1 files changed, 81 insertions, 0 deletions
diff --git a/2023/src/bin/day_1.rs b/2023/src/bin/day_1.rs
new file mode 100644
index 0000000..fe3ef1e
--- /dev/null
+++ b/2023/src/bin/day_1.rs
@@ -0,0 +1,81 @@
+use nom::{
+    branch::alt,
+    bytes::complete::tag,
+    character::complete::{alpha1, anychar, line_ending, none_of, one_of},
+    combinator::{map, map_opt, map_res, opt, peek, value},
+    multi::{many1, separated_list1},
+    sequence::pair,
+    IResult,
+};
+use std::fs;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let input = fs::read_to_string("inputs/day_1.txt")?;
+    let parsed = CalibrationInput::parser(&input).unwrap().1;
+    dbg!(parsed.calibration_sum());
+
+    Ok(())
+}
+
+#[derive(Debug)]
+struct CalibrationInput(Vec<CalibrationValue>);
+
+#[derive(Debug)]
+struct CalibrationValue(u32);
+
+#[derive(Debug)]
+struct CalibrationDigit(u8);
+
+impl CalibrationInput {
+    fn calibration_sum(&self) -> u32 {
+        self.0.iter().map(|d| d.0).sum()
+    }
+
+    fn parser(input: &str) -> IResult<&str, Self> {
+        map(
+            separated_list1(line_ending, CalibrationValue::parser),
+            CalibrationInput,
+        )(input)
+    }
+}
+
+impl CalibrationValue {
+    fn parser(input: &str) -> IResult<&str, Self> {
+        map(
+            many1(pair(
+                opt(peek(CalibrationDigit::parser)), // peek is to not consume the 'one' in 'twone'
+                none_of("\n"),                       // this is just to advance the input
+            )),
+            |digits| {
+                let digits: Vec<u32> = digits
+                    .into_iter()
+                    .filter_map(|(d, _)| d.map(|d| d.0 as u32))
+                    .collect();
+                CalibrationValue(digits[0] * 10 + digits[digits.len() - 1])
+            },
+        )(input)
+    }
+}
+
+impl CalibrationDigit {
+    fn parser(input: &str) -> IResult<&str, Self> {
+        map(
+            alt((
+                map(one_of("0123456789"), |c| {
+                    c.to_string().parse::<u8>().unwrap()
+                }),
+                value(0, tag("zero")),
+                value(1, tag("one")),
+                value(2, tag("two")),
+                value(3, tag("three")),
+                value(4, tag("four")),
+                value(5, tag("five")),
+                value(6, tag("six")),
+                value(7, tag("seven")),
+                value(8, tag("eight")),
+                value(9, tag("nine")),
+            )),
+            CalibrationDigit,
+        )(input)
+    }
+}