... and shared module

day1/src/elven_calories.rs

@@ -0,0 +1,39 @@
+//! Extends the BufReader Lines to support summing based on newlines.
+use std::io::BufRead;
+use std::io::Lines;
+
+pub struct Accumulator<B> {
+    lines: Lines<B>,
+    current: u32,
+}
+
+pub trait Elvish<B> {
+    fn elf(self) -> Accumulator<B>;
+}
+
+impl<B> Elvish<B> for Lines<B> {
+    fn elf(self) -> Accumulator<B> {
+        Accumulator {
+            lines: self,
+            current: 0,
+        }
+    }
+}
+
+impl<B: BufRead> Iterator for Accumulator<B> {
+    type Item = u32;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while let Some(Ok(line)) = self.lines.next() {
+            let line = line.trim();
+            if line.is_empty() {
+                let result = self.current;
+                self.current = 0;
+                return Some(result);
+            } else {
+                self.current += line.parse::<u32>().unwrap();
+            }
+        }
+        None
+    }
+}

day1/src/step1.rs

@@ -1,46 +1,13 @@
+mod elven_calories;
+
 use std::fs::File;
 use std::io::BufRead;
 use std::io::BufReader;
-use std::io::Lines;
 
 use clap::Arg;
 use clap::Command;
 
-struct Accumulator<B> {
-    lines: Lines<B>,
-    current: u32,
-}
-
-trait Elvish<B> {
-    fn elf(self) -> Accumulator<B>;
-}
-
-impl<B> Elvish<B> for Lines<B> {
-    fn elf(self) -> Accumulator<B> {
-        Accumulator {
-            lines: self,
-            current: 0,
-        }
-    }
-}
-
-impl<B: BufRead> Iterator for Accumulator<B> {
-    type Item = u32;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        while let Some(Ok(line)) = self.lines.next() {
-            let line = line.trim();
-            if line.is_empty() {
-                let result = self.current;
-                self.current = 0;
-                return Some(result);
-            } else {
-                self.current += line.parse::<u32>().unwrap();
-            }
-        }
-        None
-    }
-}
+use elven_calories::Elvish;
 
 fn main() {
     let matches = Command::new("Day1").arg(Arg::new("filename")).get_matches();

day1/src/step2.rs

@@ -1,48 +1,14 @@
+mod elven_calories;
+
 use std::fs::File;
 use std::io::BufRead;
 use std::io::BufReader;
-use std::io::Lines;
 
 use clap::Arg;
 use clap::Command;
-
 use itertools::Itertools;
 
-struct Accumulator<B> {
-    lines: Lines<B>,
-    current: u32,
-}
-
-trait Elvish<B> {
-    fn elf(self) -> Accumulator<B>;
-}
-
-impl<B> Elvish<B> for Lines<B> {
-    fn elf(self) -> Accumulator<B> {
-        Accumulator {
-            lines: self,
-            current: 0,
-        }
-    }
-}
-
-impl<B: BufRead> Iterator for Accumulator<B> {
-    type Item = u32;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        while let Some(Ok(line)) = self.lines.next() {
-            let line = line.trim();
-            if line.is_empty() {
-                let result = self.current;
-                self.current = 0;
-                return Some(result);
-            } else {
-                self.current += line.parse::<u32>().unwrap();
-            }
-        }
-        None
-    }
-}
+use elven_calories::Elvish;
 
 fn main() {
     let matches = Command::new("Day1").arg(Arg::new("filename")).get_matches();