Introduce DisplayRow, MultiBufferRow newtypes and BufferRow type alias (#11656)

Part of https://github.com/zed-industries/zed/issues/8081

To avoid confusion and bugs when converting between various row `u32`'s,
use different types for each.
Further PRs should split `Point` into buffer and multi buffer variants
and make the code more readable.

Release Notes:

- N/A

---------

Co-authored-by: Piotr <piotr@zed.dev>

crates/vim/src/normal/case.rs

@@ -1,6 +1,7 @@
 use editor::scroll::Autoscroll;
 use gpui::ViewContext;
 use language::{Bias, Point};
+use multi_buffer::MultiBufferRow;
 use workspace::Workspace;
 
 use crate::{
@@ -48,8 +49,10 @@ where
                 match vim.state().mode {
                     Mode::VisualLine => {
                         let start = Point::new(selection.start.row, 0);
-                        let end =
-                            Point::new(selection.end.row, snapshot.line_len(selection.end.row));
+                        let end = Point::new(
+                            selection.end.row,
+                            snapshot.line_len(MultiBufferRow(selection.end.row)),
+                        );
                         ranges.push(start..end);
                         cursor_positions.push(start..start);
                     }
@@ -71,7 +74,7 @@ where
                         }
                         ranges.push(start..end);
 
-                        if end.column == snapshot.line_len(end.row) {
+                        if end.column == snapshot.line_len(MultiBufferRow(end.row)) {
                             end = snapshot.clip_point(end - Point::new(0, 1), Bias::Left);
                         }
                         cursor_positions.push(end..end)

crates/vim/src/normal/delete.rs

@@ -7,6 +7,7 @@ use editor::{
 };
 use gpui::WindowContext;
 use language::{Point, Selection};
+use multi_buffer::MultiBufferRow;
 
 pub fn delete_motion(vim: &mut Vim, motion: Motion, times: Option<usize>, cx: &mut WindowContext) {
     vim.stop_recording();
@@ -29,7 +30,7 @@ pub fn delete_motion(vim: &mut Vim, motion: Motion, times: Option<usize>, cx: &m
                         if selection.is_empty()
                             && map
                                 .buffer_snapshot
-                                .line_len(selection.start.to_point(&map).row)
+                                .line_len(MultiBufferRow(selection.start.to_point(&map).row))
                                 == 0
                         {
                             selection.end = map
@@ -79,7 +80,7 @@ pub fn delete_object(vim: &mut Vim, object: Object, around: bool, cx: &mut Windo
                     let mut move_selection_start_to_previous_line =
                         |map: &DisplaySnapshot, selection: &mut Selection<DisplayPoint>| {
                             let start = selection.start.to_offset(map, Bias::Left);
-                            if selection.start.row() > 0 {
+                            if selection.start.row().0 > 0 {
                                 should_move_to_start.insert(selection.id);
                                 selection.start = (start - '\n'.len_utf8()).to_display_point(map);
                             }

crates/vim/src/normal/paste.rs

@@ -2,6 +2,7 @@ use std::cmp;
 
 use editor::{
     display_map::ToDisplayPoint, movement, scroll::Autoscroll, ClipboardSelection, DisplayPoint,
+    RowExt,
 };
 use gpui::{impl_actions, AppContext, ViewContext};
 use language::{Bias, SelectionGoal};
@@ -99,13 +100,13 @@ fn paste(_: &mut Workspace, action: &Paste, cx: &mut ViewContext<Workspace>) {
                         .map(|selection| cmp::min(selection.start.column(), selection.end.column()))
                         .min()
                         .unwrap();
-                    let mut row = current_selections.last().unwrap().end.row() + 1;
+                    let mut row = current_selections.last().unwrap().end.row().next_row();
                     while i < clipboard_selections.len() {
                         let cursor =
                             display_map.clip_point(DisplayPoint::new(row, left), Bias::Left);
                         selections_to_process.push((cursor..cursor, false));
                         i += 1;
-                        row += 1;
+                        row.0 += 1;
                     }
                 }
 

crates/vim/src/normal/scroll.rs

@@ -1,6 +1,8 @@
 use crate::Vim;
 use editor::{
-    display_map::ToDisplayPoint, scroll::ScrollAmount, DisplayPoint, Editor, EditorSettings,
+    display_map::{DisplayRow, ToDisplayPoint},
+    scroll::ScrollAmount,
+    DisplayPoint, Editor, EditorSettings,
 };
 use gpui::{actions, ViewContext};
 use language::Bias;
@@ -85,11 +87,13 @@ fn scroll_editor(
 
                 if preserve_cursor_position {
                     let old_top = old_top_anchor.to_display_point(map);
-                    let new_row = top.row() + selection.head().row() - old_top.row();
+                    let new_row =
+                        DisplayRow(top.row().0 + selection.head().row().0 - old_top.row().0);
                     head = map.clip_point(DisplayPoint::new(new_row, head.column()), Bias::Left)
                 }
-                let min_row = top.row() + vertical_scroll_margin as u32;
-                let max_row = top.row() + visible_rows - vertical_scroll_margin as u32 - 1;
+                let min_row = DisplayRow(top.row().0 + vertical_scroll_margin as u32);
+                let max_row =
+                    DisplayRow(top.row().0 + visible_rows - vertical_scroll_margin as u32 - 1);
 
                 let new_head = if head.row() < min_row {
                     map.clip_point(DisplayPoint::new(min_row, head.column()), Bias::Left)

crates/vim/src/normal/search.rs

@@ -509,7 +509,7 @@ fn parse_replace_all(query: &str) -> Replacement {
 
 #[cfg(test)]
 mod test {
-    use editor::DisplayPoint;
+    use editor::{display_map::DisplayRow, DisplayPoint};
     use indoc::indoc;
     use search::BufferSearchBar;
 
@@ -582,7 +582,7 @@ mod test {
             let highlights = editor.all_text_background_highlights(cx);
             assert_eq!(3, highlights.len());
             assert_eq!(
-                DisplayPoint::new(2, 0)..DisplayPoint::new(2, 2),
+                DisplayPoint::new(DisplayRow(2), 0)..DisplayPoint::new(DisplayRow(2), 2),
                 highlights[0].0
             )
         });