Shorten Threshold variant to Thresh

We have `Terminal::Thresh` but `Policy::Threshold` (concrete and
semantic). We can shorten the policy variants to mirror the
`Terminal::Thresh` variant with no loss of clarity.

Done in preparation for adding a `Threshold` type which will clash with
the variant when we locally import all variants within functions.

Author: tcharding

src/descriptor/sortedmulti.rs

@@ -197,7 +197,7 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> SortedMultiVec<Pk, Ctx> {
 
 impl<Pk: MiniscriptKey, Ctx: ScriptContext> policy::Liftable<Pk> for SortedMultiVec<Pk, Ctx> {
     fn lift(&self) -> Result<policy::semantic::Policy<Pk>, Error> {
-        let ret = policy::semantic::Policy::Threshold(
+        let ret = policy::semantic::Policy::Thresh(
             self.k,
             self.pks
                 .iter()

src/descriptor/tr.rs

@@ -621,7 +621,7 @@ impl<Pk: MiniscriptKey> Liftable<Pk> for TapTree<Pk> {
         fn lift_helper<Pk: MiniscriptKey>(s: &TapTree<Pk>) -> Result<Policy<Pk>, Error> {
             match *s {
                 TapTree::Tree { ref left, ref right, height: _ } => {
-                    Ok(Policy::Threshold(1, vec![lift_helper(left)?, lift_helper(right)?]))
+                    Ok(Policy::Thresh(1, vec![lift_helper(left)?, lift_helper(right)?]))
                 }
                 TapTree::Leaf(ref leaf) => leaf.lift(),
             }
@@ -636,7 +636,7 @@ impl<Pk: MiniscriptKey> Liftable<Pk> for Tr<Pk> {
     fn lift(&self) -> Result<Policy<Pk>, Error> {
         match &self.tree {
             Some(root) => {
-                Ok(Policy::Threshold(1, vec![Policy::Key(self.internal_key.clone()), root.lift()?]))
+                Ok(Policy::Thresh(1, vec![Policy::Key(self.internal_key.clone()), root.lift()?]))
             }
             None => Ok(Policy::Key(self.internal_key.clone())),
         }

src/iter/mod.rs

@@ -77,7 +77,7 @@ impl<'a, Pk: MiniscriptKey> TreeLike for &'a policy::Concrete<Pk> {
             | Ripemd160(_) | Hash160(_) => Tree::Nullary,
             And(ref subs) => Tree::Nary(subs.iter().map(Arc::as_ref).collect()),
             Or(ref v) => Tree::Nary(v.iter().map(|(_, p)| p.as_ref()).collect()),
-            Threshold(_, ref subs) => Tree::Nary(subs.iter().map(Arc::as_ref).collect()),
+            Thresh(_, ref subs) => Tree::Nary(subs.iter().map(Arc::as_ref).collect()),
         }
     }
 }
@@ -90,7 +90,7 @@ impl<'a, Pk: MiniscriptKey> TreeLike for Arc<policy::Concrete<Pk>> {
             | Ripemd160(_) | Hash160(_) => Tree::Nullary,
             And(ref subs) => Tree::Nary(subs.iter().map(Arc::clone).collect()),
             Or(ref v) => Tree::Nary(v.iter().map(|(_, p)| Arc::clone(p)).collect()),
-            Threshold(_, ref subs) => Tree::Nary(subs.iter().map(Arc::clone).collect()),
+            Thresh(_, ref subs) => Tree::Nary(subs.iter().map(Arc::clone).collect()),
         }
     }
 }

src/policy/compiler.rs

@@ -920,7 +920,7 @@ where
             compile_binary!(&mut l_comp[3], &mut r_comp[2], [lw, rw], Terminal::OrI);
             compile_binary!(&mut r_comp[3], &mut l_comp[2], [rw, lw], Terminal::OrI);
         }
-        Concrete::Threshold(k, ref subs) => {
+        Concrete::Thresh(k, ref subs) => {
             let n = subs.len();
             let k_over_n = k as f64 / n as f64;
 
