New unicode-graphemes addon.

Handle grapheme cluster lookup as well as wcwidth.
This is based on Unicode 15, and could replace the unicode11 addon.

src/common/buffer/BufferLine.test.ts

@@ -431,7 +431,7 @@ describe('BufferLine', function(): void {
   describe('addCharToCell', () => {
     it('should set width to 1 for empty cell', () => {
       const line = new TestBufferLine(3, CellData.fromCharData([DEFAULT_ATTR, NULL_CELL_CHAR, NULL_CELL_WIDTH, NULL_CELL_CODE]), false);
-      line.addCodepointToCell(0, '\u0301'.charCodeAt(0));
+      line.addCodepointToCell(0, '\u0301'.charCodeAt(0), 0);
       const cell = line.loadCell(0, new CellData());
       // chars contains single combining char
       // width is set to 1
@@ -444,7 +444,7 @@ describe('BufferLine', function(): void {
       const cell = line .loadCell(0, new CellData());
       cell.setFromCharData([123, 'e\u0301', 1, 'e\u0301'.charCodeAt(1)]);
       line.setCell(0, cell);
-      line.addCodepointToCell(0, '\u0301'.charCodeAt(0));
+      line.addCodepointToCell(0, '\u0301'.charCodeAt(0), 0);
       line.loadCell(0, cell);
       // chars contains 3 chars
       // width is set to 1
@@ -457,7 +457,7 @@ describe('BufferLine', function(): void {
       const cell = line .loadCell(0, new CellData());
       cell.setFromCharData([123, 'e', 1, 'e'.charCodeAt(1)]);
       line.setCell(0, cell);
-      line.addCodepointToCell(0, '\u0301'.charCodeAt(0));
+      line.addCodepointToCell(0, '\u0301'.charCodeAt(0), 0);
       line.loadCell(0, cell);
       // chars contains 2 chars
       // width is set to 1

src/common/buffer/BufferLine.ts

@@ -227,7 +227,7 @@ export class BufferLine implements IBufferLine {
    * onto a leading char. Since we already set the attrs
    * by the previous `setDataFromCodePoint` call, we can omit it here.
    */
-  public addCodepointToCell(index: number, codePoint: number): void {
+    public addCodepointToCell(index: number, codePoint: number, width: number): void {
     let content = this._data[index * CELL_SIZE + Cell.CONTENT];
     if (content & Content.IS_COMBINED_MASK) {
       // we already have a combined string, simply add
@@ -245,8 +245,12 @@ export class BufferLine implements IBufferLine {
         // simply set the data in the cell buffer with a width of 1
         content = codePoint | (1 << Content.WIDTH_SHIFT);
       }
-      this._data[index * CELL_SIZE + Cell.CONTENT] = content;
     }
+    if (width) {
+      content &= ~Content.WIDTH_MASK;
+      content |= width << Content.WIDTH_SHIFT;
+    }
+    this._data[index * CELL_SIZE + Cell.CONTENT] = content;
   }
 
   public insertCells(pos: number, n: number, fillCellData: ICellData, eraseAttr?: IAttributeData): void {