Remove explicit_script() from DescriptorTrait

Now that `Descriptor` no longer implements `DesciptorTrait` we can
remove the `explicit_script` method from the trait entirely, instead
just implementing a method of the same name on `Descriptor` that calls
through to the required underlying method.

Author: tcharding

src/descriptor/bare.rs

@@ -75,8 +75,7 @@ impl<Pk: MiniscriptKey + ToPublicKey> Bare<Pk> {
         self.ms.encode()
     }
 
-    /// Obtain the underlying miniscript for this descriptor
-    /// Non failing verion of [`DescriptorTrait::explicit_script`] for this descriptor
+    /// Obtains the underlying miniscript for this descriptor.
     pub fn inner_script(&self) -> Script {
         self.script_pubkey()
     }
@@ -146,13 +145,6 @@ impl<Pk: MiniscriptKey> DescriptorTrait<Pk> for Bare<Pk> {
         Script::new()
     }
 
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey,
-    {
-        Ok(self.inner_script())
-    }
-
     fn get_satisfaction<S>(&self, satisfier: S) -> Result<(Vec<Vec<u8>>, Script), Error>
     where
         Pk: ToPublicKey,
@@ -256,8 +248,7 @@ impl<Pk: MiniscriptKey + ToPublicKey> Pkh<Pk> {
         Address::p2pkh(&self.pk.to_public_key(), network)
     }
 
-    /// Obtain the underlying miniscript for this descriptor
-    /// Non failing verion of [`DescriptorTrait::explicit_script`] for this descriptor
+    /// Obtains the underlying miniscript for this descriptor.
     pub fn inner_script(&self) -> Script {
         self.script_pubkey()
     }
@@ -335,13 +326,6 @@ impl<Pk: MiniscriptKey> DescriptorTrait<Pk> for Pkh<Pk> {
         Script::new()
     }
 
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey,
-    {
-        Ok(self.inner_script())
-    }
-
     fn get_satisfaction<S>(&self, satisfier: S) -> Result<(Vec<Vec<u8>>, Script), Error>
     where
         Pk: ToPublicKey,

src/descriptor/mod.rs

@@ -91,15 +91,6 @@ pub trait DescriptorTrait<Pk: MiniscriptKey> {
     where
         Pk: ToPublicKey;
 
-    /// Computes the "witness script" of the descriptor, i.e. the underlying
-    /// script before any hashing is done. For `Bare`, `Pkh` and `Wpkh` this
-    /// is the scriptPubkey; for `ShWpkh` and `Sh` this is the redeemScript;
-    /// for the others it is the witness script.
-    /// For `Tr` descriptors, this will error as there is no underlying script
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey;
-
     /// Returns satisfying non-malleable witness and scriptSig with minimum weight to spend an
     /// output controlled by the given descriptor if it possible to
     /// construct one using the satisfier S.
@@ -492,16 +483,17 @@ impl<Pk: MiniscriptKey + ToPublicKey> Descriptor<Pk> {
     /// script before any hashing is done. For `Bare`, `Pkh` and `Wpkh` this
     /// is the scriptPubkey; for `ShWpkh` and `Sh` this is the redeemScript;
     /// for the others it is the witness script.
-    /// Errors:
-    /// - When the descriptor is Tr
+    ///
+    /// # Errors
+    /// If the descriptor is a taproot descriptor.
     pub fn explicit_script(&self) -> Result<Script, Error> {
         match *self {
-            Descriptor::Bare(ref bare) => bare.explicit_script(),
-            Descriptor::Pkh(ref pkh) => pkh.explicit_script(),
-            Descriptor::Wpkh(ref wpkh) => wpkh.explicit_script(),
-            Descriptor::Wsh(ref wsh) => wsh.explicit_script(),
-            Descriptor::Sh(ref sh) => sh.explicit_script(),
-            Descriptor::Tr(ref tr) => tr.explicit_script(),
+            Descriptor::Bare(ref bare) => Ok(bare.script_pubkey()),
+            Descriptor::Pkh(ref pkh) => Ok(pkh.script_pubkey()),
+            Descriptor::Wpkh(ref wpkh) => Ok(wpkh.script_pubkey()),
+            Descriptor::Wsh(ref wsh) => Ok(wsh.inner_script()),
+            Descriptor::Sh(ref sh) => Ok(sh.inner_script()),
+            Descriptor::Tr(_) => Err(Error::TrNoScriptCode),
         }
     }
 

src/descriptor/segwitv0.rs

@@ -101,8 +101,7 @@ impl<Pk: MiniscriptKey + ToPublicKey> Wsh<Pk> {
         }
     }
 
-    /// Obtain the underlying miniscript for this descriptor
-    /// Non failing verion of [`DescriptorTrait::explicit_script`] for this descriptor
+    /// Obtains the underlying miniscript for this descriptor.
     pub fn inner_script(&self) -> Script {
         match self.inner {
             WshInner::SortedMulti(ref smv) => smv.encode(),
@@ -205,13 +204,6 @@ impl<Pk: MiniscriptKey> DescriptorTrait<Pk> for Wsh<Pk> {
         Script::new()
     }
 
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey,
-    {
-        Ok(self.inner_script())
-    }
-
     fn get_satisfaction<S>(&self, satisfier: S) -> Result<(Vec<Vec<u8>>, Script), Error>
     where
         Pk: ToPublicKey,
@@ -368,8 +360,7 @@ impl<Pk: MiniscriptKey + ToPublicKey> Wpkh<Pk> {
             .expect("Rust Miniscript types don't allow uncompressed pks in segwit descriptors")
     }
 
-    /// Obtain the underlying miniscript for this descriptor
-    /// Non failing verion of [`DescriptorTrait::explicit_script`] for this descriptor
+    /// Obtains the underlying miniscript for this descriptor.
     pub fn inner_script(&self) -> Script {
         self.script_pubkey()
     }
@@ -452,13 +443,6 @@ impl<Pk: MiniscriptKey> DescriptorTrait<Pk> for Wpkh<Pk> {
         Script::new()
     }
 
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey,
-    {
-        Ok(self.inner_script())
-    }
-
     fn get_satisfaction<S>(&self, satisfier: S) -> Result<(Vec<Vec<u8>>, Script), Error>
     where
         Pk: ToPublicKey,

src/descriptor/sh.rs

@@ -296,13 +296,6 @@ impl<Pk: MiniscriptKey> DescriptorTrait<Pk> for Sh<Pk> {
         }
     }
 
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey,
-    {
-        Ok(self.inner_script())
-    }
-
     fn get_satisfaction<S>(&self, satisfier: S) -> Result<(Vec<Vec<u8>>, Script), Error>
     where
         Pk: ToPublicKey,

src/descriptor/tr.rs

@@ -566,13 +566,6 @@ impl<Pk: MiniscriptKey> DescriptorTrait<Pk> for Tr<Pk> {
         Script::new()
     }
 
-    fn explicit_script(&self) -> Result<Script, Error>
-    where
-        Pk: ToPublicKey,
-    {
-        Err(Error::TrNoScriptCode)
-    }
-
     fn get_satisfaction<S>(&self, satisfier: S) -> Result<(Vec<Vec<u8>>, Script), Error>
     where
         Pk: ToPublicKey,