@@ -1301,7 +1301,7 @@ mod tests {
         let policy: BPolicy = Concrete::Or(vec![
             (
                 127,
-                Arc::new(Concrete::Threshold(
+                Arc::new(Concrete::Thresh(
                     3,
                     key_pol[0..5].iter().map(|p| (p.clone()).into()).collect(),
                 )),
@@ -1310,7 +1310,7 @@ mod tests {
                 1,
                 Arc::new(Concrete::And(vec![
                     Arc::new(Concrete::Older(Sequence::from_height(10000))),
-                    Arc::new(Concrete::Threshold(
+                    Arc::new(Concrete::Thresh(
                         2,
                         key_pol[5..8].iter().map(|p| (p.clone()).into()).collect(),
                     )),
@@ -1430,7 +1430,7 @@ mod tests {
                 .iter()
                 .map(|pubkey| Arc::new(Concrete::Key(*pubkey)))
                 .collect();
-            let big_thresh = Concrete::Threshold(*k, pubkeys);
+            let big_thresh = Concrete::Thresh(*k, pubkeys);
             let big_thresh_ms: SegwitMiniScript = big_thresh.compile().unwrap();
             if *k == 21 {
                 // N * (PUSH + pubkey + CHECKSIGVERIFY)
@@ -1466,8 +1466,8 @@ mod tests {
             .collect();
 
         let thresh_res: Result<SegwitMiniScript, _> = Concrete::Or(vec![
-            (1, Arc::new(Concrete::Threshold(keys_a.len(), keys_a))),
-            (1, Arc::new(Concrete::Threshold(keys_b.len(), keys_b))),
+            (1, Arc::new(Concrete::Thresh(keys_a.len(), keys_a))),
+            (1, Arc::new(Concrete::Thresh(keys_b.len(), keys_b))),
         ])
         .compile();
         let script_size = thresh_res.clone().and_then(|m| Ok(m.script_size()));
@@ -1484,8 +1484,7 @@ mod tests {
             .iter()
             .map(|pubkey| Arc::new(Concrete::Key(*pubkey)))
             .collect();
-        let thresh_res: Result<SegwitMiniScript, _> =
-            Concrete::Threshold(keys.len(), keys).compile();
+        let thresh_res: Result<SegwitMiniScript, _> = Concrete::Thresh(keys.len(), keys).compile();
         let n_elements = thresh_res
             .clone()
             .and_then(|m| Ok(m.max_satisfaction_witness_elements()));
@@ -1506,7 +1505,7 @@ mod tests {
             .map(|pubkey| Arc::new(Concrete::Key(*pubkey)))
             .collect();
         let thresh_res: Result<SegwitMiniScript, _> =
-            Concrete::Threshold(keys.len() - 1, keys).compile();
+            Concrete::Thresh(keys.len() - 1, keys).compile();
         let ops_count = thresh_res.clone().and_then(|m| Ok(m.ext.ops.op_count()));
         assert_eq!(
             thresh_res,
@@ -1520,7 +1519,7 @@ mod tests {
             .iter()
             .map(|pubkey| Arc::new(Concrete::Key(*pubkey)))
             .collect();
-        let thresh_res = Concrete::Threshold(keys.len() - 1, keys).compile::<Legacy>();
+        let thresh_res = Concrete::Thresh(keys.len() - 1, keys).compile::<Legacy>();
         let ops_count = thresh_res.clone().and_then(|m| Ok(m.ext.ops.op_count()));
         assert_eq!(
             thresh_res,

src/policy/concrete.rs

@@ -67,7 +67,7 @@ pub enum Policy<Pk: MiniscriptKey> {
     /// relative probabilities for each one.
     Or(Vec<(usize, Arc<Policy<Pk>>)>),
     /// A set of descriptors, satisfactions must be provided for `k` of them.
-    Threshold(usize, Vec<Arc<Policy<Pk>>>),
+    Thresh(usize, Vec<Arc<Policy<Pk>>>),
 }
 
