Add extension type for Block

3 files changed, 42 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index a9b8f8c..faf5d6d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,6 +23,7 @@ mod cli_ui;
 mod configuration;
 mod repository;
 mod state;
+mod typeext;
 mod types;
 mod version;
 
diff --git a/src/typeext/block.rs b/src/typeext/block.rs
new file mode 100644
index 0000000..e899082
--- /dev/null
+++ b/src/typeext/block.rs
@@ -0,0 +1,40 @@
+use failure::Error;
+use futures::Future;
+use futures::stream;
+use futures::stream::Stream;
+
+use crate::types::block::Block;
+use crate::repository::Repository;
+
+/// Wrapper for Block type which holds a reference to the repository and is thus able to provide
+/// convenient functionality out of the box
+pub struct BlockExt {
+    block: Block,
+    repo: Repository,
+}
+
+impl Into<Block> for BlockExt {
+    fn into(self) -> Block {
+        self.block
+    }
+}
+
+impl BlockExt {
+    pub fn from_block(block: Block, repo: Repository) -> Self {
+        BlockExt { block, repo }
+    }
+
+    pub fn parents(&self) -> impl Stream<Item = BlockExt, Error = Error> {
+        let parents = self.block.parents().clone();
+        let repo    = self.repo.clone();
+
+        stream::unfold(parents, move |mut state| {
+            let repo = repo.clone(); // dont understand why this is necessary
+            state.pop().map(move |hash| {
+                repo.get_block(hash).map(move |block| {
+                    (BlockExt::from_block(block, repo.clone()), state)
+                })
+            })
+        })
+    }
+}
diff --git a/src/typeext/mod.rs b/src/typeext/mod.rs
new file mode 100644
index 0000000..a863eaa
--- /dev/null
+++ b/src/typeext/mod.rs
@@ -0,0 +1 @@
+pub mod block;