Move block hash types

We would like all the various hash types to be defined where they
rightly live instead of in the `hash_types` module.

Move the block hash types to the `block` module. While moving, add full
stops to the rustdoc of each hash.

Re-export _all four_ types from lib.rs (previously `WitnessMerkleNode`
was not re-exported).

bitcoin/src/bip152.rs

@@ -373,10 +373,10 @@ mod test {
     use hex::FromHex;
 
     use super::*;
+    use crate::blockdata::block::TxMerkleNode;
     use crate::blockdata::locktime::absolute;
     use crate::blockdata::transaction;
     use crate::consensus::encode::{deserialize, serialize};
-    use crate::hash_types::TxMerkleNode;
     use crate::{
         Amount, CompactTarget, OutPoint, ScriptBuf, Sequence, Transaction, TxIn, TxOut, Txid,
         Witness,

bitcoin/src/bip158.rs

@@ -44,12 +44,12 @@ use core::fmt::{self, Display, Formatter};
 use hashes::{siphash24, Hash};
 use internals::write_err;
 
-use crate::blockdata::block::Block;
+use crate::blockdata::block::{Block, BlockHash};
 use crate::blockdata::script::Script;
 use crate::blockdata::transaction::OutPoint;
 use crate::consensus::encode::VarInt;
 use crate::consensus::{Decodable, Encodable};
-use crate::hash_types::{BlockHash, FilterHash, FilterHeader};
+use crate::hash_types::{FilterHash, FilterHeader};
 use crate::prelude::*;
 
 /// Golomb encoding parameter as in BIP-158, see also https://gist.github.com/sipa/576d5f09c3b86c3b1b75598d799fc845
@@ -554,8 +554,8 @@ mod test {
     use serde_json::Value;
 
     use super::*;
+    use crate::blockdata::block::BlockHash;
     use crate::consensus::encode::deserialize;
-    use crate::hash_types::BlockHash;
     use crate::ScriptBuf;
 
     #[test]

bitcoin/src/blockdata/block.rs

@@ -10,23 +10,39 @@
 
 use core::fmt;
 
-use hashes::{Hash, HashEngine};
+use hashes::{sha256d, Hash, HashEngine};
 
 use super::Weight;
 use crate::blockdata::script;
 use crate::blockdata::transaction::Transaction;
 use crate::consensus::{encode, Decodable, Encodable};
-use crate::hash_types::{TxMerkleNode, WitnessCommitment, WitnessMerkleNode, Wtxid};
+use crate::hash_types::{impl_hashencode, Txid, Wtxid};
 use crate::internal_macros::impl_consensus_encoding;
 use crate::pow::{CompactTarget, Target, Work};
 use crate::prelude::*;
 use crate::{merkle_tree, Network, VarInt};
 
-#[rustfmt::skip]                // Keep public re-exports separate.
-#[doc(inline)]
-pub use crate::{
-    hash_types::BlockHash,
-};
+hashes::hash_newtype! {
+    /// A bitcoin block hash.
+    pub struct BlockHash(sha256d::Hash);
+    /// A hash of the Merkle tree branch or root for transactions.
+    pub struct TxMerkleNode(sha256d::Hash);
+    /// A hash corresponding to the Merkle tree root for witness data.
+    pub struct WitnessMerkleNode(sha256d::Hash);
+    /// A hash corresponding to the witness structure commitment in the coinbase transaction.
+    pub struct WitnessCommitment(sha256d::Hash);
+}
+impl_hashencode!(BlockHash);
+impl_hashencode!(TxMerkleNode);
+impl_hashencode!(WitnessMerkleNode);
+
+impl From<Txid> for TxMerkleNode {
+    fn from(txid: Txid) -> Self { Self::from_byte_array(txid.to_byte_array()) }
+}
+
+impl From<Wtxid> for WitnessMerkleNode {
+    fn from(wtxid: Wtxid) -> Self { Self::from_byte_array(wtxid.to_byte_array()) }
+}
 
 /// Bitcoin block header.
 ///

bitcoin/src/consensus/encode.rs

@@ -23,9 +23,9 @@ use internals::write_err;
 use io::{Cursor, Read};
 
 use crate::bip152::{PrefilledTransaction, ShortId};
-use crate::blockdata::block;
+use crate::blockdata::block::{self, BlockHash, TxMerkleNode};
 use crate::blockdata::transaction::{Transaction, TxIn, TxOut};
-use crate::hash_types::{BlockHash, FilterHash, FilterHeader, TxMerkleNode};
+use crate::hash_types::{FilterHash, FilterHeader};
 #[cfg(feature = "std")]
 use crate::p2p::{
     address::{AddrV2Message, Address},

bitcoin/src/hash_types.rs

@@ -25,6 +25,7 @@ macro_rules! impl_hashencode {
         }
     };
 }
+pub(crate) use impl_hashencode;
 
 #[rustfmt::skip]
 macro_rules! impl_asref_push_bytes {
@@ -69,15 +70,6 @@ mod newtypes {
 
