Rename semantic module to abstract

We used "semantic" so as not to clash with the reserved Rust keyword
"abstract", however there is a language feature to deal with such name
clashes - the raw identifier syntax `r#foo`.

Use `r#abstract` and rename the `policy/semantic.rs` file to
`policy/abstract.rs`. There is more re-naming to do to complete the
semantic -> abstract change but here we _only_ do the module name to
ease review.

Author: tcharding

src/descriptor/bare.rs

@@ -18,7 +18,7 @@ use crate::expression::{self, FromTree};
 use crate::miniscript::context::{ScriptContext, ScriptContextError};
 use crate::miniscript::satisfy::{Placeholder, Satisfaction, Witness};
 use crate::plan::AssetProvider;
-use crate::policy::{semantic, Liftable};
+use crate::policy::{r#abstract, Liftable};
 use crate::prelude::*;
 use crate::util::{varint_len, witness_to_scriptsig};
 use crate::{
@@ -165,7 +165,7 @@ impl<Pk: MiniscriptKey> fmt::Display for Bare<Pk> {
 }
 
 impl<Pk: MiniscriptKey> Liftable<Pk> for Bare<Pk> {
-    fn lift(&self) -> Result<semantic::Policy<Pk>, Error> { self.ms.lift() }
+    fn lift(&self) -> Result<r#abstract::Policy<Pk>, Error> { self.ms.lift() }
 }
 
 impl_from_tree!(
@@ -362,8 +362,8 @@ impl<Pk: MiniscriptKey> fmt::Display for Pkh<Pk> {
 }
 
 impl<Pk: MiniscriptKey> Liftable<Pk> for Pkh<Pk> {
-    fn lift(&self) -> Result<semantic::Policy<Pk>, Error> {
-        Ok(semantic::Policy::Key(self.pk.clone()))
+    fn lift(&self) -> Result<r#abstract::Policy<Pk>, Error> {
+        Ok(r#abstract::Policy::Key(self.pk.clone()))
     }
 }
 

src/descriptor/segwitv0.rs

@@ -16,7 +16,7 @@ use crate::expression::{self, FromTree};
 use crate::miniscript::context::{ScriptContext, ScriptContextError};
 use crate::miniscript::satisfy::{Placeholder, Satisfaction, Witness};
 use crate::plan::AssetProvider;
-use crate::policy::{semantic, Liftable};
+use crate::policy::{r#abstract, Liftable};
 use crate::prelude::*;
 use crate::util::varint_len;
 use crate::{
@@ -220,7 +220,7 @@ pub enum WshInner<Pk: MiniscriptKey> {
 }
 
 impl<Pk: MiniscriptKey> Liftable<Pk> for Wsh<Pk> {
-    fn lift(&self) -> Result<semantic::Policy<Pk>, Error> {
+    fn lift(&self) -> Result<r#abstract::Policy<Pk>, Error> {
         match self.inner {
             WshInner::SortedMulti(ref smv) => smv.lift(),
             WshInner::Ms(ref ms) => ms.lift(),
@@ -469,8 +469,8 @@ impl<Pk: MiniscriptKey> fmt::Display for Wpkh<Pk> {
 }
 
 impl<Pk: MiniscriptKey> Liftable<Pk> for Wpkh<Pk> {
-    fn lift(&self) -> Result<semantic::Policy<Pk>, Error> {
-        Ok(semantic::Policy::Key(self.pk.clone()))
+    fn lift(&self) -> Result<r#abstract::Policy<Pk>, Error> {
+        Ok(r#abstract::Policy::Key(self.pk.clone()))
     }
 }
 

src/descriptor/sh.rs

@@ -20,7 +20,7 @@ use crate::expression::{self, FromTree};
 use crate::miniscript::context::ScriptContext;
 use crate::miniscript::satisfy::{Placeholder, Satisfaction};
 use crate::plan::AssetProvider;
-use crate::policy::{semantic, Liftable};
+use crate::policy::{r#abstract, Liftable};
 use crate::prelude::*;
 use crate::util::{varint_len, witness_to_scriptsig};
 use crate::{
@@ -49,10 +49,10 @@ pub enum ShInner<Pk: MiniscriptKey> {
 }
 
 impl<Pk: MiniscriptKey> Liftable<Pk> for Sh<Pk> {
-    fn lift(&self) -> Result<semantic::Policy<Pk>, Error> {
+    fn lift(&self) -> Result<r#abstract::Policy<Pk>, Error> {
         match self.inner {
             ShInner::Wsh(ref wsh) => wsh.lift(),
-            ShInner::Wpkh(ref pk) => Ok(semantic::Policy::Key(pk.as_inner().clone())),
+            ShInner::Wpkh(ref pk) => Ok(r#abstract::Policy::Key(pk.as_inner().clone())),
             ShInner::SortedMulti(ref smv) => smv.lift(),
             ShInner::Ms(ref ms) => ms.lift(),
         }

