Fix more clippy warnings

src/diff/graph.rs

@@ -731,7 +731,7 @@ pub fn get_set_neighbours<'syn, 'b>(
         }
     }
     assert!(
-        res.len() > 0,
+        !res.is_empty(),
         "Must always find some next steps if node is not the end"
     );
 

src/display/style.rs

@@ -130,7 +130,7 @@ pub fn split_and_apply(
             let end_col = span.end_col as usize;
 
             // The remaining spans are beyond the end of this line_part.
-            if start_col >= part_start + byte_len(&line_part) {
+            if start_col >= part_start + byte_len(line_part) {
                 break;
             }
 

src/main.rs

@@ -142,7 +142,7 @@ fn main() {
                 print!("{}", name);
 
                 let mut extensions: Vec<&str> = (*extensions).into();
-                extensions.sort();
+                extensions.sort_unstable();
 
                 for extension in extensions {
                     print!(" .{}", extension);

src/parse/guess_language.rs

@@ -120,7 +120,7 @@ pub fn language_name(language: Language) -> &'static str {
     }
 }
 
-pub const LANG_EXTENSIONS: &'static [(Language, &[&str])] = &[
+pub const LANG_EXTENSIONS: &[(Language, &[&str])] = &[
     (
         Bash,
         &[

src/parse/syntax.rs

@@ -246,7 +246,7 @@ impl<'a> Syntax<'a> {
     ) -> &'a Syntax<'a> {
         // If a parser hasn't cleaned up \r on CRLF files with
         // comments, discard it.
-        if content.ends_with("\r") {
+        if content.ends_with('\r') {
             content = &content[..content.len() - 1];
         }