Method binarySearchBoundary

src/utils/Cursor.ts:1198–1230

* Binary search for boundaries. * @param boundaries: Sorted array of boundaries * @param target: Target offset * @param findNext: If true, finds first boundary > target. If false, finds last boundary < target. * @returns The found boundary index, or appropriate default

(
    boundaries: number[],
    target: number,
    findNext: boolean,
  )

   * @returns The found boundary index, or appropriate default
   */
  private binarySearchBoundary(
    boundaries: number[],
    target: number,
    findNext: boolean,
  ): number {
    let left = 0
    let right = boundaries.length - 1
    let result = findNext ? this.text.length : 0

    while (left <= right) {
      const mid = Math.floor((left + right) / 2)
      const boundary = boundaries[mid]
      if (boundary === undefined) break

      if (findNext) {
        if (boundary > target) {
          result = boundary
          right = mid - 1
        } else {
          left = mid + 1
        }
      } else {
        if (boundary < target) {
          result = boundary
          left = mid + 1
        } else {
          right = mid - 1
        }
      }
    }

    return result
  }

  // Convert string index to display width
  public stringIndexToDisplayWidth(text: string, index: number): number {