -> impl FnMut(I) -> Result<O, Err<E>>
+where
+    F: FnMut(I) -> IResult<I, O, E>,
+{
+    move |input: I| parser(input).map(|(_, value)| value)
+}
+
+pub fn ignore<I, F, O, E: ParseError<I>>(mut parser: F) -> impl FnMut(I) -> Result<I, Err<E>>
+where
+    F: FnMut(I) -> IResult<I, O, E>,
+{
+    move |input: I| parser(input).map(|(i, _)| i)
+}
+
+pub fn eol_terminated<'a, F, O, E: ParseError<&'a str>>(
+    line: F,
+) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
+where
+    F: Parser<&'a str, O, E>,
+{
+    terminated(line, alt((line_ending, eof)))
+}
+
+pub fn true_false<'a, E: ParseError<&'a str>>(input: &'a str) -> IResult<&'a str, bool, E> {
+    alt((value(true, tag("true")), value(false, tag("false"))))(input)
+}
+
+pub fn empty_lines<'a, E: ParseError<&'a str>>(input: &'a str) -> Result<&'a str, Err<E>> {
+    ignore(tuple((many0(line_ending), opt(eof))))(input)
+}
+
+pub fn trim_left1<'a, F, O, E: ParseError<&'a str>>(
+    inner: F,
+) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
+where
+    F: Parser<&'a str, O, E>,
+{
+    preceded(space1, inner)
+}
+
+pub fn trim0<'a, F, O, E: ParseError<&'a str>>(
+    inner: F,
+) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
+where
+    F: Parser<&'a str, O, E>,
+{
+    delimited(space0, inner, space0)
+}
+
+pub fn trim1<'a, F, O, E: ParseError<&'a str>>(
+    inner: F,
+) -> impl FnMut(&'a str) -> IResult<&'a str, O, E>
+where
+    F: Parser<&'a str, O, E>,
+{
+    delimited(space1, inner, space1)
+}
diff --git a/src/days/day08/mod.rs b/src/days/day08/mod.rs
index aa671ea..c031b2a 100644
--- a/src/days/day08/mod.rs
+++ b/src/days/day08/mod.rs
@@ -1,3 +1,5 @@
+use std::str::FromStr;
+
 use crate::common::file::split_lines;
 
 use super::template::{DayTrait, ResultType};
@@ -14,13 +16,13 @@ impl DayTrait for Day {
     }
 
     fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
-        let forest = Forest::try_from(lines)?;
+        let forest: Forest = lines.parse()?;
         let result = forest.count_visible();
         Ok(ResultType::Integer(result))
     }
 
     fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
-        let forest = Forest::try_from(lines)?;
+        let forest: Forest = lines.parse()?;
         let result = forest.best_score();
         Ok(ResultType::Integer(result))
     }
@@ -181,10 +183,10 @@ impl Forest {
     }
 }
 
-impl TryFrom<&str> for Forest {
-    type Error = ForestError;
+impl FromStr for Forest {
+    type Err = ForestError;
 
-    fn try_from(lines: &str) -> Result<Self, Self::Error> {
+    fn from_str(lines: &str) -> Result<Self, Self::Err> {
         split_lines(lines)
             .map(|line| {
                 line.chars()
@@ -206,7 +208,7 @@ mod test {
     fn test_parse() -> Result<()> {
         let day = Day {};
         let lines = read_string(day.get_day_number(), "example01.txt")?;
-        let forest = Forest::try_from(lines.as_str())?;
+        let forest: Forest = lines.parse()?;
         assert_eq!(forest.width, 5);
         assert_eq!(forest.height, 5);
 
diff --git a/src/days/day11/mod.rs b/src/days/day11/mod.rs
index 058cb57..ddb6f62 100644
--- a/src/days/day11/mod.rs
+++ b/src/days/day11/mod.rs
@@ -1,9 +1,19 @@
-use crate::common::file::split_lines;
+use crate::common::parser::{
+    empty_lines, eol_terminated, extract_result, ignore, trim0, trim_left1, true_false,
+};
 
 use super::template::{DayTrait, ResultType};
-use once_cell::sync::Lazy;
-use regex::Regex;
-use std::{iter::zip, num::ParseIntError};
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::{char, i64, u32},
+    combinator::{map, value, verify},
+    error::Error,
+    multi::{many1, separated_list1},
+    sequence::{preceded, tuple},
+    Err, IResult, Parser,
+};
+use std::{iter::zip, str::FromStr};
 use thiserror::Error;
 
 const DAY_NUMBER: usize = 11;
@@ -16,50 +26,50 @@ impl DayTrait for Day {
     }
 
     fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
-        let troop = Troop::try_from(lines)?;
+        let troop: Troop = lines.parse()?;
         Ok(ResultType::Integer(troop.play(20)))
     }
 
     fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
-        let troop = Troop::try_from(lines)?;
+        let troop: Troop = lines.parse()?;
         Ok(ResultType::Integer(troop.play_again(10_000)))
     }
 }
 
 #[derive(Debug, Error)]
 enum MonkeyError {
-    #[error("Not an Integer")]
-    NotAnInteger(#[from] ParseIntError),
-
-    #[error("Can't parse line: {0}")]
-    UnknownLine(String),
-
-    #[error("Did not expect end of Input")]
-    PrematureEndOfInput,
+    #[error("Error while parsing: {0}")]
+    ParsingError(String),
 }
 
-#[derive(Debug, PartialEq)]
+impl From<Err<Error<&str>>> for MonkeyError {
+    fn from(value: Err<Error<&str>>) -> Self {
+        MonkeyError::ParsingError(value.to_string())
+    }
+}
+
+#[derive(Debug, PartialEq, Clone, Copy)]
 enum Operation {
-    Plus(i64),
-    Times(i64),
     Squared,
+    Times(i64),
+    Plus(i64),
 }
 
 impl Operation {
-    pub fn parse(line: &str) -> Operation {
-        match line.split_whitespace().collect::<Vec<_>>()[..] {
-            ["*", "old"] => Operation::Squared,
-            ["*", value] => Operation::Times(value.parse().unwrap()),
-            ["+", value] => Operation::Plus(value.parse().unwrap()),
-            _ => unreachable!(),
-        }
+    fn parse(input: &str) -> IResult<&str, Self> {
+        let (input, _) = tag("new = old ")(input)?;
+        alt((
+            value(Operation::Squared, tag("* old")),
+            preceded(char('*'), trim0(i64.map(|a| Operation::Times(a)))),
+            preceded(char('+'), trim0(i64.map(|a| Operation::Plus(a)))),
+        ))(input)
     }
 
     pub fn calc(&self, old: i64) -> i64 {
         match self {
-            Operation::Plus(value) => old + *value,
-            Operation::Times(value) => old * value,
             Operation::Squared => old.pow(2),
+            Operation::Times(value) => old * value,
+            Operation::Plus(value) => old + value,
         }
     }
 }
@@ -74,90 +84,96 @@ struct Monkey {
     bad_monkey: usize,
 }
 
