Separate taptree in identifiers and docs

We use `TapTree` therefore the all lowercase version should be
`tap_tree` not `taptree`.

Author: tcharding

examples/taproot.rs

@@ -101,7 +101,7 @@ fn main() {
     let real_desc = desc.translate_pk(&mut t).unwrap();
 
     // Max satisfaction weight for compilation, corresponding to the script-path spend
-    // `multi_a(2,PUBKEY_1,PUBKEY_2) at taptree depth 1, having:
+    // `multi_a(2,PUBKEY_1,PUBKEY_2) at tap tree depth 1, having:
     //
     //     max_witness_size = varint(control_block_size) + control_block size +
     //                        varint(script_size) + script_size + max_satisfaction_size

src/descriptor/tr.rs

@@ -186,10 +186,16 @@ impl<Pk: MiniscriptKey> Tr<Pk> {
     }
 
     /// Obtain the [`TapTree`] of the [`Tr`] descriptor
-    pub fn taptree(&self) -> &Option<TapTree<Pk>> {
+    pub fn tap_tree(&self) -> &Option<TapTree<Pk>> {
         &self.tree
     }
 
+    /// Obtain the [`TapTree`] of the [`Tr`] descriptor
+    #[deprecated(since = "11.0.0", note = "use tap_tree instead")]
+    pub fn taptree(&self) -> &Option<TapTree<Pk>> {
+        self.tap_tree()
+    }
+
     /// Iterate over all scripts in merkle tree. If there is no script path, the iterator
     /// yields [`None`]
     pub fn iter_scripts(&self) -> TapTreeIter<Pk> {
@@ -258,7 +264,7 @@ impl<Pk: MiniscriptKey> Tr<Pk> {
     /// # Errors
     /// When the descriptor is impossible to safisfy (ex: sh(OP_FALSE)).
     pub fn max_weight_to_satisfy(&self) -> Result<usize, Error> {
-        let tree = match self.taptree() {
+        let tree = match self.tap_tree() {
             None => {
                 // key spend path
                 // item: varint(sig+sigHash) + <sig(64)+sigHash(1)>
@@ -309,7 +315,7 @@ impl<Pk: MiniscriptKey> Tr<Pk> {
     /// When the descriptor is impossible to safisfy (ex: sh(OP_FALSE)).
     #[deprecated(note = "use max_weight_to_satisfy instead")]
     pub fn max_satisfaction_weight(&self) -> Result<usize, Error> {
-        let tree = match self.taptree() {
+        let tree = match self.tap_tree() {
             // key spend path:
             // scriptSigLen(4) + stackLen(1) + stack[Sig]Len(1) + stack[Sig](65)
             None => return Ok(4 + 1 + 1 + 65),

src/policy/concrete.rs

@@ -403,8 +403,8 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                                 compilation.sanity_check()?;
                                 leaf_compilations.push((OrdF64(prob), compilation));
                             }
-                            let taptree = with_huffman_tree::<Pk>(leaf_compilations)?;
-                            Some(taptree)
+                            let tap_tree = with_huffman_tree::<Pk>(leaf_compilations)?;
+                            Some(tap_tree)
                         }
                     },
                 )?;
@@ -462,8 +462,8 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                                     )
                                 })
                                 .collect();
-                            let taptree = with_huffman_tree::<Pk>(leaf_compilations).unwrap();
-                            Some(taptree)
+                            let tap_tree = with_huffman_tree::<Pk>(leaf_compilations).unwrap();
+                            Some(tap_tree)
                         }
                     },
                 )?;

src/psbt/mod.rs

@@ -1222,7 +1222,7 @@ fn update_item_with_descriptor_helper<F: PsbtFields>(
             match item.tap_tree() {
                 // Only set the tap_tree if the item supports it (it's an output) and the descriptor actually
                 // contains one, otherwise it'll just be empty
-                Some(tap_tree) if tr_derived.taptree().is_some() => {
+                Some(tap_tree) if tr_derived.tap_tree().is_some() => {
                     *tap_tree = Some(
                         taproot::TapTree::try_from(builder)
                             .expect("The tree should always be valid"),