Compartmentalize part 1 and 2

2023/day1/src/main.rs

@@ -1,4 +1,53 @@
-struct NumberPair(Option<u32>, Option<u32>);
+pub struct NumberPair(Option<u32>, Option<u32>);
+
+type Approach = Box<dyn Fn(&[char]) -> LineResult>;
+type LineResult = NumberPair;
+
+mod part1 {
+    use super::{Approach, NumberPair};
+
+    pub fn approaches() -> Vec<Approach> {
+        vec![Box::new(|line| {
+            struct Recorder {
+                first: Option<u32>,
+                last: Option<u32>,
+            }
+
+            impl Recorder {
+                fn new() -> Self {
+                    Self {
+                        first: None,
+                        last: None,
+                    }
+                }
+
+                fn record(&mut self, n: u32) {
+                    if self.first.is_none() {
+                        self.first = Some(n)
+                    } else {
+                        self.last = Some(n)
+                    }
+                }
+
+                fn finish(self) -> NumberPair {
+                    NumberPair(self.first, self.last)
+                }
+            }
+
+            line.iter()
+                .fold(Recorder::new(), |mut val, char| {
+                    if let Some(digit) = char.to_digit(10) {
+                        val.record(digit)
+                    }
+                    val
+                })
+                .finish()
+        })]
+    }
+}
+
+mod part2 {
+    use super::{Approach, NumberPair};
 
     struct SpelledOutNumber(u32);
 
@@ -37,48 +86,7 @@ fn try_parse_at(input: &[char]) -> Option<u32> {
         }
     }
 
-fn main() {
-    let input = std::fs::read_to_string("./input").unwrap();
-
-    type Approach = Box<dyn Fn(&[char]) -> NumberPair>;
-
-    let parts: [Vec<Approach>; 2] = [
-        vec![Box::new(|line| {
-            struct Recorder {
-                first: Option<u32>,
-                last: Option<u32>,
-            }
-
-            impl Recorder {
-                fn new() -> Self {
-                    Self {
-                        first: None,
-                        last: None,
-                    }
-                }
-
-                fn record(&mut self, n: u32) {
-                    if self.first.is_none() {
-                        self.first = Some(n)
-                    } else {
-                        self.last = Some(n)
-                    }
-                }
-
-                fn finish(self) -> NumberPair {
-                    NumberPair(self.first, self.last)
-                }
-            }
-
-            line.iter()
-                .fold(Recorder::new(), |mut val, char| {
-                    if let Some(digit) = char.to_digit(10) {
-                        val.record(digit)
-                    }
-                    val
-                })
-                .finish()
-        })],
+    pub fn approaches() -> Vec<Approach> {
         vec![
             // go through the string one by one, check the value at that position and record it into
             // a `FirstLast` recorder that holds state
@@ -163,10 +171,14 @@ fn main() {
                     },
                 )
             }),
-        ],
-    ];
+        ]
+    }
+}
 
-    let results: [u32; 2] = parts.map(|approaches| {
+fn main() {
+    let input = std::fs::read_to_string("./input").unwrap();
+
+    let results: [u32; 2] = [part1::approaches(), part2::approaches()].map(|approaches| {
         input
             .lines()
             .map(|line| line.chars().collect::<Vec<char>>())