-static MONKEY: Lazy<Regex> = Lazy::new(|| Regex::new(r"Monkey (\d+)").unwrap());
-static STARTING: Lazy<Regex> =
-    Lazy::new(|| Regex::new(r"Starting items: (\d+(?:, \d+)*)").unwrap());
-static OP: Lazy<Regex> =
-    Lazy::new(|| Regex::new(r"Operation: new = old ([+*] \d+|\* old)").unwrap());
-static TEST: Lazy<Regex> = Lazy::new(|| Regex::new(r"Test: divisible by (\d+)").unwrap());
-static NEXT: Lazy<Regex> =
-    Lazy::new(|| Regex::new(r"If (?:true|false): throw to monkey (\d+)").unwrap());
-
 impl Monkey {
-    fn parse_line<'a>(re: &Regex, line: &'a str) -> Result<&'a str, MonkeyError> {
-        let caps = re
-            .captures(line)
-            .ok_or(MonkeyError::UnknownLine(line.to_owned()))?;
-        Ok(caps.get(1).unwrap().as_str())
+    fn number_parse(input: &str) -> IResult<&str, usize> {
+        let input = ignore(tag("Monkey "))(input)?;
+        let (input, number) = trim0(u32.map(|val| val as usize))(input)?;
+        let input = ignore(char(':'))(input)?;
+
+        Ok((input, number))
     }
 
-    pub fn parse_one(
-        iterator: &mut dyn Iterator<Item = &str>,
-    ) -> Result<Option<Monkey>, MonkeyError> {
-        if let Some(line) = iterator.next() {
-            let number: usize = Monkey::parse_line(&MONKEY, line)?.parse()?;
+    fn starting_items_parse(input: &str) -> IResult<&str, Vec<i64>> {
+        let input = ignore(tag("Starting items:"))(input)?;
+        separated_list1(char(','), trim0(i64))(input)
+    }
 
-            let line = iterator.next().ok_or(MonkeyError::PrematureEndOfInput)?;
-            let start = Monkey::parse_line(&STARTING, line)?;
-            let items = start
-                .split(", ")
-                .map(|item| item.parse::<i64>())
-                .collect::<Result<Vec<i64>, _>>()?;
+    fn operation_parse(input: &str) -> IResult<&str, Operation> {
+        let input = ignore(tag("Operation:"))(input)?;
+        trim0(Operation::parse)(input)
+    }
 
-            let line = iterator.next().ok_or(MonkeyError::PrematureEndOfInput)?;
-            let operation = Operation::parse(Monkey::parse_line(&OP, line)?);
+    fn divisor_parse(input: &str) -> IResult<&str, i64> {
+        let input = ignore(tag("Test: divisible by"))(input)?;
+        trim0(i64)(input)
+    }
 
-            let line = iterator.next().ok_or(MonkeyError::PrematureEndOfInput)?;
-            let divisor: i64 = Monkey::parse_line(&TEST, line)?.parse()?;
+    fn target_parse(want_good: bool) -> impl FnMut(&str) -> IResult<&str, usize> {
+        move |input: &str| {
+            let input = ignore(tuple((
+                tag("If"),
+                trim_left1(verify(true_false, |is_good| *is_good == want_good)),
+                tag(": throw to monkey"),
+            )))(input)?;
+            trim0(u32.map(|val| val as usize))(input)
+        }
+    }
 
-            let line = iterator.next().ok_or(MonkeyError::PrematureEndOfInput)?;
-            let good_monkey: usize = Monkey::parse_line(&NEXT, line)?.parse()?;
+    fn parse(input: &str) -> IResult<&str, Monkey> {
+        let input = empty_lines(input)?;
+        let (input, number) = eol_terminated(trim0(Monkey::number_parse))(input)?;
+        let (input, items) = eol_terminated(trim0(Monkey::starting_items_parse))(input)?;
+        let (input, operation) = eol_terminated(trim0(Monkey::operation_parse))(input)?;
+        let (input, divisor) = eol_terminated(trim0(Monkey::divisor_parse))(input)?;
+        let (input, good_monkey) = eol_terminated(trim0(Monkey::target_parse(true)))(input)?;
+        let (input, bad_monkey) = eol_terminated(trim0(Monkey::target_parse(false)))(input)?;
 
-            let line = iterator.next().ok_or(MonkeyError::PrematureEndOfInput)?;
-            let bad_monkey: usize = Monkey::parse_line(&NEXT, line)?.parse()?;
-
-            iterator.next();
-
-            Ok(Some(Monkey {
+        Ok((
+            input,
+            Monkey {
                 number,
                 items,
                 operation,
                 divisor,
                 good_monkey,
                 bad_monkey,
-            }))
-        } else {
-            Ok(None)
-        }
+            },
+        ))
     }
 
+    #[inline]
     pub fn process(&self, value: i64) -> i64 {
         self.operation.calc(value)
     }
 
+    #[inline]
     pub fn check(&self, value: i64) -> bool {
         value % self.divisor == 0
     }
+
+    #[allow(dead_code)]
+    fn parse_one(lines: &str) -> Result<Monkey, MonkeyError> {
+        Ok(extract_result(Monkey::parse)(lines)?)
+    }
 }
 
 struct Troop {
     monkeys: Vec<Monkey>,
 }
 
-impl TryFrom<&str> for Troop {
-    type Error = MonkeyError;
+impl FromStr for Troop {
+    type Err = MonkeyError;
 
-    fn try_from(value: &str) -> Result<Self, Self::Error> {
-        let mut iter = split_lines(value);
-        let mut monkeys = Vec::new();
-        while let Some(monkey) = Monkey::parse_one(&mut iter)? {
-            monkeys.push(monkey);
-        }
-        Ok(Troop { monkeys })
+    fn from_str(lines: &str) -> Result<Self, Self::Err> {
+        Ok(extract_result(Troop::parse)(lines)?)
     }
 }
 
 impl Troop {
+    fn parse(input: &str) -> IResult<&str, Troop> {
+        map(many1(Monkey::parse), |monkeys| Troop { monkeys })(input)
+    }
+
     fn do_play<F>(&self, rounds: usize, alter: F) -> i64
     where
         F: Fn(i64) -> i64,
@@ -204,7 +220,6 @@ mod test {
     fn test_parse() -> Result<()> {
         let day = Day {};
         let lines = read_string(day.get_day_number(), "example01.txt")?;
-        let mut lines = split_lines(&lines);
         let expected = Monkey {
             number: 0,
             items: vec![79, 98],
@@ -213,7 +228,7 @@ mod test {
             good_monkey: 2,
             bad_monkey: 3,
         };
-        let result = Monkey::parse_one(&mut lines)?.unwrap();
+        let result = Monkey::parse_one(&lines)?;
         assert_eq!(result, expected);
 
