dnglab · Compizfox · Jul 6, 2025 · Jul 6, 2025 · Jul 6, 2025 · Jul 6, 2025
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/rawler/Cargo.toml b/rawler/Cargo.toml
@@ -54,6 +54,8 @@ toml = "0.8"
 uuid = {version = "1.0", features = ["serde", "v4"]}
 weezl = "0.1.7"
 memmap2 = "0.9.4"
+num-integer = "0.1.46"
+impl_ops = "0.1.1"
 
 [dev-dependencies]
 criterion = {version = "0.6", features = ["html_reports"]}

diff --git a/rawler/src/formats/tiff/value.rs b/rawler/src/formats/tiff/value.rs
@@ -4,6 +4,9 @@
 use byteorder::{NativeEndian, WriteBytesExt};
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use std::{convert::Infallible, ffi::CString, fmt::Display, io::Write, num::TryFromIntError};
+use std::iter::Sum;
+use num_integer::lcm;
+use std::ops;
 
 use super::{Result, TiffError};
 
@@ -53,6 +56,51 @@ impl Display for SRational {
   }
 }
 
+impl_op_ex!(+ |lhs: &Rational, rhs: &Rational| -> Rational {
+  if lhs.d == rhs.d {
+    return Rational::new(lhs.n + rhs.n, lhs.d);
+  }
+
+  let lcm = lcm(lhs.d, rhs.d);
+  let lhs_n = lhs.n * (lcm / lhs.d);
+  let rhs_n = rhs.n * (lcm / rhs.d);
+
+  Rational::new(lhs_n + rhs_n, lcm)
+});
+
+impl_op_ex!(+ |lhs: &SRational, rhs: &SRational| -> SRational {
+  if lhs.d == rhs.d {
+    return SRational::new(lhs.n + rhs.n, lhs.d);
+  }
+
+  let lcm = lcm(lhs.d, rhs.d);
+  let lhs_n = lhs.n * (lcm / lhs.d);
+  let rhs_n = rhs.n * (lcm / rhs.d);
+
+  SRational::new(lhs_n + rhs_n, lcm)
+});
+
+impl Sum for Rational {
+  fn sum<I: Iterator<Item=Self>>(iter: I) -> Self {
+    iter.fold(Self{n: 0, d: 1}, |acc, x| acc + x)
+  }
+}
+impl<'a> Sum<&'a Rational> for Rational {
+  fn sum<I: Iterator<Item=&'a Self>>(iter: I) -> Self {
+    iter.fold(Self{n: 0, d: 1}, |acc, x| acc + x)
+  }
+}
+impl Sum for SRational {
+  fn sum<I: Iterator<Item=Self>>(iter: I) -> Self {
+    iter.fold(Self{n: 0, d: 1}, |acc, x| acc + x)
+  }
+}
+impl<'a> Sum<&'a SRational> for SRational {
+  fn sum<I: Iterator<Item=&'a Self>>(iter: I) -> Self {
+    iter.fold(Self{n: 0, d: 1}, |acc, x| acc + x)
+  }
+}
+
 impl TryFrom<Rational> for usize {
   type Error = TryFromIntError;
 
@@ -300,6 +348,10 @@ impl SRational {
   pub fn new(n: i32, d: i32) -> Self {
     Self { n, d }
   }
+
+  pub fn as_f32(&self) -> f32 {
+    self.n as f32 / self.d as f32
+  }
 }
 
 impl PartialEq for SRational {
@@ -1354,4 +1406,20 @@ mod tests {
     let b = SRational::new(-300, 10);
     assert!(a < b);
   }
+
+  #[test]
+  fn rational_sum() {
+    let a = Rational::new(1, 2);
+    let b = Rational::new(1, 4);
+
+    assert_eq!([a, b].iter().sum::<Rational>(), Rational::new(3, 4));
+  }
+
+  #[test]
+  fn srational_sum() {
+    let a = SRational::new(1, 2);
+    let b = SRational::new(-3, 4);
+
+    assert_eq!([a, b].iter().sum::<SRational>(), SRational::new(-1, 4));
+  }
 }
diff --git a/rawler/src/lib.rs b/rawler/src/lib.rs
@@ -112,6 +112,8 @@ use std::io::Seek;
 use std::path::Path;
 use thiserror::Error;
 
+#[macro_use] extern crate impl_ops;
+
 pub(crate) const ISSUE_HINT: &str = "Please open an issue at https://github.com/dnglab/dnglab/issues and provide this message (optionally the RAW file, if you can license it under CC0-license).";
 
 pub trait ReadTrait: Read + Seek {}