Fibonacci sequence example.

This example allows you to learn a bit of route parsing and how to bind URL parameters to variables.
This example, combined with the hello and json ones will hopefully give a newcomer enough data to start building simple yet powerful webservers.

Author: o0Ignition0o

examples/fib.rs

@@ -0,0 +1,38 @@
+use async_std::task;
+use tide::Request;
+
+fn fib(n: usize) -> usize {
+    if n == 0 || n == 1 {
+        n
+    } else {
+        fib(n - 1) + fib(n - 2)
+    }
+}
+
+async fn fibsum(req: Request<()>) -> String {
+    use std::time::Instant;
+    let n: usize = req.param("n").unwrap_or(0);
+    // Start a stopwatch
+    let start = Instant::now();
+    // Compute the nth number in the fibonacci sequence
+    let fib_n = fib(n);
+    // Stop the stopwatch
+    let duration = Instant::now().duration_since(start).as_secs();
+    // Return the answer
+    format!(
+        "The fib of {} is {}.\nIt was computed in {} secs.\n",
+        n, fib_n, duration,
+    )
+}
+// Example: HTTP GET to http://localhost:8080/fib/42
+// $ curl "http://localhost:8080/fib/42"
+// The fib of 42 is 267914296.
+// It was computed in 2 secs.
+fn main() -> Result<(), std::io::Error> {
+    task::block_on(async {
+        let mut app = tide::new();
+        app.at("/fib/:n").get(fibsum);
+        app.listen("0.0.0.0:8080").await?;
+        Ok(())
+    })
+}