src/descriptor/sortedmulti.rs

@@ -16,6 +16,7 @@ use crate::miniscript::decode::Terminal;
 use crate::miniscript::limits::MAX_PUBKEYS_PER_MULTISIG;
 use crate::miniscript::satisfy::{Placeholder, Satisfaction};
 use crate::plan::AssetProvider;
+use crate::policy::r#abstract;
 use crate::prelude::*;
 use crate::{
     errstr, expression, policy, script_num_size, Error, ForEachKey, Miniscript, MiniscriptKey,
@@ -196,12 +197,12 @@ 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(
+    fn lift(&self) -> Result<r#abstract::Policy<Pk>, Error> {
+        let ret = r#abstract::Policy::Threshold(
             self.k,
             self.pks
                 .iter()
-                .map(|k| policy::semantic::Policy::Key(k.clone()))
+                .map(|k| r#abstract::Policy::Key(k.clone()))
                 .collect(),
         );
         Ok(ret)

src/descriptor/tr.rs

@@ -16,7 +16,7 @@ use crate::expression::{self, FromTree};
 use crate::miniscript::satisfy::{Placeholder, Satisfaction, SchnorrSigType, Witness};
 use crate::miniscript::Miniscript;
 use crate::plan::AssetProvider;
-use crate::policy::semantic::Policy;
+use crate::policy::r#abstract::Policy;
 use crate::policy::Liftable;
 use crate::prelude::*;
 use crate::util::{varint_len, witness_size};

src/policy/semantic.rs renamed to src/policy/abstract.rs

@@ -10,8 +10,8 @@ use core::{fmt, str};
 
 use bitcoin::{absolute, Sequence};
 
-use super::concrete::PolicyError;
-use super::ENTAILMENT_MAX_TERMINALS;
+use crate::policy::concrete::PolicyError;
+use crate::policy::ENTAILMENT_MAX_TERMINALS;
 use crate::prelude::*;
 use crate::{errstr, expression, AbsLockTime, Error, ForEachKey, MiniscriptKey, Translator};
 
@@ -93,7 +93,7 @@ impl<Pk: MiniscriptKey> Policy<Pk> {
     /// use std::collections::HashMap;
     /// use std::str::FromStr;
     /// use miniscript::bitcoin::{hashes::hash160, PublicKey};
-    /// use miniscript::{translate_hash_fail, policy::semantic::Policy, Translator};
+    /// use miniscript::{translate_hash_fail, policy::r#abstract::Policy, Translator};
     /// let alice_pk = "02c79ef3ede6d14f72a00d0e49b4becfb152197b64c0707425c4f231df29500ee7";
     /// let bob_pk = "03d008a849fbf474bd17e9d2c1a827077a468150e58221582ec3410ab309f5afe4";
     /// let placeholder_policy = Policy::<String>::from_str("and(pk(alice_pk),pk(bob_pk))").unwrap();

src/policy/concrete.rs

@@ -557,7 +557,7 @@ impl<Pk: MiniscriptKey> ForEachKey<Pk> for Policy<Pk> {
 impl<Pk: MiniscriptKey> Policy<Pk> {
     /// Converts a policy using one kind of public key to another type of public key.
     ///
-    /// For example usage please see [`crate::policy::semantic::Policy::translate_pk`].
+    /// For example usage please see [`crate::policy::abstract::Policy::translate_pk`].
     pub fn translate_pk<Q, E, T>(&self, t: &mut T) -> Result<Policy<Q>, E>
     where
         T: Translator<Pk, Q, E>,

src/policy/mod.rs

@@ -13,20 +13,20 @@ use core::fmt;
 #[cfg(feature = "std")]
 use std::error;
 
+pub mod r#abstract;
 #[cfg(feature = "compiler")]
 pub mod compiler;
 pub mod concrete;
-pub mod semantic;
 
 pub use self::concrete::Policy as Concrete;
-pub use self::semantic::Policy as Semantic;
+pub use self::r#abstract::Policy as Semantic;
 use crate::descriptor::Descriptor;
 use crate::miniscript::{Miniscript, ScriptContext};
 use crate::sync::Arc;
 use crate::{Error, MiniscriptKey, Terminal};
 
 /// Policy entailment algorithm maximum number of terminals allowed.
-const ENTAILMENT_MAX_TERMINALS: usize = 20;
+pub(crate) const ENTAILMENT_MAX_TERMINALS: usize = 20;
 
 /// Trait describing script representations which can be lifted into
 /// an abstract policy, by discarding information.