Implement `hx --tutor` and `:tutor` to load `tutor.txt` (#898)

* Implement `hx --tutor` and `:tutor` to load `tutor.txt`

* Document `hx --tutor` and `:tutor`

* Change `Document::set_path` to take an `Option`

* `Document::set_path` accepts an `Option<&Path>` instead of `&Path`.
* Remove `Editor::open_tutor` and make tutor-open functionality use
  `Editor::open` and `Document::set_path`.

* Use `PathBuf::join`

Co-authored-by: Ivan Tham <pickfire@riseup.net>

* Add comments explaining unsetting tutor path

Co-authored-by: Ivan Tham <pickfire@riseup.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 662573c6..55b12c5a 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -97,7 +97,12 @@ impl Application {
         let editor_view = Box::new(ui::EditorView::new(std::mem::take(&mut config.keys)));
         compositor.push(editor_view);
 
-        if !args.files.is_empty() {
+        if args.load_tutor {
+            let path = helix_core::runtime_dir().join("tutor.txt");
+            editor.open(path, Action::VerticalSplit)?;
+            // Unset path to prevent accidentally saving to the original tutor file.
+            doc_mut!(editor).set_path(None)?;
+        } else if !args.files.is_empty() {
             let first = &args.files[0]; // we know it's not empty
             if first.is_dir() {
                 std::env::set_current_dir(&first)?;