feat: GenerateBreakpoints::is_empty and ::len (#258)

Author: molpopgen

forrustts-genetics/src/genetic_maps.rs

@@ -41,6 +41,16 @@ impl Ord for Breakpoint {
 pub trait GenerateBreakpoints {
     fn generate_breakpoints<T: Rng>(&mut self, rng: &mut T);
     fn breakpoints(&self) -> &[Breakpoint];
+
+    /// Number of generated breakpoints.
+    fn len(&self) -> usize {
+        self.breakpoints().len()
+    }
+
+    /// Checks if generated breakpoints are empty.
+    fn is_empty(&self) -> bool {
+        self.breakpoints().is_empty()
+    }
 }
 
 #[derive(Copy, Clone, Debug, PartialEq)]

forrustts-genetics/tests/test_genetic_maps.rs

@@ -28,6 +28,8 @@ fn test_generate_bernoulli_breakpoints() {
     map.generate_breakpoints(&mut rng);
     assert_eq!(map.breakpoints().len(), 2);
     assert!(map.breakpoints().windows(2).all(|w| { w[0] <= w[1] }));
+    assert_eq!(map.len(), map.breakpoints().iter().count());
+    assert_eq!(map.is_empty(), map.len() == 0);
 }
 
 #[test]
@@ -40,6 +42,8 @@ fn test_generate_poisson_breakpoints() {
     let mut rng = rand::rngs::StdRng::seed_from_u64(0);
     map.generate_breakpoints(&mut rng);
     assert!(map.breakpoints().windows(2).all(|w| { w[0] <= w[1] }));
+    assert_eq!(map.len(), map.breakpoints().iter().count());
+    assert_eq!(map.is_empty(), map.len() == 0);
 }
 
 #[test]