feat(hydro_lang): KeyedStream and KeyedSingleton get() supports Optional

hydro_lang/src/live_collections/keyed_singleton.rs

@@ -553,6 +553,7 @@ impl<'a, K, V, L: Location<'a>, B: KeyedSingletonBound> KeyedSingleton<K, V, L,
     }
 
     /// Gets the value associated with a specific key from the keyed singleton.
+    /// Returns `None` if the key is `None` or there is no associated value.
     ///
     /// # Example
     /// ```rust
@@ -574,7 +575,7 @@ impl<'a, K, V, L: Location<'a>, B: KeyedSingletonBound> KeyedSingleton<K, V, L,
     /// # }));
     /// # }
     /// ```
-    pub fn get(self, key: Singleton<K, L, Bounded>) -> Optional<V, L, Bounded>
+    pub fn get(self, key: impl Into<Optional<K, L, Bounded>>) -> Optional<V, L, Bounded>
     where
         B: IsBounded,
         K: Hash + Eq,

hydro_lang/src/live_collections/keyed_stream/mod.rs

@@ -12,7 +12,6 @@ use stageleft::{IntoQuotedMut, QuotedWithContext, QuotedWithContextWithProps, q}
 use super::boundedness::{Bounded, Boundedness, IsBounded, Unbounded};
 use super::keyed_singleton::KeyedSingleton;
 use super::optional::Optional;
-use super::singleton::Singleton;
 use super::stream::{
     ExactlyOnce, IsExactlyOnce, IsOrdered, MinOrder, MinRetries, NoOrder, Stream, TotalOrder,
 };
@@ -2103,6 +2102,7 @@ impl<'a, K, V, L: Location<'a>, B: Boundedness, O: Ordering, R: Retries>
     }
 
     /// Gets the values associated with a specific key from the keyed stream.
+    /// Returns an empty stream if the key is `None` or there are no associated values.
     ///
     /// # Example
     /// ```rust
@@ -2128,14 +2128,14 @@ impl<'a, K, V, L: Location<'a>, B: Boundedness, O: Ordering, R: Retries>
     /// # }));
     /// # }
     /// ```
-    pub fn get(self, key: Singleton<K, L, Bounded>) -> Stream<V, L, Bounded, NoOrder, R>
+    pub fn get(self, key: impl Into<Optional<K, L, Bounded>>) -> Stream<V, L, Bounded, NoOrder, R>
     where
         B: IsBounded,
         K: Eq + Hash,
     {
         self.make_bounded()
             .entries()
-            .join(key.into_stream().map(q!(|k| (k, ()))))
+            .join(key.into().into_stream().map(q!(|k| (k, ()))))
             .map(q!(|(_, (v, _))| v))
     }