Improve XprivAccount APIs

derive/src/index.rs

@@ -30,6 +30,16 @@ use std::str::FromStr;
 /// is treated as hardened
 pub const HARDENED_INDEX_BOUNDARY: u32 = 1 << 31;
 
+#[macro_export]
+macro_rules! h {
+    ($idx:literal) => {
+        HardenedIndex::from($idx as u16)
+    };
+    [$( $idx:literal ),+] => {
+        [$( HardenedIndex::from($idx as u16) ),+]
+    };
+}
+
 #[derive(Copy, Clone, Eq, PartialEq, Debug, Display, Error)]
 #[display("provided {what} {invalid} is invalid: it lies outside allowed range {start}..={end}")]
 pub struct IndexError {
@@ -580,3 +590,19 @@ impl FromStr for DerivationIndex {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn macro_h_index() {
+        assert_eq!(h!(1), HardenedIndex::ONE);
+    }
+
+    #[test]
+    fn macro_h_path() {
+        let path = [HardenedIndex::from(86u8), HardenedIndex::from(1u8), HardenedIndex::from(0u8)];
+        assert_eq!(h![86, 1, 0], path);
+    }
+}

derive/src/lib.rs

@@ -50,7 +50,7 @@ pub use taptree::{
     TapTreeBuilder, UnfinalizedTree,
 };
 pub use xkey::{
-    ChainCode, KeyOrigin, OriginParseError, XkeyDecodeError, XkeyMeta, XkeyOrigin, XkeyParseError,
-    Xpriv, XprivAccount, XprivCore, Xpub, XpubAccount, XpubCore, XpubDerivable, XpubFp, XpubId,
-    XPRIV_MAINNET_MAGIC, XPRIV_TESTNET_MAGIC,
+    ChainCode, KeyOrigin, OriginParseError, XkeyAccountError, XkeyDecodeError, XkeyMeta,
+    XkeyOrigin, XkeyParseError, Xpriv, XprivAccount, XprivCore, Xpub, XpubAccount, XpubCore,
+    XpubDerivable, XpubFp, XpubId, XPRIV_MAINNET_MAGIC, XPRIV_TESTNET_MAGIC,
 };

derive/src/path.rs

@@ -178,6 +178,10 @@ where
 )]
 pub struct DerivationPath<I = DerivationIndex>(Vec<I>);
 
+impl<I: Clone, const LEN: usize> From<[I; LEN]> for DerivationPath<I> {
+    fn from(path: [I; LEN]) -> Self { Self(path.to_vec()) }
+}
+
 impl<I: Clone> From<&[I]> for DerivationPath<I> {
     fn from(path: &[I]) -> Self { Self(path.to_vec()) }
 }
@@ -239,6 +243,8 @@ impl<I: Idx> DerivationPath<I> {
     /// Constructs empty derivation path.
     pub fn new() -> Self { Self(vec![]) }
 
+    pub fn with_capacity(capacity: usize) -> Self { Self(Vec::with_capacity(capacity)) }
+
     pub fn terminal(&self) -> Option<Terminal> {
         let mut iter = self.iter().rev();
         let index = iter.next()?;