rewrite async converter

(poll_next removed // not work)

lib/src/questions.rs

@@ -143,11 +143,12 @@ pub use convert::QuestionsConverter;
 
 #[cfg(feature = "convert_async")]
 pub mod convert_async {
-    use async_stream::stream;
+    use futures::stream;
     use futures_core::stream::Stream;
     use futures_core::Future;
     use futures_util::{pin_mut, StreamExt};
 
+    use std::future;
     use std::pin::Pin;
     use std::task::{Context, Poll};
 
@@ -220,39 +221,19 @@ pub mod convert_async {
         T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
             + std::marker::Unpin,
     {
-        fn convert(&mut self) -> impl Stream<Item = Question> + '_ {
-            stream! {
-                while let Some((filename, Ok(batch))) = self.inner.next().await {
-                    let mut batch = batch;
-                    batch.filename = filename;
-                    let questions: Vec<Question> = batch.into();
-                    for question in questions {
-                        yield question
-                    }
+        pub fn convert(self) -> impl Stream<Item = Question> {
+            self.inner.filter_map(|(name,r)| async move {
+                if r.is_err() {
+                    None
+                } else {
+                    Some((name, r.unwrap()))
                 }
-            }
-        }
-    }
-
-    impl<T> Stream for QuestionsConverterAsync<T>
-    where
-        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
-            + std::marker::Unpin,
-    {
-        type Item = Question;
-
-        fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-            let convert = self.convert();
-            pin_mut!(convert);
-            match Pin::new(&mut convert.next()).poll(cx) {
-                Poll::Ready(Some(item)) => Poll::Ready(Some(item)),
-                Poll::Ready(None) => Poll::Ready(None),
-                Poll::Pending => Poll::Pending,
-            }
-        }
-
-        fn size_hint(&self) -> (usize, Option<usize>) {
-            self.inner.size_hint()
+            }).flat_map(|(filename, batch)| stream::iter({
+                let mut batch = batch;
+                batch.filename = filename;
+                let questions: Vec<Question> = batch.into();
+                questions
+            }))
         }
     }
 }