edits

* Use a BTreeSet instead of a Vec. `Vec::dedup` only works on
  consecutive entries so we need a set to deduplicate instead.
* Use the `filename` completer as-is in `repeating_filenames` when the
  input is empty. This makes `:sh cat <cursor here>` for example show
  all files (same as`:open <cursor here>`).
* Refactor `shell` completer in terms of `repeating_filenames` (and
  inline `get_last_argument` helper)
* Remove comment about bash completion scripts. If anything that could
  be a plugin but we shouldn't be parsing bash in core: any shell can
  be configured for use in `:sh`.

helix-term/src/ui/mod.rs

@@ -371,7 +371,7 @@ fn directory_content(path: &Path) -> Result<Vec<(PathBuf, bool)>, std::io::Error
 pub mod completers {
     use super::Utf8PathBuf;
     use crate::ui::prompt::Completion;
-    use helix_core::command_line::{self, Token, Tokenizer};
+    use helix_core::command_line::{self, Tokenizer};
     use helix_core::fuzzy::fuzzy_match;
     use helix_core::syntax::LanguageServerFeature;
     use helix_view::document::SCRATCH_BUFFER_NAME;
@@ -379,6 +379,7 @@ pub mod completers {
     use helix_view::{editor::Config, Editor};
     use once_cell::sync::Lazy;
     use std::borrow::Cow;
+    use std::collections::BTreeSet;
     use tui::text::Span;
 
     pub type Completer = fn(&Editor, &str) -> Vec<Completion>;
@@ -680,27 +681,24 @@ pub mod completers {
     }
 
     pub fn program(_editor: &Editor, input: &str) -> Vec<Completion> {
-        static PROGRAMS_IN_PATH: Lazy<Vec<String>> = Lazy::new(|| {
-            // Go through the entire PATH and read all files into a vec.
+        static PROGRAMS_IN_PATH: Lazy<BTreeSet<String>> = Lazy::new(|| {
+            // Go through the entire PATH and read all files into a set.
             let Some(path) = std::env::var_os("PATH") else {
-                return Vec::new();
+                return Default::default();
             };
 
-            let mut vec = std::env::split_paths(&path)
-                .flat_map(|s| {
-                    std::fs::read_dir(s)
-                        .map_or_else(|_| vec![], |res| res.into_iter().collect::<Vec<_>>())
+            std::env::split_paths(&path)
+                .filter_map(|path| std::fs::read_dir(path).ok())
+                .flatten()
+                .filter_map(|res| {
+                    let entry = res.ok()?;
+                    if entry.metadata().ok()?.is_file() {
+                        entry.file_name().into_string().ok()
+                    } else {
+                        None
+                    }
                 })
-                .filter_map(|it| it.ok())
-                .map(|f| f.path())
-                .filter(|p| !p.is_dir())
-                .filter_map(|p| p.file_name().and_then(|s| s.to_str().map(|s| s.to_owned())))
-                .collect::<Vec<_>>();
-
-            // Paths can share programs like /bin and /usr/bin sometimes contain the same.
-            vec.dedup();
-
-            vec
+                .collect()
         });
 
         fuzzy_match(input, PROGRAMS_IN_PATH.iter(), false)
@@ -709,22 +707,15 @@ pub mod completers {
             .collect()
     }
 
-    fn get_last_argument(input: &str) -> Option<Token> {
-        let tokenizer = Tokenizer::new(input, false);
-        let last = tokenizer.last()?;
-
-        Some(last.unwrap())
-    }
-
     /// This expects input to be a raw string of arguments, because this is what Signature's raw_after does.
     pub fn repeating_filenames(editor: &Editor, input: &str) -> Vec<Completion> {
-        let Some(token) = get_last_argument(input) else {
-            return Vec::new();
+        let token = match Tokenizer::new(input, false).last() {
+            Some(token) => token.unwrap(),
+            None => return filename(editor, input),
         };
 
         let offset = token.content_start;
 
-        // Theoretically one could now parse bash completion scripts, but filename should suffice for now.
         let mut completions = filename(editor, &input[offset..]);
         for completion in completions.iter_mut() {
             completion.0.start += offset;
@@ -733,20 +724,16 @@ pub mod completers {
     }
 
     pub fn shell(editor: &Editor, input: &str) -> Vec<Completion> {
-        let (_, _, complete_command) = command_line::split(input);
+        let (command, args, complete_command) = command_line::split(input);
 
         if complete_command {
-            return program(editor, input);
+            return program(editor, command);
         }
 
-        let Some(token) = get_last_argument(input) else {
-            return Vec::new();
-        };
-
-        let mut completions = repeating_filenames(editor, &token.content);
-
+        let mut completions = repeating_filenames(editor, args);
         for completion in completions.iter_mut() {
-            completion.0.start += token.content_start;
+            // + 1 for separator between `command` and `args`
+            completion.0.start += command.len() + 1;
         }
 
         completions