         /// A bitcoin witness transaction ID.
         pub struct Wtxid(sha256d::Hash);
-        /// A bitcoin block hash.
-        pub struct BlockHash(sha256d::Hash);
-
-        /// A hash of the Merkle tree branch or root for transactions
-        pub struct TxMerkleNode(sha256d::Hash);
-        /// A hash corresponding to the Merkle tree root for witness data
-        pub struct WitnessMerkleNode(sha256d::Hash);
-        /// A hash corresponding to the witness structure commitment in the coinbase transaction
-        pub struct WitnessCommitment(sha256d::Hash);
 
         /// Filter hash, as defined in BIP-157
         pub struct FilterHash(sha256d::Hash);
@@ -87,23 +79,10 @@ mod newtypes {
 
     impl_hashencode!(Txid);
     impl_hashencode!(Wtxid);
-    impl_hashencode!(BlockHash);
-
-    impl_hashencode!(TxMerkleNode);
-    impl_hashencode!(WitnessMerkleNode);
 
     impl_hashencode!(FilterHash);
     impl_hashencode!(FilterHeader);
-
-    impl From<Txid> for TxMerkleNode {
-        fn from(txid: Txid) -> Self {
-            Self::from(txid.0)
-        }
 }
 
-    impl From<Wtxid> for WitnessMerkleNode {
-        fn from(wtxid: Wtxid) -> Self {
-            Self::from(wtxid.0)
-        }
-    }
-}
+#[deprecated(since = "0.0.0-NEXT-RELEASE", note = "use crate::T instead")]
+pub use crate::{BlockHash, TxMerkleNode, WitnessCommitment, WitnessMerkleNode};

bitcoin/src/lib.rs

@@ -122,7 +122,7 @@ pub use crate::{
     address::{Address, AddressType},
     amount::{Amount, Denomination, SignedAmount},
     bip32::XKeyIdentifier,
-    blockdata::block::{self, Block},
+    blockdata::block::{self, Block, BlockHash, TxMerkleNode, WitnessMerkleNode, WitnessCommitment},
     blockdata::constants,
     blockdata::fee_rate::FeeRate,
     blockdata::locktime::{self, absolute, relative},
@@ -137,7 +137,7 @@ pub use crate::{
     crypto::ecdsa,
     crypto::key::{self, PrivateKey, PubkeyHash, PublicKey, WPubkeyHash, XOnlyPublicKey},
     crypto::sighash::{self, LegacySighash, SegwitV0Sighash, TapSighash, TapSighashTag},
-    hash_types::{BlockHash, FilterHash, FilterHeader, TxMerkleNode, Txid, WitnessCommitment, Wtxid},
+    hash_types::{FilterHash, FilterHeader, Txid, Wtxid},
     merkle_tree::MerkleBlock,
     network::Network,
     pow::{CompactTarget, Target, Work},

bitcoin/src/merkle_tree/block.rs

@@ -43,11 +43,11 @@ use core::fmt;
 use hashes::Hash;
 
 use self::MerkleBlockError::*;
-use crate::blockdata::block::{self, Block};
+use crate::blockdata::block::{self, Block, TxMerkleNode};
 use crate::blockdata::transaction::Transaction;
 use crate::blockdata::weight::Weight;
 use crate::consensus::encode::{self, Decodable, Encodable};
-use crate::hash_types::{TxMerkleNode, Txid};
+use crate::hash_types::Txid;
 use crate::prelude::*;
 
 /// Data structure that represents a block header paired to a partial merkle tree.
@@ -540,8 +540,6 @@ mod tests {
 
     use super::*;
     use crate::consensus::encode::{deserialize, serialize};
-    #[cfg(feature = "rand-std")]
-    use crate::hash_types::TxMerkleNode;
     use crate::{Block, Txid};
 
     #[cfg(feature = "rand-std")]

bitcoin/src/p2p/message_blockdata.rs

@@ -8,8 +8,9 @@
 
 use hashes::{sha256d, Hash as _};
 
+use crate::blockdata::block::BlockHash;
 use crate::consensus::encode::{self, Decodable, Encodable};
-use crate::hash_types::{BlockHash, Txid, Wtxid};
+use crate::hash_types::{Txid, Wtxid};
 use crate::internal_macros::impl_consensus_encoding;
 use crate::prelude::*;
 use crate::{io, p2p};

bitcoin/src/p2p/message_filter.rs

@@ -5,7 +5,8 @@
 //! This module describes BIP157 Client Side Block Filtering network messages.
 //!
 
-use crate::hash_types::{BlockHash, FilterHash, FilterHeader};
+use crate::blockdata::block::BlockHash;
+use crate::hash_types::{FilterHash, FilterHeader};
 use crate::internal_macros::impl_consensus_encoding;
 
 /// getcfilters message

bitcoin/src/pow.rs

@@ -13,10 +13,10 @@ use io::{Read, Write};
 #[cfg(all(test, mutate))]
 use mutagen::mutate;
 
+use crate::blockdata::block::BlockHash;
 use crate::consensus::encode::{self, Decodable, Encodable};
 #[cfg(doc)]
 use crate::consensus::Params;
-use crate::hash_types::BlockHash;
 use crate::prelude::String;
 use crate::string::FromHexStr;
 use crate::Network;