fix formatting and improve naming

Author: bryanhitc

examples/completion.rs

@@ -29,7 +29,12 @@ impl Default for MyCompletion {
 impl Completion for MyCompletion {
     /// Simple completion implementation based on substring
     fn get(&self, input: &str) -> Option<String> {
-        let matches = self.options.iter().filter(|x| x.starts_with(input)).collect::<Vec<_>>();
+        let matches = self
+            .options
+            .iter()
+            .filter(|option| option.starts_with(input))
+            .collect::<Vec<_>>();
+
         if matches.len() == 1 {
             Some(matches[0].to_string())
         } else {