         Ok(())
@@ -224,7 +239,7 @@ mod test {
         let day = Day {};
         let lines = read_string(day.get_day_number(), "example01.txt")?;
         let expected = 4;
-        let result = Troop::try_from(lines.as_str())?;
+        let result: Troop = lines.parse()?;
         assert_eq!(result.monkeys.len(), expected);
 
         Ok(())
diff --git a/src/days/day15/mod.rs b/src/days/day15/mod.rs
index 8292730..81e69f8 100644
--- a/src/days/day15/mod.rs
+++ b/src/days/day15/mod.rs
@@ -1,37 +1,44 @@
 use super::template::{DayTrait, ResultType};
-use crate::common::{file::split_lines, pos::Pos};
+use crate::common::{
+    parser::{eol_terminated, extract_result, ignore, trim0},
+    pos::Pos,
+};
 use itertools::Itertools;
-use once_cell::sync::Lazy;
-use regex::Regex;
-use std::{collections::HashSet, num::ParseIntError};
+use nom::{
+    bytes::complete::tag,
+    character::complete::{char, i64},
+    error::Error,
+    multi::many0,
+    sequence::{separated_pair, tuple},
+    Err, IResult,
+};
+use std::collections::HashSet;
 use thiserror::Error;
 
 const DAY_NUMBER: usize = 15;
 
 pub struct Day;
 
+fn parse_row(input: &str) -> IResult<&str, i64> {
+    eol_terminated(i64)(input)
+}
+
 impl DayTrait for Day {
     fn get_day_number(&self) -> usize {
         DAY_NUMBER
     }
 
     fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
-        let lines = split_lines(lines).collect_vec();
-        if lines.len() < 2 {
-            Err(SensorError::ToFewLines)?;
-        }
-        let row = lines[0].parse()?;
-        let (sensors, beacons) = Day::parse_all(&lines[1..])?;
+        let (lines, row) = parse_row(lines).map_err(|_| SensorError::RowLineNotFound)?;
+        let (sensors, beacons) = Day::parse_all(lines)?;
+
         let result = Day::count_coverage_at(&sensors, &beacons, row);
         Ok(ResultType::Integer(result))
     }
 
     fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
-        let lines = split_lines(lines).collect_vec();
-        if lines.len() < 2 {
-            Err(SensorError::ToFewLines)?;
-        }
-        let (sensors, _) = Day::parse_all(&lines[1..])?;
+        let (lines, _) = parse_row(lines).map_err(|_| SensorError::RowLineNotFound)?;
+        let (sensors, _) = Day::parse_all(lines)?;
         let mid_lines = Day::dividing_lines(&sensors);
         let points = mid_lines
             .iter()
@@ -51,11 +58,12 @@ impl DayTrait for Day {
 }
 
 impl Day {
-    fn parse_all(lines: &[&str]) -> Result<(HashSet<Sensor>, HashSet<Pos<i64>>), SensorError> {
+    fn parse_all(lines: &str) -> Result<(HashSet<Sensor>, HashSet<Pos<i64>>), SensorError> {
+        let data = extract_result(many0(eol_terminated(Sensor::parse)))(lines)?;
+
         let mut sensors = HashSet::new();
         let mut beacons = HashSet::new();
-        for line in lines {
-            let (sensor, beacon) = Sensor::parse(line)?;
+        for (sensor, beacon) in data {
             sensors.insert(sensor);
             beacons.insert(beacon);
         }
@@ -91,17 +99,20 @@ impl Day {
 
 #[derive(Debug, Error)]
 enum SensorError {
-    #[error("Not an Integer")]
-    NotAnInt(#[from] ParseIntError),
-
-    #[error("Unknown line: {0}")]
-    UnknownLine(String),
+    #[error("Error Parsing Input: {0}")]
+    ParsingError(String),
 
     #[error("Did not find exactly one point for the sensor: {0}")]
     NotExactlyOneResult(usize),
 
-    #[error("Too few lines in input.txt")]
-    ToFewLines,
+    #[error("Row line not found at start of Input")]
+    RowLineNotFound,
+}
+
+impl From<Err<Error<&str>>> for SensorError {
+    fn from(error: Err<Error<&str>>) -> Self {
+        SensorError::ParsingError(error.to_string())
+    }
 }
 
 #[derive(Debug)]
@@ -220,28 +231,30 @@ struct Sensor {
     radius: i64,
 }
 
-static SENSOR: Lazy<Regex> =
-    Lazy::new(|| Regex::new(r"x=(-?\d+), y=(-?\d+).*x=(-?\d+), y=(-?\d+)").unwrap());
-
 impl Sensor {
-    pub fn parse(line: &str) -> Result<(Sensor, Pos<i64>), SensorError> {
-        let caps = SENSOR
-            .captures(line)
-            .ok_or(SensorError::UnknownLine(line.to_owned()))?;
-        let sensor_x = caps.get(1).unwrap().as_str().parse()?;
-        let sensor_y = caps.get(2).unwrap().as_str().parse()?;
-        let beacon_x = caps.get(3).unwrap().as_str().parse()?;
-        let beacon_y = caps.get(4).unwrap().as_str().parse()?;
-        let sensor = Pos::new(sensor_x, sensor_y);
-        let beacon = Pos::new(beacon_x, beacon_y);
-        let radius = sensor.taxicab(&beacon);
-        Ok((
-            Sensor {
-                pos: sensor,
-                radius,
-            },
-            beacon,
-        ))
+    fn component<'a>(name: &'a str) -> impl FnMut(&'a str) -> IResult<&'a str, i64> {
+        move |input: &str| {
+            let input = ignore(tuple((tag(name), char('='))))(input)?;
+            trim0(i64)(input)
+        }
+    }
+
+    fn parse_pos(input: &str) -> IResult<&str, Pos<i64>> {
+        let (input, (x, y)) = separated_pair(
+            Sensor::component("x"),
+            trim0(char(',')),
+            Sensor::component("y"),
+        )(input)?;
+        Ok((input, Pos::new(x, y)))
+    }
+
+    pub fn parse(input: &str) -> IResult<&str, (Sensor, Pos<i64>)> {
+        let input = ignore(tag("Sensor at"))(input)?;
+        let (input, pos) = trim0(Sensor::parse_pos)(input)?;
+        let input = ignore(tag(": closest beacon is at"))(input)?;
+        let (input, beacon) = trim0(Sensor::parse_pos)(input)?;
+        let radius = pos.taxicab(&beacon);
+        Ok((input, (Sensor { pos, radius }, beacon)))
     }
 
     pub fn range_at(&self, y: i64) -> Option<Range> {
@@ -279,7 +292,7 @@ mod test {
             },
             Pos::new(-2, 15),
         );
-        let result = Sensor::parse(input)?;
+        let result = extract_result(Sensor::parse)(input)?;
         assert_eq!(result, expected);
 
