Unfold example.

2 files changed, 20 insertions, 0 deletions

diff --git a/rust/graph/Cargo.toml b/rust/graph/Cargo.toml
index eb0841b..1cd21d8 100644
--- a/rust/graph/Cargo.toml
+++ b/rust/graph/Cargo.toml
@@ -13,3 +13,7 @@ path = "graph.rs"
 [[bin]]
 name = "graph2"
 path = "graph2.rs"
+
+[[bin]]
+name = "unfold"
+path = "unfold.rs"
diff --git a/rust/graph/unfold.rs b/rust/graph/unfold.rs
new file mode 100644
index 0000000..90de74c
--- /dev/null
+++ b/rust/graph/unfold.rs
@@ -0,0 +1,16 @@
+extern crate itertools;
+
+use itertools::Unfold;
+
+fn main() {
+    for n in Unfold::new(1, |state| {
+        if *state < 100 {
+            *state += 1;
+            Some(*state)
+        } else {
+            None
+        }
+    }) {
+        println!("{}", n);
+    }
+}