more doc

Author: molpopgen

src/edge_table.rs

@@ -83,40 +83,40 @@ impl<'a> EdgeTable<'a> {
 
     /// Return the ``parent`` value from row ``row`` of the table.
     ///
-    /// # Errors
+    /// # Returns
     ///
-    /// Will return [``IndexError``](crate::TskitError::IndexError)
-    /// if ``row`` is out of range.
+    /// * `Some(parent)` if `u` is valid.
+    /// * `None` otherwise.
     pub fn parent<E: Into<EdgeId> + Copy>(&'a self, row: E) -> Option<NodeId> {
         unsafe_tsk_column_access!(row.into().0, 0, self.num_rows(), self.table_.parent, NodeId)
     }
 
     /// Return the ``child`` value from row ``row`` of the table.
     ///
-    /// # Errors
+    /// # Returns
     ///
-    /// Will return [``IndexError``](crate::TskitError::IndexError)
-    /// if ``row`` is out of range.
+    /// * `Some(child)` if `u` is valid.
+    /// * `None` otherwise.
     pub fn child<E: Into<EdgeId> + Copy>(&'a self, row: E) -> Option<NodeId> {
         unsafe_tsk_column_access!(row.into().0, 0, self.num_rows(), self.table_.child, NodeId)
     }
 
     /// Return the ``left`` value from row ``row`` of the table.
     ///
-    /// # Errors
+    /// # Returns
     ///
-    /// Will return [``IndexError``](crate::TskitError::IndexError)
-    /// if ``row`` is out of range.
+    /// * `Some(position)` if `u` is valid.
+    /// * `None` otherwise.
     pub fn left<E: Into<EdgeId> + Copy>(&'a self, row: E) -> Option<Position> {
         unsafe_tsk_column_access!(row.into().0, 0, self.num_rows(), self.table_.left, Position)
     }
 
     /// Return the ``right`` value from row ``row`` of the table.
     ///
-    /// # Errors
+    /// # Returns
     ///
-    /// Will return [``IndexError``](crate::TskitError::IndexError)
-    /// if ``row`` is out of range.
+    /// * `Some(position)` if `u` is valid.
+    /// * `None` otherwise.
     pub fn right<E: Into<EdgeId> + Copy>(&'a self, row: E) -> Option<Position> {
         unsafe_tsk_column_access_and_map_into!(row.into().0, 0, self.num_rows(), self.table_.right)
     }