         Ok(())
diff --git a/src/days/day16/mod.rs b/src/days/day16/mod.rs
index 67dd832..e068986 100644
--- a/src/days/day16/mod.rs
+++ b/src/days/day16/mod.rs
@@ -1,17 +1,20 @@
+use super::template::{DayTrait, ResultType};
+use crate::common::parser::{eol_terminated, extract_result, ignore, trim0, trim1, trim_left1};
+use itertools::Itertools;
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::{alpha1, i64},
+    error::Error,
+    multi::{many1, separated_list1},
+    Err, IResult,
+};
+use std::collections::BinaryHeap;
 use std::collections::HashMap;
 use std::fmt::{Debug, Display};
 use std::hash::Hash;
 use std::iter::Sum;
 use std::ops::{Add, Deref, Mul, Sub};
-use std::{collections::BinaryHeap, num::ParseIntError};
-
-use crate::common::file::split_lines;
-
-use super::template::{DayTrait, ResultType};
-use const_format::concatcp;
-use itertools::Itertools;
-use once_cell::sync::Lazy;
-use regex::Regex;
 use thiserror::Error;
 
 const DAY_NUMBER: usize = 16;
@@ -129,11 +132,8 @@ impl Deref for Index {
 
 #[derive(Debug, Error)]
 enum ValveError {
-    #[error("Not an Integer")]
-    NotAnInt(#[from] ParseIntError),
-
     #[error("Not a valid description: {0}")]
-    CouldNotParse(String),
+    ParsingError(String),
 
     #[error("Not a valid valve: {0}")]
     ValveNotFound(String),
@@ -142,17 +142,11 @@ enum ValveError {
     NoOptimumFound,
 }
 
-const ID: &str = "[[:alpha:]]+";
-const COMMON: &str = concatcp!("^Valve (?<id>", ID, r") has flow rate=(?<rate>\d+); ");
-const PLURAL_STR: &str = concatcp!(
-    COMMON,
-    "tunnels lead to valves (?<exits>",
-    ID,
-    "(?:, ",
-    ID,
-    ")+)$"
-);
-const SINGULAR_STR: &str = concatcp!(COMMON, "tunnel leads to valve (?<exits>", ID, ")$");
+impl From<Err<Error<&str>>> for ValveError {
+    fn from(error: Err<Error<&str>>) -> Self {
+        ValveError::ParsingError(error.to_string())
+    }
+}
 
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
 struct RawValve<'a> {
@@ -170,29 +164,45 @@ impl<'a> RawValve<'a> {
         }
     }
 
-    fn from_regex(regex: &Regex, line: &'a str) -> Option<Result<RawValve<'a>, ValveError>> {
-        regex.captures(line).map(|caps| {
-            match (caps.name("id"), caps.name("rate"), caps.name("exits")) {
-                (Some(id), Some(rate), Some(exits)) => {
-                    let rate = rate.as_str().parse()?;
-                    let neighbors = exits.as_str().split(",").map(|s| s.trim_start()).collect();
-                    Ok(RawValve::create(id.as_str(), Flow(rate), neighbors))
-                }
-                _ => Err(ValveError::CouldNotParse(line.to_string())),
-            }
-        })
+    fn parse_start(input: &str) -> IResult<&str, (&str, Flow)> {
+        let input = ignore(tag("Valve"))(input)?;
+        let (input, valve) = trim1(alpha1)(input)?;
+        let input = ignore(tag("has flow rate="))(input)?;
+        let (input, flow) = trim0(i64)(input)?;
+        let input = ignore(tag(";"))(input)?;
+        Ok((input, (valve, Flow(flow))))
+    }
+
+    fn parse_singular(input: &str) -> IResult<&str, Vec<&str>> {
+        let input = ignore(tag("tunnel leads to valve "))(input)?;
+        let (input, valve) = alpha1(input)?;
+
+        Ok((input, vec![valve]))
+    }
+
+    fn parse_plural(input: &str) -> IResult<&str, Vec<&str>> {
+        let input = ignore(tag("tunnels lead to valves "))(input)?;
+        let (input, valve) = separated_list1(tag(","), trim0(alpha1))(input)?;
+
+        Ok((input, valve))
+    }
+
+    fn parse(input: &str) -> IResult<&str, RawValve> {
+        let (input, (id, flow)) = RawValve::parse_start(input)?;
+        let (input, neighbors) = trim_left1(eol_terminated(alt((
+            RawValve::parse_plural,
+            RawValve::parse_singular,
+        ))))(input)?;
+
+        Ok((input, RawValve::create(id, flow, neighbors)))
     }
 }
 
 impl<'a> TryFrom<&'a str> for RawValve<'a> {
     type Error = ValveError;
 
-    fn try_from(value: &'a str) -> Result<RawValve<'a>, Self::Error> {
-        static PLURAL: Lazy<Regex> = Lazy::new(|| Regex::new(PLURAL_STR).unwrap());
-        static SINGULAR: Lazy<Regex> = Lazy::new(|| Regex::new(SINGULAR_STR).unwrap());
-        RawValve::from_regex(&PLURAL, value)
-            .or_else(|| RawValve::from_regex(&SINGULAR, value))
-            .unwrap_or_else(|| Err(ValveError::CouldNotParse(value.to_string())))
+    fn try_from(value: &'a str) -> Result<Self, Self::Error> {
+        Ok(extract_result(RawValve::parse)(value)?)
     }
 }
 
