solution: factor out common functionality

Signed-off-by: Matej Focko <mfocko@redhat.com>

src/lib.rs

@@ -1,8 +1,11 @@
 mod input;
 pub use input::*;
 
-mod vector2d;
-pub use vector2d::*;
+mod solution;
+pub use solution::*;
 
 mod testing;
 pub use testing::*;
+
+mod vector2d;
+pub use vector2d::*;

src/solution.rs

@@ -0,0 +1,64 @@
+use std::fmt::Display;
+use std::path::Path;
+
+use color_eyre::eyre::Result;
+use tracing::info;
+use tracing_subscriber::EnvFilter;
+
+pub trait Solution<Input, Output: Display> {
+    fn day() -> &'static str;
+
+    fn parse_input<P: AsRef<Path>>(pathname: P) -> Input;
+
+    fn part_1(input: &Input) -> Output;
+    fn part_2(input: &Input) -> Output;
+
+    fn main() -> Result<()>
+    where
+        Self: Sized,
+    {
+        tracing_subscriber::fmt()
+            .with_env_filter(EnvFilter::from_default_env())
+            .with_target(false)
+            .with_file(true)
+            .with_line_number(true)
+            .without_time()
+            .compact()
+            .init();
+        color_eyre::install()?;
+
+        let input = Self::parse_input(format!("inputs/day{}.txt", Self::day()));
+
+        info!("Part 1: {}", Self::part_1(&input));
+        info!("Part 2: {}", Self::part_2(&input));
+
+        Ok(())
+    }
+}
+
+#[macro_export]
+macro_rules! test_sample {
+    ($mod_name:ident, $day_struct:tt, $part_1:expr, $part_2:expr) => {
+        #[cfg(test)]
+        mod $mod_name {
+            use lazy_static::lazy_static;
+
+            use super::*;
+
+            lazy_static! {
+                static ref SAMPLE: Input =
+                    $day_struct::parse_input(&format!("samples/day{}.txt", $day_struct::day()));
+            }
+
+            #[test]
+            fn test_part_1() {
+                assert_eq!($day_struct::part_1(&SAMPLE), $part_1);
+            }
+
+            #[test]
+            fn test_part_2() {
+                assert_eq!($day_struct::part_2(&SAMPLE), $part_2);
+            }
+        }
+    };
+}