Adding digital locker example (#117)

examples/simple_login.rs

@@ -142,34 +142,6 @@ fn account_login(
     client_login_finish_result.shared_secret == server_login_finish_result.shared_secret
 }
 
-// A function run on the client which extracts a username and password from the CLI
-fn get_username_and_password(rl: &mut Editor<()>, username: Option<String>) -> (String, String) {
-    let query = if username.is_none() {
-        "Username: "
-    } else {
-        "Password: "
-    };
-    let readline = rl.readline(query);
-    match readline {
-        Ok(line) => match username {
-            Some(x) => (x, line),
-            None => get_username_and_password(rl, Some(line)),
-        },
-        Err(ReadlineError::Interrupted) => {
-            println!("CTRL-C");
-            exit(0)
-        }
-        Err(ReadlineError::Eof) => {
-            println!("CTRL-D");
-            exit(0)
-        }
-        Err(err) => {
-            println!("Error: {:?}", err);
-            exit(0)
-        }
-    }
-}
-
 fn main() {
     let mut rng = OsRng;
     let server_kp = Default::generate_random_keypair(&mut rng).unwrap();
@@ -192,7 +164,7 @@ fn main() {
                     println!("Error: Invalid option (either specify 1 or 2)");
                     continue;
                 }
-                let (username, password) = get_username_and_password(&mut rl, None);
+                let (username, password) = get_two_strings("Username", "Password", &mut rl, None);
                 match line.as_ref() {
                     "1" => {
                         registered_users
@@ -217,18 +189,48 @@ fn main() {
                     _ => exit(0),
                 }
             }
-            Err(ReadlineError::Interrupted) => {
-                println!("CTRL-C");
-                exit(0)
-            }
-            Err(ReadlineError::Eof) => {
-                println!("CTRL-D");
-                exit(0)
-            }
             Err(err) => {
-                println!("Error: {:?}", err);
+                handle_error(err);
                 exit(0)
             }
         }
     }
 }
+
+// Helper functions
+
+// Handle readline errors
+fn handle_error(err: ReadlineError) {
+    match err {
+        ReadlineError::Interrupted => {
+            println!("CTRL-C");
+        }
+        ReadlineError::Eof => {
+            println!("CTRL-D");
+        }
+        err => {
+            println!("Error: {:?}", err);
+        }
+    }
+}
+
+// A function run on the client which extracts two strings from the CLI
+fn get_two_strings(
+    s1: &str,
+    s2: &str,
+    rl: &mut Editor<()>,
+    string1: Option<String>,
+) -> (String, String) {
+    let query = if string1.is_none() { s1 } else { s2 };
+    let readline = rl.readline(&format!("{}: ", query));
+    match readline {
+        Ok(line) => match string1 {
+            Some(x) => (x, line),
+            None => get_two_strings(s1, s2, rl, Some(line)),
+        },
+        Err(err) => {
+            handle_error(err);
+            exit(0)
+        }
+    }
+}