feat: add flags method to Args

This can simplify the boilerplate of returning, and advancing, the Args
iterator, returning only when there is matching flags.

helix-core/src/shellwords.rs

@@ -195,6 +195,24 @@ impl<'a> Args<'a> {
             count: 0,
         }
     }
+
+    pub fn flags<'f, F: Iterator<Item = &'f str>>(&mut self, mut flags: F) -> Option<&'a str> {
+        if self.is_empty() {
+            return None;
+        }
+
+        let mut args = self.peekable();
+
+        if let Some(arg) = args.peek() {
+            if flags.any(|f| f == arg.trim_start_matches('-').trim_start_matches("--")) {
+                return self
+                    .next()
+                    .map(|flag| flag.trim_start_matches('-').trim_start_matches("--"));
+            }
+        }
+
+        None
+    }
 }
 
 impl<'a> Iterator for Args<'a> {

helix-term/src/commands/typed.rs

@@ -2131,16 +2131,15 @@ fn sort(
         return Ok(());
     }
 
-    if let Some(flag) = args.next() {
-        let flag = flag.trim_start_matches("--").trim_start_matches('-');
+    let flags = flags
+        .iter()
+        .map(|flag| flag.long)
+        .chain(flags.iter().filter_map(|flag| flag.short));
 
-        if flags
-            .iter()
-            .any(|x| x.long == flag || x.short == Some(flag))
-        {
-            sort_impl(cx, true);
-        } else {
-            bail!("There is no flag `--{flag}` on sort");
+    if let Some(flag) = args.flags(flags) {
+        match flag {
+            "reverse" | "r" => sort_impl(cx, true),
+            _ => bail!("unhandle command flag `{flag}`, implementation failed to cover all flags."),
         }
     } else {
         sort_impl(cx, false);