 impl<Pk> Policy<Pk>
@@ -210,7 +210,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                     })
                     .collect::<Vec<_>>()
             }
-            Policy::Threshold(k, ref subs) if *k == 1 => {
+            Policy::Thresh(k, ref subs) if *k == 1 => {
                 let total_odds = subs.len();
                 subs.iter()
                     .flat_map(|policy| policy.to_tapleaf_prob_vec(prob / total_odds as f64))
@@ -265,7 +265,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
     /// ### TapTree compilation
     ///
     /// The policy tree constructed by root-level disjunctions over [`Policy::Or`] and
-    /// [`Policy::Threshold`](1, ..) which is flattened into a vector (with respective
+    /// [`Policy::Thresh`](1, ..) which is flattened into a vector (with respective
     /// probabilities derived from odds) of policies.
     ///
     /// For example, the policy `thresh(1,or(pk(A),pk(B)),and(or(pk(C),pk(D)),pk(E)))` gives the
@@ -317,7 +317,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
     /// ### TapTree compilation
     ///
     /// The policy tree constructed by root-level disjunctions over [`Policy::Or`] and
-    /// [`Policy::Threshold`](k, ..n..) which is flattened into a vector (with respective
+    /// [`Policy::Thresh`](k, ..n..) which is flattened into a vector (with respective
     /// probabilities derived from odds) of policies. For example, the policy
     /// `thresh(1,or(pk(A),pk(B)),and(or(pk(C),pk(D)),pk(E)))` gives the vector
     /// `[pk(A),pk(B),and(or(pk(C),pk(D)),pk(E)))]`.
@@ -430,13 +430,13 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                     .map(|(odds, pol)| (prob * *odds as f64 / total_odds as f64, pol.clone()))
                     .collect::<Vec<_>>()
             }
-            Policy::Threshold(k, subs) if *k == 1 => {
+            Policy::Thresh(k, subs) if *k == 1 => {
                 let total_odds = subs.len();
                 subs.iter()
                     .map(|pol| (prob / total_odds as f64, pol.clone()))
                     .collect::<Vec<_>>()
             }
-            Policy::Threshold(k, subs) if *k != subs.len() => generate_combination(subs, prob, *k),
+            Policy::Thresh(k, subs) if *k != subs.len() => generate_combination(subs, prob, *k),
             pol => vec![(prob, Arc::new(pol.clone()))],
         }
     }
@@ -579,7 +579,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                 Hash160(ref h) => t.hash160(h).map(Hash160)?,
                 Older(ref n) => Older(*n),
                 After(ref n) => After(*n),
-                Threshold(ref k, ref subs) => Threshold(*k, (0..subs.len()).map(child_n).collect()),
+                Thresh(ref k, ref subs) => Thresh(*k, (0..subs.len()).map(child_n).collect()),
                 And(ref subs) => And((0..subs.len()).map(child_n).collect()),
                 Or(ref subs) => Or(subs
                     .iter()
@@ -605,9 +605,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
 
             let new_policy = match data.node.as_ref() {
                 Policy::Key(ref k) if k.clone() == *key => Some(Policy::Unsatisfiable),
-                Threshold(k, ref subs) => {
-                    Some(Threshold(*k, (0..subs.len()).map(child_n).collect()))
-                }
+                Thresh(k, ref subs) => Some(Thresh(*k, (0..subs.len()).map(child_n).collect())),
                 And(ref subs) => Some(And((0..subs.len()).map(child_n).collect())),
                 Or(ref subs) => Some(Or(subs
                     .iter()
@@ -638,7 +636,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
     }
 
