miniscript: eliminate recursion in substitute_raw_pkh

As always, dropping the same method from Terminal

Author: apoelstra

src/miniscript/astelem.rs

@@ -45,77 +45,6 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
     }
 }
 
-impl<Pk: MiniscriptKey, Ctx: ScriptContext> Terminal<Pk, Ctx> {
-    /// Substitutes raw public keys hashes with the public keys as provided by map.
-    pub fn substitute_raw_pkh(&self, pk_map: &BTreeMap<hash160::Hash, Pk>) -> Terminal<Pk, Ctx> {
-        match self {
-            Terminal::RawPkH(ref p) => match pk_map.get(p) {
-                Some(pk) => Terminal::PkH(pk.clone()).into(),
-                None => Terminal::RawPkH(*p).into(),
-            },
-            Terminal::PkK(..)
-            | Terminal::PkH(..)
-            | Terminal::Multi(..)
-            | Terminal::MultiA(..)
-            | Terminal::After(..)
-            | Terminal::Older(..)
-            | Terminal::Sha256(..)
-            | Terminal::Hash256(..)
-            | Terminal::Ripemd160(..)
-            | Terminal::Hash160(..)
-            | Terminal::True
-            | Terminal::False => self.clone().into(),
-            Terminal::Alt(ref sub) => Terminal::Alt(Arc::new(sub.substitute_raw_pkh(pk_map))),
-            Terminal::Swap(ref sub) => Terminal::Swap(Arc::new(sub.substitute_raw_pkh(pk_map))),
-            Terminal::Check(ref sub) => Terminal::Check(Arc::new(sub.substitute_raw_pkh(pk_map))),
-            Terminal::DupIf(ref sub) => Terminal::DupIf(Arc::new(sub.substitute_raw_pkh(pk_map))),
-            Terminal::Verify(ref sub) => Terminal::Verify(Arc::new(sub.substitute_raw_pkh(pk_map))),
-            Terminal::NonZero(ref sub) => {
-                Terminal::NonZero(Arc::new(sub.substitute_raw_pkh(pk_map)))
-            }
-            Terminal::ZeroNotEqual(ref sub) => {
-                Terminal::ZeroNotEqual(Arc::new(sub.substitute_raw_pkh(pk_map)))
-            }
-            Terminal::AndV(ref left, ref right) => Terminal::AndV(
-                Arc::new(left.substitute_raw_pkh(pk_map)),
-                Arc::new(right.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::AndB(ref left, ref right) => Terminal::AndB(
-                Arc::new(left.substitute_raw_pkh(pk_map)),
-                Arc::new(right.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::AndOr(ref a, ref b, ref c) => Terminal::AndOr(
-                Arc::new(a.substitute_raw_pkh(pk_map)),
-                Arc::new(b.substitute_raw_pkh(pk_map)),
-                Arc::new(c.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::OrB(ref left, ref right) => Terminal::OrB(
-                Arc::new(left.substitute_raw_pkh(pk_map)),
-                Arc::new(right.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::OrD(ref left, ref right) => Terminal::OrD(
-                Arc::new(left.substitute_raw_pkh(pk_map)),
-                Arc::new(right.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::OrC(ref left, ref right) => Terminal::OrC(
-                Arc::new(left.substitute_raw_pkh(pk_map)),
-                Arc::new(right.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::OrI(ref left, ref right) => Terminal::OrI(
-                Arc::new(left.substitute_raw_pkh(pk_map)),
-                Arc::new(right.substitute_raw_pkh(pk_map)),
-            ),
-            Terminal::Thresh(k, ref subs) => {
-                let subs: Vec<Arc<Miniscript<_, _>>> = subs
-                    .iter()
-                    .map(|s| Arc::new(s.substitute_raw_pkh(pk_map)))
-                    .collect();
-                Terminal::Thresh(*k, subs)
-            }
-        }
-    }
-}
-
 impl<Pk: MiniscriptKey, Ctx: ScriptContext> fmt::Debug for Terminal<Pk, Ctx> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.write_str("[")?;

src/miniscript/mod.rs

@@ -449,7 +449,22 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Miniscript<Pk, Ctx> {
 
     /// Substitutes raw public keys hashes with the public keys as provided by map.
     pub fn substitute_raw_pkh(&self, pk_map: &BTreeMap<hash160::Hash, Pk>) -> Miniscript<Pk, Ctx> {
-        Miniscript::from_ast(self.node.substitute_raw_pkh(pk_map)).expect("type check failed")
+        let mut translated = vec![];
+        for data in Arc::new(self.clone()).post_order_iter() {
+            let new_term = if let Terminal::RawPkH(ref p) = data.node.node {
+                match pk_map.get(p) {
+                    Some(pk) => Terminal::PkH(pk.clone()).into(),
+                    None => Terminal::RawPkH(*p).into(),
+                }
+            } else {
+                data.node.node.clone()
+            };
+
+            let new_ms = Miniscript::from_ast(new_term).expect("typeck");
+            translated.push(Arc::new(new_ms));
+        }
+
+        Arc::try_unwrap(translated.pop().unwrap()).unwrap()
     }
 }