Add a simple repl example

examples/repl.rs

@@ -0,0 +1,30 @@
+//! This example shows a simple read-evaluate-print-loop (REPL).
+
+extern crate rlua;
+
+use rlua::*;
+use std::io::prelude::*;
+use std::io::{stdin, stdout, stderr, BufReader};
+
+fn main() {
+    let lua = Lua::new();
+    let mut stdout = stdout();
+    let mut stdin = BufReader::new(stdin());
+
+    loop {
+        write!(stdout, "> ").unwrap();
+        stdout.flush().unwrap();
+
+        let mut line = String::new();
+        stdin.read_line(&mut line).unwrap();
+
+        match lua.eval::<LuaMultiValue>(&line) {
+            Ok(values) => {
+                println!("{}", values.iter().map(|value| format!("{:?}", value)).collect::<Vec<_>>().join("\t"));
+            }
+            Err(e) => {
+                writeln!(stderr(), "error: {}", e).unwrap();
+            }
+        }
+    }
+}