     /// Gets the number of [TapLeaf](`TapTree::Leaf`)s considering exhaustive root-level [`Policy::Or`]
-    /// and [`Policy::Threshold`] disjunctions for the `TapTree`.
+    /// and [`Policy::Thresh`] disjunctions for the `TapTree`.
     #[cfg(feature = "compiler")]
     fn num_tap_leaves(&self) -> usize {
         use Policy::*;
@@ -649,7 +647,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
 
             let num = match data.node {
                 Or(subs) => (0..subs.len()).map(num_for_child_n).sum(),
-                Threshold(k, subs) if *k == 1 => (0..subs.len()).map(num_for_child_n).sum(),
+                Thresh(k, subs) if *k == 1 => (0..subs.len()).map(num_for_child_n).sum(),
                 _ => 1,
             };
             nums.push(num);
@@ -724,7 +722,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                     cltv_with_time: false,
                     contains_combination: false,
                 },
-                Threshold(ref k, subs) => {
+                Thresh(ref k, subs) => {
                     let iter = (0..subs.len()).map(info_for_child_n);
                     TimelockInfo::combine_threshold(*k, iter)
                 }
@@ -772,7 +770,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
                     Ok(())
                 }
             }
-            Policy::Threshold(k, ref subs) => {
+            Policy::Thresh(k, ref subs) => {
                 if k == 0 || k > subs.len() {
                     Err(PolicyError::IncorrectThresh)
                 } else {
@@ -821,7 +819,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
             | Policy::Hash160(_)
             | Policy::After(_)
             | Policy::Older(_) => (false, true),
-            Policy::Threshold(k, ref subs) => {
+            Policy::Thresh(k, ref subs) => {
                 let (safe_count, non_mall_count) = subs
                     .iter()
                     .map(|sub| sub.is_safe_nonmalleable())
@@ -884,7 +882,7 @@ impl<Pk: MiniscriptKey> fmt::Debug for Policy<Pk> {
                 }
                 f.write_str(")")
             }
-            Policy::Threshold(k, ref subs) => {
+            Policy::Thresh(k, ref subs) => {
                 write!(f, "thresh({}", k)?;
                 for sub in subs {
                     write!(f, ",{:?}", sub)?;
@@ -927,7 +925,7 @@ impl<Pk: MiniscriptKey> fmt::Display for Policy<Pk> {
                 }
                 f.write_str(")")
             }
-            Policy::Threshold(k, ref subs) => {
+            Policy::Thresh(k, ref subs) => {
                 write!(f, "thresh({}", k)?;
                 for sub in subs {
                     write!(f, ",{}", sub)?;
@@ -1052,7 +1050,7 @@ impl_block_str!(
                 for arg in &top.args[1..] {
                     subs.push(Policy::from_tree(arg)?);
                 }
-                Ok(Policy::Threshold(thresh as usize, subs.into_iter().map(Arc::new).collect()))
+                Ok(Policy::Thresh(thresh as usize, subs.into_iter().map(Arc::new).collect()))
             }
             _ => Err(errstr(top.name)),
         }
@@ -1095,7 +1093,7 @@ fn with_huffman_tree<Pk: MiniscriptKey>(
     Ok(node)
 }
 
-/// Enumerates a [`Policy::Threshold(k, ..n..)`] into `n` different thresh's.
+/// Enumerates a [`Policy::Thresh(k, ..n..)`] into `n` different thresh's.
 ///
 /// ## Strategy
 ///
@@ -1117,7 +1115,7 @@ fn generate_combination<Pk: MiniscriptKey>(
             .enumerate()
             .filter_map(|(j, sub)| if j != i { Some(Arc::clone(sub)) } else { None })
             .collect();
-        ret.push((prob / policy_vec.len() as f64, Arc::new(Policy::Threshold(k, policies))));
+        ret.push((prob / policy_vec.len() as f64, Arc::new(Policy::Thresh(k, policies))));
     }
     ret
 }
@@ -1165,10 +1163,7 @@ mod compiler_tests {
             .map(|sub_pol| {
                 (
                     0.25,
-                    Arc::new(Policy::Threshold(
-                        2,
-                        sub_pol.into_iter().map(|p| Arc::new(p)).collect(),
-                    )),
+                    Arc::new(Policy::Thresh(2, sub_pol.into_iter().map(|p| Arc::new(p)).collect())),
                 )
             })
             .collect::<Vec<_>>();

