Change: rename Transition to BeforeAfter; deprecate Transition

Author: drmingdrmer

src/impls/level.rs

@@ -25,13 +25,13 @@ use std::ops::RangeBounds;
 use futures_util::StreamExt;
 use log::warn;
 
+use crate::BeforeAfter;
 use crate::KVResultStream;
 use crate::MapApi;
 use crate::MapApiRO;
 use crate::MapKey;
 use crate::Marked;
 use crate::MarkedOf;
-use crate::Transition;
 
 /// A simple in-memory implementation of the Map API using a BTreeMap.
 ///
@@ -129,7 +129,7 @@ where M: Clone + Unpin + Send + Sync + 'static
         &mut self,
         key: String,
         value: Option<(<String as MapKey<M>>::V, Option<M>)>,
-    ) -> Result<Transition<MarkedOf<String, M>>, io::Error> {
+    ) -> Result<BeforeAfter<MarkedOf<String, M>>, io::Error> {
         // The chance it is the bottom level is very low in a loaded system.
         // Thus, we always tombstone the key if it is None.
 

src/lib.rs

@@ -84,9 +84,17 @@ pub use crate::map_key::MapKey;
 pub use crate::map_value::MapValue;
 pub use crate::marked::Marked;
 
+#[deprecated(since = "0.2.0", note = "Use `BeforeAfter` instead")]
+pub type Transition<T> = BeforeAfter<T>;
+
 /// Represents a transition from one state to another.
-/// The tuple contains the initial state and the resulting state.
-pub type Transition<T> = (T, T);
+///
+/// This type is a tuple containing two elements:
+/// - The first element represents the state before the transition (initial state)
+/// - The second element represents the state after the transition (resulting state)
+///
+/// It's commonly used to track changes in values or system states.
+pub type BeforeAfter<T> = (T, T);
 
 /// A boxed stream that yields `Result` of key-value pairs or an `io::Error`.
 /// The stream is 'static to ensure it can live for the entire duration of the program.

src/map_api.rs

@@ -22,7 +22,7 @@ use std::io;
 
 use crate::map_api_ro::MapApiRO;
 use crate::map_key::MapKey;
-use crate::Transition;
+use crate::BeforeAfter;
 
 /// Provides a read-write key-value map API, used to access state machine data.
 ///
@@ -80,7 +80,7 @@ where
     ///
     /// # Returns
     ///
-    /// A [`Transition`] containing:
+    /// A [`BeforeAfter`] containing:
     /// - The old value (before the operation)
     /// - The new value (after the operation)
     ///
@@ -92,5 +92,5 @@ where
         &mut self,
         key: K,
         value: Option<(K::V, Option<M>)>,
-    ) -> Result<Transition<crate::MarkedOf<K, M>>, io::Error>;
+    ) -> Result<BeforeAfter<crate::MarkedOf<K, M>>, io::Error>;
 }