@@ -267,9 +277,7 @@ struct ValveSystem {
 
 impl ValveSystem {
     fn build(lines: &str, start: &str) -> Result<ValveSystem, ValveError> {
-        let mut raw = split_lines(lines)
-            .map(|line| RawValve::try_from(line))
-            .collect::<Result<Vec<_>, _>>()?;
+        let mut raw = extract_result(many1(RawValve::parse))(lines)?;
         raw.sort_unstable_by_key(|valve| valve.id);
 
         let start_idx = raw
@@ -931,7 +939,7 @@ mod test {
     fn parse_plural() -> Result<()> {
         let line = "Valve BB has flow rate=13; tunnels lead to valves CC, AA";
         let expected = RawValve::create("BB", Flow(13), vec!["CC", "AA"]);
-        let result = RawValve::try_from(line)?;
+        let result = line.try_into()?;
         assert_eq!(expected, result);
 
         Ok(())
@@ -941,7 +949,7 @@ mod test {
     fn parse_singular() -> Result<()> {
         let line = "Valve HH has flow rate=22; tunnel leads to valve GG";
         let expected = RawValve::create("HH", Flow(22), vec!["GG"]);
-        let result = RawValve::try_from(line)?;
+        let result = line.try_into()?;
         assert_eq!(expected, result);
 
         Ok(())

From 062ede1df143dfba5f8453f42f287ae23d4a0c09 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=BCdiger=20Ludwig?= <ruediger.ludwig@posteo.de>
Date: Wed, 2 Aug 2023 17:58:09 +0200
Subject: [PATCH 3/3] day 19 finished

---
 data/day19/example01.txt |  11 +
 data/day19/input.txt     |  30 ++
 src/days/day19/mod.rs    | 587 +++++++++++++++++++++++++++++++++++++++
 src/days/mod.rs          |   4 +-
 4 files changed, 631 insertions(+), 1 deletion(-)
 create mode 100644 data/day19/example01.txt
 create mode 100644 data/day19/input.txt
 create mode 100644 src/days/day19/mod.rs

