Move params to network module

The `Params` struct is currently defined in the `consensus` module which
has become a collection of orthogonal consensus-ish things. We would
like to put things in more descriptive places.

The `Params` struct defines constants that are network specific so it
makes sense to put it in the `network` module. As soft proof of this
argument note in this patch how often the `Params` type is imported
along with the `Network` type.

API break:

The type is no longer available at `bitcoin::consensus::Params` but
rather is re-exported at `bitcoin::network::Params`.

bitcoin/src/address/mod.rs

@@ -39,7 +39,6 @@ use hashes::{hash160, HashEngine};
 use secp256k1::{Secp256k1, Verification, XOnlyPublicKey};
 
 use crate::address::script_pubkey::ScriptBufExt as _;
-use crate::consensus::Params;
 use crate::constants::{
     PUBKEY_ADDRESS_PREFIX_MAIN, PUBKEY_ADDRESS_PREFIX_TEST, SCRIPT_ADDRESS_PREFIX_MAIN,
     SCRIPT_ADDRESS_PREFIX_TEST,
@@ -47,7 +46,7 @@ use crate::constants::{
 use crate::crypto::key::{
     CompressedPublicKey, PubkeyHash, PublicKey, TweakedPublicKey, UntweakedPublicKey,
 };
-use crate::network::{Network, NetworkKind};
+use crate::network::{Network, NetworkKind, Params};
 use crate::prelude::{String, ToOwned};
 use crate::script::witness_program::WitnessProgram;
 use crate::script::witness_version::WitnessVersion;
@@ -892,7 +891,7 @@ mod tests {
     use hex_lit::hex;
 
     use super::*;
-    use crate::consensus::params;
+    use crate::network::params;
     use crate::network::Network::{Bitcoin, Testnet};
 
     fn roundtrips(addr: &Address, network: Network) {

bitcoin/src/blockdata/block.rs

@@ -13,9 +13,10 @@ use hashes::{sha256d, HashEngine};
 use io::{BufRead, Write};
 
 use super::Weight;
-use crate::consensus::{encode, Decodable, Encodable, Params};
+use crate::consensus::{encode, Decodable, Encodable};
 use crate::internal_macros::{impl_consensus_encoding, impl_hashencode};
 use crate::merkle_tree::{MerkleNode as _, TxMerkleNode, WitnessMerkleNode};
+use crate::network::Params;
 use crate::pow::{CompactTarget, Target, Work};
 use crate::prelude::Vec;
 use crate::transaction::{Transaction, Wtxid};

bitcoin/src/blockdata/constants.rs

@@ -10,10 +10,9 @@ use hashes::sha256d;
 use internals::impl_array_newtype;
 
 use crate::block::{self, Block};
-use crate::consensus::Params;
 use crate::internal_macros::impl_array_newtype_stringify;
 use crate::locktime::absolute;
-use crate::network::Network;
+use crate::network::{Network, Params};
 use crate::opcodes::all::*;
 use crate::pow::CompactTarget;
 use crate::transaction::{self, OutPoint, Transaction, TxIn, TxOut};
@@ -216,7 +215,7 @@ mod test {
 
     use super::*;
     use crate::consensus::encode::serialize;
-    use crate::consensus::params;
+    use crate::network::params;
     use crate::Txid;
 
     #[test]

bitcoin/src/blockdata/transaction.rs

@@ -118,9 +118,8 @@ impl OutPoint {
     /// # Examples
     ///
     /// ```rust
-    /// use bitcoin::consensus::params;
     /// use bitcoin::constants::genesis_block;
-    /// use bitcoin::Network;
+    /// use bitcoin::{params, Network};
     ///
     /// let block = genesis_block(&params::MAINNET);
     /// let tx = &block.txdata[0];

bitcoin/src/consensus/mod.rs

@@ -6,7 +6,6 @@
 //! conform to Bitcoin consensus.
 
 pub mod encode;
-pub mod params;
 #[cfg(feature = "serde")]
 pub mod serde;
 #[cfg(feature = "bitcoinconsensus")]
@@ -23,7 +22,6 @@ use crate::consensus;
 #[doc(inline)]
 pub use self::{
     encode::{deserialize, deserialize_partial, serialize, Decodable, Encodable, ReadExt, WriteExt},
-    params::Params,
 };
 
 #[cfg(feature = "bitcoinconsensus")]

bitcoin/src/lib.rs

@@ -123,12 +123,12 @@ pub use crate::{
     blockdata::weight::Weight,
     blockdata::witness::{self, Witness},
     consensus::encode::VarInt,
-    consensus::params,
     crypto::ecdsa,
     crypto::key::{self, PrivateKey, PubkeyHash, PublicKey, CompressedPublicKey, WPubkeyHash, XOnlyPublicKey},
     crypto::sighash::{self, LegacySighash, SegwitV0Sighash, TapSighash, TapSighashTag},
     merkle_tree::{MerkleBlock, TxMerkleNode, WitnessMerkleNode},
     network::{Network, NetworkKind},
+    network::params::{self, Params},
     pow::{CompactTarget, Target, Work},
     psbt::Psbt,
     sighash::{EcdsaSighashType, TapSighashType},

bitcoin/src/network/mod.rs

@@ -18,6 +18,8 @@
 //! assert_eq!(&bytes[..], &[0xF9, 0xBE, 0xB4, 0xD9]);
 //! ```
 
+pub mod params;
+
 use core::fmt;
 use core::str::FromStr;
 
@@ -25,11 +27,14 @@ use internals::write_err;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-use crate::consensus::Params;
 use crate::constants::ChainHash;
 use crate::p2p::Magic;
 use crate::prelude::{String, ToOwned};
 
+#[rustfmt::skip]                // Keep public re-exports separate.
+#[doc(inline)]
+pub use self::params::Params;
+
 /// What kind of network we are on.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum NetworkKind {

bitcoin/src/network/params.rs

@@ -11,7 +11,7 @@
 //! custom type that can be used is such places you might want to do the following:
 //!
 //! ```
-//! use bitcoin::consensus::Params;
+//! use bitcoin::network::Params;
 //! use bitcoin::{p2p, Script, ScriptBuf, Network, Target};
 //!
 //! const POW_TARGET_SPACING: u64 = 120; // Two minutes.

bitcoin/src/p2p/mod.rs

@@ -28,9 +28,8 @@ use internals::{debug_from_display, write_err};
 use io::{BufRead, Write};
 
 use crate::consensus::encode::{self, Decodable, Encodable};
-use crate::consensus::Params;
+use crate::network::{Network, Params};
 use crate::prelude::{Borrow, BorrowMut, String, ToOwned};
-use crate::Network;
 
 #[rustfmt::skip]
 #[doc(inline)]

bitcoin/src/pow.rs

@@ -15,7 +15,7 @@ use units::parse::{self, ParseIntError, PrefixedHexError, UnprefixedHexError};
 
 use crate::block::{BlockHash, Header};
 use crate::consensus::encode::{self, Decodable, Encodable};
-use crate::consensus::Params;
+use crate::network::Params;
 
 /// Implement traits and methods shared by `Target` and `Work`.
 macro_rules! do_impl {