Refactor code based on clippy suggestions

src/parser.rs

@@ -16,7 +16,7 @@ pub fn parse_key_value(text: &str) -> HashMap<String, String> {
     let mut result = HashMap::new();
     tokens = scan(text, 0, tokens);
     for token_chunk in tokens.chunks(4) {
-        match &token_chunk[..] {
+        match token_chunk {
             [Token::Identifier(key), Token::Equal, Token::Identifier(value), Token::Ampersand] => {
                 result.insert(key.to_string(), value.to_string());
             }
@@ -54,8 +54,8 @@ fn scan(code: &str, mut ix: usize, mut tokens: Tokens) -> Tokens {
 
 fn scan_identifier(code: &str, mut ix: usize, mut tokens: Tokens) -> Tokens {
     let start_ix = ix;
-    let mut chars = code[ix..].chars();
-    while let Some(c) = chars.next() {
+    let chars = code[ix..].chars();
+    for c in chars {
         if c.is_ascii_alphanumeric() || SPECIAL_CHARS.contains(&c) {
             ix += 1;
         } else {