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

@@ -55,7 +55,6 @@ use diff::sliders::fix_all_sliders;
 use options::{DisplayMode, DisplayOptions, FileArgument, Mode, DEFAULT_TAB_WIDTH};
 use owo_colors::OwoColorize;
 use rayon::prelude::*;
-use std::path::PathBuf;
 use std::{env, path::Path};
 use summary::{DiffResult, FileContent};
 use syntax::init_next_prev;
@@ -142,7 +141,7 @@ fn main() {
                 print!("{}", name);
 
                 let mut extensions: Vec<&str> = (*extensions).into();
-                extensions.sort();
+                extensions.sort_unstable();
 
                 for extension in extensions {
                     print!(" .{}", extension);
@@ -179,8 +178,8 @@ fn main() {
                     options::FileArgument::NamedPath(rhs_path),
                 ) if lhs_path.is_dir() && rhs_path.is_dir() => {
                     diff_directories(
-                        &lhs_path,
-                        &rhs_path,
+                        lhs_path,
+                        rhs_path,
                         &display_options,
                         graph_limit,
                         byte_limit,
@@ -403,8 +402,8 @@ fn diff_file_content(
 /// When more than one file is modified, the hg extdiff extension passes directory
 /// paths with the all the modified files.
 fn diff_directories<'a>(
-    lhs_dir: &'a PathBuf,
-    rhs_dir: &'a PathBuf,
+    lhs_dir: &'a Path,
+    rhs_dir: &'a Path,
     display_options: &DisplayOptions,
     graph_limit: usize,
     byte_limit: usize,

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];
         }