diff --git a/src/main.rs b/src/main.rs
index 0306a43..a099dd4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -279,7 +279,8 @@ struct WriteQueueItem {
 
 type WriteQueue = Arc<Mutex<VecDeque<Option<WriteQueueItem>>>>;
 
-async fn data_reader(queue: WriteQueue) {
+/// read txt files from zip and convert to json
+async fn reader_converter(queue: WriteQueue) {
     // open archive just to list files
     let archive = ZipFileReader::new(String::from(INPUT_FILENAME))
         .await
@@ -315,7 +316,9 @@ async fn data_reader(queue: WriteQueue) {
     println!("convert done ✅");
 }
 
-async fn data_writer(queue: WriteQueue) {
+
+/// write json data to zip files
+async fn zip_writer(queue: WriteQueue) {
     let mut file = fs::File::create(OUTPUT_FILENAME).await.unwrap();
     let mut writer = ZipFileWriter::new(&mut file);
 
@@ -370,8 +373,8 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let queue_w = Arc::clone(&queue);
 
     tokio::try_join!(
-        tokio::spawn(data_reader(queue_r)),
-        tokio::spawn(data_writer(queue_w))
+        tokio::spawn(reader_converter(queue_r)),
+        tokio::spawn(zip_writer(queue_w))
     )?;
 
     println!("all done ✅");