Bind to uniffi using proc macros

Proc macros let rust-analyzer check that types are compatible
at rust compile time, and thus let downstream projects more easily
depend on bitcoin-ffi.

A couple types needed explicit wrappers in order to use macros.

src/bitcoin.udl

@@ -1,152 +1 @@
 namespace bitcoin {};
-
-// ------------------------------------------------------------------------
-// Core types
-// ------------------------------------------------------------------------
-
-interface Script {
-  constructor(sequence<u8> raw_output_script);
-
-  sequence<u8> to_bytes();
-};
-
-interface Amount {
-  [Name=from_sat]
-  constructor(u64 from_sat);
-
-  [Name=from_btc, Throws=ParseAmountError]
-  constructor(f64 from_btc);
-
-  u64 to_sat();
-
-  f64 to_btc();
-};
-
-interface FeeRate {
-  [Name=from_sat_per_vb, Throws=FeeRateError]
-  constructor(u64 sat_per_vb);
-
-  [Name=from_sat_per_kwu]
-  constructor(u64 sat_per_kwu);
-
-  u64 to_sat_per_vb_ceil();
-
-  u64 to_sat_per_vb_floor();
-
-  u64 to_sat_per_kwu();
-};
-
-[Custom]
-typedef string Txid;
-
-[Custom]
-typedef string BlockHash;
-
-dictionary OutPoint {
-  Txid txid;
-  u32 vout;
-};
-
-dictionary TxIn {
-  OutPoint previous_output;
-  Script script_sig;
-  u32 sequence;
-  sequence<sequence<u8>> witness;
-};
-
-[NonExhaustive]
-enum Network {
-  "Bitcoin",
-  "Testnet",
-  "Signet",
-  "Regtest",
-};
-
-[Traits=(Display)]
-interface Address {
-  [Throws=AddressParseError]
-  constructor(string address, Network network);
-
-  [Name=from_script, Throws=FromScriptError]
-  constructor(Script script, Network network);
-
-  Script script_pubkey();
-
-  string to_qr_uri();
-
-  boolean is_valid_for_network(Network network);
-};
-
-dictionary TxOut {
-  Amount value;
-  Script script_pubkey;
-};
-
-interface Transaction {
-  [Name=deserialize, Throws=EncodeError]
-  constructor([ByRef] bytes transaction_bytes);
-  bytes serialize();
-  string compute_txid();
-  u64 total_size();
-  u64 vsize();
-  boolean is_coinbase();
-  boolean is_explicitly_rbf();
-  boolean is_lock_time_enabled();
-  i32 version();
-  u64 weight();
-  sequence<TxIn> input();
-  sequence<TxOut> output();
-  u32 lock_time();
-};
-
-// ------------------------------------------------------------------------
-// Errors
-// ------------------------------------------------------------------------
-
-[Error]
-enum AddressParseError {
-    "Base58",
-    "Bech32",
-    "WitnessVersion",
-    "WitnessProgram",
-    "UnknownHrp",
-    "LegacyAddressTooLong",
-    "InvalidBase58PayloadLength",
-    "InvalidLegacyPrefix",
-    "NetworkValidation",
-    "OtherAddressParseErr",
-};
-
-[Error]
-interface FromScriptError {
-  UnrecognizedScript();
-  WitnessProgram(string error_message);
-  WitnessVersion(string error_message);
-  OtherFromScriptErr();
-};
-
-[Error]
-interface ParseAmountError {
-  OutOfRange();
-  TooPrecise();
-  MissingDigits();
-  InputTooLarge();
-  InvalidCharacter(string error_message);
-  OtherParseAmountErr();
-};
-
-[Error]
-interface FeeRateError {
-  ArithmeticOverflow();
-};
-
-[Error]
-interface EncodeError {
-  Io();
-  OversizedVectorAllocation();
-  InvalidChecksum(string expected, string actual);
-  NonMinimalVarInt();
-  ParseFailed();
-  UnsupportedSegwitFlag(u8 flag);
-  OtherEncodeErr();
-};

src/error.rs

@@ -4,7 +4,7 @@ use bitcoin::amount::ParseAmountError as BitcoinParseAmountError;
 use bitcoin::consensus::encode::Error as BitcoinEncodeError;
 use bitcoin::hex::DisplayHex;
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, uniffi::Error)]
 pub enum AddressParseError {
     #[error("base58 address encoding error")]
     Base58,
@@ -51,13 +51,13 @@ impl From<BitcoinParseError> for AddressParseError {
     }
 }
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, uniffi::Error)]
 pub enum FeeRateError {
     #[error("arithmetic overflow on feerate")]
     ArithmeticOverflow,
 }
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, uniffi::Error)]
 pub enum FromScriptError {
     #[error("script is not a p2pkh, p2sh or witness program")]
     UnrecognizedScript,
@@ -88,7 +88,7 @@ impl From<BitcoinFromScriptError> for FromScriptError {
     }
 }
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, uniffi::Error)]
 pub enum ParseAmountError {
     #[error("amount out of range")]
     OutOfRange,
@@ -125,7 +125,7 @@ impl From<BitcoinParseAmountError> for ParseAmountError {
     }
 }
 
-#[derive(Debug, thiserror::Error)]
+#[derive(Debug, thiserror::Error, uniffi::Error)]
 pub enum EncodeError {
     #[error("io error")]
     Io,