fix(rust/cardano-blockchain-types): add more functionality to Slot

rust/cardano-blockchain-types/Cargo.toml

@@ -33,4 +33,5 @@ dashmap = "6.1.0"
 blake2b_simd = "1.0.2"
 minicbor = { version = "0.25.1", features = ["alloc"] }
 num-traits = "0.2.19"
-ed25519-dalek = "2.1.1"
+ed25519-dalek = "2.1.1"
+serde = "1.0.210"

rust/cardano-blockchain-types/src/slot.rs

@@ -1,7 +1,16 @@
 //! Block Slot
+
+use std::{
+    cmp::Ordering,
+    ops::{MulAssign, Sub},
+};
+
+use serde::Serialize;
+
 use crate::conversion::from_saturating;
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Default, Serialize)]
+
 /// Slot on the blockchain, typically one slot equals one second.  However chain
 /// parameters can alter how long a slot is.
 pub struct Slot(u64);
@@ -33,3 +42,23 @@ impl From<Slot> for u64 {
         val.0
     }
 }
+
+impl MulAssign<u64> for Slot {
+    fn mul_assign(&mut self, rhs: u64) {
+        self.0 = self.0.saturating_mul(rhs);
+    }
+}
+
+impl PartialOrd for Slot {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        self.0.partial_cmp(&other.0)
+    }
+}
+
+impl Sub for Slot {
+    type Output = Slot;
+
+    fn sub(self, rhs: Slot) -> Self::Output {
+        Slot(self.0.saturating_sub(rhs.0))
+    }
+}