diff --git a/data/day19/example01.txt b/data/day19/example01.txt
new file mode 100644
index 0000000..6f9d45b
--- /dev/null
+++ b/data/day19/example01.txt
@@ -0,0 +1,11 @@
+Blueprint 1:
+  Each ore robot costs 4 ore.
+  Each clay robot costs 2 ore.
+  Each obsidian robot costs 3 ore and 14 clay.
+  Each geode robot costs 2 ore and 7 obsidian.
+  
+Blueprint 2:
+  Each ore robot costs 2 ore.
+  Each clay robot costs 3 ore.
+  Each obsidian robot costs 3 ore and 8 clay.
+  Each geode robot costs 3 ore and 12 obsidian.
\ No newline at end of file
diff --git a/data/day19/input.txt b/data/day19/input.txt
new file mode 100644
index 0000000..f8f652c
--- /dev/null
+++ b/data/day19/input.txt
@@ -0,0 +1,30 @@
+Blueprint 1: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 2 ore and 14 clay. Each geode robot costs 4 ore and 11 obsidian.
+Blueprint 2: Each ore robot costs 3 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 20 clay. Each geode robot costs 2 ore and 12 obsidian.
+Blueprint 3: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 3 ore and 20 clay. Each geode robot costs 2 ore and 10 obsidian.
+Blueprint 4: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 4 ore and 16 clay. Each geode robot costs 2 ore and 15 obsidian.
+Blueprint 5: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 3 ore and 7 clay. Each geode robot costs 4 ore and 20 obsidian.
+Blueprint 6: Each ore robot costs 2 ore. Each clay robot costs 4 ore. Each obsidian robot costs 4 ore and 19 clay. Each geode robot costs 2 ore and 18 obsidian.
+Blueprint 7: Each ore robot costs 2 ore. Each clay robot costs 3 ore. Each obsidian robot costs 2 ore and 14 clay. Each geode robot costs 3 ore and 20 obsidian.
+Blueprint 8: Each ore robot costs 2 ore. Each clay robot costs 4 ore. Each obsidian robot costs 4 ore and 16 clay. Each geode robot costs 4 ore and 17 obsidian.
+Blueprint 9: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 11 clay. Each geode robot costs 4 ore and 7 obsidian.
+Blueprint 10: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 2 ore and 17 clay. Each geode robot costs 3 ore and 16 obsidian.
+Blueprint 11: Each ore robot costs 2 ore. Each clay robot costs 4 ore. Each obsidian robot costs 3 ore and 19 clay. Each geode robot costs 4 ore and 12 obsidian.
+Blueprint 12: Each ore robot costs 3 ore. Each clay robot costs 3 ore. Each obsidian robot costs 2 ore and 16 clay. Each geode robot costs 2 ore and 18 obsidian.
+Blueprint 13: Each ore robot costs 2 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 13 clay. Each geode robot costs 2 ore and 20 obsidian.
+Blueprint 14: Each ore robot costs 3 ore. Each clay robot costs 4 ore. Each obsidian robot costs 3 ore and 16 clay. Each geode robot costs 3 ore and 14 obsidian.
+Blueprint 15: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 4 ore and 17 clay. Each geode robot costs 4 ore and 16 obsidian.
+Blueprint 16: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 4 ore and 8 clay. Each geode robot costs 3 ore and 19 obsidian.
+Blueprint 17: Each ore robot costs 3 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 19 clay. Each geode robot costs 3 ore and 19 obsidian.
+Blueprint 18: Each ore robot costs 3 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 11 clay. Each geode robot costs 2 ore and 8 obsidian.
+Blueprint 19: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 2 ore and 7 clay. Each geode robot costs 3 ore and 10 obsidian.
+Blueprint 20: Each ore robot costs 3 ore. Each clay robot costs 4 ore. Each obsidian robot costs 4 ore and 18 clay. Each geode robot costs 4 ore and 12 obsidian.
+Blueprint 21: Each ore robot costs 3 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 19 clay. Each geode robot costs 3 ore and 17 obsidian.
+Blueprint 22: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 4 ore and 20 clay. Each geode robot costs 2 ore and 12 obsidian.
+Blueprint 23: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 7 clay. Each geode robot costs 3 ore and 9 obsidian.
+Blueprint 24: Each ore robot costs 2 ore. Each clay robot costs 2 ore. Each obsidian robot costs 2 ore and 17 clay. Each geode robot costs 2 ore and 10 obsidian.
+Blueprint 25: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 2 ore and 15 clay. Each geode robot costs 2 ore and 8 obsidian.
+Blueprint 26: Each ore robot costs 4 ore. Each clay robot costs 4 ore. Each obsidian robot costs 2 ore and 14 clay. Each geode robot costs 3 ore and 17 obsidian.
+Blueprint 27: Each ore robot costs 3 ore. Each clay robot costs 4 ore. Each obsidian robot costs 3 ore and 19 clay. Each geode robot costs 3 ore and 8 obsidian.
+Blueprint 28: Each ore robot costs 3 ore. Each clay robot costs 3 ore. Each obsidian robot costs 3 ore and 8 clay. Each geode robot costs 2 ore and 12 obsidian.
+Blueprint 29: Each ore robot costs 4 ore. Each clay robot costs 3 ore. Each obsidian robot costs 2 ore and 19 clay. Each geode robot costs 3 ore and 13 obsidian.
+Blueprint 30: Each ore robot costs 3 ore. Each clay robot costs 4 ore. Each obsidian robot costs 3 ore and 6 clay. Each geode robot costs 4 ore and 11 obsidian.
\ No newline at end of file
diff --git a/src/days/day19/mod.rs b/src/days/day19/mod.rs
new file mode 100644
index 0000000..32bf5a4
--- /dev/null
+++ b/src/days/day19/mod.rs
@@ -0,0 +1,587 @@
+use super::template::{DayTrait, ResultType};
+use crate::common::parser::{extract_result, ignore, trim0, trim1, trim_left1};
+use itertools::Itertools;
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::{char, i64, multispace0, u32},
+    combinator::{value, verify},
+    error::Error,
+    multi::{count, many0, separated_list1},
+    sequence::{preceded, tuple},
+    Err, IResult, Parser,
+};
+use std::{
+    collections::{BinaryHeap, HashMap},
+    mem,
+    ops::{Add, IndexMut, Sub},
+    sync::mpsc,
+    thread,
+};
+use std::{ops::Index, str::FromStr};
+use thiserror::Error;
+
+const DAY_NUMBER: usize = 19;
+
+const NUMBER_MATERIALS: usize = 4;
+const USE_THREADED: bool = true;
+
+pub struct Day;
+
+impl DayTrait for Day {
+    fn get_day_number(&self) -> usize {
+        DAY_NUMBER
+    }
+
+    fn part1(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let cabinet: Cabinet = lines.parse()?;
+        let result = if USE_THREADED {
+            cabinet.threaded_quality_level(24)?
+        } else {
+            cabinet.quality_level(24)?
+        };
+        Ok(ResultType::Integer(result))
+    }
+
+    fn part2(&self, lines: &str) -> anyhow::Result<ResultType> {
+        let cabinet: Cabinet = lines.parse()?;
+        let result = if USE_THREADED {
+            cabinet.threaded_reduced_quality(3, 32)?
+        } else {
+            cabinet.reduced_quality(3, 32)?
+        };
+        Ok(ResultType::Integer(result))
+    }
+}
+
+#[derive(Debug, Error)]
+enum RobotError {
+    #[error("Not a valid description: {0}")]
+    ParsingError(String),
+
+    #[error("No optimum was found")]
+    NoOptimumFound,
+}
+
+impl From<Err<Error<&str>>> for RobotError {
+    fn from(error: Err<Error<&str>>) -> Self {
+        RobotError::ParsingError(error.to_string())
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, PartialOrd, Ord, Eq, Hash)]
+enum Material {
+    Geode = 0,
+    Obsidian = 1,
+    Clay = 2,
+    Ore = 3,
+}
+
+impl Material {
+    pub fn prev(&self) -> Option<Material> {
+        match self {
+            Material::Geode => None,
+            Material::Obsidian => Some(Material::Geode),
+            Material::Clay => Some(Material::Obsidian),
+            Material::Ore => Some(Material::Clay),
+        }
+    }
+
+    pub fn next(&self) -> Option<Material> {
+        match self {
+            Material::Geode => Some(Material::Obsidian),
