editor: Newtype WrapRow (#41843)

Makes a better distinction between `WrapRow` and `BlockRow`

Release Notes:

- N/A *or* Added/Fixed/Improved ...

crates/text/src/text.rs

@@ -496,22 +496,26 @@ pub struct Edit<D> {
     pub old: Range<D>,
     pub new: Range<D>,
 }
-
 impl<D> Edit<D>
 where
-    D: Sub<D, Output = D> + PartialEq + Copy,
+    D: PartialEq,
 {
-    pub fn old_len(&self) -> D {
+    pub fn is_empty(&self) -> bool {
+        self.old.start == self.old.end && self.new.start == self.new.end
+    }
+}
+
+impl<D, DDelta> Edit<D>
+where
+    D: Sub<D, Output = DDelta> + Copy,
+{
+    pub fn old_len(&self) -> DDelta {
         self.old.end - self.old.start
     }
 
-    pub fn new_len(&self) -> D {
+    pub fn new_len(&self) -> DDelta {
         self.new.end - self.new.start
     }
-
-    pub fn is_empty(&self) -> bool {
-        self.old.start == self.old.end && self.new.start == self.new.end
-    }
 }
 
 impl<D1, D2> Edit<(D1, D2)> {