1 files changed, 22 insertions, 0 deletions
diff --git a/examples/03_sample-filter.rs b/examples/03_sample-filter.rs
new file mode 100644
index 0000000..3fc0bff
--- /dev/null
+++ b/examples/03_sample-filter.rs
@@ -0,0 +1,22 @@
+fn main() {
+    // A simple integer calculator:
+    // `+` or `-` means add or subtract by 1
+    // `*` or `/` means multiply or divide by 2
+
+    let program = "+ + * - /";
+    let mut accumulator = 0i;
+
+    for token in program.chars().filter(|&x| { x != ' ' }) {
+        match token {
+            '+' => accumulator += 1,
+            '-' => accumulator -= 1,
+            '*' => accumulator *= 2,
+            '/' => accumulator /= 2,
+            _   => fail!("unknown character"),
+        }
+    }
+
+    println!("The program \"{}\" calculates the value {}",
+              program, accumulator);
+}
+