Clippy lints

src/primitives/mod.rs

@@ -23,7 +23,7 @@ pub fn any_char(input: &str) -> ParseResult<&str, char, &str> {
 
 pub fn one_of<'a>(items: &'static str) -> impl Parser<&'a str, &'a str, &'a str> {
     move |input: &'a str| {
-        if let Some(ch) = input.chars().nth(0) {
+        if let Some(ch) = input.chars().next() {
             if items.contains(ch) {
                 let (first, rest) = input.split_at(1);
                 return Ok((first, rest));
@@ -60,7 +60,7 @@ pub fn identifier(input: &str) -> ParseResult<&str, String, &str> {
         _ => return Err(input),
     }
 
-    while let Some(next) = chars.next() {
+    for next in chars {
         if next.is_alphanumeric() {
             buf.push(next);
         } else {