src/policy/mod.rs

@@ -136,27 +136,27 @@ impl<Pk: MiniscriptKey, Ctx: ScriptContext> Liftable<Pk> for Terminal<Pk, Ctx> {
             | Terminal::NonZero(ref sub)
             | Terminal::ZeroNotEqual(ref sub) => sub.node.lift()?,
             Terminal::AndV(ref left, ref right) | Terminal::AndB(ref left, ref right) => {
-                Semantic::Threshold(2, vec![left.node.lift()?, right.node.lift()?])
+                Semantic::Thresh(2, vec![left.node.lift()?, right.node.lift()?])
             }
-            Terminal::AndOr(ref a, ref b, ref c) => Semantic::Threshold(
+            Terminal::AndOr(ref a, ref b, ref c) => Semantic::Thresh(
                 1,
                 vec![
-                    Semantic::Threshold(2, vec![a.node.lift()?, b.node.lift()?]),
+                    Semantic::Thresh(2, vec![a.node.lift()?, b.node.lift()?]),
                     c.node.lift()?,
                 ],
             ),
             Terminal::OrB(ref left, ref right)
             | Terminal::OrD(ref left, ref right)
             | Terminal::OrC(ref left, ref right)
             | Terminal::OrI(ref left, ref right) => {
-                Semantic::Threshold(1, vec![left.node.lift()?, right.node.lift()?])
+                Semantic::Thresh(1, vec![left.node.lift()?, right.node.lift()?])
             }
             Terminal::Thresh(k, ref subs) => {
                 let semantic_subs: Result<_, Error> = subs.iter().map(|s| s.node.lift()).collect();
-                Semantic::Threshold(k, semantic_subs?)
+                Semantic::Thresh(k, semantic_subs?)
             }
             Terminal::Multi(k, ref keys) | Terminal::MultiA(k, ref keys) => {
-                Semantic::Threshold(k, keys.iter().map(|k| Semantic::Key(k.clone())).collect())
+                Semantic::Thresh(k, keys.iter().map(|k| Semantic::Key(k.clone())).collect())
             }
         }
         .normalized();
@@ -198,16 +198,16 @@ impl<Pk: MiniscriptKey> Liftable<Pk> for Concrete<Pk> {
             Concrete::Hash160(ref h) => Semantic::Hash160(h.clone()),
             Concrete::And(ref subs) => {
                 let semantic_subs: Result<_, Error> = subs.iter().map(Liftable::lift).collect();
-                Semantic::Threshold(2, semantic_subs?)
+                Semantic::Thresh(2, semantic_subs?)
             }
             Concrete::Or(ref subs) => {
                 let semantic_subs: Result<_, Error> =
                     subs.iter().map(|(_p, sub)| sub.lift()).collect();
-                Semantic::Threshold(1, semantic_subs?)
+                Semantic::Thresh(1, semantic_subs?)
             }
-            Concrete::Threshold(k, ref subs) => {
+            Concrete::Thresh(k, ref subs) => {
                 let semantic_subs: Result<_, Error> = subs.iter().map(Liftable::lift).collect();
-                Semantic::Threshold(k, semantic_subs?)
+                Semantic::Thresh(k, semantic_subs?)
             }
         }
         .normalized();
@@ -345,10 +345,10 @@ mod tests {
                 .parse()
                 .unwrap();
         assert_eq!(
-            Semantic::Threshold(
+            Semantic::Thresh(
                 1,
                 vec![
-                    Semantic::Threshold(
+                    Semantic::Thresh(
                         2,
                         vec![
                             Semantic::Key(key_a),