feat: add syntax highlighting to text buffers

src/editor.rs

@@ -693,6 +693,7 @@ struct Buffer {
     id: usize,
     lines: Vec<String>,
     saved_lines: Vec<String>,
+    text_revision: u64,
     targets: Vec<Target>,
     primary: usize,
     mode: Mode,
@@ -731,6 +732,7 @@ impl Buffer {
             id,
             saved_lines: lines.clone(),
             lines,
+            text_revision: 0,
             targets: vec![Target::caret(Cursor::default())],
             primary: 0,
             mode: Mode::Normal,
@@ -938,6 +940,10 @@ impl Editor {
     pub fn lines(&self) -> &[String] {
         &self.active.lines
     }
+    /// Changes only when this buffer's text changes, independent of cursor/view state.
+    pub fn text_revision(&self) -> u64 {
+        self.active.text_revision
+    }
     pub fn cursor(&self) -> Cursor {
         self.active.targets[self.active.primary].active
     }
@@ -2267,7 +2273,11 @@ impl Editor {
             match effect {
                 Effect::Insert(text) => self.insert_text(&normalize_newlines(&text)),
                 Effect::Replace(text) => {
-                    self.active.lines = split_lines(&text);
+                    let lines = split_lines(&text);
+                    if lines != self.active.lines {
+                        self.active.text_revision = self.active.text_revision.wrapping_add(1);
+                    }
+                    self.active.lines = lines;
                     self.active.search_match = None;
                     self.normalize_targets();
                 }
@@ -3165,6 +3175,9 @@ impl Editor {
     }
 
     fn restore(&mut self, snapshot: Snapshot) {
+        if self.active.lines != snapshot.lines {
+            self.active.text_revision = self.active.text_revision.wrapping_add(1);
+        }
         self.active.lines = snapshot.lines;
         self.active.targets = snapshot.targets;
         self.active.primary = snapshot.primary;
@@ -3377,6 +3390,7 @@ impl Editor {
             destinations[edit.target] = (remap(edit.start, false) + edit.caret, edit.round_up);
         }
         if text != old {
+            self.active.text_revision = self.active.text_revision.wrapping_add(1);
             self.active.search_match = None;
         }
         self.active.lines = text.split('\n').map(str::to_owned).collect();