Simplify source_layer_ids computation

Author: TrueDoctor

core/document/src/document.rs

@@ -229,14 +229,10 @@ impl Document {
 	pub fn reorder_layers(&mut self, source_paths: &[Vec<LayerId>], target_path: &[LayerId]) -> Result<(), DocumentError> {
 		// TODO: Detect when moving between folders and handle properly
 
-		let mut source_layer_ids = Vec::with_capacity(source_paths.len());
-		for path in source_paths {
-			let result = path.last();
-			match result {
-				Some(result) => source_layer_ids.push(*result),
-				None => return Err(DocumentError::LayerNotFound),
-			}
-		}
+		let source_layer_ids = source_paths
+			.iter()
+			.map(|x| x.last().cloned().ok_or(DocumentError::LayerNotFound))
+			.collect::<Result<Vec<LayerId>, DocumentError>>()?;
 
 		self.root.as_folder_mut()?.reorder_layers(source_layer_ids, *target_path.last().ok_or(DocumentError::LayerNotFound)?)?;