crdt: Make some improvements to the types

Signed-off-by: Alexis Sellier <alexis@radicle.xyz>

radicle-crdt/src/change.rs

@@ -25,12 +25,14 @@ pub struct Change<A> {
     pub clock: LClock,
 }
 
-impl<'de, A: Serialize + Deserialize<'de>> Change<A> {
+impl<A> Change<A> {
     /// Get the change id.
     pub fn id(&self) -> ChangeId {
         (self.clock, self.author)
     }
+}
 
+impl<A: Serialize> Change<A> {
     /// Serialize the change into a byte string.
     pub fn encode(&self) -> Vec<u8> {
         let mut buf = Vec::new();
@@ -41,7 +43,9 @@ impl<'de, A: Serialize + Deserialize<'de>> Change<A> {
 
         buf
     }
+}
 
+impl<'de, A: Deserialize<'de>> Change<A> {
     /// Deserialize a change from a byte string.
     pub fn decode(bytes: &'de [u8]) -> Result<Self, serde_json::Error> {
         serde_json::from_slice(bytes)

radicle-crdt/src/lwwreg.rs

@@ -1,3 +1,5 @@
+use num_traits::Bounded;
+
 use crate::ord::Max;
 use crate::Semilattice;
 
@@ -43,10 +45,28 @@ impl<T: PartialOrd + Semilattice, C: PartialOrd> LWWReg<T, C> {
     }
 }
 
+impl<T, C: Default> From<T> for LWWReg<T, C> {
+    fn from(value: T) -> Self {
+        Self {
+            clock: Max::from(C::default()),
+            value,
+        }
+    }
+}
+
+impl<T: Default, C: Default + Bounded> Default for LWWReg<T, C> {
+    fn default() -> Self {
+        Self {
+            clock: Max::default(),
+            value: T::default(),
+        }
+    }
+}
+
 impl<T, C> Semilattice for LWWReg<T, C>
 where
-    T: PartialOrd + Default + Semilattice,
-    C: PartialOrd + Default,
+    T: PartialOrd + Semilattice,
+    C: PartialOrd,
 {
     fn merge(&mut self, other: Self) {
         self.set(other.value, other.clock.into_inner());