impl chain,zip on stream ext

Author: yoshuawuyts

src/stream/stream_ext.rs

@@ -1,7 +1,7 @@
 use crate::stream::{IntoStream, Merge};
 use futures_core::Stream;
 
-use super::merge::tuple::Merge2;
+use super::{chain::tuple::Chain2, merge::tuple::Merge2, zip::tuple::Zip2, Chain, Zip};
 
 /// An extension trait for the `Stream` trait.
 pub trait StreamExt: Stream {
@@ -10,6 +10,18 @@ pub trait StreamExt: Stream {
     where
         Self: Stream<Item = T> + Sized,
         S2: IntoStream<Item = T>;
+
+    /// Takes two streams and creates a new stream over all in sequence
+    fn chain<T, S2>(self, other: S2) -> Chain2<Self, S2::IntoStream>
+    where
+        Self: Stream<Item = T> + Sized,
+        S2: IntoStream<Item = T>;
+
+    /// ‘Zips up’ multiple streams into a single stream of pairs.
+    fn zip<T, S2>(self, other: S2) -> Zip2<Self, S2::IntoStream>
+    where
+        Self: Stream<Item = T> + Sized,
+        S2: IntoStream<Item = T>;
 }
 
 impl<S1> StreamExt for S1
@@ -23,4 +35,22 @@ where
     {
         Merge::merge((self, other))
     }
+
+    fn chain<T, S2>(self, other: S2) -> Chain2<Self, S2::IntoStream>
+    where
+        Self: Stream<Item = T> + Sized,
+        S2: IntoStream<Item = T>,
+    {
+        // TODO(yosh): fix the bounds on the tuple impl
+        Chain::chain((self, other.into_stream()))
+    }
+
+    fn zip<T, S2>(self, other: S2) -> Zip2<Self, S2::IntoStream>
+    where
+        Self: Stream<Item = T> + Sized,
+        S2: IntoStream<Item = T>,
+    {
+        // TODO(yosh): fix the bounds on the tuple impl
+        Zip::zip((self, other.into_stream()))
+    }
 }