Adds Stream:ge (#285)

* Adds partial_cmp.rs file and partial_cmp signature to mod.rs

* adds tests that compare streams of same length

* Adds Stream::ge

* cargo fmt

* fixes rustdoc error

Author: assemblaj

src/stream/stream/ge.rs

@@ -0,0 +1,47 @@
+use std::cmp::Ordering;
+use std::pin::Pin;
+
+use super::partial_cmp::PartialCmpFuture;
+use crate::future::Future;
+use crate::prelude::*;
+use crate::stream::Stream;
+use crate::task::{Context, Poll};
+
+// Determines if the elements of this `Stream` are lexicographically
+// greater than or equal to those of another.
+#[doc(hidden)]
+#[allow(missing_debug_implementations)]
+pub struct GeFuture<L: Stream, R: Stream> {
+    partial_cmp: PartialCmpFuture<L, R>,
+}
+
+impl<L: Stream, R: Stream> GeFuture<L, R>
+where
+    L::Item: PartialOrd<R::Item>,
+{
+    pin_utils::unsafe_pinned!(partial_cmp: PartialCmpFuture<L, R>);
+
+    pub(super) fn new(l: L, r: R) -> Self {
+        GeFuture {
+            partial_cmp: l.partial_cmp(r),
+        }
+    }
+}
+
+impl<L: Stream, R: Stream> Future for GeFuture<L, R>
+where
+    L: Stream + Sized,
+    R: Stream + Sized,
+    L::Item: PartialOrd<R::Item>,
+{
+    type Output = bool;
+
+    fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
+        let result = futures_core::ready!(self.as_mut().partial_cmp().poll(cx));
+
+        match result {
+            Some(Ordering::Greater) | Some(Ordering::Equal) => Poll::Ready(true),
+            _ => Poll::Ready(false),
+        }
+    }
+}

src/stream/stream/mod.rs

@@ -32,6 +32,7 @@ mod find_map;
 mod fold;
 mod for_each;
 mod fuse;
+mod ge;
 mod gt;
 mod inspect;
 mod le;
@@ -58,6 +59,7 @@ use find::FindFuture;
 use find_map::FindMapFuture;
 use fold::FoldFuture;
 use for_each::ForEachFuture;
+use ge::GeFuture;
 use gt::GtFuture;
 use le::LeFuture;
 use lt::LtFuture;
@@ -1240,6 +1242,7 @@ extension_trait! {
             #
             use async_std::prelude::*;
             use std::collections::VecDeque;
+
             use std::cmp::Ordering;
 
             let s1 = VecDeque::from(vec![1]);
@@ -1267,6 +1270,43 @@ extension_trait! {
             PartialCmpFuture::new(self, other)
         }
 
+
+        #[doc = r#"
+            Determines if the elements of this `Stream` are lexicographically
+            greater than or equal to those of another.
+
+            # Examples
+
+            ```
+            # fn main() { async_std::task::block_on(async {
+            #
+            use async_std::prelude::*;
+            use std::collections::VecDeque;
+
+            let single:     VecDeque<isize> = vec![1].into_iter().collect();
+            let single_gt:  VecDeque<isize> = vec![10].into_iter().collect();
+            let multi:      VecDeque<isize> = vec![1,2].into_iter().collect();
+            let multi_gt:   VecDeque<isize> = vec![1,5].into_iter().collect();
+            assert_eq!(single.clone().ge(single.clone()).await, true);
+            assert_eq!(single_gt.clone().ge(single.clone()).await, true);
+            assert_eq!(multi.clone().ge(single_gt.clone()).await, false);
+            assert_eq!(multi_gt.clone().ge(multi.clone()).await, true);
+            #
+            # }) }
+            ```
+        "#]
+        fn ge<S>(
+           self,
+           other: S
+        ) -> impl Future<Output = bool> [GeFuture<Self, S>]
+        where
+            Self: Sized + Stream,
+            S: Stream,
+            <Self as Stream>::Item: PartialOrd<S::Item>,
+        {
+            GeFuture::new(self, other)
+        }
+
         #[doc = r#"
             Determines if the elements of this `Stream` are lexicographically
             greater than those of another.