From 2715a6e7779390390d45ae8ce87d0ced8985802f Mon Sep 17 00:00:00 2001
From: Carl Dong <accounts@carldong.me>
Date: Sat, 8 Sep 2018 20:50:45 -0700
Subject: [PATCH] Add trait for PSBT key-value maps

---
 src/util/psbt/map/mod.rs | 15 +++++++++++++++
 src/util/psbt/mod.rs     |  3 +++
 2 files changed, 18 insertions(+)
 create mode 100644 src/util/psbt/map/mod.rs

diff --git a/src/util/psbt/map/mod.rs b/src/util/psbt/map/mod.rs
new file mode 100644
index 00000000..621b865a
--- /dev/null
+++ b/src/util/psbt/map/mod.rs
@@ -0,0 +1,15 @@
+use consensus::encode;
+use util::psbt;
+use util::psbt::raw;
+
+/// A trait that describes a PSBT key-value map.
+pub trait Map {
+    /// Attempt to insert a key-value pair.
+    fn insert_pair(&mut self, pair: raw::Pair) -> Result<(), encode::Error>;
+
+    /// Attempt to get all key-value pairs.
+    fn get_pairs(&self) -> Result<Vec<raw::Pair>, encode::Error>;
+
+    /// Attempt to merge with another key-value map of the same type.
+    fn merge(&mut self, other: Self) -> Result<(), psbt::Error>;
+}
diff --git a/src/util/psbt/mod.rs b/src/util/psbt/mod.rs
index 421c7cb5..7d87d59b 100644
--- a/src/util/psbt/mod.rs
+++ b/src/util/psbt/mod.rs
@@ -9,6 +9,9 @@ pub use self::error::Error;
 
 pub mod raw;
 
+mod map;
+pub use self::map::Map;
+
 #[cfg(test)]
 mod tests {
     use consensus::encode::{deserialize, serialize};