+            Material::Obsidian => Some(Material::Clay),
+            Material::Clay => Some(Material::Ore),
+            Material::Ore => None,
+        }
+    }
+
+    pub fn parse(input: &str) -> IResult<&str, Material> {
+        alt((
+            value(Material::Ore, tag("ore")),
+            value(Material::Clay, tag("clay")),
+            value(Material::Obsidian, tag("obsidian")),
+            value(Material::Geode, tag("geode")),
+        ))(input)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+struct Ingredients([i64; NUMBER_MATERIALS]);
+
+impl Ingredients {
+    pub fn new(items: Vec<(i64, Material)>) -> Self {
+        let mut ingredients = [0; NUMBER_MATERIALS];
+        for (amount, material) in items {
+            ingredients[material as usize] = amount;
+        }
+        Ingredients(ingredients)
+    }
+
+    pub fn is_non_negative(&self) -> bool {
+        self.0.iter().all(|item| *item >= 0)
+    }
+
+    fn inc(&self, mat: Material) -> Ingredients {
+        let mut next = self.0.clone();
+        next[mat as usize] += 1;
+        Ingredients(next)
+    }
+
+    fn pos_max(&self, other: &Ingredients) -> Self {
+        let next = self
+            .0
+            .iter()
+            .zip(other.0.iter())
+            .map(|(a, b)| *a.max(b))
+            .collect_vec()
+            .try_into()
+            .unwrap();
+        Ingredients(next)
+    }
+
+    fn none_smaller(&self, other: &Ingredients) -> bool {
+        self.0.iter().zip(other.0.iter()).all(|(a, b)| a >= b)
+    }
+}
+
+impl Index<Material> for Ingredients {
+    type Output = i64;
+
+    fn index(&self, index: Material) -> &Self::Output {
+        &self.0[index as usize]
+    }
+}
+
+impl IndexMut<Material> for Ingredients {
+    fn index_mut(&mut self, index: Material) -> &mut Self::Output {
+        &mut self.0[index as usize]
+    }
+}
+
+impl Add<&Ingredients> for Ingredients {
+    type Output = Ingredients;
+
+    fn add(self, rhs: &Ingredients) -> Self::Output {
+        let mut result = self.clone();
+        for pos in 0..NUMBER_MATERIALS {
+            result.0[pos] += rhs.0[pos];
+        }
+        result
+    }
+}
+
+impl Add<&Ingredients> for &Ingredients {
+    type Output = Ingredients;
+
+    fn add(self, rhs: &Ingredients) -> Self::Output {
+        let mut result = self.clone();
+        for pos in 0..NUMBER_MATERIALS {
+            result.0[pos] += rhs.0[pos];
+        }
+        result
+    }
+}
+
+impl Sub<&Ingredients> for Ingredients {
+    type Output = Ingredients;
+
+    fn sub(self, rhs: &Self) -> Self::Output {
+        let mut result = self.clone();
+        for pos in 0..NUMBER_MATERIALS {
+            result.0[pos] -= rhs.0[pos];
+        }
+        result
+    }
+}
+
+impl Sub<&Ingredients> for &Ingredients {
+    type Output = Ingredients;
+
+    fn sub(self, rhs: &Ingredients) -> Self::Output {
+        let mut result = self.clone();
+        for pos in 0..NUMBER_MATERIALS {
+            result.0[pos] -= rhs.0[pos];
+        }
+        result
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+struct Blueprint {
+    id: usize,
+    material: [Ingredients; NUMBER_MATERIALS],
+    max_robots: Ingredients,
+}
+
+impl Blueprint {
+    pub fn new(id: usize, material: [Ingredients; NUMBER_MATERIALS]) -> Self {
+        let mut max_robots = material[Material::Geode as usize]
+            .pos_max(&material[Material::Obsidian as usize])
+            .pos_max(&material[Material::Clay as usize]);
+        max_robots[Material::Geode] = i32::MAX as i64;
+
+        Blueprint {
+            id,
+            material,
+            max_robots,
+        }
+    }
+
+    pub fn ingredients_for(&self, mat: Material) -> &Ingredients {
+        &self.material[mat as usize]
+    }
+
+    fn parse_line(input: &str) -> IResult<&str, (Material, Ingredients)> {
+        let input = ignore(tag("Each"))(input)?;
+        let (input, robot) = trim1(Material::parse)(input)?;
+        let input = ignore(tag("robot costs"))(input)?;
+        let (input, ingredients) =
+            separated_list1(tag("and"), tuple((trim0(i64), trim0(Material::parse))))(input)?;
+        let input = ignore(char('.'))(input)?;
+        Ok((input, (robot, Ingredients::new(ingredients))))
+    }
+
+    fn parse(start: &str) -> IResult<&str, Self> {
+        let input = ignore(tag("Blueprint"))(start)?;
+        let (input, id) = trim_left1(u32.map(|v| v as usize))(input)?;
+        let input = ignore(char(':'))(input)?;
+        let (input, robots) = verify(
+            count(
+                preceded(multispace0, Blueprint::parse_line),
+                NUMBER_MATERIALS,
+            ),
+            |robots: &[(Material, Ingredients)]| {
+                robots.iter().map(|(material, _)| material).all_unique()
+            },
+        )(input)?;
+
+        let material: [Ingredients; NUMBER_MATERIALS] = robots
+            .into_iter()
+            .sorted_by_key(|(material, _)| *material)
+            .map(|(_, ingreditents)| ingreditents)
+            .collect_vec()
+            .try_into()
+            .unwrap();
+
+        Ok((input, Blueprint::new(id, material)))
+    }
+
+    pub fn simulate(&self, max_time: usize) -> Result<(usize, i64), RobotError> {
+        let simulation = Simulation::new(max_time);
+        let mut queue = BinaryHeap::new();
+        let mut seen: HashMap<(Ingredients, usize), Ingredients> = HashMap::new();
+        queue.push(simulation);
+
+        while let Some(current) = queue.pop() {
+            if current.time == 0 {
+                return Ok((self.id, current.material(Material::Geode)));
+            }
+            let key = (current.all_robots().clone(), current.time);
+            if let Some(last) = seen.get(&key) {
+                if last.none_smaller(current.all_material()) {
+                    continue;
+                }
+            }
+            seen.insert(key, current.all_material().clone());
+
+            queue.extend(current.next_round(self));
+        }
+
+        Err(RobotError::NoOptimumFound)
+    }
+}
+
+impl FromStr for Blueprint {
+    type Err = RobotError;
+
+    fn from_str(input: &str) -> Result<Self, Self::Err> {
+        Ok(extract_result(Blueprint::parse)(input)?)
+    }
+}
+
+struct Cabinet(Vec<Blueprint>);
+
+impl FromStr for Cabinet {
+    type Err = RobotError;
+
+    fn from_str(line: &str) -> Result<Self, Self::Err> {
+        let blueprints = extract_result(many0(preceded(multispace0, Blueprint::parse)))(line)?;
+        Ok(Cabinet(blueprints))
+    }
+}
+
+impl Cabinet {
+    pub fn quality_level(&self, max_time: usize) -> Result<i64, RobotError> {
+        self.0
+            .iter()
+            .map(|blueprint| blueprint.simulate(max_time))
+            .map_ok(|(id, geodes)| id as i64 * geodes)
+            .fold_ok(0, |a, b| a + b)
+    }
+
+    pub fn reduced_quality(&self, count: usize, max_time: usize) -> Result<i64, RobotError> {
+        self.0
+            .iter()
+            .take(count)
+            .map(|blueprint| blueprint.simulate(max_time))
+            .map_ok(|(_, geodes)| geodes)
+            .fold_ok(1, |a, b| a * b)
+    }
+
+    pub fn threaded_quality_level(self, max_time: usize) -> Result<i64, RobotError> {
+        let (sender, receiver) = mpsc::channel();
+        for blueprint in self.0 {
+            let sender = sender.clone();
+            thread::spawn(move || {
+                let result = blueprint.simulate(max_time);
+                let _ = sender.send(result);
+            });
+        }
+        mem::drop(sender);
+
+        receiver
+            .into_iter()
+            .map_ok(|(id, geodes)| id as i64 * geodes)
+            .fold_ok(0, |a, b| a + b)
+    }
+
+    pub fn threaded_reduced_quality(
