Use find instead of chaining filter and next

Clippy emits a bunch of warnings of type:

 warning: called `filter(..).next()` on an `Iterator`. This is more succinctly expressed by calling `.find(..)` instead

As suggested, use `find` instead of chaining `filter` and `next`.

Author: tcharding

src/psbt/finalizer.rs

@@ -148,37 +148,29 @@ fn get_descriptor(psbt: &Psbt, index: usize) -> Result<Descriptor<PublicKey>, In
         }
     } else if script_pubkey.is_p2pkh() {
         // 2. `Pkh`: creates a `PkH` descriptor if partial_sigs has the corresponding pk
-        let partial_sig_contains_pk = inp
-            .partial_sigs
-            .iter()
-            .filter(|&(&pk, _sig)| {
-                // Indirect way to check the equivalence of pubkey-hashes.
-                // Create a pubkey hash and check if they are the same.
-                // THIS IS A BUG AND *WILL* PRODUCE WRONG SATISFACTIONS FOR UNCOMPRESSED KEYS
-                // Partial sigs loses the compressed flag that is necessary
-                // TODO: See https://github.com/rust-bitcoin/rust-bitcoin/pull/836
-                // The type checker will fail again after we update to 0.28 and this can be removed
-                let addr = bitcoin::Address::p2pkh(&pk, bitcoin::Network::Bitcoin);
-                *script_pubkey == addr.script_pubkey()
-            })
-            .next();
+        let partial_sig_contains_pk = inp.partial_sigs.iter().find(|&(&pk, _sig)| {
+            // Indirect way to check the equivalence of pubkey-hashes.
+            // Create a pubkey hash and check if they are the same.
+            // THIS IS A BUG AND *WILL* PRODUCE WRONG SATISFACTIONS FOR UNCOMPRESSED KEYS
+            // Partial sigs loses the compressed flag that is necessary
+            // TODO: See https://github.com/rust-bitcoin/rust-bitcoin/pull/836
+            // The type checker will fail again after we update to 0.28 and this can be removed
+            let addr = bitcoin::Address::p2pkh(&pk, bitcoin::Network::Bitcoin);
+            *script_pubkey == addr.script_pubkey()
+        });
         match partial_sig_contains_pk {
             Some((pk, _sig)) => Ok(Descriptor::new_pkh(*pk)),
             None => Err(InputError::MissingPubkey),
         }
     } else if script_pubkey.is_v0_p2wpkh() {
         // 3. `Wpkh`: creates a `wpkh` descriptor if the partial sig has corresponding pk.
-        let partial_sig_contains_pk = inp
-            .partial_sigs
-            .iter()
-            .filter(|&(&pk, _sig)| {
-                // Indirect way to check the equivalence of pubkey-hashes.
-                // Create a pubkey hash and check if they are the same.
-                let addr = bitcoin::Address::p2wpkh(&pk, bitcoin::Network::Bitcoin)
-                    .expect("Address corresponding to valid pubkey");
-                *script_pubkey == addr.script_pubkey()
-            })
-            .next();
+        let partial_sig_contains_pk = inp.partial_sigs.iter().find(|&(&pk, _sig)| {
+            // Indirect way to check the equivalence of pubkey-hashes.
+            // Create a pubkey hash and check if they are the same.
+            let addr = bitcoin::Address::p2wpkh(&pk, bitcoin::Network::Bitcoin)
+                .expect("Address corresponding to valid pubkey");
+            *script_pubkey == addr.script_pubkey()
+        });
         match partial_sig_contains_pk {
             Some((pk, _sig)) => Ok(Descriptor::new_wpkh(*pk)?),
             None => Err(InputError::MissingPubkey),
@@ -228,15 +220,11 @@ fn get_descriptor(psbt: &Psbt, index: usize) -> Result<Descriptor<PublicKey>, In
                     }
                 } else if redeem_script.is_v0_p2wpkh() {
                     // 6. `ShWpkh` case
-                    let partial_sig_contains_pk = inp
-                        .partial_sigs
-                        .iter()
-                        .filter(|&(&pk, _sig)| {
-                            let addr = bitcoin::Address::p2wpkh(&pk, bitcoin::Network::Bitcoin)
-                                .expect("Address corresponding to valid pubkey");
-                            *redeem_script == addr.script_pubkey()
-                        })
-                        .next();
+                    let partial_sig_contains_pk = inp.partial_sigs.iter().find(|&(&pk, _sig)| {
+                        let addr = bitcoin::Address::p2wpkh(&pk, bitcoin::Network::Bitcoin)
+                            .expect("Address corresponding to valid pubkey");
+                        *redeem_script == addr.script_pubkey()
+                    });
                     match partial_sig_contains_pk {
                         Some((pk, _sig)) => Ok(Descriptor::new_sh_wpkh(*pk)?),
                         None => Err(InputError::MissingPubkey),

src/psbt/mod.rs

@@ -278,10 +278,9 @@ impl<'psbt, Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for PsbtInputSatisfie
         self.psbt.inputs[self.index]
             .tap_script_sigs
             .iter()
-            .filter(|&((pubkey, lh), _sig)| {
+            .find(|&((pubkey, lh), _sig)| {
                 pubkey.to_pubkeyhash() == Pk::hash_to_hash160(&pkh.0) && *lh == pkh.1
             })
-            .next()
             .map(|((x_only_pk, _leaf_hash), sig)| (*x_only_pk, *sig))
     }
 
@@ -299,8 +298,7 @@ impl<'psbt, Pk: MiniscriptKey + ToPublicKey> Satisfier<Pk> for PsbtInputSatisfie
         self.psbt.inputs[self.index]
             .partial_sigs
             .iter()
-            .filter(|&(pubkey, _sig)| pubkey.to_pubkeyhash() == Pk::hash_to_hash160(pkh))
-            .next()
+            .find(|&(pubkey, _sig)| pubkey.to_pubkeyhash() == Pk::hash_to_hash160(pkh))
             .map(|(pk, sig)| (*pk, *sig))
     }