refactor: remove redundant internal Series APIs

Author: martinohmann

src/series/mod.rs

@@ -203,8 +203,7 @@ where
     /// assert_eq!(series.first_event(), Some(Event::at(date(2025, 1, 1).at(0, 0, 0, 0))));
     /// ```
     pub fn first_event(&self) -> Option<Event> {
-        self.get_event(self.range.start)
-            .or_else(|| self.get_event_after(self.range.start))
+        self.get_closest_event(self.range.start)
     }
 
     /// Gets the last event in the series.
@@ -263,12 +262,10 @@ where
     /// assert!(series.get_event(date(2026, 12, 31).at(14, 0, 0, 0)).is_some());
     /// ```
     pub fn get_event(&self, instant: DateTime) -> Option<Event> {
-        let closest = self.closest_to(instant)?;
-        if closest == instant {
-            return self.get_event_unchecked(instant);
-        }
-
-        None
+        self.pattern
+            .closest_to(instant, self.range)
+            .filter(|&start| start == instant)
+            .and_then(|start| self.get_event_unchecked(start))
     }
 
     /// Gets the event containing `instant`.
@@ -312,8 +309,11 @@ where
     /// # Ok::<(), Box<dyn core::error::Error>>(())
     /// ```
     pub fn get_event_containing(&self, instant: DateTime) -> Option<Event> {
-        self.get_event(instant)
-            .or_else(|| self.get_event_before(instant))
+        self.pattern
+            .closest_to(instant, self.range)
+            .filter(|&start| start <= instant)
+            .or_else(|| self.pattern.previous_before(instant, self.range))
+            .and_then(|start| self.get_event_unchecked(start))
             .filter(|event| event.contains(instant))
     }
 
@@ -359,7 +359,8 @@ where
     /// # Ok::<(), Box<dyn core::error::Error>>(())
     /// ```
     pub fn get_event_after(&self, instant: DateTime) -> Option<Event> {
-        self.next_after(instant)
+        self.pattern
+            .next_after(instant, self.range)
             .and_then(|next| self.get_event_unchecked(next))
     }
 
@@ -396,7 +397,8 @@ where
     /// );
     /// ```
     pub fn get_event_before(&self, instant: DateTime) -> Option<Event> {
-        self.previous_before(instant)
+        self.pattern
+            .previous_before(instant, self.range)
             .and_then(|previous| self.get_event_unchecked(previous))
     }
 
@@ -431,7 +433,8 @@ where
     /// );
     /// ```
     pub fn get_closest_event(&self, instant: DateTime) -> Option<Event> {
-        self.closest_to(instant)
+        self.pattern
+            .closest_to(instant, self.range)
             .and_then(|closest| self.get_event_unchecked(closest))
     }
 }
@@ -441,24 +444,6 @@ impl<P> Series<P>
 where
     P: Pattern,
 {
-    /// Find the next `DateTime` after `instant` within the series.
-    #[inline]
-    fn next_after(&self, instant: DateTime) -> Option<DateTime> {
-        self.pattern.next_after(instant, self.range)
-    }
-
-    /// Find the previous `DateTime` before `instant` within the series.
-    #[inline]
-    fn previous_before(&self, instant: DateTime) -> Option<DateTime> {
-        self.pattern.previous_before(instant, self.range)
-    }
-
-    /// Find a `DateTime` closest to `instant` within the series.
-    #[inline]
-    fn closest_to(&self, instant: DateTime) -> Option<DateTime> {
-        self.pattern.closest_to(instant, self.range)
-    }
-
     /// Get an event without any bound checks. The datetime at `start` is assumed to be aligned to
     /// the series and within the series start and end bounds.
     #[inline]