+        self,
+        count: usize,
+        max_time: usize,
+    ) -> Result<i64, RobotError> {
+        let (sender, receiver) = mpsc::channel();
+        let mut done = 0;
+        for blueprint in self.0 {
+            let sender = sender.clone();
+            thread::spawn(move || {
+                let result = blueprint.simulate(max_time);
+                let _ = sender.send(result);
+            });
+
+            done = done + 1;
+            if done >= count {
+                break;
+            }
+        }
+        mem::drop(sender);
+
+        receiver
+            .into_iter()
+            .map_ok(|(_, geodes)| geodes)
+            .fold_ok(1, |a, b| a * b)
+    }
+}
+
+#[derive(Debug, Clone)]
+struct Simulation {
+    time: usize,
+    robots: Ingredients,
+    material: Ingredients,
+}
+
+impl Simulation {
+    pub fn new(time: usize) -> Self {
+        let _robots = Ingredients::new(vec![(1, Material::Ore)]);
+        let _material = Ingredients::new(vec![]);
+        Self {
+            time,
+            robots: _robots,
+            material: _material,
+        }
+    }
+
+    #[inline]
+    pub fn all_robots(&self) -> &Ingredients {
+        &self.robots
+    }
+
+    #[inline]
+    pub fn robots_for(&self, mat: Material) -> i64 {
+        self.robots[mat]
+    }
+
+    #[inline]
+    pub fn all_material(&self) -> &Ingredients {
+        &self.material
+    }
+
+    #[inline]
+    pub fn material(&self, mat: Material) -> i64 {
+        self.material[mat]
+    }
+
+    pub fn no_production(mut self) -> Self {
+        self.time = self.time - 1;
+        self.material = self.material + &self.robots;
+        self
+    }
+
+    fn check_create(&self, blueprint: &Blueprint, mat: Material) -> Option<Simulation> {
+        let rest = self.all_material() - blueprint.ingredients_for(mat);
+        if rest.is_non_negative() {
+            let robots = self.all_robots().inc(mat);
+            let material = rest + self.all_robots();
+            Some(Simulation {
+                time: self.time - 1,
+                robots,
+                material,
+            })
+        } else {
+            None
+        }
+    }
+
+    pub fn next_round(self, blueprint: &Blueprint) -> Vec<Simulation> {
+        let mut result = vec![];
+        if let Some(next) = self.check_create(blueprint, Material::Geode) {
+            result.push(next);
+        }
+
+        let mut current = Some(Material::Obsidian);
+        while let Some(mat) = current {
+            if self.robots_for(mat) < blueprint.max_robots[mat]
+                && self.material(mat) <= 4 * blueprint.max_robots[mat] / 3
+            {
+                if let Some(next) = self.check_create(blueprint, mat) {
+                    result.push(next);
+                }
+            }
+            current = mat.next();
+        }
+        if result.len() <= 1 {
+            result.push(self.no_production());
+        }
+        result
+    }
+}
+
+impl PartialEq for Simulation {
+    fn eq(&self, other: &Self) -> bool {
+        self.time == other.time && self.material == other.material
+    }
+}
+
+impl Eq for Simulation {}
+
+impl PartialOrd for Simulation {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for Simulation {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        match self.time.cmp(&other.time) {
+            core::cmp::Ordering::Equal => {}
+            ord => return ord,
+        }
+        self.material.cmp(&other.material)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use crate::common::file::read_string;
+    use anyhow::Result;
+
+    #[test]
+    fn test_part1() -> Result<()> {
+        let day = Day {};
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let expected = ResultType::Integer(33);
+        let result = day.part1(&lines)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn test_part2() -> Result<()> {
+        let day = Day {};
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let expected = ResultType::Integer(56 * 62);
+        let result = day.part2(&lines)?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn parse() -> Result<()> {
+        let line = "Blueprint 1: Each ore robot costs 4 ore.  Each clay robot costs 2 ore.  Each obsidian robot costs 3 ore and 14 clay.  Each geode robot costs 2 ore and 7 obsidian.";
+        let expected = Blueprint::new(
+            1,
+            [
+                Ingredients([0, 7, 0, 2]),
+                Ingredients([0, 0, 14, 3]),
+                Ingredients([0, 0, 0, 2]),
+                Ingredients([0, 0, 0, 4]),
+            ],
+        );
+        let result: Blueprint = line.parse()?;
+        assert_eq!(result, expected);
+
+        Ok(())
+    }
+
+    #[test]
+    fn parse_faulty() {
+        let line = "Blueprint 1: Each ore robot costs 4 ore.  Each ore robot costs 2 ore.  Each obsidian robot costs 3 ore and 14 clay.  Each geode robot costs 2 ore and 7 obsidian.";
+        let result: Result<Blueprint, _> = line.parse();
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn parse_many() -> Result<()> {
+        let day = Day {};
+        let lines = read_string(day.get_day_number(), "example01.txt")?;
+        let cabinet: Cabinet = lines.parse()?;
+        assert_eq!(cabinet.0.len(), 2);
+
+        Ok(())
+    }
+
+    #[test]
+    fn simulate_one() -> Result<()> {
+        let line = "Blueprint 1: Each ore robot costs 4 ore.  Each clay robot costs 2 ore.  Each obsidian robot costs 3 ore and 14 clay.  Each geode robot costs 2 ore and 7 obsidian.";
+        let blueprint: Blueprint = line.parse()?;
+        let result = blueprint.simulate(24)?;
+        assert_eq!(result, (1, 9));
+
+        Ok(())
+    }
+
+    #[test]
+    fn simulate_two() -> Result<()> {
+        let line = "Blueprint 2: Each ore robot costs 2 ore.  Each clay robot costs 3 ore.  Each obsidian robot costs 3 ore and 8 clay.  Each geode robot costs 3 ore and 12 obsidian.";
+        let blueprint: Blueprint = line.parse()?;
+        let result = blueprint.simulate(24)?;
+        assert_eq!(result, (2, 12));
+
+        Ok(())
+    }
+
+    #[test]
+    fn simulate_one_two() -> Result<()> {
+        let line = "Blueprint 1: Each ore robot costs 4 ore.  Each clay robot costs 2 ore.  Each obsidian robot costs 3 ore and 14 clay.  Each geode robot costs 2 ore and 7 obsidian.";
+        let blueprint: Blueprint = line.parse()?;
+        let result = blueprint.simulate(32)?;
+        assert_eq!(result, (1, 56));
+
+        Ok(())
+    }
+
+    #[test]
+    fn simulate_two_two() -> Result<()> {
+        let line = "Blueprint 2: Each ore robot costs 2 ore.  Each clay robot costs 3 ore.  Each obsidian robot costs 3 ore and 8 clay.  Each geode robot costs 3 ore and 12 obsidian.";
+
+        let blueprint: Blueprint = line.parse()?;
+        let result = blueprint.simulate(32)?;
+        assert_eq!(result, (2, 62));
+
+        Ok(())
+    }
+}
diff --git a/src/days/mod.rs b/src/days/mod.rs
index d74c58b..80b70ea 100644
--- a/src/days/mod.rs
+++ b/src/days/mod.rs
@@ -16,6 +16,7 @@ mod day15;
 mod day16;
 mod day17;
 mod day18;
+mod day19;
 mod template;
 
 pub use template::DayTrait;
@@ -25,7 +26,7 @@ pub mod day_provider {
     use super::*;
     use thiserror::Error;
 
-    const MAX_DAY: usize = 18;
+    const MAX_DAY: usize = 19;
 
     pub fn get_day(day_num: usize) -> Result<Box<dyn DayTrait>, ProviderError> {
         match day_num {
@@ -47,6 +48,7 @@ pub mod day_provider {
             16 => Ok(Box::new(day16::Day)),
             17 => Ok(Box::new(day17::Day)),
             18 => Ok(Box::new(day18::Day)),
+            19 => Ok(Box::new(day19::Day)),
             _ => Err(ProviderError::InvalidNumber(day_num)),
         }
     }