Function sp

src/ink/selection.ts:553–558

(p: Point)

  // irrelevant to the keyboard-scroll round-trip case.
  if (s.anchorSpan) {
    const sp = (p: Point): Point => {
      const r = p.row + dRow
      if (r < minRow) return { col: 0, row: minRow }
      if (r > maxRow) return { col: width - 1, row: maxRow }
      return { col: p.col, row: r }
    }
    s.anchorSpan = {
      lo: sp(s.anchorSpan.lo),
      hi: sp(s.anchorSpan.hi),