Add * # { } vi motions

This patch adds Vi's semantic search and paragraph motion.

The semantic search uses either the selection or the semantic word under
the cursor and jumps to the next match in the desired direction.

Paragraph motion jumps to just above or below the current paragraph.

Closes #7961.

Co-authored-by: Fletcher Gornick <fletcher@gornick.dev>

1 files changed, 21 insertions, 0 deletions

diff --git a/alacritty/src/input/mod.rs b/alacritty/src/input/mod.rs
index 3f85512f..a69d2989 100644
--- a/alacritty/src/input/mod.rs
+++ b/alacritty/src/input/mod.rs
@@ -112,6 +112,7 @@ pub trait ActionContext<T: EventListener> {
     fn clipboard_mut(&mut self) -> &mut Clipboard;
     fn scheduler_mut(&mut self) -> &mut Scheduler;
     fn start_search(&mut self, _direction: Direction) {}
+    fn start_seeded_search(&mut self, _direction: Direction, _text: String) {}
     fn confirm_search(&mut self) {}
     fn cancel_search(&mut self) {}
     fn search_input(&mut self, _c: char) {}
@@ -132,6 +133,7 @@ pub trait ActionContext<T: EventListener> {
     fn hint_input(&mut self, _character: char) {}
     fn trigger_hint(&mut self, _hint: &HintMatch) {}
     fn expand_selection(&mut self) {}
+    fn semantic_word(&self, point: Point) -> String;
     fn on_terminal_input_start(&mut self) {}
     fn paste(&mut self, _text: &str, _bracketed: bool) {}
     fn spawn_daemon<I, S>(&self, _program: &str, _args: I)
@@ -278,6 +280,21 @@ impl<T: EventListener> Execute<T> for Action {
             },
             Action::Vi(ViAction::InlineSearchNext) => ctx.inline_search_next(),
             Action::Vi(ViAction::InlineSearchPrevious) => ctx.inline_search_previous(),
+            Action::Vi(ViAction::SemanticSearchForward | ViAction::SemanticSearchBackward) => {
+                let seed_text = match ctx.terminal().selection_to_string() {
+                    Some(selection) if !selection.is_empty() => selection,
+                    // Get semantic word at the vi cursor position.
+                    _ => ctx.semantic_word(ctx.terminal().vi_mode_cursor.point),
+                };
+
+                if !seed_text.is_empty() {
+                    let direction = match self {
+                        Action::Vi(ViAction::SemanticSearchForward) => Direction::Right,
+                        _ => Direction::Left,
+                    };
+                    ctx.start_seeded_search(direction, seed_text);
+                }
+            },
             action @ Action::Search(_) if !ctx.search_active() => {
                 debug!("Ignoring {action:?}: Search mode inactive");
             },
@@ -1237,6 +1254,10 @@ mod tests {
         fn scheduler_mut(&mut self) -> &mut Scheduler {
             unimplemented!();
         }
+
+        fn semantic_word(&self, _point: Point) -> String {
+            unimplemented!();
+        }
     }
 
     macro_rules! test_clickstate {