Refactor all types in their own modules.

src/iter.rs

@@ -0,0 +1,36 @@
+use crate::{Key, Spline};
+
+/// Iterator over spline keys.
+///
+/// This iterator type assures you to iterate over sorted keys.
+pub struct Iter<'a, T, V> where T: 'a, V: 'a {
+  anim_param: &'a Spline<T, V>,
+  i: usize
+}
+
+impl<'a, T, V> Iterator for Iter<'a, T, V> {
+  type Item = &'a Key<T, V>;
+
+  fn next(&mut self) -> Option<Self::Item> {
+    let r = self.anim_param.0.get(self.i);
+
+    if let Some(_) = r {
+      self.i += 1;
+    }
+
+    r
+  }
+}
+
+impl<'a, T, V> IntoIterator for &'a Spline<T, V> {
+  type Item = &'a Key<T, V>;
+  type IntoIter = Iter<'a, T, V>;
+
+  fn into_iter(self) -> Self::IntoIter {
+    Iter {
+      anim_param: self,
+      i: 0
+    }
+  }
+}
+