units: rename relative::HeightInterval constructors

Rename `value` to `to_height` to be symmetric with `from_height`;
deprecate `to_consensus_u32` which had no symmetric `from_consensus_u32`
and was only used to implement the corresponding methods in primitives
and bitcoin.

primitives/src/locktime/relative.rs

@@ -132,7 +132,7 @@ impl LockTime {
     #[inline]
     pub fn to_consensus_u32(self) -> u32 {
         match self {
-            LockTime::Blocks(ref h) => h.to_consensus_u32(),
+            LockTime::Blocks(ref h) => u32::from(h.to_height()),
             LockTime::Time(ref t) =>
                 Sequence::LOCK_TYPE_MASK | u32::from(t.to_512_second_intervals()),
         }
@@ -353,7 +353,7 @@ impl LockTime {
         use LockTime as L;
 
         match self {
-            L::Blocks(ref required_height) => Ok(required_height.value() <= height.value()),
+            L::Blocks(required_height) => Ok(required_height <= height),
             L::Time(time) => Err(IncompatibleHeightError { height, time }),
         }
     }

primitives/src/sequence.rs

@@ -261,8 +261,8 @@ impl<'a> Arbitrary<'a> for Sequence {
             1 => Ok(Sequence::ZERO),
             2 => Ok(Sequence::MIN_NO_RBF),
             3 => Ok(Sequence::ENABLE_LOCKTIME_AND_RBF),
-            4 => Ok(Sequence::from_consensus(relative::HeightInterval::MIN.to_consensus_u32())),
-            5 => Ok(Sequence::from_consensus(relative::HeightInterval::MAX.to_consensus_u32())),
+            4 => Ok(Sequence::from_consensus(u32::from(relative::HeightInterval::MIN.to_height()))),
+            5 => Ok(Sequence::from_consensus(u32::from(relative::HeightInterval::MAX.to_height()))),
             6 => Ok(Sequence::from_consensus(
                 Sequence::LOCK_TYPE_MASK
                     | u32::from(relative::MtpInterval::MIN.to_512_second_intervals()),

units/src/block.rs

@@ -134,7 +134,7 @@ impl From<relative::HeightInterval> for BlockInterval {
     ///
     /// A relative locktime block height has a maximum value of `u16::MAX` where as a
     /// [`BlockInterval`] is a thin wrapper around a `u32`, the two types are not interchangeable.
-    fn from(h: relative::HeightInterval) -> Self { Self::from_u32(h.value().into()) }
+    fn from(h: relative::HeightInterval) -> Self { Self::from_u32(h.to_height().into()) }
 }
 
 impl TryFrom<BlockInterval> for relative::HeightInterval {

units/src/locktime/relative.rs

@@ -34,14 +34,24 @@ impl HeightInterval {
     #[inline]
     pub const fn from_height(blocks: u16) -> Self { Self(blocks) }
 
+    /// Express the [`Height`] as a count of blocks.
+    #[inline]
+    #[must_use]
+    pub const fn to_height(self) -> u16 { self.0 }
+
     /// Returns the inner `u16` value.
     #[inline]
     #[must_use]
+    #[deprecated(since = "TBD", note = "use `to_height` instead")]
+    #[doc(hidden)]
     pub const fn value(self) -> u16 { self.0 }
 
     /// Returns the `u32` value used to encode this locktime in an nSequence field or
     /// argument to `OP_CHECKSEQUENCEVERIFY`.
-    #[inline]
+    #[deprecated(
+        since = "TBD",
+        note = "use `LockTime::from` followed by `to_consensus_u32` instead"
+    )]
     pub const fn to_consensus_u32(self) -> u32 {
         self.0 as u32 // cast safety: u32 is wider than u16 on all architectures
     }
@@ -60,7 +70,7 @@ impl HeightInterval {
     pub fn is_satisfied_by(self, chain_tip: MtpAndHeight, utxo_mined_at: MtpAndHeight) -> bool {
         // let chain_tip_height = BlockHeight::from(chain_tip);
         // let utxo_mined_at_height = BlockHeight::from(utxo_mined_at);
-        match self.to_consensus_u32().checked_add(utxo_mined_at.to_height().to_u32()) {
+        match u32::from(self.to_height()).checked_add(utxo_mined_at.to_height().to_u32()) {
             Some(target_height) => chain_tip.to_height().to_u32() >= target_height,
             None => false,
         }