Implement "Goto last modification" command

helix-core/src/history.rs

@@ -133,6 +133,18 @@ impl History {
         Some(&self.revisions[last_child.get()].transaction)
     }
 
+    pub fn last_edit_pos(&mut self) -> Option<usize> {
+        let current_revision = &self.revisions[self.current];
+        if let Some(op) = &current_revision.transaction.changes().changes.first() {
+            if let crate::Operation::Retain(pos) = op {
+                return Some(*pos);
+            }
+            Some(0)
+        } else {
+            None
+        }
+    }
+
     fn lowest_common_ancestor(&self, mut a: usize, mut b: usize) -> usize {
         use std::collections::HashSet;
         let mut a_path_set = HashSet::new();

helix-term/src/commands.rs

@@ -257,6 +257,7 @@ impl Command {
         goto_window_middle, "Goto window middle",
         goto_window_bottom, "Goto window bottom",
         goto_last_accessed_file, "Goto last accessed file",
+        goto_last_modification, "Goto last modification",
         goto_line, "Goto line",
         goto_last_line, "Goto last line",
         goto_first_diag, "Goto first diagnostic",
@@ -3187,6 +3188,19 @@ fn goto_last_accessed_file(cx: &mut Context) {
     }
 }
 
+fn goto_last_modification(cx: &mut Context) {
+    let (view, doc) = current!(cx.editor);
+    let pos = doc.history.get_mut().last_edit_pos();
+    let text = doc.text().slice(..);
+    if let Some(pos) = pos {
+        let selection = doc
+            .selection(view.id)
+            .clone()
+            .transform(|range| range.put_cursor(text, pos, doc.mode == Mode::Select));
+        doc.set_selection(view.id, selection);
+    }
+}
+
 fn select_mode(cx: &mut Context) {
     let (view, doc) = current!(cx.editor);
     let text = doc.text().slice(..);

helix-term/src/keymap.rs

@@ -488,6 +488,7 @@ impl Default for Keymaps {
                 "a" => goto_last_accessed_file,
                 "n" => goto_next_buffer,
                 "p" => goto_previous_buffer,
+                ";" => goto_last_modification,
             },
             ":" => command_mode,
 

helix-view/src/document.rs

@@ -96,7 +96,7 @@ pub struct Document {
     // It can be used as a cell where we will take it out to get some parts of the history and put
     // it back as it separated from the edits. We could split out the parts manually but that will
     // be more troublesome.
-    history: Cell<History>,
+    pub history: Cell<History>,
 
     pub savepoint: Option<Transaction>,