add MerklePrefix::apply (#28)

Author: avahowell

crates/ibc-types-core-commitment/src/prefix.rs

@@ -1,4 +1,5 @@
 use crate::prelude::*;
+use crate::MerklePath;
 
 use crate::Error;
 
@@ -10,6 +11,18 @@ pub struct MerklePrefix {
     pub key_prefix: Vec<u8>,
 }
 
+impl MerklePrefix {
+    /// apply the prefix to the supplied paths
+    pub fn apply(&self, paths: Vec<String>) -> MerklePath {
+        let commitment_str =
+            core::str::from_utf8(&self.key_prefix).expect("commitment prefix is not valid utf-8");
+        let mut key_path: Vec<String> = vec![format!("{commitment_str:?}")];
+        key_path.append(paths.clone().as_mut());
+
+        MerklePath { key_path }
+    }
+}
+
 impl TypeUrl for MerklePrefix {
     const TYPE_URL: &'static str = "/ibc.core.commitment.v1.MerklePrefix";
 }