vim: Fix paragraphs with softwrap (#20259)

Closes #19778

Release Notes:

- vim: Fixed paragraph object in the presence of softwrap

crates/editor/src/display_map.rs

@@ -1172,7 +1172,7 @@ impl Sub for DisplayPoint {
 #[serde(transparent)]
 pub struct DisplayRow(pub u32);
 
-impl Add for DisplayRow {
+impl Add<DisplayRow> for DisplayRow {
     type Output = Self;
 
     fn add(self, other: Self) -> Self::Output {
@@ -1180,7 +1180,15 @@ impl Add for DisplayRow {
     }
 }
 
-impl Sub for DisplayRow {
+impl Add<u32> for DisplayRow {
+    type Output = Self;
+
+    fn add(self, other: u32) -> Self::Output {
+        DisplayRow(self.0 + other)
+    }
+}
+
+impl Sub<DisplayRow> for DisplayRow {
     type Output = Self;
 
     fn sub(self, other: Self) -> Self::Output {
@@ -1188,6 +1196,14 @@ impl Sub for DisplayRow {
     }
 }
 
+impl Sub<u32> for DisplayRow {
+    type Output = Self;
+
+    fn sub(self, other: u32) -> Self::Output {
+        DisplayRow(self.0 - other)
+    }
+}
+
 impl DisplayPoint {
     pub fn new(row: DisplayRow, column: u32) -> Self {
         Self(BlockPoint(Point::new(row.0, column)))

crates/vim/src/object.rs

@@ -738,11 +738,11 @@ fn paragraph(
             let paragraph_start_row = paragraph_start.row();
             if paragraph_start_row.0 != 0 {
                 let previous_paragraph_last_line_start =
-                    Point::new(paragraph_start_row.0 - 1, 0).to_display_point(map);
+                    DisplayPoint::new(paragraph_start_row - 1, 0);
                 paragraph_start = start_of_paragraph(map, previous_paragraph_last_line_start);
             }
         } else {
-            let next_paragraph_start = Point::new(paragraph_end_row.0 + 1, 0).to_display_point(map);
+            let next_paragraph_start = DisplayPoint::new(paragraph_end_row + 1, 0);
             paragraph_end = end_of_paragraph(map, next_paragraph_start);
         }
     }