Added RaceDistance

README.md

@@ -1,6 +1,9 @@
 # Oddsidizer
 
-Rust library converting betting odds between American, Decimal and Fractional formats producing pretty and traditional fractions for display.
+Rust library with tools for converting and formatting data around betting:
+
+1. odds: american, decimal and fractional, formats producing pretty and traditional fractions for display,
+2. race distance (miles, furlongs, yards).
 
 ## Features
 

src/distance.rs

@@ -0,0 +1,114 @@
+use std::fmt;
+
+/// Represents a race distance in miles, furlongs, and yards.
+#[derive(Debug, PartialEq)]
+pub struct RaceDistance {
+    pub miles: u32,
+    pub furlongs: u32,
+    pub yards: u32,
+}
+
+impl RaceDistance {
+    /// Creates a `RaceDistance` instance from a total distance in yards.
+    pub fn from_yards(total_yards: u32) -> Self {
+        const YARDS_IN_MILE: u32 = 1760;
+        const YARDS_IN_FURLONG: u32 = 220;
+
+        let miles = total_yards / YARDS_IN_MILE;
+        let yards_after_miles = total_yards % YARDS_IN_MILE;
+
+        let furlongs = yards_after_miles / YARDS_IN_FURLONG;
+        let yards = yards_after_miles % YARDS_IN_FURLONG;
+
+        Self {
+            miles,
+            furlongs,
+            yards,
+        }
+    }
+}
+
+impl fmt::Display for RaceDistance {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.miles == 0 && self.furlongs == 0 && self.yards == 0 {
+            return write!(f, "0y");
+        }
+
+        let mut parts = Vec::new();
+
+        if self.miles > 0 {
+            parts.push(format!("{}m", self.miles));
+        }
+        if self.furlongs > 0 {
+            parts.push(format!("{}f", self.furlongs));
+        }
+        if self.yards > 0 {
+            parts.push(format!("{}y", self.yards));
+        }
+
+        write!(f, "{}", parts.join(" "))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_distance_conversions_with_yards() {
+        let test_cases = [
+            // Sprints
+            (1100, 0, 5, 0), // 5f
+            (1320, 0, 6, 0), // 6f
+            (1540, 0, 7, 0), // 7f
+            // Middle Distances
+            (1760, 1, 0, 0), // 1m
+            (1980, 1, 1, 0), // 1m 1f
+            (2200, 1, 2, 0), // 1m 2f
+            (2420, 1, 3, 0), // 1m 3f
+            // Routes / Stayers
+            (2640, 1, 4, 0), // 1m 4f
+            (3080, 1, 6, 0), // 1m 6f
+            (3520, 2, 0, 0), // 2m
+            // Edge cases with remaining yards
+            (0, 0, 0, 0),      // Zero yards
+            (219, 0, 0, 219),  // Just under one furlong
+            (1759, 0, 7, 219), // Just under one mile
+            (2000, 1, 1, 20),
+        ];
+
+        for &(input_yards, expected_miles, expected_furlongs, expected_yards) in &test_cases {
+            let expected = RaceDistance {
+                miles: expected_miles,
+                furlongs: expected_furlongs,
+                yards: expected_yards,
+            };
+            // Updated to use the new associated function syntax.
+            let result = RaceDistance::from_yards(input_yards);
+
+            assert_eq!(result, expected, "Failed on input of {} yards", input_yards);
+        }
+    }
+
+    #[test]
+    fn test_display_formatting_with_yards() {
+        fn rd(miles: u32, furlongs: u32, yards: u32) -> RaceDistance {
+            RaceDistance {
+                miles,
+                furlongs,
+                yards,
+            }
+        }
+
+        // Test various combinations to check the formatting logic.
+        assert_eq!(rd(1, 6, 0).to_string(), "1m 6f");
+        assert_eq!(rd(0, 7, 219).to_string(), "7f 219y");
+        assert_eq!(rd(2, 0, 50).to_string(), "2m 50y");
+        assert_eq!(rd(0, 6, 0).to_string(), "6f");
+        assert_eq!(rd(0, 0, 100).to_string(), "100y");
+        assert_eq!(rd(0, 0, 0).to_string(), "0y");
+
+        let converted_dist = RaceDistance::from_yards(2000);
+        assert_eq!(format!("{}", converted_dist), "1m 1f 20y");
+    }
+}

src/lib.rs

@@ -4,6 +4,9 @@ pub use config::*;
 mod convert;
 pub use convert::*;
 
+mod distance;
+pub use distance::RaceDistance;
+
 mod lookup_tables;
 
 mod odds;

src/testing_helpers.rs

@@ -5,7 +5,6 @@ use crate::ConversionError;
 
 // --- Helper for comparing Decimals in tests ---
 pub fn assert_decimal_eq(a: Decimal, b: Decimal) {
-    use rust_decimal_macros::dec;
     let tolerance = dec!(0.001);
     assert!(
         (a - b).abs() < tolerance,